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In previous work, despite the positive effect of the titanium carbide + titanium diboride (TiC+TiB2) on the wear, hardness and erosion properties of the epoxy/glass fiber composites, the particles reduced tensile and flexural strength. This research targets to improve the tensile and flexural properties of the epoxy/glass fiber/TiC+TiB2 composites by adding clay nanoparticles in content of 1, 3, and 5 wt%. The effect of nano-clay content on mechanical (tensile, flexural, and hardness) properties and wear behavior of the hybrid composites was investigated. The field Emission Scanning Electron Microscopy (FE-SEM) images revealed the morphology, the fracture surface and failure mechanisms of the composites. The X-ray diffraction confirmed the formation of TiC+TiB2 particles and the nanocomposites. Tensile and flexural results showed that introducing clay nanoparticles increases tensile strength and flexural strength by 92% (from 116 to 223 MPa) and 67% (from 194 to 324 MPa), respectively. The nano-clay did not have a significant effect on the tensile and flexural modulus. The hardness increased from 35.1 to 79.4 HRP. Wear properties results revealed that clay nanoparticles improve the wear resistance of the composite samples significantly. The addition of 5 wt% of clay nanoparticles decreased wear rate from 3.7 to 0.4 mg/Nm. [ABSTRACT FROM AUTHOR]

Introduction. Nanotechnology has received a lot of attention in the oil and gas industry as an effective means of improving properties and increasing production rates, especially in harsh environments such as ultra-deep and shallow gas fields, deviated and horizontal wells, geothermal zones, and high pressure/high temperature (HPHT) areas. These environments present numerous economic, technical, operational, and HSE challenges that need to be addressed.Cementing operations play a critical role in these environments, as the cement sheath serves as a barrier to meet the different well conditions, including pressure, temperature, and the flow of liquids or gases. The use of nanomaterials as additives to cement has been credited with improving its properties and performance under these complicated conditions. Methods and materials. The study presents an analysis of the effect of pressure and temperature on the behavior and complexity of cementing operations in high-pressure wells. Analytical performance of the main characteristics of nanoclay (structural and mechanical) and evaluation of its effect on the durability and strength of cement slurry during well construction are presented. Results and Discussion. The results of the study allow us to conclude that nanoclay can be widely used as an additive to improve the durability and properties of cement-based materials under difficult conditions. Conclusions. The results of this study provide valuable information to researchers, engineers and practitioners in the field of cementing oil and gas wells, especially in solving problems related to providing the most favorable conditions for well operation with the long-term use of more durable cement slurry

Abstract This paper contributes to the expanding knowledge base on nanomaterial-enhanced cementitious composites, offering valuable insights for developing high-performance, sustainable concrete solutions. The study assessed the effects of three different types of nanomaterials—nano clay (NC), nano silica (NS), and nano cellulose (NCel)—on the compressive strength of high-early-strength concrete (HESC) through both experimental studies and a 23 factorial design. Incorporating nanomaterials into the HESC matrix led to a decrease in workability, with NCel demonstrating the least impact on this property across all studied replacement percentages. All HESC mixes containing nanomaterials exhibited higher compressive strength than the control mix (M mix) across all ages. The optimal percentages for compressive strength enhancement were 4.5% NC (33.43% increase at 3 days, 22.29% at 7 days, and 12.15% at 28 days), 4.5% NS (20.12%, 11.14%, and 4.89% respectively), and 0.0375% NCel (34.91%, 25.76%, and 13.46% respectively). The highest compressive strength was observed in the hybrid mix containing 4.5% NC and 0.0375% NCel, yielding strength enhancements of 35.7%, 26%, and 12.75% compared to the M mix. Statistical analysis indicated that nano cellulose had the most significant contribution to enhancing compressive strength, followed by nano clay. The mathematical models derived from the statistical analyses provide a reliable means of predicting the compressive strength of HESC at 3, 7, and 28 days based on nanomaterial content. Contour plots illustrated the optimization of compressive strength across different nanomaterial contents at each age. In summary, the findings underscore the potential of waste-derived nanomaterials to enhance the performance of HESC, paving the way for innovative waste utilization strategies in construction. The study emphasizes the importance of reducing curing times, improving structural durability, and minimizing the environmental impact associated with concrete production.

This paper contributes to the expanding knowledge base on nanomaterial-enhanced cementitious composites, offering valuable insights for developing high-performance, sustainable concrete solutions. The study assessed the effects of three different types of nanomaterials—nano clay (NC), nano silica (NS), and nano cellulose (NCel)—on the compressive strength of high-early-strength concrete (HESC) through both experimental studies and a 23 factorial design. Incorporating nanomaterials into the HESC matrix led to a decrease in workability, with NCel demonstrating the least impact on this property across all studied replacement percentages. All HESC mixes containing nanomaterials exhibited higher compressive strength than the control mix (M mix) across all ages. The optimal percentages for compressive strength enhancement were 4.5% NC (33.43% increase at 3 days, 22.29% at 7 days, and 12.15% at 28 days), 4.5% NS (20.12%, 11.14%, and 4.89% respectively), and 0.0375% NCel (34.91%, 25.76%, and 13.46% respectively). The highest compressive strength was observed in the hybrid mix containing 4.5% NC and 0.0375% NCel, yielding strength enhancements of 35.7%, 26%, and 12.75% compared to the M mix. Statistical analysis indicated that nano cellulose had the most significant contribution to enhancing compressive strength, followed by nano clay. The mathematical models derived from the statistical analyses provide a reliable means of predicting the compressive strength of HESC at 3, 7, and 28 days based on nanomaterial content. Contour plots illustrated the optimization of compressive strength across different nanomaterial contents at each age. In summary, the findings underscore the potential of waste-derived nanomaterials to enhance the performance of HESC, paving the way for innovative waste utilization strategies in construction. The study emphasizes the importance of reducing curing times, improving structural durability, and minimizing the environmental impact associated with concrete production. [ABSTRACT FROM AUTHOR]

Floor coating is a contemporary technique used to substitute traditional flooring materials like ceramic, oak, and alabaster with epoxy paint. The properties of epoxy floor coatings were studied in terms of mechanical properties, wear resistance, and tribological properties. Nano-clays (MMT for epoxy) were added for reinforcement in different proportions (0, 0.5, 1, 2, and 4 wt.%) using the ultrasound dispersing device. The results show that the wear resistance of the nanocomposite coating reinforced with 2% nanoclay is improved by 82% compared to pure epoxy. The hardness increases by about 13.8% and 19.7% when the nanoclay content is 0.5% and 4%, respectively, compared to pure epoxy, while the adhesive strength decreases with increasing the weight percentage of nanoclay in the composites. In addition, results show that scratch hardness improved by 37.5% and 118.75% when nanoclay content was 0.5% and 4%, respectively. [ABSTRACT FROM AUTHOR]

Clay-based mortars are susceptible to water intake and exhibit low mechanical strength, presenting challenges in their application within the construction sector. This research addresses these vulnerabilities by investigating the combination of alkali activators with waterproofing agents, specifically a nano-clay and an acrylic emulsion, to enhance the properties of clay mortars. Alkali-activated materials are known for their superior mechanical properties and sustainable potential, especially when derived from low-cost by-products. Recent studies have focused on alkali activation using clays and soils as precursors to improve their physical and mechanical properties while increasing durability. However, the high absorbency of these mortars remains a concern, as it can lead to matrix degradation. Therefore, to address these problems, this research studied the combination of a highly alkaline activator (potassium metasilicate) with hydrophobic agents, such as a nano-clay and an acrylic emulsion, using two different clayey soils. The results indicated that potassium metasilicate (PO) enhanced the mechanical properties and stability for both aluminosilicate systems, while nano-clay (PONC) significantly reduced the capillary absorption through time, especially in A2 systems. The addition of acrylic emulsion (POD) proved highly effective in both systems, significantly improving durability. By integrating these agents, the mortar systems were protected against water intake, while durable construction materials were formed. [ABSTRACT FROM AUTHOR]

