114 results on '"Torre, Luigi"'
Search Results
2. Effect of boron carbide nanoparticles on the thermal stability of carbon/phenolic composites.
- Author
-
Rallini, Marco, Torre, Luigi, Kenny, Josè M., and Natali, Maurizio
- Subjects
- *
BORON carbides , *NANOCOMPOSITE materials , *PHENOLS , *CARBON fibers , *THERMOGRAVIMETRY - Abstract
In this work, the use of nano-boron carbide as a nanomodifier of phenolic matrix was envisioned. Particularly, nano-boron carbide/phenolic-based nanocomposites were produced and investigated. The obtained nanostructured matrices were also used to produce carbon fiber-based bulk molding compounds (BMC). The thermal stability of nanocomposites and BMCs was investigated by thermogravimetric analysis both in nitrogen and in air atmospheres. The good dispersion and distribution of the nanosized particles in the matrix was confirmed by transmission electron microscopy while the post-burning appearance of the BMCs was investigated by visual inspection and scanning electron microscopy. The experimental data highlighted the remarkable effects of nano-boron carbide on the thermal stability and oxidation resistance of the carbon fiber-based BMCs. Moreover, the boron oxide produced by the conversion of boron carbide allowed a substantial improvement of the dimensional stability of the BMC which also exhibited considerable residual structural integrity after burning. POLYM. COMPOS., 38:1819-1827, 2017. © 2015 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
3. Thermal degradation of phenolics and their carbon fiber derived composites: A feasible protocol to assess the heat capacity as a function of temperature through the use of common DSC and TGA analysis.
- Author
-
Natali, Maurizio, Torre, Luigi, Puri, Ivan, and Rallini, Marco
- Subjects
- *
ENTHALPY , *HEAT capacity , *FIBROUS composites , *CARBON fibers , *ROCKET engines - Abstract
• A feasible approach able to assess the heat capacity as a function of temperature (up to 550 °C) of carbon/phenolic composites has been validated. • Common DSC and TGA equipments were used. • The protocol was studied using both bulk or powdered samples. • The protocol was validated on ad hoc made CPCs and compared to state-of-the-art aerospace-qualified materials such as the MX-4926. • The possibility to evaluate the heat of decomposition of high char yield was also discussed. Carbon/Phenolic Composites (CPCs) are among most important Thermal Protection System (TPS) materials. In addition to the challenges related to the manufacturing issues - partially covered in this paper - the possibility to properly characterize the thermo-physical and thermo-mechanical properties of CPCs is extremely important. These data are not only used to size the TPS of a space vehicle or the nozzle components of a Solid Rocket Motor (SRM) but they are also essential to model the response of a CPC in a given hyperthermal environment. However, most of the papers reporting the thermo-physical and thermo-mechanical properties of CPCs are based on very old testing facilities and, in many cases, special equipments have been developed ad-hoc. As a result, the aim of this paper was to identify a feasible approach able to assess the heat capacity as a function of temperature (up to 550 °C) of CPCs through the use of common DSC and TGA analysis, taking into account all the degradation steps of the polymeric matrix undergoing charring. The possibility to evaluate the heat of decomposition of high char yield matrices through the introduced protocols was also discussed. [Display omitted] [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
4. Preparation and Applications of Green Thermoplastic and Thermosetting Nanocomposites Based on Nanolignin.
- Author
-
Puglia, Debora, Luzi, Francesca, and Torre, Luigi
- Subjects
- *
POLYMERIC nanocomposites , *CROSSLINKED polymers , *BIOPOLYMERS , *NANOCOMPOSITE materials , *POLYMER structure , *LIGNINS - Abstract
The development of bio-based materials is of great importance in the present environmental circumstances; hence, research has greatly advanced in the valorization of lignin from lignocellulosic wastes. Lignin is a natural polymer with a crosslinked structure, valuable antiradical activity, unique thermal- and UV-absorption properties, and biodegradability, which justify its use in several prospective and useful application sectors. The active functionalities of lignin promote its use as a valuable material to be adopted in the composite and nanocomposites arenas, being useful and suitable for consideration both for the synthesis of matrices and as a nanofiller. The aim of this review is to summarize, after a brief introduction on the need for alternative green solutions to petroleum-based plastics, the synthesis methods for bio-based and/or biodegradable thermoplastic and thermosetting nanocomposites, along with the application of lignin nanoparticles in all green polymeric matrices, thus generating responsiveness towards the sustainable use of this valuable product in the environment. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
5. Cellulose Nanocrystals and Lignin Nanoparticles Extraction from Lemna minor L.: Acid Hydrolysis of Bleached and Ionic Liquid-Treated Biomass.
- Author
-
Puglia, Debora, Luzi, Francesca, Tolisano, Ciro, Rallini, Marco, Priolo, Dario, Brienza, Monica, Costantino, Ferdinando, Torre, Luigi, and Del Buono, Daniele
- Subjects
- *
NANOPARTICLES , *LIGNINS , *CELLULOSE nanocrystals , *NANOSTRUCTURED materials , *LEMNA minor , *BIOMASS , *CHEMICAL properties - Abstract
Using biomass to develop and obtain environmentally friendly and industrially applicable biomaterials is increasingly attracting global interest. Herein, cellulose nanocrystals (CNCs) and lignin nanoparticles (LNPs) were extracted from Lemna minor L., a freshwater free-floating aquatic species commonly called duckweed. To obtain CNCs and LNPs, two different procedures and biomass treatment processes based on bleaching or on the use of an ionic liquid composed of triethylammonium and sulfuric acid ([TEA][HSO4]), followed by acid hydrolysis, were carried out. Then, the effects of these treatments in terms of the thermal, morphological, and chemical properties of the CNCs and LNPs were assessed. The resulting nanostructured materials were characterized by using Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD) spectroscopy, thermo-gravimetric analysis (TGA), and scanning electron microscopy (SEM). The results showed that the two methodologies applied resulted in both CNCs and LNPs. However, the bleaching-based treatment produced CNCs with a rod-like shape, length of 100–300 nm and width in the range of 10–30 nm, and higher purity than those obtained with ILs that were spherical in shape. In contrast, regarding lignin, IL made it possible to obtain spherical nanoparticles, as in the case of the other treatment, but they were characterized by higher purity and thermal stability. In conclusion, this research highlights the possibility of obtaining nanostructured biopolymers from an invasive aquatic species that is largely available in nature and how it is possible, by modifying experimental procedures, to obtain nanomaterials with different morphological, purity, and thermal resistance characteristics. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
6. Antioxidant Packaging Films Based on Ethylene Vinyl Alcohol Copolymer (EVOH) and Caffeic Acid.
- Author
-
Luzi, Francesca, Torre, Luigi, Puglia, Debora, Grdadolnik, Simona Golič, and Garrigós, María del Carmen
- Subjects
- *
PACKAGING film , *GLYCOLS , *CAFFEIC acid , *FOOD packaging , *COLORIMETRIC analysis , *TENSILE tests - Abstract
The main objective of this research activity was to design and realize active films with tunable food functional properties. In detail, caffeic acid (CA), a polyphenol with high antioxidant effect, was used as active ingredient in poly (vinyl alcohol-co-ethylene) (EVOH) films at 5 wt.% and 15 wt.% and successfully realized by means of the solvent casting process. Optical, morphological, thermal and mechanical studies were considered to define the effect of the presence of the CA component on the structural properties of the matrix. In addition, moisture content and antioxidant activity were evaluated, to have clear information on the CA effect in terms of functional characteristics of realized food packaging systems. Results from tensile tests showed increased values for strength and deformation at break in EVOH_CA based films. Results from colorimetric and transparency analysis underlined that the presence of caffeic acid in EVOH copolymer induces some alterations, whereas the addition of the active ingredient determined a positive radical scavenging activity of the formulations, confirming the possibility of practically using these polymeric systems in the food packaging sector. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
7. Multisensor Integrated Platform Based on MEMS Charge Variation Sensing Technology for Biopotential Acquisition.
- Author
-
Irrera, Fernanda, Gumiero, Alessandro, Zampogna, Alessandro, Boscari, Federico, Avogaro, Angelo, Gazzanti Pugliese di Cotrone, Michele Antonio, Patera, Martina, Della Torre, Luigi, Picozzi, Nicola, and Suppa, Antonio
- Subjects
- *
TECHNOLOGICAL innovations , *WEARABLE technology , *AUTOMOBILE industry , *ELECTROMYOGRAPHY , *ELECTROENCEPHALOGRAPHY - Abstract
We propose a new methodology for long-term biopotential recording based on an MEMS multisensor integrated platform featuring a commercial electrostatic charge-transfer sensor. This family of sensors was originally intended for presence tracking in the automotive industry, so the existing setup was engineered for the acquisition of electrocardiograms, electroencephalograms, electrooculograms, and electromyography, designing a dedicated front-end and writing proper firmware for the specific application. Systematic tests on controls and nocturnal acquisitions from patients in a domestic environment will be discussed in detail. The excellent results indicate that this technology can provide a low-power, unexplored solution to biopotential acquisition. The technological breakthrough is in that it enables adding this type of functionality to existing MEMS boards at near-zero additional power consumption. For these reasons, it opens up additional possibilities for wearable sensors and strengthens the role of MEMS technology in medical wearables for the long-term synchronous acquisition of a wide range of signals. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
8. Bio- and Fossil-Based Polymeric Blends and Nanocomposites for Packaging: Structure–Property Relationship.
- Author
-
Luzi, Francesca, Torre, Luigi, Kenny, José Maria, and Puglia, Debora
- Subjects
- *
POLYMERIC composites , *NANOCOMPOSITE materials , *PACKAGING , *BIODEGRADABLE plastics , *POLYMERS - Abstract
In the present review, the possibilities for blending of commodities and bio-based and/or biodegradable polymers for packaging purposes has been considered, limiting the analysis to this class of materials without considering blends where both components have a bio-based composition or origin. The production of blends with synthetic polymeric materials is among the strategies to modulate the main characteristics of biodegradable polymeric materials, altering disintegrability rates and decreasing the final cost of different products. Special emphasis has been given to blends functional behavior in the frame of packaging application (compostability, gas/water/light barrier properties, migration, antioxidant performance). In addition, to better analyze the presence of nanosized ingredients on the overall behavior of a nanocomposite system composed of synthetic polymers, combined with biodegradable and/or bio-based plastics, the nature and effect of the inclusion of bio-based nanofillers has been investigated. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
9. Experimental investigation of a cementitious heat storage medium incorporating a solar salt/diatomite composite phase change material.
