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By using piezoelectric materials, it is possible to convert clean and renewable energy sources into electrical energy. In this paper, the effect on the piezoelectro-elastic response of piezoelectric-fiber-reinforced nanocomposites by adding silica nanoparticles into the polyimide matrix is investigated by a micromechanical method. First, the Ji and Mori–Tanaka models are used to calculate the properties of the nanoscale silica-filled polymer. The nanoparticle agglomeration and silica–polymer interphase are considered in the micromechanical modeling. Then, considering the filled polymer as the matrix and the piezoelectric fiber as the reinforcement, the Mori–Tanaka model is used to estimate the elastic and piezoelectric constants of the piezoelectric fibrous nanocomposites. It was found that adding silica nanoparticles into the polymer improves the elastic and piezoelectric properties of the piezoelectric fibrous nanocomposites. When the fiber volume fraction is 60%, the nanocomposite with the 3% silica-filled polyimide exhibits 39%, 31.8%, and 37% improvements in the transverse Young's modulus E T , transverse shear modulus G T L , and piezoelectric coefficient e 31 in comparison with the composite without nanoparticles. Furthermore, the piezoelectro-elastic properties such as E T , G T L , and e 31 can be improved as the nanoparticle diameter decreases. However, the elastic and piezoelectric constants of the piezoelectric fibrous nanocomposites decrease once the nanoparticles are agglomerated in the polymer matrix. A thick interphase with a high stiffness enhances the nanocomposite's piezoelectro-elastic performance. Also, the influence of volume fractions of the silica nanoparticles and piezoelectric fibers on the nanocomposite properties is studied. [ABSTRACT FROM AUTHOR]

Given the inevitable human exposure owing to its increasing production and utilization, the comprehensive safety evaluation of silica nanoparticles (SiNPs) has sparked concerns. Substantial evidence indicated liver damage by inhaled SiNPs. Notwithstanding, few reports focused on the persistence or reversibility of hepatic injuries, and the intricate molecular mechanisms involved remain limited. Here, rats are intratracheally instilled with SiNPs in two regimens (a 3‐month exposure and a subsequent 6‐week recovery after terminating SiNPs administration) to assess the hepatic effects. Nontargeted lipidomics revealed alterations in lipid metabolites as a contributor to the hepatic response and recovery effects of SiNPs. In line with the functional analysis of differential lipid metabolites, SiNPs activated oxidative stress, and induced lipid peroxidation and lipid deposition in the liver, as evidenced by the elevated hepatic levels of ROS, MDA, TC, and TG. Of note, these indicators showed great improvements after a 6‐week recovery, even returning to the control levels. According to the correlation, ROC curve, and SEM analysis, 11 lipids identified as potential regulatory molecules for ameliorating liver injury by SiNPs. Collectively, the work first revealed the reversibility of SiNP‐elicited hepatotoxicity from the perspective of lipidomics and offered valuable laboratory evidence and therapeutic strategy to facilitate nanosafety. [ABSTRACT FROM AUTHOR]

Dodecenylsuccinic anhydride was used as a surface modifier to further modify amino-functionalized silica nanoparticles, and the modified nanoparticles (RNS-1A-DDSA) showed good dispersion stability in both nonpolar PAO6 and polar DIOS base oils. The tribological properties of RNS-1A-DDSA were evaluated using an oscillating reciprocal friction and wear tester (SRV-5), and it was found to exhibit excellent tribological properties in both base oils with different polarities. EDS and SEM were used to characterize the wear surfaces, and combined with the results of AFM and QCM adsorption experiments, the reason for the applicability of RNS-1A-DDSA in both polar and non-polar base oils was deduced. [ABSTRACT FROM AUTHOR]

The coconut (Cocosnucifera) is renowned for its endocarp, commonly referred to as the coconut shell, which is believed to harbor a high concentration of silicon, potentially serving as a source for the production of silicon nanoparticles (SiO2NPs). This study demonstrated the synthesis of SiO2NPs derived from coconut shells and their application in the removal of metal contaminants, notably copper. SiO2NPs were synthesized with a recovery rate of 25.6%, yielding a white powder through the sol–gel method. Analysis via ultraviolet–visible (UV–Vis) spectroscopy revealed an absorbance peak maximum at 345 nm, indicative of strong surface plasmon resonance, thus confirming SiO2NPs formation. Morphological characterization conducted through field-emission scanning electron microscopy (FE-SEM) and field-emission transmission electron microscopy (FE-TEM) confirmed the smooth-faced nature of the SiO2NPs, presenting finely clumped particles with an average size of 62 nm. Furthermore, X-ray photoelectron spectroscopy (XPS) and energy-dispersive X-ray spectroscopy (EDX) analyses exhibited distinct peaks corresponding to oxygen (O) and silicon (Si), confirming SiO2NPs formation. X-ray diffraction (XRD) analysis confirmed the amorphous nature of the particles, with a 25% weight loss observed at 500 °C according to thermogravimetric analysis (TGA). Assessment of the adsorption capacity for heavy metals from water solutions by spiking various copper (II) sulfate concentrations indicated the highest adsorption rate at 0.05 M copper, diminishing with increased copper ion concentrations. Evaluations utilizing different SiO2NPs concentrations demonstrated optimal copper (Cu) removal efficiency at 0.2 g/mL SiO2NPs. [ABSTRACT FROM AUTHOR]