More than 50% of the flame retardants used in the polymer and plastic industries are metal hydroxides. Among them, aluminum trihydroxide (ATH) is the most widely used due to its low toxicity and corrosiveness and its cost-effectiveness. The use of high-volume ATH in polymers reduces the mechanical properties. In this work, clay nanoparticles were added into epoxy/glass fiber/ATH hybrid composites to improve the mechanical and thermal properties of the composites. The effect of nano-clay content (1, 3, and 5 phr) on mechanical properties such as tensile and flexural strength and modulus, and thermal properties was investigated. Thermal properties were evaluated by Differential Scanning Calorimetry (DSC), and Thermogravimetric Analysis (TGA). The result of mechanical tests showed that adding 3 phr of clay nanoparticles increases tensile and flexural strength by 10% and 9.2%, respectively. The flammability of the composites was measured in horizontal mode. The flammability results revealed that introducing 3 phr of nano-clay improves the flammability of the composites by 41%. [ABSTRACT FROM AUTHOR]

An understanding of the mechanical behavior of polymeric materials is crucial for making advancements in the applications and efficiency of nanocomposites, and encompasses their service life, load resistance, and overall reliability. The present study focused on the prediction of the mechanical behavior of biopolymeric nanocomposites with nano-clays as the nanoadditives, using a new modeling and simulation method based on Comsol Multiphysics software 6.1. This modeling considered the complex case of flake-shaped nano-clay additives that could form aggregates along the polymeric matrix, varying the nanoadditive thickness, and consequently affecting the resulting mechanical properties of the polymeric nanocomposite. The polymeric matrix investigated was biopolyamide 11 (BIOPA11). Several BIOPA11 samples reinforced with three different contents of nano-clays (0, 3, and 10 wt%), and with three different nano-clay dispersion grades (employing three different extrusion screw configurations) were obtained by the compounding extrusion process. The mechanical behavior of these samples was studied by the experimental tensile test. The experimental results indicate an enhancement of Young's modulus as the nano-clay content was increased from 0 to 10 wt% for the same dispersion grades. In addition, the Young's modulus value increased when the dispersion rate of the nano-clays was improved, showing the highest increase of around 93% for the nanocomposite with 10 wt% nano-clay. A comparison of the modeled mechanical properties and the experimental measurements values was performed to validate the modeling results. The simulated results fit well with the experimental values of Young's modulus. [ABSTRACT FROM AUTHOR]

Fiber‐reinforced polymer composites (FRPCs) are utilized for myriad applications owing to their exceptional characteristics like high specific strength and stiffness. However, the low‐to‐moderate impact strength of these materials is a major constraint restricting their usage in fields requiring high‐impact performance. To ensure the reliable performance of FRPCs throughout the intended life span, a combination of good static mechanical properties and high impact resistance is crucial. Recent advancements in this field have yielded a breakthrough by developing novel materials that overcome this limitation. This groundbreaking achievement was realized by processing epoxy‐based GFRPs containing a synergistic blend of surface‐modified nano‐clay and compatibilized polymeric fiber micro‐reinforcement. This review provides an overview of advancements in the development of FRPCs, starting from the single‐filler to multi‐scale filler‐reinforced materials. The review elaborates on the effect of reinforcement of various thermoplastic fibers (polyethylene, para‐aramid, and spandex) on the mechanical performance of FRPCs. The necessity of filler compatibilization to enhance interfacial bonding constituents is also discussed. It can be concluded that the choice of surface treatment for a given thermoplastic fiber is governed by its chemical composition, the functional groups to be added on its surface through a specific compatibilization treatment, and the chemical nature of other constituents of the composite system with which the treated fiber surface interacts. Further, the greater the elasticity and ductility of the reinforced thermoplastic fiber, the higher the impact strength of the resulting epoxy‐based GFRPs. Finally, the review brings forth the potential opportunities for future research in this area. Highlights: Discussed recent advancements in epoxy‐based GFRPs with multi‐scale filler reinforcement.Multi‐scale filler‐reinforced epoxy‐based GFRPs have myriad applications in aviation, automobile, marine, sports, etc.Nano‐/micro‐fillers in their pristine state degrade the mechanical performance of epoxy‐based GFRPs.Filler compatibilization is essential for achieving superior mechanical performance in epoxy‐based GFRPs.Reinforcing compatibilized soft/ductile thermoplastic fibers resulted in a notable increase in impact strength while maintaining tensile properties. [ABSTRACT FROM AUTHOR]

The sandwich panels are widely used in many industrial applications due to their high mechanical properties. Their core design is most important parameter in enhancing their mechanical strength. Flexibility in the design of the core structure leads to the achievement of high strength and light structures. In this paper, the results of the optimized geometry in the previous work are used to investigate the capability of the core geometry design with different materials. Therefore, using the different materials, the peak enhancement of strength-to-weight ratio in sandwich panels besides core behavior during pressure testing are investigated. To this end, a new lattice core is brought forth as the first level; then, three types of materials including AL3105, glass, and innegra fiber/epoxy composites are used to fabricate the cores, in order to compare the compressive strength and the peak. The Nano-clay cloisite 20A is also utilized in construction of sandwich panels. The result indicates that the AL3105 lattice core has the highest strength-to-weight ratio, while the innegra fiber composite core has the highest toughness. Applying curve studies and the SEM Fig. 13, it is concluded that the addition of Nano-clay to composites leads to an increase in both of the strain and the core strength. Comparing the results of experimental and finite element modeling (FEM) data (in ABAQUS software) represented that there is a suitable compliance between them. Our results with the positional variation in core design can pave way in designing advanced engineered sandwich structures in aerospace, shipping, automotive industries. Therefore, these structures will have wide applications in the field of light structure, heat and fluid transfer, sound and vibration control. [ABSTRACT FROM AUTHOR]

Due to the exceptional biomedical properties of ultra-high molecular weight polyethylene (UHMWPE), it is used in various biomedical applications including orthopedic applications. Montmorillonite (MMT) as a reinforcement material is excellent for biomedical applications. The purpose of this study is to justify the use of UHMWPE composite as a material for liners in total hip anisotropy (THA). UHMWPE/MMT nanocomposites with different percentages including 1, 3, 5, 7, and 10% have been fabricated by two-roll milling and compression molding techniques. The prepared nanocomposite specimens have been characterized using XRD and SEM. The investigations revealed that the hardness, abrasion resistance, compressive modulus, and ultimate compressive strength experienced a notable improvement, with different percentages of nano-clay reinforcement. Izod energy absorption experienced an increased absorbed energy with all percentages of reinforcing except 10% MMT. This experimentation helps predict the optimal amount of nano-clay with UHMWPE. The dispersion of the nano-clay in the matrix has influenced the mechanical properties enhancement at the optimal percentage of MMT. Additionally, biocompatibility testing in MTT assay with UHMWPE/MMT composite at the optimal composition, exhibited the highest cell growth after 24 h and 96 h incubation. It is concluded that the UHMWPE/5%MMT displayed better biocompatibility and enhanced mechanical properties making it an attractive candidate for artificial joints. [ABSTRACT FROM AUTHOR]