- Author
-
Miliozzi, Adio, Chieruzzi, Manila, and Torre, Luigi
- Subjects
- *
PHASE change materials , *HEAT storage , *HEAT , *THERMAL conductivity , *LATENT heat , *HEAT capacity - Abstract
• Experimental investigation of high temperature thermal storage concrete materials. • Phase change materials (solar salt) added to concrete to increase energy density. • Thermal and mechanical characterization of concrete and 2 wt% phase change material. • Thermal and mechanical properties increase with no phase change materials leakage. • Better behaviour of phase change material/diatomite even after 250 °C. Thermal energy storage is one of the most appropriate technologies to correct the gap between the energy generation and supply and to address energy challenges. Concrete is generally the preferred "solid" heat storage material because its low cost and good thermal conductivity. The major disadvantage is its low heat stored density involving the use of large amounts of concrete. Latent heat storage materials (or phase change materials), have received more attention due to much higher heat storage density and extremely smaller temperature variation during the thermal energy charge/discharge process. These materials can be incorporated in the concrete by using different methods. When the phase change material is encapsulated or added in a shape-stabilized new material, as diatomite, the phase change material leakage is avoided. Thermal and mechanical characteristics of a new heat storage material, composed by concrete with the addition of 2% Solar Salts by weight (as phase change material) in powder or capsules form, were analyzed. The results showed an increase of the main thermal (volumetric heat capacity and conductivity) and mechanical properties while phase change material leakage was not observed. In particular, the phase change material/diatomite capsules provide a better behavior even after 250 °C. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
10. Novel Nanostructured Scaffolds of Poly(butylene trans -1,4-cyclohexanedicarboxylate)-Based Copolymers with Tailored Hydrophilicity and Stiffness: Implication for Tissue Engineering Modeling.
- Author
-
Guidotti, Giulia, Soccio, Michelina, Argentati, Chiara, Luzi, Francesca, Aluigi, Annalisa, Torre, Luigi, Armentano, Ilaria, Emiliani, Carla, Morena, Francesco, Martino, Sabata, and Lotti, Nadia
- Subjects
- *
TISSUE engineering , *ENGINEERING models , *BUTENE , *COPOLYMERS , *STROMAL cells , *RANDOM copolymers , *POLYBUTENES - Abstract
Here, we present novel biocompatible poly(butylene trans-1,4-cyclohexanedicarboxylate) (PBCE)-based random copolymer nanostructured scaffolds with tailored stiffness and hydrophilicity. The introduction of a butylene diglycolate (BDG) co-unit, containing ether oxygen atoms, along the PBCE chain remarkably improved the hydrophilicity and chain flexibility. The copolymer containing 50 mol% BDG co-units (BDG50) and the parent homopolymer (PBCE) were synthesized and processed as electrospun scaffolds and compression-molded films, added for the sake of comparison. We performed thermal, wettability, and stress–strain measures on the PBCE-derived scaffolds and films. We also conducted biocompatibility studies by evaluating the adhesion and proliferation of multipotent mesenchymal/stromal cells (hBM-MSCs) on each polymeric film and scaffold. We demonstrated that solid-state properties can be tailored by altering sample morphology besides chemical structure. Thus, scaffolds were characterized by a higher hydrophobicity and a lower elastic modulus than the corresponding films. The three-dimensional nanostructure conferred a higher adsorption protein capability to the scaffolds compared to their film counterparts. Finally, the PBCE and BDG50 scaffolds were suitable for the long-term culture of hBM-MSCs. Collectively, the PBCE homopolymer and copolymer are good candidates for tissue engineering applications. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
11. Development of biodegradable PLA composites and tangerine peel flour with improved toughness containing a natural-based terpenoid.
- Author
-
Gomez-Caturla, Jaume, Montanes, Nestor, Quiles-Carrillo, Luis, Balart, Rafael, Garcia-Garcia, Daniel, Dominici, Franco, Puglia, Debora, and Torre, Luigi
- Subjects
- *
BIODEGRADABLE plastics , *FIELD emission electron microscopy , *GLASS transition temperature , *DYNAMIC mechanical analysis , *ENGINEERED wood , *DIFFERENTIAL scanning calorimetry , *INJECTION molding - Abstract
The present work reports on the development of environmentally friendly, completely biodegradable wood plastic composites based on polylactide (PLA) and tangerine peel flour (TPF), plasticized by α-terpinyl acetate (TA). The TPF varied in the 10--30 wt% while the PLA to TA (wt%/wt%) was set to 4 (i.e., 25 wt% TA plasticizer was added with regard to the PLA wt%). The developed composites were processed by extrusion and injection molding. The composites presented excellent elongation at break, achieving values of 300% for the PLA+TA sample. Elongation at break values of 200% for the PLA composite with 10 wt% TPF and plasticized with TA were obtained. Those results were confirmed by the appearance of filament-like structures observed in field emission scanning electron microscopy images. Differential scanning calorimetry and dynamic mechanical thermal analysis revealed a remarkable decrease in the glass transition temperature of PLA as a result of the plasticizing effect of TA. Glass transition was reduced from 63°C down to 41°C approximately. This implied an increase in the ductility of the material. The samples with TPF exhibited a dark brown color, making them perfect for wood plastic composite applications. Water contact angle results show that TA and TPF change the wetting properties of the obtained composites. A general decrease in the water contact angle was observed with the addition of TPF and TA. Finally, disintegration tests proved that the developed composites are fully biodegradable. All the samples except for neat PLA achieved 100% disintegration in controlled compost soil conditions after 5 weeks, while neat PLA reached complete disintegration in 6 weeks. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
12. Boron based fillers as char enhancers of EPDM based heat shielding materials for SRMs: A comparative analysis.
- Author
-
Rallini, Marco, Puri, Ivan, Torre, Luigi, and Natali, Maurizio
- Subjects
- *
BORON , *FILLER materials , *ARTIFICIAL rubber , *THERMAL shielding , *SOLID propellant rockets - Abstract
Solid Rocket Motors (SRMs) are used to launch satellites and other civilian or military payloads in orbit. Due to their low density and outstanding insulation capability, EPDM/aramid fibers ablatives represent the state of the art of Elastomeric Heat Shielding Materials (EHSMs) SRMs. However, this class of polymeric ablatives tend to exhibit a limited ablation resistance induced by thermo-oxidation and mechanical erosion due to the propellant combustion byproducts. In order to increase the thermo-oxidation resistance, char retention, and insulation index, boron based fillers can be considered in the material formulation of the SRM insulation liner. In this work we systematically studied the effect of different boron containing fillers embedded in EPDM based EHSMs. The heat capacity, thermal stability, mechanical properties, ablation resistance, pre- and post-oxy-acetylene torch testing morphology of these materials were analyzed evidencing the clear benefits of these fillers. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
13. Manufacturing and characterization of highly environmentally-friendly composites with polylactide matrix and mango kernel seed flour.
- Author
-
Gomez-Caturla, Jaume, Lascano, Diego, Montanes, Nestor, Balart, Rafael, Dominici, Franco, Puglia, Debora, and Torre, Luigi
- Subjects
- *
POLYLACTIC acid , *FIELD emission electron microscopy , *DIFFERENTIAL scanning calorimetry , *MANGO , *GLASS transition temperature , *PLASTICIZERS , *EXTRUSION process - Abstract
This work reports on the development of polylactide (PLA)/mango kernel seed flour (MKSF) composites combined with tributyrin (TBN) and triacetin (TCN) as plasticizers. Thus, wood plastic composites (WPC) are obtained by extrusion and injection-molding processes. The solubility, mechanical, morphological, thermal, colorimetric, water absorbance, flowability, and disintegrability properties are evaluated. The ductility of the PLA+MKSF composite is improved by the plasticizing effect of TBN and TCN (10 phr (parts per hundred resin) each). Elongation at break is increased from 4.4 up to 9.5 and 8.3%, respectively. The theoretical solubility analysis supports the good miscibility between PLA with TBN and TCN (relative energy difference (RED) values of 0.86 and 0.73, respectively) deduced from the mechanical performance. Field emission scanning electron microscopy (FESEM) images also corroborate the mechanical findings, where a decrease in the presence of voids in the PLA matrix suggests certain compatibility between MKSF and TBN, and TCN. Differential scanning calorimetry (DSC) and dynamic-mechanical-thermal analysis (DMTA) results show that the plasticizers decrease the glass transition temperature and the melting temperature of PLA, thus improving its ductility. Thermogravimetric analysis (TGA) results indicate that the thermal stability of the composite is slightly decreased due to the relatively high volatility of the plasticizers, while MKSF does not affect this matter. The composites exhibit excellent biodegradability, presenting more than 90% of disintegration in compost soil conditions in 12 weeks. Finally, MKSF provided the composites with a wood-like dark brown color and with high water absorbance. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
14. Science and technology of polymeric ablative materials for thermal protection systems and propulsion devices: A review.