A concept to prepare a highly hydrophobic composite with self-healing properties has been designed and verified. The new material is based on a composite of a crystalline hydrophobic fluoro wax, synthesized from montan waxes and perfluoroethylene alcohols, combined with spherical silica nanoparticles equipped with a hydrophobic shell. Highly repellent layers were prepared using this combination of a hydrophobic crystalline wax and silica nanoparticles. The novel aspect of our concept was to prepare a ladder-like structure of the hydrophobic shell allowing the inclusion of a certain share of wax molecules. Wax molecules trapped in the hydrophobic structure during mixing are hindered from crystallizing; therefore, these molecules maintain a higher mobility compared to crystallized molecules. When a thin layer of the composite material is mechanically damaged, the mobile wax molecules can migrate and heal the defects to a certain extent. The general preparation of the composite is described and XRD analysis demonstrated that a certain share of wax molecules in the composite are hindered to crystallize. Furthermore, we show that the resulting material can recovery its repellent properties after surface damage. [ABSTRACT FROM AUTHOR]

Hollow silica nanoparticles (HSNPs) have hygroscopic properties because of their high specific surface area and surface hydroxyl groups. However, compared with other hygroscopic materials, their hygroscopic properties are relatively weak, which limits the further application of HSNPs. One feasible method to enhance their hygroscopic properties is by combining highly hygroscopic materials with hollow silica nanoparticles. To take advantage of the high hygroscopicity of polyacrylic acid (PAA) when combined with the high specific surface area of the hollow particles, PAA was coated on the inner and outer surfaces of the silica shell of the nanoparticles in this study to prepare hollow nanoparticles with a PAA/silica/PAA multilayer structure. The size of the PAA/silica/PAA multi-layer nanoparticles is about 85 nm, and the shell thickness is 25 nm. The specific surface area of the multi-layer nanoparticles is 58 m2/g. The water vapor adsorption capacity of multi-layer structure hollow nanoparticles was increased by 160% compared with the HSNPs (increased from 45.9 cm3/m2 to 109.1 cm3/m2). Meanwhile, at the same content of PAA, the PAA/silica/PAA-structured particles will adsorb 9% more water vapor than the PAA/silica-structured particles. This indicates that the high specific surface area structure of the hollow particles will enhance the adsorption ability of PAA toward water vapor. This novel structure of PAA-HSNPs is expected to be used as a humidity-regulating material for filler in environmental and architectural applications. [ABSTRACT FROM AUTHOR]

Background: Silica nanoparticles (SNPs) have immense potential in biomedical research, particularly in drug delivery and imaging applications, owing to their stability and minimal interactions with biological entities such as tissues or cells. Results: With synthesized and characterized cyanine-dye-doped fluorescent SNPs (CSNPs) using cyanine 3.5, 5.5, and 7 (Cy3.5, Cy5.5, and Cy7). Through systematic analysis, we discerned variations in the surface charge and fluorescence properties of the nanoparticles contingent on the encapsulated dye-(3-aminopropyl)triethoxysilane conjugate, while their size and shape remained constant. The fluorescence emission spectra exhibited a redshift correlated with increasing dye concentration, which was attributed to cascade energy transfer and self-quenching effects. Additionally, the fluorescence signal intensity showed a linear relationship with the particle concentration, particularly at lower dye equivalents, indicating a robust performance suitable for imaging applications. In vitro assessments revealed negligible cytotoxicity and efficient cellular uptake of the nanoparticles, enabling long-term tracking and imaging. Validation through in vivo imaging in mice underscored the versatility and efficacy of CSNPs, showing single-switching imaging capabilities and linear signal enhancement within subcutaneous tissue environment. Conclusions: This study provides valuable insights for designing fluorescence imaging and optimizing nanoparticle-based applications in biomedical research, with potential implications for targeted drug delivery and in vivo imaging of tissue structures and organs. [ABSTRACT FROM AUTHOR]