The purpose of this study is to determine the impact of nano-clay and nano-silica particles on the vibrational characteristics of composite cylindrical panels in corrosive environments. In this context, due to the presence of diluted sulfuric acid as the corrosive solution, the coupling effects of material degradation and hygroscopic loading on the natural frequencies are taken into consideration. In order to achieve this, it is first explored through experiment how adding nanoparticles affects the coefficient of hygroscopic expansion of the glass/epoxy specimens. Using this coefficient, the in-plane loading caused by corrosive solution is then applied in the equations. The mechanical properties and hygroscopic expansion coefficients of the composite samples exposed to the corrosive environment are first determined by certain experimental testing. The equations of motion are derived using the first-order shear deformation theory (FSDT), and the vibration problem is solved using the generalized differential quadrature (GDQ) technique. Investigation is conducted into the effects of various nanoparticles, immersion time, geometrical elements, and boundary conditions on the natural frequencies of the cylindrical panels. It is found that adding nanoparticles can significantly improve the mechanical properties, the corrosion resistance, and the natural frequencies of composites in which the nano-clay is more effective. For example, adding nano-clay and nano-silica particles, respectively, results in 32.32% and 26.29% increase in elasticity modulus of reinforced glass/epoxy composite. In addition, 12.71% and 47.32% improvements are observed in the natural frequency of the nano-clay reinforced composite panel before and after 90 days of immersion in sulfuric acid. In comparison, the nano-silica particles are responsible for 7.80% and 23.03% increase in natural frequency before and after immersion time. [ABSTRACT FROM AUTHOR]

This work aims to experimentally investigate the influence of screw elements on the dispersion of Cloisite-15A in vinyl ester based on the design of experiments using MINITAB-V16 software. Experiments were designed considering two main factors such as Cloisite-15A loading (1, 2, 3, and 4 wt%) and type of screw elements with a varying number of kneading elements (type 1 with 55 mm, kneading elements and type 2 with 90 mm, kneading elements). The dispersion procedure of Cloisite-15A in vinyl ester was carried out by a combination of both ultrasonication and then twin-screw extrusion. The influence of these factors on the tensile strength and hardness was studied using an experimental layout possessing Taguchi's L8 Orthogonal Array technique. ANOVA of the experimental results revealed the dispersion of Cloisite-15A with vinyl ester proved to be better when processed with type 2 screw elements having more kneading screws. The S/N ratio study showed that the Cloisite-15A loading had the greatest impact on the type 2 screw's tensile and hardness values for the Cloisite-15A/vinyl ester gel coats when treated at 230 rpm with 10 passes. The probability graphs led to the conclusion that, with a 95% confidence interval, all response values were distributed equally along the normal probability plot's trend. In order to achieve the best response in terms of mechanical strength, the Grey Relational Analysis (GRA) helped identify the best combination of process variables. This combination was known to be 4 wt% Cloisite-15A loading, with type 2 screw processed at 230 rpm with 10 passes. The SEM and XRD showed the absence of agglomeration and better exfoliation of Cloisite-15A in the gel coats with 4 wt% of clay loading. [ABSTRACT FROM AUTHOR]

Surface treatments applied to new or existing concrete elements provide effective protection against intrusive media, helping to reduce maintenance and repair costs. However, technical data are scarce on documenting the field performance of concrete surface treatments in cold regions with aggressive conditions, particularly for emerging nano-modified coatings. To address this gap, a field study was conducted to evaluate the efficacy of different plain and nanocomposites as surface treatments on 34-year-old concrete bridge deck sections in Winnipeg, Manitoba, Canada. The study compared neat resins (silane, methyl methacrylate, and ethyl silicate) and nano-based coatings (nano-silica 50 % solution, silane with nano-clay, and silane with nano-silica at 2.5 % and 5 % by mass) on cores extracted from cracked and uncracked concrete prepared with two surface preparation methods. The experiments compared the initial performance (transport properties and microstructural features) of coated concrete to its performance after one year under service conditions. The results indicate that coatings play a significant role in providing protection against intrusive media and reducing maintenance efforts and costs. Among the coatings tested, silane and methyl methacrylate offered the least improvement in concrete protection with time in cold regions. The 50 % nano-silica solution provided moderate performance, whereas ethyl silicate and silane nanocomposites demonstrated superior performance in reducing transport properties regardless of the surface preparation methods. Given the improvement in long-term durability and cost, silane nanocomposites with a 2.5 % loading ratio may be a viable treatment method for concrete flatwork in cold regions.

Freezing and thawing (F/T) is an important occurrence in cold regions influencing soil geotechnical characteristics. Current study investigates effects of lime, Rice Husk Ash (RHA) and Nano-clay on unconfined compressive strength and F/T of loess under open and closed schemes. Loess was treated with 2, 4, 6 and 8% lime and RHA and 0.5, 1.0, 1.5 and 2% Nano-clay and compacted at optimum conditions. Samples were cured for 1, 7, 14 and 28 days at 35 °C before freezing at −23 °C and thawing at room temperature for 24 h intervals. Tests conducted on untreated and RHA and Nano-clay treated samples showed total loss of strength after one F/T cycle with noticeable weight and volume changes by samples subjected to open F/T. Exposing samples to closed F/T resulted in smaller changes in volume and strength. Samples treated independently with lime or concurrently with RHA and Nano-clay showed significant resistance to F/T particularly with curing time. Formations of chemical compounds bind particles, reduce void ratio resulting in a solid durable structure resisting freezing. Open F/T proved more detrimental than closed F/T scheme exhibiting moisture accessibility to be a dominant factor on F/T process. [ABSTRACT FROM AUTHOR]

Simple Summary: Natural feed additives have gained significant scientific attention as growth-promoting substances instead of synthetic antibiotics. The objectives of this study were to develop and investigate the physicochemical properties and effects of Arabic gum–nano montmorillonite (AGNM) compared to monensin as feed additives in Holstein dairy cows. However, the practical application of gum Arabic as a production enhancer for ruminant feeding has not been widely adopted. In this study, the AGNM additive showed great promise for improving rumen fermentation, increasing nutrient digestibility and utilization, and benefiting the environment. The exploration of natural alternatives to antibiotics for enhancing productivity and performance in dairy cows is a crucial objective in farm animal management. This is the first study aimed at developing and evaluating the physicochemical properties and effects of Arabic gum–nano montmorillonite (AGNM) compost compared to ionophore monensin as feed additives on rumen fermentation, blood metabolites, and milk production of Holstein dairy cows. In a replicated 4 × 4 Latin square design, four multiparous mid-lactation Holstein dairy cows with an average body weight of 520 ± 15 kg were enrolled. The dietary treatments included a control diet (basal diet without feed additives), monensin diet [a basal diet supplemented with 35 mg/kg dry matter (DM) monensin], and AGNM diets comprising basal diet supplemented with two levels: low (L-AGNM) at 1.5 g/kg DM, and high (H-AGNM) at 3 g/kg DM. AGNM as a feed additive demonstrated promising physiochemical parameters, including containing highly bioactive components (α-amyrin and lupeol), functional groups (OH and Si-O), and essential mineral contents (Mg2+). Supplementations with H-AGNM significantly improved ruminal (p = 0.031) concentrations of total volatile fatty acids (VFAs), acetic (p = 0.05) and butyric (p = 0.05), enhanced (p < 0.05) digestibility of fiber and organic matter, while decreased (p = 0.013) estimated methane production. However, an increase (p = 0.04) in blood high-density lipoprotein levels and decrease (p < 0.05) in concentrations of creatinine (CREA), bilirubin (BILT), cholesterol (CHOL), and sodium (Na) were observed with H-AGNM supplementation. Both monensin and H-AGNM improved (p = 0.008) feed efficiency compared to L-AGNM; however, neither AGNM nor monensin affected the milk composition or energy status indicators of the dairy cows. The findings of this study highlight the potential of AGNM as a natural candidate to replace monensin in enhancing ruminal VFA production, nutrient digestibility, feed efficiency, blood metabolites, and milk yield in dairy cows. [ABSTRACT FROM AUTHOR]

To sustain the life of flexible pavement materials, the quality of the binder needs to be modified and improved. The purpose of the current research is to investigate the optimum mechanical performances, Marshall characteristics, and moisture damages of hot asphalt mixtures containing nano-clay (nC) additives. Three nominated contents of nC additives of 3, 5, and 7% of the hot asphalt weight were combined by a shear blender at 4,000 rpm for 45 min at 150 ± 5°C. Significant mechanical tests were carried out to estimate the modified asphalt mixture characteristics, such as Marshall stability and moisture susceptibility. Mechanical test results showed that the use of nC as an additive was suitable for enhancing the main characteristics of hot asphalt mixes. Generally, it was found that the indirect tensile strength ratio and stability values of the asphalt mixtures containing 3, 5, and 7% of nC were improved by 8, 23, and 24% and 12.5, 40, and 52%, respectively. The 7% nano-clay additive showed superior values of tensile strength and stability as compared with all asphalt mixtures (i.e., 94% and 15.8 kN, respectively).