- Author
-
Natali, Maurizio, Kenny, Jose Maria, and Torre, Luigi
- Subjects
- *
POLYMERS , *ABLATIVE materials , *THERMAL shielding , *PROPULSION systems , *ROCKET engines - Abstract
Ablative materials are at the base of entire aerospace industry; these sacrificial materials are used to manage the heat shielding of propulsion devices (such as liquid and Solid Rocket Motors (SRMs)) or to protect vehicles and probes during the hypersonic flight through a planetary atmosphere. Accordingly they are also known as Thermal Protection System (TPS) materials. Some non-polymeric materials have been successfully used as ablatives; however, due to their versatility, Polymeric Ablatives (PAs) represent the widest family of sacrificial TPS materials. In fact, when compared to non-polymeric ablatives such as high melting point metals, inorganic polymers (or metal oxides or carbides), PAs have some intrinsic advantages such as: tunable density, lower cost, and higher heat shock resistance. This review covers all main topics related to the science and technology of ablative materials with current and potential applications in the aerospace industry. After a short, yet comprehensive, introduction on non-ablative materials, this review paper summarizes fifty years of research efforts on polymeric ablatives, starting from the state of the art solutions currently used as TPS, up to covering the most recent efforts for nanostructuring their formulations. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
15. Thermal treatment of magnesium particles in polylactic acid polymer films elicits the expression of osteogenic differentiation markers and lipidome profile remodeling in human adipose stem cells.
- Author
-
Argentati, Chiara, Dominici, Franco, Morena, Francesco, Rallini, Marco, Tortorella, Ilaria, Ferrandez-Montero, Ana, Pellegrino, Roberto Maria, Ferrari, Begoña, Emiliani, Carla, Lieblich, Marcela, Torre, Luigi, Martino, Sabata, and Armentano, Ilaria
- Subjects
- *
POLYLACTIC acid , *HUMAN stem cells , *POLYMER films , *STEM cells , *ALKALINE phosphatase , *MAGNESIUM , *TISSUE engineering - Abstract
The efficacy of polylactic acid (PLA)/Magnesium (Mg)-based materials for driving stem cells toward bone tissue engineering applications requires specific Mg surface properties to modulate the interface of stem cells with the film. Here, we have developed novel PLA/Mg-based composites and explored their osteogenic differentiation potential on human adipose stem cells (hASCs). Mg-particles/polymer interface was improved by two treatments: heating in oxidative atmosphere (TT) and surface modification with a compatibilizer (PEI). Different contents of Mg particles were dispersed in PLA and composite surface and bulk properties, protein adsorption, stem cell-PLA/Mg interactions, osteogenic markers expressions, and lipids composition profile were evaluated. Mg particles were uniformly distributed on the surface and in the bulk PLA polymer. Improved and modulated particle-polymer adhesion was observed in Mg particle-treated composites. After 21 days in canonical growth culture conditions, hASCs on PLA/MgTT displayed the highest expression of the general osteogenic markers, RUNX2, SSP1, and BGLAP genes, Alkaline Phosphatase, type I Collagen, Osteopontin, and Calcium deposits. Moreover, by LC/MS QTOF mass-spectrophotometry lipidomic analysis, we found in PLA/MgTT-cells, for the first time, a remodeling of the lipid classes composition associated with the osteogenic differentiation. We ascribed these results to MgTT characteristics, which improve Mg availability and composite osteoinductive performance. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
16. Processing of nanostructured polymers and advanced polymeric based nanocomposites.
- Author
-
Peponi, Laura, Puglia, Debora, Torre, Luigi, Valentini, Luca, and Kenny, José M.
- Subjects
- *
NANOSTRUCTURED materials , *POLYMERS , *POLYMERIC nanocomposites , *COPOLYMERS , *THERMOSETTING polymers , *PARTICLE interactions , *INDUSTRIAL applications - Abstract
The control of the nanostructure and the addition of nanoparticles to polymers have led to structural and functional property enhancements in a number of polymeric systems as a material answer to continuous requirements from advanced industrial sectors. The availability of new nanoparticles with extraordinary properties (i.e. carbon nanotubes, graphenes, but also nanoclays, nanocellulose, metals and ceramics) have determined new and exciting possibilities for a continuous enlargement of polymer markets. However, the potentialities of these new materials are still strongly dependent on the development and scaling-up of reliable processing routes. Therefore, the purpose of this report is to review the main processing approaches for nanostructured polymers and nanocomposites starting with a brief review of available nanoparticles and on their functionalization to promote a better polymer–particle interaction. Regarding processing, the review firstly addresses the bottom-up approaches typically adopted for nanostructured polymers, blends and copolymers. Then, the different technologies required by the top-down processing of thermoplastic and thermosetting polymer matrix systems are reviewed. Finally, the report addresses the recent applications of nanostructured polymers and nanocomposites as matrices of advanced composite materials. In all cases, the main processing approaches and the main structural and functional properties characterizing these materials and their potential and current industrial applications are specifically addressed. [ABSTRACT FROM AUTHOR]
- Published
- 2014
- Full Text
- View/download PDF
17. Long-Term Polygraphic Monitoring through MEMS and Charge Transfer for Low-Power Wearable Applications.
- Author
-
Manoni, Alessandro, Gumiero, Alessandro, Zampogna, Alessandro, Ciarlo, Chiara, Panetta, Lorenzo, Suppa, Antonio, Della Torre, Luigi, and Irrera, Fernanda
- Subjects
- *
CHARGE transfer , *ELECTROENCEPHALOGRAPHY , *DATA recorders & recording , *WIRELESS power transmission , *CONFORMANCE testing , *SCALP - Abstract
In this work, we propose a wireless wearable system for the acquisition of multiple biopotentials through charge transfer electrostatic sensors realized in MEMS technology. The system is designed for low power consumption and low invasiveness, and thus candidates for long-time monitoring in free-living conditions, with data recording on an SD or wireless transmission to an external elaborator. Thanks to the wide horizon of applications, research is very active in this field, and in the last few years, some devices have been introduced on the market. The main problem with those devices is that their operation is time-limited, so they do not match the growing demand for long monitoring, which is a must-have feature in diagnosing specific diseases. Furthermore, their versatility is hampered by the fact that they have been designed to record just one type of signal. Using ST-Qvar sensors, we acquired an electrocardiogram trace and single-channel scalp electroencephalogram from the frontal lobes, together with an electrooculogram. Excellent results from all three types of acquisition tests were obtained. The power consumption is very low, demonstrating that, thanks to the MEMS technology, a continuous acquisition is feasible for several days. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
18. Kinetic and chemorheological modeling of the vitrification effect of highly reactive poly(urethane-isocyanurate) thermosets.
- Author
-
Chiacchiarelli, Leonel M., Kenny, Josè M., and Torre, Luigi
- Subjects
- *
VITRIFICATION , *REACTIVE polymers , *POLYURETHANES , *THERMOSETTING polymers , *AUTOCATALYSIS , *TRANSITION temperature - Abstract
Highlights: [•] The kinetics of a poly(urethane-isocyanurate) were modeled with an autocatalytic approach. [•] The relationship between the transition temperatures and conversion of the urethane and isocyanurate networks was measured with DSC analysis. [•] The urethane network was found to interact with the isocyanurate network through the vitrification effect. [•] A chemorheological model which contemplated the viscosity contribution of each network was proposed. [•] The chemorheological model was able to predict the experimental data and it was used to predict the behavior at elevated temperatures, where the rheometer was unable to measure the viscosity variation as a function of time. [Copyright &y& Elsevier]
- Published
- 2013
- Full Text
- View/download PDF
19. Thermal Properties of Shape-Stabilized Phase Change Materials Based on Porous Supports for Thermal Energy Storage.
- Author
-
Dominici, Franco, Miliozzi, Adio, and Torre, Luigi
- Subjects
- *
HEAT storage , *PHASE change materials , *POROUS materials , *THERMAL properties , *ENERGY storage - Abstract
The use of phase change materials (PCM) for thermal energy storage (TES) is of great relevance, especially for the exploitation, in various ways, of the major ecological resource offered by solar energy. Unfortunately, the transition to the liquid state of PCM requires complex systems and limits their application. The goal of producing shape-stabilized phase change materials (SSPCM) is mainly pursued with the use of media capable of containing PCM during solid/liquid cycles. In this work, four cheap shape stabilizers were considered: sepiolite, diatomite, palygorskite and zeolite and two molten salts as PCM, for medium (MT) and high temperature (HT). The SSPCM, produced with an energy saving method, showed good stability and thermal storage performances. Diatomite reaches up to 400% wt. of encapsulated PCM, with a shape stabilization coefficient (SSc) of 97.7%. Zeolite exhibits a SSc of 87.3% with 348% wt. of HT-PCM. Sepiolite contains 330% wt. of MT-PCM with an SSc of 82.7. Therefore, these materials show characteristics such that they can be efficiently used in thermal energy storage systems, both individually and inserted in a suitable matrix (for example a cementitious matrix). [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
20. Development of starch-rich thermoplastic polymers based on mango kernel flour and different plasticizers.
- Author
-
Gomez-Caturla, Jaume, Ivorra-Martinez, Juan, Fenollar, Octavio, Balart, Rafael, Garcia-Garcia, Daniel, Dominici, Franco, Puglia, Debora, and Torre, Luigi
- Subjects
- *
SORBITOL , *MANGO , *PLASTICIZERS , *FIELD emission electron microscopy , *GLASS transition temperature , *POLYMERS - Abstract
This work reports on the development of starch-rich thermoplastic based formulations produced by using mango kernel flour, avoiding the extraction process of starch from mango kernel to produce these materials. Glycerol, sorbitol and urea at 15 wt% are used as plasticizers to obtain thermoplastic starch (TPS) formulations by extrusion and injection-moulding processes. Mechanical results show that sorbitol and urea allowed to obtain samples with tensile strength and elongation at break higher than the glycerol-plasticized sample, achieving values of 2.9 MPa of tensile strength and 42 % of elongation at break at 53 % RH. These results are supported by field emission scanning electron microscopy (FESEM) micrographs, where a limited concentration of voids was observed in the samples with sorbitol and urea, indicating a better interaction between starch and the plasticizers. Thermogravimetric analysis (TGA) shows that urea and sorbitol increase the thermal stability of TPS in comparison to the glycerol-plasticized sample. Differential scanning calorimetry (DSC) and dynamic-mechanical-thermal analysis (DMTA) verify the increase in stiffness of the sorbitol and urea plasticized TPS and also illustrate an increase in the glass transition temperature of both samples in comparison to the glycerol-plasticized sample. Glass transition temperatures of 45 °C were achieved for the sample with sorbitol. [ABSTRACT FROM AUTHOR]
- Published
- 2024
- Full Text
- View/download PDF
21. The alignment of single walled carbon nanotubes in an epoxy resin by applying a DC electric field
- Author
-
Monti, Marco, Natali, Maurizio, Torre, Luigi, and Kenny, José M.