Silica nanoparticles (SiNPs) and graphene oxide (GO) are two promising nanomaterial that have attracted considerable attention for their unique properties and applications. However, the conventional synthesis methods of SiNPs and GO often involve hazardous chemicals and high energy consumption, which pose environmental and economic challenges. Therefore, green and sustainable synthesis methods of SiNPs and GO are highly desirable. In this review, we summarize the recent advances in the green synthesis of SiNPs and GO using various natural sources, such as plants, fungi, bacteria, algae, clay, etc. We also discuss the functionalization of SiNPs and GO with acrylic resin to form hybrid nanocomposites for anti-corrosion applications. The advantages and challenges of these green methods are highlighted, and the future prospects are outlined. This review aims to provide a comprehensive overview of the current state-of-the-art in the green synthesis of SiNPs and GO-based nanocomposites for anti-corrosion applications, and to inspire further research in this emerging field. [ABSTRACT FROM AUTHOR]

A new strategy for a catalytic C−C bond forming cascade reaction comprising acetal hydrolysis and Knoevenagel condensation is presented here. The heterogeneous nanocatalyst is prepared by immobilizing an ionic liquid on the surface of highly monodisperse silica nanoparticles. This work is the first example of showing that there is no need to use bifunctional acid‐base catalysts for a cascade reaction including the hydrolysis of benzaldehyde dimethyl acetal to benzaldehyde and the subsequent Knoevenagel condensation of the resulting benzaldehyde with malononitrile. It is shown here that these reactions can proceed smoothly with a mono‐functional heterogeneous catalyst that contains a neutral ionic liquid. It has been proposed that such a neutral ionic liquid can "switch on" to an acidic catalyst in conjunction with water. The selected ionic liquid has potentially biodegradability characteristics, which is an important issue to achieve a sustainable catalyst. The simple procedure for preparing both the ionic liquid and the monodisperse silica nanoparticles provides opportunities for a large‐scale synthesis of the catalyst. This work introduces a breakthrough in the design and synthesis of heterogeneous catalysts for acid/base catalyzed cascade organic reactions. [ABSTRACT FROM AUTHOR]

Germination, development, and production of directly seeded agricultural products may be impacted by a variety of abiotic stresses. Silica nanoparticle seed priming has the ability to reduce the impact of external stressors. Stress brought on by salt has now become a barrier to wheat (Triticum turgidum) farming success. The goal of the current research was to clarify the effectiveness of seed priming with silica nanoparticles in reducing salt-induced stress in wheat plants. In this research, silica nanoparticle at three distinct concentrations—300, 600 and 900 ppm—was used for seed priming either alone or in combination with sodium chloride (2.3 and 4.6 ds/m). The application of silica nanoparticles considerably improved seedling development while salinity stress greatly decreased germination percent and seedling growth. Seed priming significantly increased shoot length (11.53%), root length (22.76%), seedling length (17.57%), shoot weight (35.56%), root weight (19.14%), germination stress tolerance index (91.55%), shoot length stress tolerance index (11.58%), root length stress tolerance index (22.6%), shoot weight stress tolerance index (35.54%) and root weight stress tolerance index (18.12%) under high saline treatment (4.6 ds/m). The significance of nano-silica in reducing the detrimental effects of salt stress on wheat seed growth is highlighted by the current investigation. The results showed that silica nanoparticle seed priming could enhance seedling early development under salt stress. [ABSTRACT FROM AUTHOR]

This work reports the fabrication of a large‐sized hydrogel sheet with enhanced mechanical and adhesive properties. The fabrication involves the introduction of carboxymethyl‐modified cellulose nanofibers (m‐CNFs) and solid silica nanoparticles (SSNs) as physical cross‐linkers into acrylic acid monomer (AA), followed by bar coating and photopolymerization. The addition of the nanomaterials to the monomer solution renders it viscous, enabling the fabrication of A4‐sized hydrogel sheets with uniform thickness and enhanced mechanical and adhesive properties. Interestingly, the combined incorporation of both the nanomaterials generates a synergistic effect to improve the properties much more, which results from the hierarchical rupture of the multiple hydrogen‐bonded interactions among the poly(acrylic acid) (PAA) matrix, m‐CNFs, and SSNs. Under optimal conditions, the hydrogel sheet incorporated with the dual crosslinkers exhibits a sevenfold higher toughness and a sixfold increased peel strength than plain PAA, together with good biocompatibility. Furthermore, when mesoporous silica nanoparticles (MSNs) with active agent loading into their pores are incorporated instead of SSNs, the active agent can be released from the hydrogel sheet in a sustained or temperature‐sensitive manner, indicating that the system is potentially applicable to transdermal drug delivery system with no additional adhesive. [ABSTRACT FROM AUTHOR]