In order to study the improvement effect of nano-clay and polypropylene fiber on the mechanical properties of recycled aggregates, unconfined compression tests and triaxial shear tests were conducted. The experimental results show that adding polypropylene fibers to recycled aggregates increases the unconfined compressive strength by 27% and significantly improves ductility. We added 6% nano-clay to fiber-reinforced recycled aggregates, which increased the unconfined compressive strength of the recycled aggregates by 49% and the residual stress by 146%. However, the ductility decreased. Under low confining pressures, with the addition of nano-clay, the peak deviatoric stress strength of the fiber-reinforced recycled aggregates first decreased and then increased. When the nano-clay content was 8%, this reached a maximum value. However, under high confining pressures, the recycled aggregate particles were tightly interlocked, so that the improvement effect of the fiber and nano-clay was not obvious. As more nano-clay was added, the friction angle of the fiber-reinforced recycled aggregates decreased, while the cohesion increased. When the content of nano-clay was 8%, the cohesive force increased by 110%. The results of this research indicate that adding both polypropylene fibers and nano-clay to recycled aggregates has a better improvement effect on their strength characteristics than adding only polypropylene fibers. This study can provide a reference for improving the mechanical properties of recycled aggregates and the use of roadbeds. [ABSTRACT FROM AUTHOR]

The movement of the construction industry towards sustainable development has drawn attention to the revision of concrete. In addition to reducing pollution, the use of nano-materials should lead to the provision of higher quality concrete in terms of regulatory items (workability, resistance characteristics, durability characteristics, microstructure). The present study investigates 15 key characteristics of concrete modified with nano-CaCO3, nano-clay, nano-TiO2, and nano-SiO2. The results of the study showed that nanomaterials significantly have a positive effect on the hydration mechanism and the production of more C-S-H gel. The evaluation of resistance characteristics also indicates the promising results of these valuable materials. The durability characteristics of nano-containing concrete showed significant improvement despite high dispersion. Concrete in coastal areas (such as bridges or platforms), concrete exposed to radiation (such as hospitals), concrete exposed to impact load (such as nuclear power plants), and concrete containing recycled aggregate (such as bricks, tiles, ceramics) can be effectively improved by using nanomaterials. It is hoped that the current review paper can provide an effective image and idea for future applied studies by other researchers. [ABSTRACT FROM AUTHOR]

Cement has shaped the modern built environment, but its production generates substantial carbon dioxide emissions. Consequently, there is an urgent need to identify alternative cementitious building materials for sustainable construction. In this study, cement mortars (CMs) were produced by partially replacing cement with nanoclay (NC) and granite dust (GD). The replacement proportions (% by weight of cement) of these materials were 1.5, 3, and 4.5% for NC and 10, 20, and 30% for GD. For mortars containing NC but not GD, the strength was maximized when the NC replacement proportion was 3%. To evaluate the combined effect of partially replacing cement with both NC and GD on the fresh and hardening properties of cement-blended mortars, ternary binder mixtures containing 3% NC together with 10, 20, or 30% GD were prepared, and their workability, bulk density, compressive strength (at 7, 28, and 90 days), and flexural strength were measured. Increasing the content of NC and/or GD reduced the flowability of these mortars relative to that of the reference mortar mix because it increased the content of fine materials. CM containing 3% NC and 10% GD had the highest compressive strength at 7, 28, and 90 days while also having the greatest flexural strength when compared to the control mix. This is most likely due to the high silica and alumina content of NC and GD, as well as their high specific surface area, which would improve the maturity and density of the matrix when compared to cement alone.

Improvement of the mechanical properties of clayey soils by additional elements to enhance the strength under numerous freezing and thawing cycles has been considered as a serious concern for engineering applications in cold regions. The objective of the current study is to investigate the effect of nano-clay as a stabiliser on the mechanical properties of clay. To this end, the clay specimens were prepared by adding various percentages of nano-clay ranging from 0.5% to 3% by dry weight of soil and were experimentally tested under the uniaxial compression and tensile splitting tests under different curing times (0, 7 and 28 days) after experiencing various freeze–thaw cycles ranging from 0 to 11. It can be concluded from the results that nano-clay particles may be used as a stabiliser in geotechnical applications to improve soil property. The results indicate that the optimum moisture content (OMC) of specimens increases and the maximum dry density (MDD) decreases with the increasing nano-clay content. The specimens containing about 1% nano-clay recorded maximum values of unconfined compressive strength (UCS) as well as tensile strength. For example, the addition 1% nano-clay increased the UCS and tensile values of clay specimens under the curing time of 28 days by 34% and 247%, respectively. In addition, the long-term durability of specimens against freeze–thaw cycles increases further with the addition of nano-clay content ranging from 2% to 3%.

The present study aimed at the casing of nano-material-reinforced fibrous for adsorbing polycyclic aromatic hydrocarbons (PAH) generated during the processing of smoked dry sausage. Fibrous casings were made with two adsorbents including nano-carbon and nano-clay in loading content of 0, 0.5% and 1%, and evaluated for PAH adsorption. Mechanical and thermal properties, water vapor permeability and opacity of nanoparticle-reinforced fibrous casing were investigated. The total concentration of 16 PAHs measured in sausages packed in the non-adsorbent fibrous casing and fibrous casings reinforced with 0.5% and 1% nano-clay and nano-carbon were 69.6, 68.8, 17.1, 80.2 and 110.5 μg/kg, respectively. Fibrous casing loaded with 1% nano-clay showed the highest PAH adsorption. Benzo[a]pyrene, benzo[a]anthracene, benzo[b]fluoranthene and chrysene were detected ND, 0.4 and 1.8 (μg/kg), respectively. The highest and lowest tensile and elongation values in fibrous casings were obtained when 1% of the nano-clay and 1% of nano-carbon were incorporated, respectively. The addition of nano-clay and nano-carbon increased the melting and glass transition temperatures. Enhancement of nanoparticles content significantly decreased water vapor permeability and film opacity. It was concluded that fibrous casing reinforced with 1% nano-clay exhibited prospects as eco-friendly adsorbents that effectively removed PAHs from smoked sausage. [ABSTRACT FROM AUTHOR]

Nano-clay has the potential to improve the properties of cement-based materials. However, the effectiveness of this improvement is influenced by the dispersion of the nano-clay. The effects of different nano-clay dispersion techniques on cement-based material properties and pore structure complexity were studied. The samples were prepared using manual and mechanical dispersion methods. The mechanical properties of the specimens were evaluated, and the pore characteristics of the cement-based materials were analysed using mercury intrusion porosimetry. The study investigated the effect of the dispersion method on the nano-clay dispersion. The complexity of the pore structure was evaluated using a fractal model, and the relationship between the fractal dimension, mechanical properties, and pore structure was analysed. The findings indicate that mechanical dispersion results in better dispersion than manual dispersion, and the mechanical properties of mechanical dispersion are superior to those of manual dispersion. Nano-clay particles can improve the internal pore structure of cement materials. Through mathematical calculation, the surface fractal dimension is between 2.90 and 2.95, with good fractal characteristics. There is a good correlation between the surface fractal dimension and the mechanical properties. The addition of nano-clay can reduce the complexity of the pore structure, and the fractal dimension has an excellent linear relationship with the pore structure. [ABSTRACT FROM AUTHOR]