- Subjects
- *
CARBON nanotubes , *EPOXY resins , *ELECTRIC fields , *MONOMERS , *MOLECULAR structure , *RELAXATION phenomena , *MICROSCOPY , *PREDICTION models - Abstract
Abstract: The alignment of single walled carbon nanotubes (SWCNTs) in an epoxy monomer liquid medium by the application of a DC electric field has been investigated, taking into account the various transport phenomena involved: the tube rotation in the electric field, the translation of polarized SWCNTs toward each other to form a chain-like structure and the migration of the tubes toward the positive electrode. Moreover, the relaxation mechanism which takes place when the electric field is switched off has also been considered. Experimental tests, performed to verify the effectiveness of the model, are based on the application of an electric field to a liquid epoxy–SWCNT colloid (0.025wt.%) while measuring the current and observing the system by optical microscopy. As a result of the modeling it is possible to identify the processing conditions that allow the alignment of SWCNTs in an epoxy resin through the short-time application of a DC electric field. Experimental measurements are in agreement with the model’s predictions. [Copyright &y& Elsevier]
- Published
- 2012
- Full Text
- View/download PDF
22. Phenolic matrix nanocomposites based on commercial grade resols: Synthesis and characterization
- Author
-
Natali, Maurizio, Kenny, Josè, and Torre, Luigi
- Subjects
- *
NANOCOMPOSITE materials , *PHENOLS , *SILICATES , *LABOR costs , *POLYMERIZATION , *FORMALDEHYDE , *MONTMORILLONITE , *X-ray diffraction - Abstract
Abstract: Polymer Layered Silicate Nanocomposites based on a commercial grade resol were produced using a simple, low labor cost, mechanical approach which allowed to avoid the process of intercalative polymerization of phenol and formaldehyde. Commercial compatibilized montmorillonite was selected as the main nanoreinforcement, while the matrix was a resol diluted in methanol. The aim of this work was to optimize the production technique of the above mentioned nanocomposites. Therefore intercalation of the resin was promoted by high speed mixing, and the processing parameters were varied in order to find the optimum dispersion. The produced nanocomposites were characterized and compared by means of X-ray diffraction, SEM and thermogravimetric analysis. The results of the characterization tests indicated that it was possible to obtain a good degree of dispersion as well as and uniform distribution of the nanoclay platelets. However, TGA measurements showed that the introduction of well dispersed nanoclays did not result in a consistent improvement of thermal stability respect that of the neat resol. [Copyright &y& Elsevier]
- Published
- 2010
- Full Text
- View/download PDF
23. Surfactant assisted selective confinement of carbon nanotubes functionalized with octadecylamine in a poly(styrene-b-isoprene-b-styrene) block copolymer matrix
- Author
-
Peponi, Laura, Valentini, Luca, Torre, Luigi, Mondragon, Iñaki, and Kenny, Josè M.
- Subjects
- *
SURFACE active agents , *CARBON nanotubes , *AMINES , *POLYSTYRENE , *BLOCK copolymers , *MOLECULAR self-assembly - Abstract
Abstract: We report how dodecanethiol (DT) surfactant can be used as a good dispersant to solubilize octadecylamine functionalized single-walled carbon nanotubes (ODA-SWCNTs) in order to confine them in the polystyrene phase of the polystyrene-b-polyisoprene-b-polystyrene (SIS) block copolymer matrix. It has been also demonstrated how the block copolymer matrix is not able to self-assemble in ordered morphology when the ODA-SWCNTs are not modified with the surfactant. DT assisted confinement of carbon nanotubes into the PS phase causes not only the nanostructuration of the host polymer matrix but also switches the self-assembled nanostructure from ordered cylinders in the case of neat SIS to a self-assembled lamellar nanostructure. [Copyright &y& Elsevier]
- Published
- 2009
- Full Text
- View/download PDF
24. Nanostructured physical gel of SBS block copolymer and Ag/DT/SBS nanocomposites.
- Author
-
Peponi, Laura, Tercjak, Agnieszka, Torre, Luigi, Mondragon, Iñaki, and Kenny, Josè
- Subjects
- *
NANOSTRUCTURES , *COLLOIDS , *BLOCK copolymers , *NANOTECHNOLOGY , *POLYSTYRENE , *SOLVENTS , *RHEOLOGY , *ADDITION reactions - Abstract
Thermoreversible physical gels of poly(styrene- b-butadiene- b-styrene) (SBS), formed by the dissolution of the block copolymer in a mid-block-selective solvent (THF), have been studied and characterized with particular attention to their morphology and rheological behavior. The effects of the addition of silver (Ag) nanoparticles to the SBS matrix, on the behavior of the physical gels, were also studied. The external surface of the Ag nanoparticles has been modified by using as surfactant material, dodecanethiol, in order to achieve their confinement in just one block of the SBS block copolymer matrix. The results of this study show that the gel stability is not affected by the presence of Ag nanoparticles. In fact, the micellar domains of the nanocomposite gel based on SBS block copolymer and Ag nanoparticles has been obtained and the physical gel behavior have been confirmed by rheological analysis. [ABSTRACT FROM AUTHOR]
- Published
- 2009
- Full Text
- View/download PDF
25. Morphological analysis of self-assembled SIS block copolymer matrices containing silver nanoparticles
- Author
-
Peponi, Laura, Tercjak, Agnieszka, Torre, Luigi, Kenny, Josè M., and Mondragon, Iñaki
- Subjects
- *
POLYMERS , *BLOCK copolymers , *SURFACE active agents , *SILVER - Abstract
Abstract: The intrinsic ability of block copolymers to self-assemble at nanoordered level into different nanoscale structures has been used in this study to obtain nanocomposites. Ordered architectures of silver nanoparticles confined in a poly(styrene-b-isoprene-b-styrene) (SIS) block copolymer matrix have been generated. Both cetyl trimethylammonium chloride (TMAC) and dodecanethiol (DT) were used as surfactants to obtain dispersed nanocomposite films. Morphologies generated in Ag/SIS nanocomposites, detected through atomic force, resulted to be more dependent on the amount of silver nanoparticles than on the other variables chosen in the present study such as amount and type of surfactant and preparation parameters. The experimental observations are consistent with phase diagram predictions obtained for hybrid systems composed of block copolymers and nanoparticles. [Copyright &y& Elsevier]
- Published
- 2008
- Full Text
- View/download PDF
26. Design, Realization, and Characterization of Advanced Adhesives for Joining Ultra‐Stable C/C Based Components.
- Author
-
Casalegno, Valentina, De la Pierre des Ambrois, Stefano, Corazzari, Ingrid, Turci, Francesco, Tatarko, Peter, Damiano, Olivier, Cornillon, Laurence, Terenzi, Andrea, Natali, Maurizio, Puglia, Deborah, Torre, Luigi, and Ferraris, Monica
- Subjects
- *
MEASUREMENT of shear strength , *THERMOGRAVIMETRY , *FIBROUS composites , *ADHESIVES , *VINYL ester resins , *PHENOLIC resins - Abstract
The aim of this work is to develop high‐performance adhesives to join carbon fiber reinforced composites (C/C) for use in aerospace applications; in order to guarantee sound mechanical strength, a low coefficient of thermal expansion, and ease of application on large components. Several different adhesive formulations, based on phenolic or cyanate‐ester resins (charged with the maximum experimentally feasible amount of carbon‐based fillers), are developed and tested. The measurements of the lap shear strength at room temperature of the C/C joined by means of one phenolic and one cyanate ester‐based resin demonstrates that these formulations are the most suitable for the given application. A complete characterization, by means of viscosimetry, dilatometry, and thermal gravimetric analysis, coupled with gas analysis by means of mass spectroscopy, confirms that the phenolic‐based formulation is the most promising joining material. A nano‐indenter is used to obtain its Young modulus and hardness, both inside the joint and as a bulk cured adhesive. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
27. Active Role of ZnO Nanorods in Thermomechanical and Barrier Performance of Poly(vinyl alcohol-co-ethylene) Formulations for Flexible Packaging.
- Author
-
Luzi, Francesca, Di Michele, Alessandro, Torre, Luigi, and Puglia, Debora
- Subjects
- *
FLEXIBLE packaging , *ZINC oxide films , *ZINC oxide , *NANORODS , *ULTRAVIOLET radiation - Abstract
Poly(vinyl alcohol-co-ethylene) (EVOH) films containing zinc oxide nanorods (ZnO Nrods) at 0.1, 0.5, and 1 wt%, were realized by solvent casting. The effect of ZnO Nrods content on morphological, thermal, optical, mechanical, and oxygen permeability properties were analyzed. In addition, moisture content and accelerated-aging test studies were performed, with the intention to determine the influence of zinc oxide nanofillers on the functional characteristics of realized packaging systems. Tensile properties showed increased values for strength and deformation-at-break in EVOH-based formulations reinforced with 0.1 and 0.5 wt% of zinc oxide nanorods. Results from the colorimetric and transparency investigations underlined that the presence of ZnO Nrods in EVOH copolymer did not induce evident alterations. In addition, after the accelerated-aging test, the colorimetric test confirmed the possibility for these materials to be used in the packaging sector. This behavior was induced by the presence of zinc oxide nanofillers that act as a UV block that made them useful as an efficient absorber of UV radiation. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
28. Durability and weatherability of a styrene-ethylene-butylene-styrene (SEBS) block copolymer-based sensing skin for civil infrastructure applications.