In this study, Taylor-vortex reactor was adopted to synthesize silica nanoparticles from sodium silicate solution and carbon dioxide. The outstanding advantages of the reactor have been demonstrated by comparing the synthesis results of silica nanoparticles by Erlenmeyer reactor. The results showed that silica particles synthesized from Taylor-vortex reactor are smaller in size than silica particles synthesized from the Erlenmeyer reactor. SEM images and histogram of particle size distribution obtained from experiments clearly exhibited that the concentration of SiO2 in the solution, reaction temperature, and rotation speed of the cylinder significantly affected morphology as well as size of the silica particles. [ABSTRACT FROM AUTHOR]

Efforts to improve the properties of composites have involved extensive studies regarding the effective incorporation of a polymer matrix and inorganic fillers. In this work, we generated a stable organosilica sol with high concentration and high purity by surface modification with silane coupling agents, then integrated it with an epoxy matrix. The silica nanoparticle/epoxy composite exhibited improved tensile strength because of the uniform distribution of silica in the matrix, as well as the interfacial chemical bonding between polymer and silica nanoparticles; these factors resulted in effective load transfer from matrix to fillers. Additionally, the application of copper-clad laminates (CCLs) with prepreg-containing silica nanoparticles led to substantial improvements in mechanical properties, including peel strength (0.46 kgf/cm) and storage modulus (30.0 GPa), compared with conventional CCLs lacking silica nanoparticles. These results suggest that prepregs containing surface-modified silica nanoparticles have great potential for use as printed circuit board substrate materials in high-performance electronics. [ABSTRACT FROM AUTHOR]

Recently, silica nanoparticles (NPs) have attracted considerable attention as biocompatible and stable templates for embedding noble metals. Noble-metal-embedded silica NPs utilize the exceptional optical properties of novel metals while overcoming the limitations of individual novel metal NPs. In addition, the structure of metal-embedded silica NPs decorated with small metal NPs around the silica core results in strong signal enhancement in localized surface plasmon resonance and surface-enhanced Raman scattering. This review summarizes recent studies on metal-embedded silica NPs, focusing on their unique designs and applications. The characteristics of the metal-embedded silica NPs depend on the type and structure of the embedded metals. Based on this progress, metal-embedded silica NPs are currently utilized in various spectroscopic applications, serving as nanozymes, detection and imaging probes, drug carriers, photothermal inducers, and bioactivation molecule screening identifiers. Owing to their versatile roles, metal-embedded silica NPs are expected to be applied in various fields, such as biology and medicine, in the future. [ABSTRACT FROM AUTHOR]

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Diabetes has affected nearly half a billion people worldwide. According to current guidelines, glycemic control is essential to mitigate diabetic complications. The antihyperglycemic effects of various chemically synthesized nanoparticles have been reported in animal models. However, their impact on humans has not been previously reported. This study was conducted to biosynthesize and assess the antihyperglycemic property of silica nanoparticles (SiO2-NPs) since they are non-toxic and biocompatible. SiO2-NPs biosynthesized using the endophytic fungus Fusarium oxysporum. In this collaborative study, 26 people, either hyperglycemic or euglycemic, diagnosed at the Endocrinology Outpatients, according to the American Diabetes Association, USA, were recruited. Silica nanoparticles were characterized and assessed for in vitro antihyperglycemic property using blood samples. Particle size distribution based on TEM images confirms that the average size of silica nanoparticle is 25 nm and is monodispersed in nature. The XRD pattern shows that only one broad peak at 2θ = 220 corresponds to the plane (101) of silica nanoparticles. UV Visible spectra show the λmax at 270 nm, peaks in FTIR at 1536 cm−1, 1640 cm−1, and 3420 cm−1 for the protein cap. The mean blood glucose was 120.2 mg/dL in the 'SiO2-NP untreated' group and decreased to 97.24 mg/dL in the 'SiO2-NP treated' group. A paired t-test (P-value < 0.0001) indicates a strong relationship between antihyperglycemia and silica NP. In our study, it has been observed that the biosynthesized silica nanoparticles using the endophytic fungus Fusarium oxysporum show antihyperglycemic property in vitro. [ABSTRACT FROM AUTHOR]