The study focuses on evaluating the influence of bentonite nano-clays on the rheological profile of intumescent fire-retardant compositions and determining optimal structures and quantities of clay thixotropic additives to increase the single-layer thickness of intumescent paint during application.The influence of hydrophobic organomodified, and hydrophilic activated, nano-clays on the rheology of intumescent fire-retardant systems was investigated by determining dynamic viscosity using a Brookfield viscometer at shear rates 2.09 s-1 to 52.25 s-1 followed by mathematical modeling using Casson equation. Addition of hydrophobic organomodified bentonites with intercalated quaternary ammonium cations at 1 wt.% increases thixotropy of both solvent-based and water-based systems by 5–12 times. Hydrophilic clays positively effects the rheology of water-based systems (4–6 times increase in thixotropic effects) and have no effect on solvent-based systems (0,8–1,5 times). Based on extensive experimental data and theoretical calculations, the optimal approximate dynamic viscosity was determined for solvent-based systems (10–7 Pa × s, spindle N6, 20–50 rpm, 20 °С), and water-based systems (17–8 Pa × s, spindle N7, 20–50 rpm, 20 °С). They can be used as markers for industrially produced intumescent paints, to ensure the absence of sedimentation and provide adequate sag resistance when the paint is applied with 1.5 mm single-layer thickness.Laboratory fire tests, and the assessment of thermal expansion of intumescent systems with and without nano-clays, demonstrate that vinyl acetate polymers in intumescent coatings are more suitable for providing higher (60 min or more) levels of fire resistance to steel structures than styrene acrylates. When developing formulations of water-based fire-retardant coatings, capable of providing fire resistance of R120 and higher, the addition of 2–3 wt.% of nano-clays can ensure the formation of a strong and durable thermo-insulating charred layer.

Infectious diseases are a leading cause of mortality around the world. Pathogenic bacteria have evolved bacterial resistance as a result of –lactamase production. The World Health Organization's (WHO) new GLASS (Global Antimicrobial Surveillance System) revealed in 2018 that antibiotic resistance is widely spread among 500,000 sick people in 22 countries infected with drug-resistant bacteria. Among billions of fungus, 300 fungi poses serious threat to human health. Due to prevalence of infectious diseases, more focus has been given on the nanoparticles application in various fields of life including textile industry, biomedicine, cosmetology, self-cleaning, antibiotics, drug delivery system, UV defense, removing impurities, water and air filtration system. Nanoparticles shows potency due to their small size, high penetration rate and cell damaging potentiality via different mechanisms. Nanoparticles are used in textiles to eliminate undesired effects such as degradation of fabrics, production of unwanted odor and potential for health risks. Natural fibers are susceptible to the accumulation, multiplication and propagation of micro-organisms due to large surface area, moisture, heat and body secretions providing ideal habitat for micro-organisms growth when in contact with human body. Consequently, variety of textiles are coated, with nanoparticles to protect the wearers from irritation and skin allergies, able to withstand the washing, drying and leaching. Green synthesis of nanoparticles is a simple, cost effective and ecofriendly approach. Nanoparticles ranges from the nano-metals like silver, copper, gold, palladium and graphene nanoparticles to the metal oxides including zinc oxide, titanium oxide, copper oxide, graphene oxide, calcium oxide and magnesium oxides to the carbon nanotubes and nano-clay. Gold nanoparticles cause the oxidative stress in the cytoplasm, which leads to microbe's death. Copper nanoparticles shows antifungal activities for food related pathogens. Copper oxide nanoparticles shows antibacterial effect on Staphylococcus aureus by releasing the Cu+2 ions which triggers the reactive oxygen species production. Copper is used as water purifier and anti-fouling agent. Introduction of copper into fabrics and other items provide them biocidal effects. Copper is vital for aerobic organisms, though excessive copper ions inhibit microbial development via enzyme deactivation, protein functional group disruption, and plasma membrane damage. Zinc oxide nanoparticles shows biocompatibility, stability, antimicrobial property, and harmless to human cells. Zinc oxide nanoparticles strongly attack the micro-organisms. Nano-silver is applied against different strains of bacteria such as Staphylococcus aureus, Klebsiella pneumonia, Bacillus subtilis, Streptococcus zooepidemicus, Escherichia coli, and Enterobacter aerogenes. Bacteria's surface is negatively charged while graphene is positively charged and graphene family nanomaterials act as bridge to transport the charge from graphene to bacteria. CaO nanoparticles functions against gram-positive, gram-negative bacteria and yeast. It is widely used against microbes in food items. This review paper emphasized on the characteristics and utilization of the inorganic nano-structured materials with anti-microbial properties in textiles. Nanoparticles exhibits best results against bacteria and fungi. Nanomaterials are promising materials because they can be made to do numerous tasks at the same time. [ABSTRACT FROM AUTHOR]

In this work, an innovative and environmentally friendly adsorbent for CO2 capture is synthesized by Choline Chloride-Urea (ChCl: U) functionalization of the acid-activated montmorillonite (MMT) for the first time. The surface area enhancement was achieved by acid activation at 3 Molarity, which resulted in 7.1 and 10.9 times increase in the specific area and pore volume, respectively. In fact, the highest reported value of the surface area of montmorillonite has been achieved. The characterization was carried out by FTIR, BET, XRD, and SEM to ensure the qualification of the modified acid-activated and then impregnated with the solvent. The optimum condition for the input variable was 30 ºC, 9 bar, and 50% of the solvent to MMT, where the response was 252 mg/g. The evaluation of the heterogeneous and mono-multilayer adsorption indicated the experimental data well-fitted to the Hill isotherm model with n higher than 1, indicating the desirability of the adsorbent (n was also 1.59 for the Freundlich isotherm model). The Elovich kinetic model was observed to be in the best agreement with the experimental data. Eight cycles of adsorption-desorption results indicated an excellent reversible adsorbent with low-temperature regeneration (90ºC) is attained. [ABSTRACT FROM AUTHOR]

The efficiency of using zeolite nano-clay and silica sand in removing iron from groundwater is investigated experimentally as an application of in situ remediation technique using permeable reactive barrier (PRB). In the first stage of the study batch experiments were conducted on coarse silica sand and fine silica gravel to determine their iron removal efficiency from contaminated water. The results showed that the removal efficiency was about 51.90% for coarse silica sand while fine silica gravel failed to reduce the iron concentration in water. A mix of zeolite nano-clay and coarse silica sand with a ratio of 1:30 was tested. It was found that iron removal efficiency significantly increases to about 99.70%. The linear adsorption isotherm was found to be the most representative for the adsorption of iron onto coarse silica sand and the mix of nano-clay and coarse silica sand with distribution coefficients equal 0.0009 and 0.001, respectively. In the second stage a glass sand tank with coarse silica sand and a mix of zeolite nano-clay and coarse silica PRBs was constructed. The sand tank was used to investigate the effect of sampling time, head difference, iron concentration, nano-clay dosage, and thickness of permeable reactive barrier on the iron removal efficiency. The results indicated that increasing iron concentration and head difference decreases iron removal efficiency. The mix of zeolite nano-clay and coarse silica sand improves iron removal efficiency. Furthermore, increasing nano-clay dosage slightly increases the removal efficiency. However, increasing the thickness of filter layer (i.e., PRB) significantly improves the removal efficiency. Finally, the experimental model data were used to test the capability of a numerical contaminant transport model to predict the removal efficiency. The MT3DMS numerical model included within the Groundwater Modeling System (GMS) was used along with the different experimental data to obtain reaction rate values as calibration parameters for linear isotherm. Reaction rates that yield modeling results matching experimental data were obtained. [ABSTRACT FROM AUTHOR]