- Author
-
Downey, Austin, Pisello, Anna Laura, Fortunati, Elena, Fabiani, Claudia, Luzi, Francesca, Torre, Luigi, Ubertini, Filippo, and Laflamme, Simon
- Subjects
- *
BLOCK copolymers , *STRUCTURAL health monitoring , *CIVIL engineering , *DURABILITY , *ACCELERATED life testing , *CARBON-black - Abstract
• Experimentally validated the durability and weatherability of a large area sensing skin for civil infrastructure. • An accelerated weathering chamber was used to apply a series of humidity, and UV radiation cycles to specimens manufactured for this study. A additional sensor deployed on a bridge in Iowa for six and a half years was removed from the field and analyzed in the laboratory • A variety of tests were performed to characterize the specimens' mechanical, thermal, optical, and electrical performance. Additionally, strain sensitivity analyses were performed on specimens of interest. • Results showed that titania inclusions improved the sensor dielectric's durability against weathering while the carbon black doped conductive layers provided the skin sensor with a high level of durability and weatherability protection. Structural health monitoring of civil infrastructure requires low-cost, scalable, long-term, and robust sensing technologies due to the size and complexity of the geometries under consideration. This paper investigates the durability and weatherability of a large area sensing skin engineered for civil infrastructure applications. This sensing skin is based on a soft elastomeric capacitor made of three thin layers based on an SEBS block co-polymer matrix. The inner layer is filled with titania and acts as the dielectric, while the external layers are doped with carbon black and work as the conductive plates. In this work, a variety of specimens, including the dielectric layer without the conductive plates, were fabricated and tested within an accelerated weathering chamber by simulating thermal, humidity, and UV radiation cycles. Beyond the accelerated weathering tests, a sensor deployed on a bridge in Iowa for six and a half years was removed from the field and analyzed in the laboratory. A variety of other tests were performed in order to characterize the specimens' mechanical, thermal, optical, and electrical performance. Additionally, strain sensitivity analyses were performed on specimens of interest. Results showed that titania inclusions improved the sensor dielectric's durability against weathering, while the carbon black doped conductive layers provided the skin sensor with a high level of durability and weatherability protection. The results in this work contribute to a better understanding of the degradation of SEBS-based matrices as well as the behavior of these skin sensors when deployed for the monitoring of civil infrastructure. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
29. Multifunctional ternary composite films based on PLA and Ag/alginate microbeads: Physical characterization and silver release kinetics.
- Author
-
Kostic, Danijela, Vukasinovic-Sekulic, Maja, Armentano, Ilaria, Torre, Luigi, and Obradovic, Bojana
- Subjects
- *
POLYLACTIC acid , *POLYMERIC composites , *SILVER nanoparticles , *ALGINATES , *PHARMACOKINETICS - Abstract
Abstract Novel multifunctional composite poly(lactic acid) (PLA) films with alginate microbeads containing silver nanoparticles (AgNPs) were developed for potential antimicrobial food packaging applications. AgNPs, 10–20 nm in size, were synthesized in a Na-alginate solution by a hydrothermal method yielding a sterile, pH neutral colloid solution of low viscosity that was electrostatically extruded to produce Ag/alginate microbeads (190 μm in size) with retained AgNPs. Dried microbeads were uniformly dispersed in PLA films with retained AgNPs as confirmed by UV–Vis spectroscopy and scanning electron microscopy. The films were characterized regarding thermal and mechanical properties as well as silver release in different food simulants. Results show that PLA matrix served as a diffusion barrier so that the released silver concentration in water after 10 days was within the prescribed limit of 0.05 mg kg−1 while the films induced inhibitory effects against Staphylococcus aureus in the agar diffusion test. Highlights • Low viscosity Ag/alginate colloid solutions were produced by hydrothermal synthesis • Electrostatic extrusion yielded microbeads with preserved silver nanoparticles • PLA composite films containing Ag/alginate microbeads were made by solvent casting. • PLA matrix in composite films served as a diffusion barrier for silver release. • PLA composite films inhibited the growth of S. aureus at low silver release. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
30. Thermal, antioxidant and swelling behaviour of transparent polyvinyl (alcohol) films in presence of hydrophobic citric acid-modified lignin nanoparticles.
- Author
-
He, Xiaoyan, Luzi, Francesca, Hao, Xiaolong, Yang, Weijun, Torre, Luigi, Xiao, Zefang, Xie, Yanjun, and Puglia, Debora
- Subjects
- *
LIGNINS , *ANTIOXIDANTS , *CITRIC acid , *THERMAL stability , *PHASE separation - Abstract
Abstract Lignin nanoparticles (LNP) have been esterified and etherified by citric acid and then blended with poly (vinyl alcohol) (PVA) at various loading levels (up to 10 wt%). Poly(vinyl alcohol) nanocomposite films containing unmodified and modified lignin nanoparticles (LNP and MLNP) were prepared through solvent casting approach. Microscopic investigation of films fractured surfaces confirmed that MLNP could be evenly dispersed in PVA matrix, and no macroscopic phase separation was generated in the nanocomposite films. Water contact angle, swelling efficiency and moisture adsorption properties of LNP and MLNP based films were measured and compared, revealing an overall increase of dimensional stability and reduced moisture adsorption for MLNP nanocomposites. MLNP based nanocomposite films outperformed the films containing LNP in antioxidant property and transparency, slight sacrificing in UV-absorbing, confirming these materials as promising candidates for applications requiring high antioxidant potential and improved performance towards light absorbance. Graphical abstract Unlabelled Image [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
31. Extraction of nanostructured starch from purified granules of waxy and non-waxy barley cultivars.
- Author
-
Del Buono, Daniele, Luzi, Francesca, Benincasa, Paolo, Kenny, José Maria, Torre, Luigi, and Puglia, Debora
- Subjects
- *
BARLEY varieties , *STARCH content of plants , *STARCH synthesis , *FLOUR , *EXTRACTION (Chemistry) , *THERMAL properties of nanoparticles - Abstract
Highlights • Waxy and non-waxy barley flours were selected for the extraction of starch nanoparticles. • Organic and alkali treatments were adopted to purify the barley waxy cultivar. • Nanoparticles with reduced mean diameter and thermal stability originated from waxy starch. • Amorphous nanoparticles derived from waxy and non-waxy barley starches were extracted. Abstract Waxy and non-waxy barley flours were selected as native material for the extraction, by acidic hydrolysis, of starch nanoparticles (NPs), with the main aim of evaluating how their different amylose/amylopectin ratio affected NPs structural characteristics. To this scope, two approaches based, respectively, on the use of NaCl/toluene (called organic treatment) and of sodium hydroxide solutions (called alkali treatment) were adopted in order to purify the waxy flours to give starch granules. Morphological investigations of waxy flour after alkali and organic treatments, before and after acetone washing, showed that the isolation methods of the starch did not affect the general morphologic characteristics of starch granules. The method found to provide the best outcomes in terms of thermal and morphological properties was also applied to purify the non-waxy barley. The results confirmed that waxy starch characterized by granules of smaller dimensions (WS) gave amorphous nanoparticles (WNP) with reduced mean diameter and thermal stability with respect to NPs obtained from non-waxy barley flour. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
32. Preparation and properties of adhesives based on phenolic resin containing lignin micro and nanoparticles: A comparative study.
- Author
-
Yang, Weijun, Rallini, Marco, Natali, Maurizio, Kenny, Jose, Ma, Piming, Dong, Weifu, Torre, Luigi, and Puglia, Debora
- Subjects
- *
LIGNINS , *NANOPARTICLES , *PHENOLIC resins , *DIFFERENTIAL scanning calorimetry , *COMPARATIVE studies , *SHEAR strength - Abstract
Abstract This work investigated, for the first time, the role of nanosized lignin (LNP), in comparison with microlignin (LMP), when introduced at two different weight amounts (5% and 10 wt%) in bulk phenol–formaldehyde resol as adhesive. Morphological analysis was performed to check out the dispersion and interfacial bonding of lignin in the phenolic resin. The curing process has been examined by differential scanning calorimetry (DSC), while the thermal stability of the composites has been evaluated by using thermogravimetric (TGA) and thermo-mechanical (TMA) analysis. Results exhibited that small amount of lignin could both favor the thermal cure reaction, due to its abundance of phenylpropane units, and the initial thermal resistance could be consequently improved, especially when the nano-sized lignin was used. Meanwhile, the effect of micro- and nano-modification on tensile shear strength of wood lap joints based on lignin-phenol–formaldehyde resol adhesives was also analyzed. Results showed that 5 wt% of LNP could positively increase the shear strength from 8.7 to 10.9 MPa, opening the possibility of using environmental friendly nanoscale lignin in cross linked traditional phenol wood adhesives with enhanced adhesion performance, strongly related to nanoparticles higher specific surface area and reactivity. Graphical abstract Unlabelled Image Highlights • Nanosized (LNP) and microlignin (LMP) were added to phenol–formaldehyde resol adhesive. • Nanolignin could both favor the cure reaction, due to its abundance of phenylpropane units. • Nanosized lignin homogenously dispersed absorbed and inhibited dimensional changes. • Higher specific surface area and reactivity for LNP increase the shear strength of wood joints. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
33. Biological, thermal and mechanical characterization of modified glass ionomer cements: The role of nanohydroxyapatite, ciprofloxacin and zinc l-carnosine.