Fumed silica (SiO2) is often applied in the modification of thin‐film composite (TFC) forward osmosis (FO) membranes due to its hydrophilicity. However, a key challenge to be solved is to improve its compatibility with organic matrices and dispersion in the material. In this study, we synthesized well‐designed nanoparticles of (3‐aminopropyl)trimethoxysilane‐modified SiO2 (APTMS‐SiO2) and applied them for the first time in the preparation of FO membranes. Furthermore, we systematically investigated the effects of different pretreated SiO2, SiO2 dosages, draw solution types, and concentrations on FO membranes. The results showed that APTMS‐SiO2 thin‐film nanocomposite with a silica dosage of 0.1 wt.% has the highest water permeate flux (Jw) (26.25 LMH, 370.43 % higher than the control TFC of 5.58 LMH) and the minimum specific reverse solute flux (SRSF) of 0.17 g/L with 1 M NaCl as the draw. The incorporation of APTMS effectively prevented mutual agglomeration of SiO2 and improved its dispersion. The Jw of 13.36 LMH after seven cycles and the rejection of above 96.6 % for Congo Red and 95.8 % for Rhodamine B indicated potential reusability and dye rejection. This work presents an alternative approach to prepare FO membranes with enhanced water flux and increased selectivity, and it also offers insights for the treatment of printing and dyeing wastewater using FO. [ABSTRACT FROM AUTHOR]

Surface-enhanced Raman scattering technology plays a prominent role in spectroscopy. By introducing plasmonic metals and photonic crystals as a substrate, SERS signals can achieve further enhancement. However, the conventional doping preparation methods of these SERS substrates are insufficient in terms of metal-loading capacity and the coupling strength between plasmonic metals and photonic crystals, both of which reduce the SERS activity and reproducibility of SERS substrates. In this work, we report an approach combining spin-coating, surface modification, and in situ reduction methods. Using this approach, a photonic crystal array of SiO2@Au core–shell structure nanoparticles was prepared as a SERS substrate (SiO2@Au NP array). To study the SERS properties of these substrates, Rhodamine 6G was employed as the probe molecule. Compared with a Au-SiO2 NP array prepared using doping methods, the SiO2@Au NP array presented better SERS properties, and it reproduced the SERS spectra after one month. The detection limit of the Rhodamine 6G on SiO2@Au NP array reached 1 × 10−8 mol/L; furthermore, the relative standard deviation (9.82%) of reproducibility and the enhancement factor (1.51 × 106) were evaluated. Our approach provides a new potential option for the preparation of SERS substrates and offers a potential advantage in trace contaminant detection, and nondestructive testing. [ABSTRACT FROM AUTHOR]

Oil-based drilling fluids for deep well drilling should have stability and high temperature resistance, and water-in-oil inverse emulsions are a good choice as oil-based drilling fluids. In deep well drilling, high temperature will cause polymer surfactants to degrade and phase separation occurs. The octadecyltrimethoxysilane modified silica nanoparticles are used to form a stable water-in-oil inverse emulsion in a drilling fluid model, so that the emulsion fluid forms 60 µm water droplets. In addition, rheology shows that the use of hydrophobic silica nanoparticles can obtain stable water-in-oil inverse emulsions, the properties of which can be modified by adjusting the properties and content of the nanoparticles. The aging test at 120 °C shows that it has good stability at high temperatures and is suitable for deep well drilling operations. [ABSTRACT FROM AUTHOR]

In this study, we were able to create highly dispersed silica nanoparticles with diameters of less than one nm by changing the sol-gel technique. During the poly-condensation process, a strong magnetic field was applied to the silica sol to control particle size. The size of silica nanoparticles has a substantial impact on preparation elements such pH, magnetic field intensity, and exposure time. These parameters can be changed in a systematic manner to reduce or increase particle size. A dynamic light scattering test was also used to investigate the effect of a magnetic field on the particle size and dispersion of silica dust. Despite the fact that silica is naturally diamagnetic, the magnetic field has a considerable impact on their size growth. Magnetic fields altered the typical influence on silicon structure, resulting in crystal formation in the silicon sample under consideration. Many applications require small particle sizes and/or a narrow particle size dispersion. The building blocks of nanotechnology are usually made of low-dimension particles. The experts concluded that additional research into such strange phenomena will be required in the future. [ABSTRACT FROM AUTHOR]