The traditional soil stabilization techniques, which primarily include calcium-rich additives, are gradually replaced by environmentally friendly techniques as the former increases the carbon footprint emissions. On the other hand, nanomaterials (particles with a size range of less than 100 nm) are gaining acceptance in geotechnical and geoenvironmental engineering due to their non-toxic nature and less energy consumption required for production. These materials have entirely different properties from conventional materials. When mixed with soil particles, their relatively larger specific surface area values trigger an easy and rapid reaction. The paper reviews the applicability of select nanomaterials such as metallic nanoparticles (which include nano-copper oxide (nano-CuO), nano-magnesium oxide (nano-MgO), iron oxide nanoparticles (nano-Fe2O3), nano-alumina (nano-Al2O3), nano-clay, nano-silica (nano-SiO2), colloidal silica, to name a few, in the areas of geotechnical and geoenvironmental engineering by highlighting the associated mechanisms of interaction. The targeted geotechnical properties include plasticity, compressibility, consolidation, permeability, and strength characteristics under different conditions. Further, the effect of the select nanoparticles on microbial activity, their applicability in remediation of organic and inorganic contaminants from different soil–water systems, and their cost-effectiveness are discussed. [ABSTRACT FROM AUTHOR]

Earthquake-induced liquefaction is prone in a region with loosely saturated sand and higher seismic activity. In recent years, improvement techniques have been used as a pre-construction or retrofitting method for the current construction. Several methods are intended as remedial techniques, which include either densifying the deposit soil, inserting a unique material, or controlling dissipated pore water pressure generated during the seismic motion. The permeation grouting technique is primarily used in remedial liquefaction schemes that aim to improve the soil deposit mainly by cementing the soil particles and filling the void spaces, thereby preventing soil disturbance caused by settlements or distress to an existing foundation or structure. Permeation grouting involves the injection of a low viscosity chemical or particulate grout into the soil pores with little to no change in the soil structure and has been shown to be effective at reducing liquefaction risk beneath existing structures in soils where it is applicable. The mitigation of liquefaction risk by incorporating nanomaterials using the permeation grouting technique, to study the performance of a pile group embedded in the liquefiable treated layer with 1/50 nano-clay and 1/30 nano-SiO2 after 48 h of curing time during the Kobe earthquake, has been adopted. The soil profile treated using nanomaterials showed that the soil stiffness and strength were preserved during shaking because it did not liquefy; simultaneously, the maximum pile bending moments and lateral pile displacements in the treated soil layer were reduced by 30%. Finally, after treatment, the nanomaterials have a significant effect on the reduction of the maximum accelerations in two depths of soil.

[Display omitted] • The formation kinetics of CO 2 hydrate were dependent on the structure of nano-clay. • 2D nano-clay is more favored for CO 2 hydrate nucleation than 1D nano-clay. • Promotion of VNs on CO 2 hydrate formation was more than most reported nanoparticles. • Cage-like water near nano-clay significantly accelerated CO 2 hydrate nucleation. Gas hydrate can separate and capture enormous carbon dioxide (CO 2) only using water cages. Capturing CO 2 in hydrate form is viewed as a green and effective technology to reduce the global CO 2 emission. However, the sluggish kinetics and high cost of kinetics promotors of CO 2 hydrate formation limited the application of hydrate-based CO 2 capture technology. Here, we used the nano-clay prepared by cheap natural clay to promote the formation kinetics of CO 2 hydrate. At the low concentration range, the formation period of CO 2 hydrate in the two-dimensional nano-clay dispersion was significantly shorter than that of the one-dimensional nano-clay dispersion. The induction time (5 min) obtained in vermiculite nanoflakes dispersion was shorter than most solid promotors of CO 2 hydrate formation kinetics in reported works. Besides, we found that the water molecules near the negatively charged two-dimensional nano-clay surface were more likely to form the cage-like structure than those around the one-dimensional nano-clay surface. The similar hydrogen-bonded structure of the cage-like water with CO 2 hydrate made them favorable for the CO 2 hydrate formation. These results shed light on the design of the effective kinetics promotors of CO 2 hydrate and contribute to develop the hydrate-based CO 2 capture technologies. [ABSTRACT FROM AUTHOR]

Two varieties of jute fiber, tossa (Corchorus olitorius) and white (Corchorus capsularis), were combined with nano-clay (montmorillonite clay) modified polyester to fabricate composites using the hand lay-up method. The goal was to examine the impact of nano-clay on structural, mechanical, and thermal properties. The two types of jute fibers were first treated with NaOH, and the polyester was then modified with montmorillonite nano-clay (1, 2, 3) (wt%). Finally, 30 cm long unidirectional fibers were used to fabricate a composite (fiber volume fraction is 19.3%). Accordingly, the structural (crystallinity), mechanical, and thermal properties of the composite were examined using the XRD, UTM, and TGA apparatus. Regarding crystallinity, treating the tossa jute fiber and its composite with nano-clay demonstrated improved crystallinity indices of 75.24% and 75.52%. The Tossa jute fiber composite treated with 1% nano-clay exhibits an increased tensile strength of 97.8805 MPa, which is 10.92% higher than the treated fiber without NC, and a flexural strength of 159.79 MPa, which is 3.12% higher than the treated fiber without NC). In comparison to white jute composite, the treated tossa jute fiber composite showed improved thermal stability; the addition of 3% nano-clay also demonstrated higher thermal stability. The use of modified polyester in composites along with nano-clay produces better outcomes in every way.

The effect of montmorillonite (MMT) nano‐clay as reinforcement in unsaturated polyester resin (UP) matrix composite was investigated under compression loading to explore the impact of MMT nano‐clay wt% in the compressive behavior of UP‐MMT nano‐clay composite. UP‐MMT nano‐clay composite samples were prepared with a varied filler content of 0.5 to 3 wt% using dual‐mixing methods, which are mechanical stirring and ultrasonic agitation. Static uniaxial compression tests were conducted using cylindrical‐shaped samples to obtain the compressive behavior of the UP‐MMT nano‐clay composites. The results of experimentation record a considerable improvement in compressive characteristics of UP‐MMT nano‐clay composites compared to pure UP matrix. The UP‐MMT nano‐clay composite samples were viewed under transmission electron microscope (TEM) to know the dispersion of MMT nano‐clay in the composites. The nano‐platelets were well dispersed and intercalated in the UP‐MMT nano‐clay composite samples below 1 wt% MMT nano‐clay loading. The optimum wt% of MMT nano‐clay in the UP‐MMT nano‐clay composite for improved compressive stress at yield and modulus were noted as 0.60 and 0.61 wt% respectively. Moreover, a mathematical model using Halpin–Tsai‐Jumahat equations was utilized to predict the compressive properties of UP‐MMT nano‐clay composites, which are in closer agreement with the experimental results. [ABSTRACT FROM AUTHOR]

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In order to study the influence of nano-clay on the crack resistance of cement-based materials, two kinds of nano-metakaolin (NMK) and two kinds of nano-attapulgite clay (NMA) were considered. The early cracking process and mechanical properties of nano-clay cement mortar (NCM) was studied by using a plate knife-edge constraint test. Based on fractal theory, the distribution characteristics of NCM surface cracks were revealed, and the calculation method forNCM maximum crack width was given. The results show that the cracking time of the NMK-3 specimen is 2 and 6 h later than that of NMK-1 and NMA-2, respectively; the smaller the particle size of nano-clay, the earlier the cracking time of the specimen. However, nano-clay effectively inhibited the expansion of mortar cracks, and the cracks on the surface of NCM were thin and sparse. At 28 days, the maximum crack width of NMK-3 was 46.7% and 33.3% lower than that of NMK-1 and NMA-2, respectively. NMK hadthe best improvement effect on the mechanical properties cement mortar. The smaller the particle size, the more pronounced the improvement effect.The flexural strength ratio and compressive strength ratio at 7 and 28 days are 76.7%, 67.4%, and 61.2%, respectively.The distribution of surface cracks on NCM has fractal characteristics, and the fractal dimension of surface cracks is smaller than that of ordinary cement mortar. The larger the particle size of nano-clay, the smaller the fractal dimension of cracks. The quantitative relationship between fracture fractal dimension and NCM elastic modulus and shrinkage tensile stress is established. [ABSTRACT FROM AUTHOR]