- Author
-
Pagano, Stefano, Chieruzzi, Manila, Balloni, Stefania, Lombardo, Guido, Torre, Luigi, Bodo, Maria, Cianetti, Stefano, and Marinucci, Lorella
- Subjects
- *
IONOMERS , *HYDROXYAPATITE in medicine , *CIPROFLOXACIN , *CARNOSINE , *MECHANICAL properties of polymers , *ANTIBACTERIAL agents - Abstract
Abstract The study evaluated the effects of 4 wt% nanohydroxyapatite (HA), 6 wt% zinc l -carnosine (MDA) and 1.5 wt% Ciprofloxacin (AB) on the mechanical, thermal and biological properties of glass ionomer cements (GIC). Filler and additive concentrations were selected after a previous study had tested single components and different percentages. Specimens included five silicon molds of each GIC cement for all tests. They were stored at room temperature for 24 h from specimen collection to analysis. Mechanical tests, calorimetric analysis, morphological investigation, antibacterial and cell viability assays were conducted. One-way analysis of variance (ANOVA) was used for data analysis with significance set at p < 0.05. Adding HA, MDA and AB to GICs modified their thermal, mechanical and microbiological properties. Polymerization increased. A slight decrease in the compressive strength of modified GICs was observed in dry condition (p < 0.05). Cement extracts affected cell viability in relation to extract dilution. Mechanical behavior improved in modified glass ionomer cements, especially with the powder formulated antibiotic. Overall cytotoxicity was reduced. Therefore adding nanohydroxyapatite, antibiotic and a mucosal defensive agent to conventional glass ionomer cement in special need patients could improve the clinical, preventive and therapeutic performance of the cements, without altering their mechanical properties. Highlights • Effects of modified GIC on human oral cells • GIC and modified GIC have variable effects on oral tissue in vitro. • HA, ciprofloxacin and zinc l -carnosine modify the mechanical properties of GICs. [ABSTRACT FROM AUTHOR]
- Published
- 2019
- Full Text
- View/download PDF
34. Processing, thermo-mechanical characterization and gas permeability of thermoplastic starch/poly(butylene trans-1,4-cyclohexanedicarboxylate) blends.
- Author
-
Genovese, Laura, Dominici, Franco, Gigli, Matteo, Armentano, Ilaria, Lotti, Nadia, Fortunati, Elena, Siracusa, Valentina, Torre, Luigi, and Munari, Andrea
- Subjects
- *
PERMEABILITY , *THERMOPLASTICS , *CITRIC acid , *MICROSTRUCTURE , *CARBON dioxide - Abstract
Abstract In this contribution, binary blends of thermoplastic starch (TPS) and poly(butylene trans -1,4-cyclohexanedicarboxylate) (PBCE) have been prepared by melt extrusion. The effect of different amounts of PBCE and the presence of citric acid as compatibilizer have been studied with respect to the blend behavior. In particular, morphological and thermal studies allowed for the determination of the compatibility between the blend components, and of their characteristic thermal transitions and thermal stability. Envisioning potential packaging applications, surface wettability, moisture absorption and migration of food simulant have been investigated. In addition, mechanical properties and gas permeability have been evaluated after conditioning the films in dry and humid environment. Highlights • Blends of thermoplastic starch and poly(butylene trans -1,4-cyclohexanedicarboxylate) have been prepared by melt extrusion. • The effect of blend composition and of the presence of citric acid have been studied with respect to the blend behavior. • Compatibilized binary blends are characterized by improved mechanical and barrier properties to oxygen and carbon dioxide. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
35. Nanostructured starch combined with hydroxytyrosol in poly(vinyl alcohol) based ternary films as active packaging system.
- Author
-
Luzi, Francesca, Fortunati, Elena, Di Michele, Alessandro, Pannucci, Elisa, Botticella, Ermelinda, Santi, Luca, Kenny, José Maria, Torre, Luigi, and Bernini, Roberta
- Subjects
- *
NANOSTRUCTURED materials , *HYDROXYTYROSOL , *POLYVINYL alcohol , *ACTIVE food packaging , *STARCH - Abstract
Novel ternary films have been realized by using poly(vinyl alcohol) (PVA) as polymeric matrix, nanostructured starch as reinforcement phase and hydroxytyrosol (HTyr), a low-molecular phenolic compound present in olive oil, as antioxidant agent. Nanostructured starch, in the form of starch nanocrystals (NC) and nanoparticles (NP) obtained by acid hydrolysis and ultrasound irradiation of starch derived from the bread wheat variety Cadenza (WT, amylose content 33%) and a derived-high amylose line (HA, amylose content 75%), was considered. The developed multifunctional films were characterized in terms of morphological, thermal and optical properties, water absorption capacity, overall and specific migration into a food simulant and antioxidant properties. Experimental data showed a prolonged release of HTyr from all ternary films and the released HTyr retained a strong antioxidant activity. The data, compared to those of PVA/HTyr binary films, demonstrated the key role of nanostructured starch in the ternary formulations in promoting a gradual release of HTyr. Overall, PVA fillm combined with nanoparticles from low amylose starch and hydroxytyrosol resulted as the most promising ternary formulation for food packaging applications. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
36. Experimental validation of a high-temperature solar box cooker with a solar-salt-based thermal storage unit.
- Author
-
Coccia, Gianluca, Di Nicola, Giovanni, Tomassetti, Sebastiano, Pierantozzi, Mariano, Chieruzzi, Manila, and Torre, Luigi
- Subjects
- *
SOLAR ovens , *HIGH temperatures , *SOLAR cooking , *SOLAR radiation , *PHASE change materials , *HEAT storage , *SALT - Abstract
Clear-sky conditions are an essential need to allow proper high-temperature solar cooking. Moreover, it is not an easy task to accomplish evening cooking, especially during wintertime when solar radiation is available only for a few hours. A solution to bypass these drawbacks lies in adopting a cooker provided with a thermal storage unit. The storage unit proposed in this work is a double-walled vessel composed by two stainless steel cylindrical pots assembled concentrically. The annular space between the pots was loaded with 4 kg of phase change material (PCM) based on a ternary mixture of nitrite and nitrate salts (solar salt: 53 wt% KNO 3 , 40 wt% NaNO 2 , 7 wt% NaNO 3 ). The thermal storage unit was characterized by means of a test rig including a high-concentration-ratio (10.78) solar box cooker. Four different sets of 14 experimental tests, divided into a heating and a cooling phase, were carried out to assess the performance of the solar cooker with the storage unit. It was found that the PCM thermal storage significantly improves the load thermal stabilization when solar radiation is not available: the load cooling time in the range 170–130 °C was determined to be from 65.12% to 107.98% higher than that without the solar-salt-based PCM thermal storage, proving the effectiveness of the proposed solution. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
37. Recycling coffee silverskin in sustainable composites based on a poly(butylene adipate-co-terephthalate)/poly(3-hydroxybutyrate-co-3-hydroxyvalerate) matrix.
- Author
-
Sarasini, Fabrizio, Tirillò, Jacopo, Zuorro, Antonio, Maffei, Gianluca, Lavecchia, Roberto, Puglia, Debora, Dominici, Franco, Luzi, Francesca, Valente, Teodoro, and Torre, Luigi
- Subjects
- *
COFFEE , *WASTE products , *ANTIOXIDANTS , *SUSTAINABLE development , *SCANNING electron microscopy - Abstract
This work investigates the feasibility of using coffee silverskin (CSS), one of the most abundant coffee waste products, as a reinforcing agent in biopolymer based composites. The chemical composition, antioxidant activity and morphology of CSS were studied by specific chemical essays and scanning electron microscopy, whilst the thermal stability and the functional groups available on the surface were investigated by thermogravimetric analysis and infrared spectroscopy, respectively. The thermal stability and fibrous structure of CSS make it suitable as a reinforcing filler in polymer composites, which was confirmed by manufacturing biocomposites with improved stiffness and tensile strength, not degraded by CSS addition when compared to the neat biopolymer. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
38. Hyperbranched poly(ethyleneimine) physically attached to silica nanoparticles to facilitate curing of epoxy nanocomposite coatings.
- Author
-
Ghiyasi, Samira, Sari, Morteza Ganjaee, Shabanian, Meisam, Hajibeygi, Mohsen, Zarrintaj, Payam, Rallini, Marco, Torre, Luigi, Puglia, Debora, Vahabi, Henri, Jouyandeh, Maryam, Laoutid, Fouad, Paran, Seyed Mohammad Reza, and Saeb, Mohammad Reza
- Subjects
- *
POLYETHYLENEIMINE , *SILICA nanoparticles , *EPOXY coatings , *NANOPARTICLE synthesis , *AMINES , *NANOCOMPOSITE materials - Abstract
There was a hope that highly reactive nanoparticles would strongly facilitate crosslinking in epoxy-amine systems. In this work, silica (SiO 2 ) nanoparticles are physically modified with poly(ethyleneimine) as surface modifier. The SiO 2 nanoparticles were synthesized and physically decorated with poly(ethyleneimine), then the untreated and surface-treated SiO 2 nanoparticles were analyzed by FTIR, TGA and SEM techniques. The results show that poly(ethyleneimine) hyperbranched molecule is successfully attached to the surface of SiO 2 nanoparticles enabling epoxy ring opening. Both untreated and modified particles are impregnated into an epoxy/amine system to fabricate nanocomposite coatings. The effect of the aforementioned SiO 2 nanoparticles on the curing behavior of the epoxy/amine system was investigated by means of dynamic DSC analysis. The results demonstrated that, while addition of untreated silica nanoparticles could not seriously curing reactions, the introduction of poly(ethyleneimine)-modified SiO 2 facilitated crosslinking of epoxy/amine system thanks to the abundance of amine reactive groups on the particle surface that gives worth to the poly(ethyleneimine)-modified SiO 2 nanoparticles as a promising nanomaterial for manufacturing highly-curable epoxy-based nanocomposite coatings. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
39. Effect of nano‐magnetite particle content on mechanical, thermal and magnetic properties of polypropylene composites.
- Author
-
Di Palma, Luca, Bavasso, Irene, Sarasini, Fabrizio, Tirillò, Jacopo, Puglia, Debora, Dominici, Franco, Torre, Luigi, Galluzzi, Armando, Polichetti, Massimiliano, Ramazanov, Mahammadali Ahmed, Hajiyeva, Flora V., and Shirinova, Habiba A.