Bleeding complications are associated with substantial tissue morbidities and mortalities. Biomimetic composite materials that possess the ability to sufficiently stimulate and augment different physiological mechanisms of hemostasis are highly desirable to reduce bleeding-related casualties, which, however, are still largely under-explored. This study aims to develop a composite hemostatic system by combining collagen hydrogel with tissue factor (TF)-integrated liposome and silica nanoparticle, which could integrate the platelet plug-promoting capacity of collagen with the abilities of the latter two components to activate the extrinsic and intrinsic pathways of coagulation respectively. Several hydrogel compositions were synthesized and characterized. We show that lipidated TF and silica were evenly distributed in the collagen-based hydrogels, while exhibiting tunable release kinetics in simulated body fluid. Time-to-coagulation test revealed that each component in the TF-liposome/silica/collagen ternary hydrogels was hemostasis-active, and their combination showed enhanced and potent procoagulant performance, without detectable cytotoxicity against NIH/3T3 model cells. These results suggest that collagen hydrogels with embedded TF-liposome and silica nanoparticle may serve as a platform for an effective hemostatic composite that incorporates all the basic known pathways of coagulation. [ABSTRACT FROM AUTHOR]

In this study, we have prepared silica nanoparticles (SiNPs) from biomass (rice husk) and organic precursor (TEOS) by sol‐gel precipitation method and compared their efficacy for theranostics applications. In the preparation of SiNPs, we have studied the effects of different parameters such as solvent, catalyst, temperature, water and precursor on the shape and size of SiNPs. It shows that the size of SiNPs was increased with an increase in the concentration of ethanol and acid catalyst; the particle size was decreased with an increase in reaction temperature and precursor. To develop the drug for photodynamic therapy against the target tumor cells, protoporphyrin (PpIX), an efficient photosensitizer is functionalized on the surface of SiNPs. The drug loading potential was studied by the conjugation of 5‐Fluorouracil on the surface of functionalized SiNPs. From the results, we suggest that the functionalized SiNPs will be used for combined therapeutic and diagnostic in biomedical applications. [ABSTRACT FROM AUTHOR]

Agro-waste can provide a non-metallic, environmentally friendly bio-precursor for the production of green silica nanoparticles. To manufacture silica nanoparticles from rice husk, biogenic silica nanoparticles were generated using an alkaline precipitation approach. Rice husk as a source of silica nanoparticles is environmentally and economically valuable because it is a plentiful lower price agricultural derivative that can be used to help with waste management. During the synthesis process, the dose of rice husk ash was used at 5 g at pH 7, alkali dose concentration of 0.5 M, reaction period of 3.5 h, and temperature of 90°C that produced maximum silica nanoparticles with a yield of 88.5%. To optimize the silica nanoparticle production from rice husk ash Box Behnken Design (BBD) a subcategory of the response surface methodology (RSM) was accomplished. BBD model was successfully matched, as evidenced by the high correlation values of adjusted R2 0.9989 and predicted R² 0.9977. Silica nanoparticles' amorphous form generated from rice husk ash is indicated by XRD analysis 2θ peak at 22.12° and UV-Vis Spectroscopy absorbance peak at 312 nm. The amorphous shape of silica is amorphous and crystalline defined through XRD. nanoparticles generated from rice husk ash is indicated by FESEM analysis and EDX analysis, confirming that the SiO2 elemental configuration comprises the highest concentration of Si and O. The existence of a siloxane group in the produced compound was revealed by FTIR spectra stretching vibrations at 803.69 and 1089.05 cm-1. [ABSTRACT FROM AUTHOR]

Plant-mediated nanoparticle synthesis is a revolutionary technique with numerous applications in fields, such as agriculture, food processing, and medicine. This study reports that Punica granatum leaf extract is capable of the green and eco-friendly synthesis of silica nanoparticles that provides a simple, cost-effective, and efficient methodology. P. granatum leaf extract was employed as a capping and stabilizing agent for the formation of silica nanoparticles, which were synthesized by a biological method using tetra ethyl ortho silicate. Biosynthesized silica nanoparticles are characterized by X-ray diffraction analysis, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. All the analyses and characterization determined that the particles were spherical in shape and amorphous in nature with an average size of 12 nm. P. granatum-assisted silica nanoparticles were tested for antibacterial activity by a well-diffusion method against two-gram negative bacterial pathogens (E. coli and Salmonella sp.). The antibacterial studies prove that P. granatum-assisted silica nanoparticles have good antibacterial properties. These studies will help us find a new nano-drug or medicine against multidrug-resistant bacteria. [ABSTRACT FROM AUTHOR]

Laser printing has become a promising alternative for large-scale fabrication of functional devices. Here, laser-induced forward transfer (LIFT) of nanosilica was successfully achieved using a lower-cost nanosecond laser with a center wavelength of 1064 nm. To enhance the light absorption of silica, a small amount of graphene oxide (GO) was added to the fumed silica. Investigations were conducted to give an insight into the role of GO in the LIFT process. Pattern deposition was achieved with a minimum line width of 221 μm. The scattering can be tuned from ~2.5% to ~17.5% by changing the laser fluence. The patternable transparent display based on laser transferred nanosilica (LTNS) film was also demonstrated, showing its capability to deliver information on multiple levels. This LIFT based technique promotes fast, flexible, and low-cost manufacturing of scattering-based translucent screens or patterns for transparent displays. [ABSTRACT FROM AUTHOR]