Modified cellulose acetate membranes with bentonite clay (CA/bent) and TiO2 nanoparticles (CA/TiO2) using the phase inversion method are successfully prepared and characterized. These Membranes are favored due to their high salt rejection properties and recyclability. The IR and EDX spectral data indicate the formation of modified membranes. The Scan Electron Microscope micrographs show that the modified membranes have smaller particle sizes with higher porosity than the neat membrane. The average pore diameter is 0.31 µm for neat cellulose acetate membrane (CA) and decreases to 0.1 µm for CA/0.05bent. All modified membranes exhibit tensile strengths and elongation percentages more than the neat membrane. The higher tensile strength and the maximum elongation% are 15.3 N/cm2 and 11.78%, respectively, for CA/0.05bent. The thermogravimetric analysis of modified membranes shows higher thermal stability than the neat membrane. The modified membranes exhibit enhanced wettability and hydrophilicity compared with cellulose acetate, by measuring the contact angle which decreases from 60° (CA) to 40° (CA/0.1bent). The ultrafiltration tests indicated that the CA/bent and CA/TiO2 are better than CA. The most efficient nanocomposite membrane is CA/0.05bent with 100% removal of (BSA) from industrial water with a flux equal to 9.5 mL/min under an applied pressure of 20 bar. Thus, this study introduces a novel ultrafiltration membrane (CA/0.05bent) that can be used effectively to completely remove bovine serum albumin from contaminated water.

Nano-clay has the potential to improve the properties of cement-based materials. However, the effectiveness of this improvement is influenced by the dispersion of the nano-clay. The effects of different nano-clay dispersion techniques on cement-based material properties and pore structure complexity were studied. The samples were prepared using manual and mechanical dispersion methods. The mechanical properties of the specimens were evaluated, and the pore characteristics of the cement-based materials were analysed using mercury intrusion porosimetry. The study investigated the effect of the dispersion method on the nano-clay dispersion. The complexity of the pore structure was evaluated using a fractal model, and the relationship between the fractal dimension, mechanical properties, and pore structure was analysed. The findings indicate that mechanical dispersion results in better dispersion than manual dispersion, and the mechanical properties of mechanical dispersion are superior to those of manual dispersion. Nano-clay particles can improve the internal pore structure of cement materials. Through mathematical calculation, the surface fractal dimension is between 2.90 and 2.95, with good fractal characteristics. There is a good correlation between the surface fractal dimension and the mechanical properties. The addition of nano-clay can reduce the complexity of the pore structure, and the fractal dimension has an excellent linear relationship with the pore structure.

Nanocomposites containing clay nanoparticles often present favorable properties such as good mechanical and thermal properties. They frequently have been studied for tissue engineering (TE) and regenerative medicine applications. On the other hand, poly(glycerol sebacate) (PGS), a revolutionary bioelastomer, has exhibited substantial potential as a promising candidate for biomedical application. Here, we present a facile approach to synthesizing stiff, elastomeric nanocomposites from sodium‐montmorillonite nano‐clay (MMT) in the commercial name of Cloisite Na+ and poly(glycerol sebacate urethane) (PGSU). The strong physical interaction between the intercalated Cloisite Na+ platelets and PGSU chains resulted in desirable property combinations for TE application to follow. The addition of 5% MMT nano‐clay resulted in an over two‐fold increase in the tensile modulus, increased the onset thermal decomposition temperature of PGSU matrix by 18°C, and noticeably improved storage modulus of the prepared scaffolds, compared with pure PGSU. As well, Cloisite Na+ enhanced the hydrophilicity and water uptake ability of the samples and accelerated the in‐vitro biodegradation rate. Finally, in‐vitro cell viability assay using L929 mouse fibroblast cells indicated that incorporating Cloisite Na+ nanoparticles into the PGSU network could improve the cell attachment and proliferation, rendering the synthesized bioelastomers potentially suitable for TE and regenerative medicine applications. [ABSTRACT FROM AUTHOR]

Incorporation of naturally occurring fillers like clay and other mineral improves mechanical, chemical, and physical properties. Herein, we report for synthesized nano-clay based superabsorbent polymer by graft copolymerization of acrylic acid and acrylamide This study focusses the effects of filler (nano-clay), crosslinking agent and initiator concentration on the absorption of the copolymer. Six specimens with varying percentages i.e., 30, 32, 34, 36, 38 and 40 wt. % were supplemented with nano-clay in the matrix of the polymer. Time based immersion was carried out in tap, de-ionized and brine for 2 to 24 h the superabsorbent polymer with 36 wt.% of nano-clay absorbed highest percentage i.e., up to 18 folds after submerging in tap water for 2 hours. Detrimental trend of absorption was observed in specimens with 38 and 40 wt. % that could be due to surge in formation of physical and chemical cross-linking networks in the polymer matrix. However, suspension of superabsorbent polymer composite in brine resulted in decreased absorbency. Such course was also observed for specimens containing 36 wt. % of nano-clay after submerging for 4, 6 and 24 hours. Thermal stability analysis also revealed that the polymer composite supplemented with 38 wt. % of nano-clay exhibited ameliorated stability to 350 °. [ABSTRACT FROM AUTHOR]

Introduction. Many research had worked on improving the performance of concrete subjected to severe environment and improve concrete corrosion resistance. Using nano-materials is one of the methods had been used recently to improve concrete properties. In this research, a comparison between the performance of nano-silica and nano-clay in enhancing the durability properties of concrete was investigated. Methods and Materials. The experimental program was carried out through examining water absorption, water permeability, rapid chloride penetration test, corrosion resistance, bond strength of steel rebar before and after subjected to corrosion, and finally microstructure test. Nano-silica and nano-clay were added at 1%, 3%, and 5% as a partial replacement by weight of cement. Results. Both nano-silica and nano-clay showed significant performance in reducing the permeability and porosity of concrete and improve corrosion resistance of concrete. For comparison, nano-clay had a significant impact than that of nano-silica on concrete properties; in which the water permeability resistance of nano-clay mixes was enhanced by 87% than that of the control mix, while for nano-silica, it was 51% only. The chloride ion penetration was reduced by 72% for nanoclay mixes, while in nano-silica was 28%. Discussion. Nano-clay had a significant effect than that of nano-silica on the concrete durability properties; the flat-shaped of nano-clay particles had improved the microstructure of the cement matrix through the damping effect, besides the filling effect through the microstructure of the matrix which reduces the chloride ion penetration and improves water absorption and permeability of concrete. Conclusion. The optimum percentage of nano-silica is 1% by weight of cement as a partial replacement of cement by weight. However, for nano-clay is 5%, which gives the best performance in improve the durability properties of concrete.

Carbon dioxide emissions and the consumption of natural resources related to the cement manufacturing have prompted the need to develop more sustainable and environmentally friendly types of concrete. Geopolymer concrete is considered eco-friendly concrete because it is free of cement. Otherwise, nanomaterials have been introduced into geopolymer concrete in previous works with the aim of improving its properties. However, very restricted studies have focused on the combined utilizing of nano-clay and nano-titanium in geopolymer concrete. Therefore, in the current research, geopolymer concrete was developed from industrial wastes (fly ash; FA) by using a novel mixture of different nanomaterials: nano-clay (NC) and nano-TiO2 (NT). Mixtures with constant water to FA (12 %), and different alkaline contents: (40 %, 45 %, and 50 %) by FA, were performed and divided into three groups. In the first group, only FA was used as a binder, meanwhile, a combination of (FA+NC) and (FA+NT) was used separately in group two (binary). In the third group, (FA+NC+NT) were mixed together (ternary). Several hardened tests have been investigated: compressive, tensile strengths and density. Also, microstructural characteristics were monitored using XRD and SEM tests. The findings revealed that the addition of nanomaterials obviously enhanced the density of the microstructure, reducing the pores of the produced geopolymer concrete. Moreover, the compressive strength was enhanced up to 38 % for NC, and 24 % for NT in the binary blends while the improvement reached 55 % in the ternary blends.