- Subjects
- *
POLYPROPYLENE , *COMPOSITE materials , *MAGNETIC nanoparticles , *SCANNING electron microscopy , *HARDNESS testing - Abstract
Magnetic nanoparticles embedded in polymer matrices have excellent potential for electromagnetic device applications, like electromagnetic interference suppression or strain sensing applications in the structural health monitoring domain. In this work, polymer nanocomposites of polypropylene loaded with varying concentrations of magnetite nanoparticles (from 2 to 40 wt%) have been synthesized by an ex situ process. The magnetite nanoparticles were produced using a simple co‐precipitation technique. The nanocomposites were characterized by differential scanning calorimetry, scanning electron microscopy, tensile and hardness testing, vibrating sample magnetometry. The mechanical properties were found to be dependent on the degree of dispersion and on the strong nucleating ability of magnetite nanoparticles, while a superparamagnetic behavior was reported. These composites have tailorable mechanical and magnetic properties highly dependent on the content of magnetic filler. POLYM. COMPOS., 39:E1742–E1750, 2018. © 2018 Society of Plastics Engineers [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
40. Effect of the addition of polyester-grafted-cellulose nanocrystals on the shape memory properties of biodegradable PLA/PCL nanocomposites.
- Author
-
Sessini, Valentina, Navarro-Baena, Iván, Arrieta, Marina P., Dominici, Franco, López, Daniel, Torre, Luigi, Kenny, José M., Dubois, Philippe, Raquez, Jean-Marie, and Peponi, Laura
- Subjects
- *
SHAPE memory polymers , *POLYESTERS , *POLYLACTIC acid , *CELLULOSE , *NANOCRYSTALS , *BIODEGRADABLE materials - Abstract
In this work the thermally-activated shape memory response of biodegradable nanocomposites based on PLA/PCL blend reinforced with different type of cellulose nanocrystals has been reported, and compared with those of the neat matrix, at the same transition temperature of 55 °C and at the same different deformations, 50%, 100% and 150%. In particular, cellulose nanocrystals have been synthesized and then functionalized by “grafting from” reaction by ring opening polymerization of both PLLA and PCL using the OH groups onto the cellulose nanocrystals surface as initiators for the reaction. The morphology, thermal and mechanical analysis have been performed in order to obtain the parameters for the thermo-mechanical shape memory cycles. Moreover, the addition of the CNC-based nanofillers on the compatibility of PLA-PCL blends in 70:30 proportion has been evaluated. All the biodegradable nanocomposite formulations showed excellent shape memory response, similar to those of the neat matrix, with strain recovery ratio and strain fixity ratio higher than 80% and 90%, respectively. This fact indicates that in this case, the shape memory response of the nanocomposites is mainly controlled by the response of the neat blend and they are slightly influenced by the increase of compatibility between the components of the blend. In addition, all nanocomposite films were fully disintegrated under composting conditions confirming their biodegradable nature, obtaining that the presence of CNC-based nanofillers speeds up the disintegration rate of the nanocomposites in comparison with the pure matrix. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
41. Thermally-activated shape memory effect on biodegradable nanocomposites based on PLA/PCL blend reinforced with hydroxyapatite.
- Author
-
Peponi, Laura, Sessini, Valentina, Arrieta, Marina P., Navarro-Baena, Iván, Sonseca, Agueda, Dominici, Franco, Gimenez, Enrique, Torre, Luigi, Tercjak, Agnieszka, López, Daniel, and Kenny, José M.
- Subjects
- *
BIODEGRADABLE nanoparticles , *HYDROXYAPATITE , *NANOCOMPOSITE materials , *RAMAN spectroscopy , *ATOMIC force microscopy , *POLYLACTIC acid , *MECHANICAL properties of metals - Abstract
In this work, the effect of the addition of different amount of nanosized hydroxyapatite (nHA) on the shape memory behavior of blends based on poly (lactic acid) (PLA) and poly (ε-caprolactone) (PCL) has been studied. In particular PLA/PCL blend with 70 wt % PLA has been reinforced with 0.5, 1 and 3 wt % nHA. Moreover, the relationship between the morphology and the final properties of the nanocomposites has been investigated by field emission scanning electron microscopy, confocal Raman spectroscopy and atomic force microscopy. In particular, PeakForce has been used to study quantitative nanomechanical properties of the multifunctional materials leading to conclusion that nHA increase the phase separation between PLA and PCL as well as act as reinforcements for the PCL-rich phase of the nanocomposites. Furthermore, excellent thermally-activated shape memory response has been obtained for all the nanocomposites at 55 °C. Finally, the disintegration under composting conditions at laboratory scale level was studied in order to confirm the biodegradable character of these nanocomposites. Indeed, these materials are able to be used for biomedical issues as well as for packaging applications where both thermally-activated shape memory effect and biodegradability are requested. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
42. Synthesis and Characterization of Nanofluids Useful in Concentrated Solar Power Plants Produced by New Mixing Methodologies for Large-Scale Production.
- Author
-
Chieruzzi, Manila, Miliozzi, Adio, Crescenzi, Tommaso, Kenny, José M., and Torre, Luigi
- Subjects
- *
NANOFLUIDS , *SOLAR power plants , *HEAT storage - Abstract
In this study, different nanofluids (NFs) were developed by mixing a molten salt mixture (60% NaNO3-40% KNO3) with 1.0 wt % of silica-alumina nanoparticles using different methods. These NFs can be used as thermal energy storage materials in concentrating solar plants with a reduction of storage material if the thermal properties of the base fluid are increased. New mixing procedures without sonication were introduced with the aim to avoid the sonication step and to allow the production of a greater amount of NF with a procedure potentially more suitable for large-scale productions. For this purpose, two mechanical mixers and a magnetic stirrer were used. Each NF was prepared in aqueous solution with a concentration of 100 g/l. The effect of different concentrations (300 g/l and 500 g/l) was also studied with the most effective mixer. Specific heat, melting temperature, and latent heat were measured by means of differential scanning calorimeter. Thermal conductivity and diffusivity in the solid state were also evaluated. The results show that the highest increase of the specific heat was obtained with 100 g/l both in solid (up to 31%) and in liquid phase (up to 14%) with the two mechanical mixers. The same NFs also showed higher amount of stored heat. An increase in thermal conductivity and diffusivity was also detected for high solution concentrations with a maximum of 25% and 47%, respectively. Scanning electron microscopy (SEM) and energy-dispersive X-ray analyses revealed that the grain size in the NFs is much smaller than in the salt mixture, especially for the NF showing the highest thermal properties increase, and a better nanoparticles distribution is achieved with the lowest concentration. NFs with enhanced thermal properties can be synthesized in a cost-effective form in high concentrated aqueous solutions by using mechanical mixers. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
43. An Experimental Study on Static and Dynamic Strain Sensitivity of Embeddable Smart Concrete Sensors Doped with Carbon Nanotubes for SHM of Large Structures.
- Author
-
Meoni, Andrea, D’Alessandro, Antonella, Downey, Austin, García-Macías, Enrique, Rallini, Marco, Materazzi, A. Luigi, Torre, Luigi, Laflamme, Simon, Castro-Triguero, Rafael, and Ubertini, Filippo
- Abstract
The availability of new self-sensing cement-based strain sensors allows the development of dense sensor networks for Structural Health Monitoring (SHM) of reinforced concrete structures. These sensors are fabricated by doping cement-matrix mterials with conductive fillers, such as Multi Walled Carbon Nanotubes (MWCNTs), and can be embedded into structural elements made of reinforced concrete prior to casting. The strain sensing principle is based on the multifunctional composites outputting a measurable change in their electrical properties when subjected to a deformation. Previous work by the authors was devoted to material fabrication, modeling and applications in SHM. In this paper, we investigate the behavior of several sensors fabricated with and without aggregates and with different MWCNT contents. The strain sensitivity of the sensors, in terms of fractional change in electrical resistivity for unit strain, as well as their linearity are investigated through experimental testing under both quasi-static and sine-sweep dynamic uni-axial compressive loadings. Moreover, the responses of the sensors when subjected to destructive compressive tests are evaluated. Overall, the presented results contribute to improving the scientific knowledge on the behavior of smart concrete sensors and to furthering their understanding for SHM applications. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
44. Synthesis, characterization and performance evaluation of Fe3O4/PES nano composite membranes for microbial fuel cell.
- Author
-
Di Palma, Luca, Bavasso, Irene, Sarasini, Fabrizio, Tirillò, Jacopo, Puglia, Debora, Dominici, Franco, and Torre, Luigi
- Subjects
- *
SYNTHESIS of Nanocomposite materials , *POLYETHERSULFONE , *PROTON exchange membrane fuel cells , *TENSILE strength , *MECHANICAL behavior of materials - Abstract
In this study, nanocomposites based on polyethersulfone (PES) with different amounts of Fe 3 O 4 nanoparticles have been synthesized, to be used as proton exchange membranes in a microbial fuel cell (MFC). Such new low-cost separators were fabricated by melt blending and tested in an MFC system. The membranes have been characterized in terms of their mechanical and thermal properties and the results compared to those of commercially available ones (Nafion 117 and CMI 7000). The efficiency of the newly synthesized membranes was assessed in H-type MFC system. Synthetic wastewater using sodium acetate as carbon source was prepared. Total Organic Carbon (TOC) reduction, pH and Open Circuit Voltage (OCV) were daily monitored. Linear Sweep Voltammetry (LSV) was used to optimize the amount of nanoparticles in terms of maximum current and power. The maximum power (9.59 ± 1.18 mW m −2 ) and current density (38.38 ± 4.73 mA m −2 ) generation were obtained by using a composite with 20 wt% of nanoparticles. Results of mechanical characterization pointed out that increasing nanoparticles content can compromise the mechanical properties of membranes leading to a significant brittle behavior, while the tensile strength was found to be suitable for durable MFC operations. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
45. Effect of Cellulose Nanocrystals and Bacterial Cellulose on Disintegrability in Composting Conditions of Plasticized PHB Nanocomposites.