Oil spills contaminate water bodies and hence, cause the death of marine animals. The Niger Delta Oil contaminated water was treated by adsorption using sisal fibre activated carbon (SFAC) doped with silica nanoparticles (SNP) synthesized from Ofada rice husk which was carbonized at temperatures 400 °C and 650 °C. The SNP was synthesized at 600 °C (SNP-1) and 800 °C (SNP-2). The proportion in SFAC: SNP for both temperature values was 4.8:0.2 with a basis of 5 grams of the adsorbent. The samples were characterized by SEM, BET analysis, XRF and XRD. The adsorption equilibrium studies obeyed Langmuir adsorption isotherm; as the linear correlation value was close to unity, with a separation factor of 0.004. SNP-1 shows amophous nature having Fe2O3 and SNP-2 shows crystalline nature which consist of quartz. SNP-2 was used for the study due to its high surface area observed in the BET. High % removal efficiency of 99.84 was attained with silica nanoparticle (SNP-2) integrated in sisal fiber activated carbon (SFAC carbonized at 400 °C). [ABSTRACT FROM AUTHOR]

Herein, a facile, scalable, and cost‐effective method was used to fabricate eco‐friendly superhydrophobic UV‐curable polyurethane‐silica nanocomposite coating with promising physicomechanical properties. Fluorinated UV‐curable polyurethane dispersion was synthesized and used as the binder of the superhydrophobic coating along with hydrophobically modified silica nanoparticles as textured topography. The chemical structures of the employed silica nanoparticles, prepared UV‐curable polymer, and superhydrophobic coating were thoroughly studied by FTIR analysis. It has been revealed that the prepared SH coating possesses well‐defined micro/nano‐scale roughness, high contact angle (159°), and low sliding angle (1.5°), which can be applied onto various substrates. Also, the exceptional durability of the fabricated coating against sandpaper abrasion (over 80 m) without losing its superhydrophobicity revealed the high capability of the prepared waterborne coating to be used in harsh practical applications. Additionally, due to the highly cross‐linked structure of the prepared SH coating, the applied coating could maintain its integrity even after 30 days of immersion in different organic solvents. Moreover, the prepared coatings showed substantial potential for use in self‐cleaning and oil/water separation fields (> 98% efficiency after 15 cycles of oil/water separations). We are convinced that the prepared hybrid coating could offer a practical approach for fabricating of superhydrophobic materials as promising nominates for disparate fields. [ABSTRACT FROM AUTHOR]

Long‐term exposure to respirable silica particles causes pulmonary inflammation and fibrosis primarily promoted by cytokines released from alveolar macrophages, yet the underlying mechanism is still unclear. From the perspective of nuclear factor kappa B (NF‐κB), we studied the mechanism of IL‐1β biosynthesis and release. Utilizing BAY 11‐7082, an NF‐κB specific inhibitor, we showed the alteration of macrophage viability and examined the expression of both IL‐1β and NF‐κB in vitro. We found that silica nanoparticles (SiNPs) were internalized by macrophages and caused damage to cell integrity. The immunofluorescence assay showed that SiNPs exposure enhanced the expression of IL‐1β and NF‐κB, which could be effectively suppressed by BAY 11‐7082. Besides, we built silica exposure mouse model by intratracheally instilling 5 mg of SiNPs and checked the effect of silica exposure on pulmonary pathological changes. Consistently, we found an upregulation of IL‐1β and NF‐κB after SiNPs exposure, along with the aggravated inflammatory cell infiltration, thickened alveolar wall, and enhanced expression of collagens. In conclusion, SiNPs exposure causes pulmonary inflammation and fibrosis that is regulated by NK‐κB through upregulating IL‐1β in alveolar macrophages. [ABSTRACT FROM AUTHOR]