Bacterial deposition is one of the techniques recently used to repair and improve concrete properties. Biological mortar is a mixture of bacteria, aggregates, cement, and a nutrient medium containing calcium salt. These bacteria created bounds in the concrete materials by producing microbiological calcium carbonate. In this study, the effect of biological healing was investigated on the properties of concrete mortars containing nano-clay. For this purpose, the effect of healing by bacillus bacteria on untreated mortar specimens was compared with those containing nano-clay. The specimens were then examined through scanning electron microscopy (SEM), weight gain, permeability, sulfate attack, carbonation, and compressive strength (UCS) tests. The results showed that the bacterial deposition rate increased in specimens containing nano-clay compared to untreated specimens. Also, the permeability rate in the nano-clay-treated specimens in the short term was higher than in untreated specimens; however, in the long term, it was lower than that of the untreated specimens. After coating, specimens containing nano-clay and untreated specimens had better performance against sulfate attack than non-coated untreated specimens. Also, the resistance of mortar in these specimens to this damage increased by 15.2 % and 9.2 %, respectively. Additionally, like sulfate attack, resistance to carbonation in the coated nano-clay treated and untreated specimens increased compared to non-coated untreated specimens by 34 % and 15.9 %, respectively. The UCS of the specimens was investigated in four cases: untreated (control) specimens experienced a 4.3 % reduction in resistance compared to the specimens created by adding nano-clay to the mortar specimen. The strength was increased by 6.7 % in untreated specimens after coating. Finally, the strength increased by 13.5 % in the coasted specimen containing nano-clay.

[Display omitted] • Fabrication of ATP-based GO nanocomposite integrated with MBT-inhibitor. • Grafted ATP on GO surface functions as a space barrier, reducing GO stacking. • Modified coatings provide better mechanical and adhesion strength. • MBT encapsulation offers passive and self-healing defense on AA2024-T3. Applications for graphene oxide (GO) in the field of corrosion protection will be severely constrained by the material's poor dispersion and compatibility with epoxy resins, as well as the absence of self-healing corrosion protection in GO-based epoxy coatings. In this work, we developed a bi-functional 2-mercaptobenzothiazole (MBT) inhibitor-encapsulating GO-based nanocomposite (GAM) with pH-responsive release by implanting attapulgite (ATP) nanorods on the surface of GO. Additionally, GO-based nanocomposite can form covalent connections with epoxy resins and be evenly distributed in epoxy film via a ring opening process. Moreover, improved epoxy film compatibility and dispersion result in elevated mechanical strength and better impermeability, which prevent corrosion in both the active and passive modes. The corrosion resistance of GAM self-healing coating increased as the submersion period exceeded 24 h up to 0.54 M Ω cm2, resulting in the release of MBT inhibitor to form a passivation film at the defective region. Moreover, the improved charge transfer resistance (R ct) and the coating's resistance to corrosive species (R c) attribute to the self-healing ability of the GAM coating. The incorporation of GAM (2 %) nanocomposites into epoxy films enables long-term protection of AA2024-T3 by combining passive and self-healing corrosion prevention. [ABSTRACT FROM AUTHOR]

A special nano-filter made of cellulose acetate (CA) was developed, including a 3D hierarchically porous structure. The nano-filter utilized nano-clay (hydrophilic bentonite (NC B)), comprising 0.5–1.5 % of its weight. The objective of this study was to evaluate the adsorption properties of four carcinogenic polyaromatic hydrocarbons (benz[α] anthracene (BαA), chrysene (CHR), benzo[β]fluoranthene (BβF), and benzo[α] pyrene (BαP)) during the rice smoking process. The evaluation of the nano-filter encompassed an analysis of its mechanical attributes, surface qualities, morphology, and adsorption efficacy. The experimental results demonstrated that adding NC B to the nano-filter composition of CA led to substantial improvements in tensile strength, elongation at break, and maximum load stress values compared to the control group. The nano-filter displayed a uniform and homogeneously distributed arrangement of nanoparticles. The GC–MS analysis demonstrated that the enhanced nano-filter, comprising nano-clay particles, successfully absorbed the polycyclic aromatic hydrocarbons (PAHs) over a 21-day rice smoking period. The performance, removal efficiency and porosity during repetitive filtering and cleaning cycles in the rice samples at different smoking times were approved reusability of CA-NC B filter. It is recommended to explore the application of hybrid CA nano-filter s, namely those containing NC B , as a cutting-edge filtration technique for smoked food products. [ABSTRACT FROM AUTHOR]

Face/core debonding is one of the crucial problems of composite sandwich panels which consist of AA3003 aluminium honeycomb and glass fiber reinforced polymer face sheets. The panel was prepared by a hand-lay process at different nano-clay weight addition of 0%, 2%, 4%, and 6% with the objective of improving face/core adhesion. Interface bonding between face sheets and honeycomb core composite sandwiches and their mechanical behavior were investigated under in-plane compression and bending load. The flexural property of sandwich panels due to the influence of variation in strain rate is further determined. The morphologies of fractured samples were investigated by scanning electron microscope (SEM). The results revealed a significant improvement in mechanical characteristics when nano-clay was loaded to the composites at a concentration from 2 to 4 wt%, and the in-plane compression and flexural failure load values increased by 45% and 81%, respectively, when compared to a pristine sample. It was observed that increasing strain rate led to the increase in failure load of the sandwich panel. SEM images of fractured surfaces showed residual aluminium honeycomb was present in the face sheet, which indicates better adhesion between aluminium honeycomb core and face sheets. [ABSTRACT FROM AUTHOR]

Abstract Cold recycling of asphalt is an effective solution to reduce the environmental impacts of pavement construction and operation. This approach reduces the use of scarce resources and fossil fuels, and prevents the spread of greenhouse pollutants in the air. Despite its benefits, recycled asphalt does have drawbacks, some of which include nibbling, stripping, and less resistance to fatigue. The use of additives can improve the mechanical properties of recycled asphalt. In this research, the addition of Nano-lime, Nano-Alumina, and Nano-clay instead of cement, to bitumen emulsion in recycled asphalt was used to improve the properties of asphalt resilient modulus and fatigue. A comparative method was used to analyze the obtained experimental results. In this study the resilient modulus and fatigue properties of asphaltic concrete were measured. The results show that asphalt fatigue properties and resilient modulus improve significantly with the addition of different Nano-particle percentages.

Adding nanomaterials to concrete extends the size range of constituent particles well into nano-scale dimensions, which could help the compacting of particles in cement-based materials. Regarding the differences between shotcrete and cast concrete, in this study, the properties of shotcrete with nano and micro-silica and nano-clay were experimentally studied. The micro and nanomaterials have been added at different percentages (6%, 9%, and 12%) to a shotcrete paste. The comparison was based on the uniaxial compressive strength, flexural strength, tensile strength, and porosity tests of different specimens. The results indicated that the maximum increase in compressive, flexural, and tensile strengths of shotcrete was related to 12% nano-SiO2, while for 12% nano-clay, all of these strengths were decreased at 28 days. The optimum percentage for shotcrete substitution by nano-clay was established to be 6%. Also, the application of the nanomaterials led to a decrease in the water absorption and porosity of shotcrete. Eventually, the results revealed that the improvement of mechanical properties by the introduction of the nanomaterials in shotcrete could be satisfactory.