- Author
-
Seoane, Irene Teresita, Manfredi, Liliana Beatriz, Cyras, Viviana Paola, Torre, Luigi, Fortunati, Elena, and Puglia, Debora
- Subjects
- *
CELLULOSE nanocrystals , *NANOCOMPOSITE materials , *TRIBUTYRIN , *PLASTICIZERS , *CHEMICAL properties , *CRYSTALLINITY - Abstract
Poly(hydroxybutyrate) (PHB)-based films, reinforced with bacterial cellulose (BC) or cellulose nanocrystals (CNC) and plasticized using a molecular (tributyrin) or a polymeric plasticizer (poly(adipate diethylene)), were produced by solvent casting. Their morphological, thermal, wettability, and chemical properties were investigated. Furthermore, the effect of adding both plasticizers (20 wt % respect to the PHB content) and biobased selected nanofillers added at different contents (2 and 4 wt %) on disintegrability in composting conditions was studied. Results of contact angle measurements and calorimetric analysis validated the observed behavior during composting experiments, indicating how CNC aggregation, due to the hydrophilic nature of the filler, slows down the degradation rate but accelerates it in case of increasing content. In contrast, nanocomposites with BC presented an evolution in composting similar to neat PHB, possibly due to the lower hydrophilic character of this material. The addition of the two plasticizers contributed to a better dispersion of the nanoparticles by increasing the interaction between the cellulosic reinforcements and the matrix, whereas the increased crystallinity of the incubated samples in a second stage in composting provoked a reduction in the disintegration rate. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
46. Cellulose nanocrystals from Actinidia deliciosa pruning residues combined with carvacrol in PVA_CH films with antioxidant/antimicrobial properties for packaging applications.
- Author
-
Luzi, Francesca, Fortunati, Elena, Giovanale, Geremia, Mazzaglia, Angelo, Torre, Luigi, and Balestra, Giorgio Mariano
- Subjects
- *
ACTINIDIA , *CELLULOSE nanocrystals , *POLYVINYL alcohol , *ANTI-infective agents , *CARVACROL - Abstract
Kiwi Actinidia deliciosa pruning residues were here used for the first time as precursors for the extraction of high performing cellulose nanocrystals (CNC) by applying a bleaching treatment followed by an acidic hydrolysis. The resultant cellulosic nanostructures, obtained by an optimize extraction procedure (0.7% wt/v two times of sodium chlorite NaClO 2 ) followed by an hydrolysis step, were then used as reinforcements phases in poly(vinyl alcohol) (PVA) blended with natural chitosan (CH) based films and also combined, for the first time, with carvacrol used here as active agent. Morphological and optical characteristics, mechanical response, thermal and migration properties, moisture content and antioxidant and antimicrobial assays were conducted. The morphological, optical and colorimetric results underlined that no particular alterations were induced on the transparency and color of PVA and PVA_CH blend by the presence of CNC and carvacrol, while they were able to modulate the mechanical responses, to induce antioxidant activities maintaining the migration levels below the permitted limits and suggesting the possible application in industrial sectors. Finally, inhibitions on bacterial development were detected for multifunctional systems, suggesting their protective function against microorganisms contamination. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
47. Design of a nanocomposite substrate inducing adult stem cell assembly and progression toward an Epiblast-like or Primitive Endoderm-like phenotype via mechanotransduction.
- Author
-
Morena, Francesco, Armentano, Ilaria, Montanucci, Pia, Argentati, Chiara, Fortunati, Elena, Montesano, Simona, Bicchi, Ilaria, Pescara, Teresa, Pennoni, Ilaria, Mattioli, Samantha, Torre, Luigi, Latterini, Loredana, Emiliani, Carla, Basta, Giuseppe, Calafiore, Riccardo, Kenny, Josè Maria, and Martino, Sabata
- Subjects
- *
STEM cells , *NANOCOMPOSITE materials , *FILAMINS , *PROTEIN analysis , *TRANSCRIPTION factors - Abstract
This work shows that the active interaction between human umbilical cord matrix stem cells and Poly ( l -lactide)acid (PLLA) and PLLA/Multi Walled Carbon Nanotubes (MWCNTs) nanocomposite films results in the stem cell assembly as a spheroid conformation and affects the stem cell fate transition. We demonstrated that spheroids directly respond to a tunable surface and the bulk properties (electric, dielectric and thermal) of plain and nanocomposite PLLA films by triggering a mechanotransduction axis. This stepwise process starts from tethering of the cells' focal adhesion proteins to the surface, together with the adherens junctions between cells. Both complexes transmit traction forces to F-Actin stress fibres that link Filamin-A and Myosin-IIA proteins, generating a biological scaffold, with increased stiffening conformation from PLLA to PLLA/MWCNTs, and enable the nucleoskeleton proteins to boost chromatin reprogramming processes. Herein, the opposite expression of NANOG and GATA6 transcription factors, together with other lineage specification related proteins, steer spheroids toward an Epiblast-like or Primitive Endoderm-like lineage commitment, depending on the absence or presence of 1 wt% MWCNTs, respectively. This work represents a pioneering effort to create a stem cell/material interface that can model the stem cell fate transition under growth culture conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
48. Heat capacity of nanofluids for solar energy storage produced by dispersing oxide nanoparticles in nitrate salt mixture directly at high temperature.
- Author
-
Chieruzzi, Manila, Cerritelli, Gian F., Miliozzi, Adio, Kenny, José M., and Torre, Luigi
- Subjects
- *
HEAT capacity , *NANOFLUIDS , *ENERGY storage , *OXIDES , *SOLAR energy , *NANOPARTICLES , *HIGH temperatures - Abstract
Molten salts as phase change materials (PCMs) can be used as thermal storage media in concentrated solar power (CSP) plants. The addition of nanoparticles into a base fluid (producing the so called nanofluid) can enhance its thermal properties. The most common technique involves the use of water. We present a new procedure based on high temperature mixing. In particular, different nanofluids were developed by mixing NaNO 3 -KNO 3 (60–40 wt%) solar salt with 1.0 wt% of SiO 2 , Al 2 O 3 and a mix of SiO 2 /Al 2 O 3 nanoparticles at 300 °C using a twin screw micro-compounder. The effect of different screw speeds (100 and 200 rpm) and mixing times (15 and 30 min) were studied. The results showed that the nanoparticles induce an increase of the heat of fusion of 1.5–7.4% while the onset temperatures decrease for all the nanofluids independently from the processing conditions (up to 9.7 °C). Moreover, an increase in the specific heat ( Cp ) is recorded mainly for the nanofluid with SiO 2 /Al 2 O 3 with a maximum of 52.1% in solid phase and 18.6% in liquid phase after 30 min of mixing at 200 rpm. The same nanofluid showed the highest stored heat. Particle aggregation into clusters in solid state was detected by scanning electron microscopy (SEM) but smaller aggregates resulted for higher mixing times and screw speed related to the highest Cp . Moreover, smaller grains in the nanofluids were detected with respect to the base salt morphology. Thus, the nanofluid produced with SiO 2 /Al 2 O 3 nanoparticles at 200 rpm for 30 min gives the best overall performances. This work showed that nanofluids with enhanced thermal properties can be obtained with an innovative mixing process directly at high temperature, eliminating the water evaporation step. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
49. Processing Conditions, Thermal and Mechanical Responses of Stretchable Poly (Lactic Acid)/Poly (Butylene Succinate) Films.
- Author
-
Fortunati, Elena, Puglia, Debora, Iannoni, Antonio, Terenzi, Andrea, Kenny, José Maria, and Torre, Luigi
- Subjects
- *
POLYLACTIC acid , *BUTENE , *PLASTICIZERS , *PLASTIC scrap & the environment , *WETTING agents - Abstract
Poly (lactic acid) (PLA) and poly (butylene succinate) (PBS) based films containing two different plasticizers [Acetyl Tributyl Citrate (ATBC) and isosorbide diester (ISE)] at three different contents (15 wt %, 20 wt % and 30 wt %) were produced by extrusion method. Thermal, morphological, mechanical and wettability behavior of produced materials was investigated as a function of plasticizer content. Filmature parameters were also adjusted and optimized for different formulations, in order to obtain similar thickness for different systems. Differential scanning calorimeter (DSC) results and evaluation of solubility parameter confirmed that similar miscibility was obtained for ATBC and ISE in PLA, while the two selected plasticizers resulted as not efficient for plasticization of PBS, to the limit that the PBS-30ATBC resulted as not processable. On the basis of these results, isosorbide-based plasticizer was considered a suitable agent for modification of a selected blend (PLA/PBS 80:20) and two mixing approaches were used to identify the role of ISE in the plasticization process: results from mechanical analysis confirmed that both produced PLA-PBS blends (PLA85-ISE15)-PBS20 and (PLA80-PBS20)-ISE15 could guarantee advantages in terms of deformability, with respect to the PLA80-PBS20 reference film, suggesting that the promising use of these stretchable PLA-PBS based films plasticized with isosorbide can provide novel solutions for food packaging applications. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
50. Microstructure and ablation behavior of an affordable and reliable nanostructured Phenolic Impregnated Carbon Ablator (PICA).
- Author
-
Natali, Maurizio, Puri, Ivan, Kenny, José M., Torre, Luigi, and Rallini, Marco
- Subjects
- *
ABLATIVE materials , *MICROSTRUCTURE , *LASER ablation , *THERMAL insulation , *CARBON fibers , *THERMAL stability - Abstract
Among polymeric Thermal Protection System (TPS) materials, Phenolic Impregnated Carbon Ablators (PICAs) offer substantial specific weight reduction. A traditional NASA developed PICA is made starting from a preform or using Milled Carbon Fibers (MCFs) to produce a porous skeleton impregnated with a liquid phenolic matrix; the production methods, allow to obtain a low density porous material showing high ablation resistance. The aim of this research was to produce a nanostructured PICA (n-PICA) based on the use of MCFs, a liquid phenolic matrix, and selected nanofillers. Two different nanofillers were used: Multi-Walled Carbon Nanotubes (MWNTs) and nanoclays. The synergistic effect of the two nanofillers was evaluated in terms of thermal and dimensional stability, mechanical properties and ablation resistance via oxy-acetylene torch. Scanning electron microscopy was used to investigate the exposed and in depth surface morphologies of the oxy-acetylene torch tested specimens in order to highlight the differences in the thermal erosion mechanisms. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.