Polymeric hydrogels can be used as artificial replacement for lesioned cartilage. However, modulating the hydrogel formulation that mimics articular cartilage tissue with respect to mechanical and tribological properties has remained a challenge. This study encompasses the tribological evaluation of a silica nanoparticle (SNP) loaded bilayer nanocomposite hydrogel (NCH), synthesized using acrylamide, acrylic acid, and alginate via modulated free-radical polymerization. Multi-factor pin-on-plate sliding wear experiments were carried out with a steel ball counterface using a linear reciprocating tribometer. Tribological properties of NCHs with 0.6 wt% SNPs showed a significant improvement in the wear resistance of the lubricious layer and a low coefficient of friction (CoF). CoF of both non-reinforced hydrogel (NRH) and NCH at maximum contact pressure ranged from 0.006 to 0.008, which is in the order of the CoF of healthy articular cartilage. Interfacial surface energy was analysed according to Johnson, Kendall, and Robert's theory, and NCHs showed superior mechanical properties and surface energy compared to NRHs. Lubrication regimes' models were drawn based on the Stribeck chart parameters, and CoF results were highlighted in the elastoviscous transition regime. [ABSTRACT FROM AUTHOR]

This article describes about feasibility of silica modified Candelilla wax (CW)/thermoplastic polyurethane (TPU) coating for hydrophobic textiles. CW/TPU blend solutions at different ratio (10:1, 10:3 and 10:5) were studied for rheological properties at different temperature and shear rates. The blend solutions were coated on the surface of cotton, polyester and nylon fabric. Water contact angle and stiffness properties of the coated fabrics were evaluated in order to optimize the blend ratio. The optimized blend ratio CW/TPU (10:5) was further modified with different weight percentage of Silica nanoparticles (0.5 to 2 wt. %) and coated on the cotton, polyester and nylon fabrics. The water contact angle of 2.0% silica modified CW/TPU coating was found to be 147°, 144° and 140° for cotton, polyester and nylon respectively. The surface morphology of coated fabrics was evaluated through scanning electron microscopy. Silica modified CW/TPU fabric showed textured surface. Coated fabrics were evaluated for properties such as thickness, weight gain and stiffness. [ABSTRACT FROM AUTHOR]

The effect of brine salinity, cation type, pH, and produced sand on zeta potential (ZP) measurements with and without the presence of silica nanoparticles is investigated through pH measurement, static tests for sand and ZP measurements as well as Field Emission Scanning Electron Microscope (FESEM) analyses. Three important factors were investigated: composition of the injected brine, surface charge and pH. Their influence on stability of nanoparticles in the injected brine and amount of sand segregation was determined and the analysis of the new outcomes based on rock/brine ZP measurements was reported. The results show that the use of silica nanoparticles with high pH helps in preventing sand production and that pH has a main effect on the surface charge of the sand particle released, affecting the ZP of the solution. Nanoparticles can be active as a coating on sand grains and prevent sand segregation during water flooding. Divalent cations have been found to acquire a more substantial impact on neutralizing the negative charge of the sand particles than monovalent cations at the same concentration and pH conditions at 25 ℃. The value of ZP becomes of higher negative value with the decrease of brine salinity. The effectiveness of SiO2 nanoparticles is quite different for soft water and smart water. For soft water, the nanoparticles work more effective at pH higher than 8; and for smart water, the nanoparticles perform better at pH lower than 8. To reduce sand production with the use of silica nanoparticles, it is highly suggested to increase pH, as pH and sand production mechanisms were observed to be inversely related. [ABSTRACT FROM AUTHOR]

In recent years, graphene has been explored as a heating membrane for studying high-temperature dynamics inside the transmission electron microscope (TEM) due to several limitations with the existing silicon nitride-based membrane. However, the transfer of monolayer graphene films for TEM experiments is challenging and requires many complicated steps with a minimum success rate. This work developed a novel in situ heating platform by combining the graphene oxide (GO) flakes in the pre-patterned chips. The isolated GO flake was self-suspended between the metal electrodes by a simple drop-casting process. The GO was reduced and characterized using Raman and electron energy-loss spectroscopy. Furthermore, a GO-based heater was used to investigate the thermal stability of gold and silica nanoparticles. The gold nanoparticles evaporated non-uniformly and left an empty carbon shell, while silica disappeared uniformly by etching carbon support. We successfully demonstrated a GO flake as a heating membrane to study high temperature thermal dynamic reactions: melting/evaporation, agglomeration, Rayleigh instability, and formation/or removal of carbon in the nanoparticles. [ABSTRACT FROM AUTHOR]

Detection method for SiO2 nanoparticles with the size of 20–300 nm was developed using triple‐quadrupole inductively coupled plasma‐mass spectrometer (TQ‐ICP‐MS). As 28Si+ ion of SiO2 nanoparticles is a difficult‐to‐determine ion via ICP‐MS due to severe molecular ion interferences, the mass‐to‐charge ratio of 28Si+ was shifted by reacting with O2 gas to form 28Si16O+. In order to confirm peak identification, a time‐resolved spectrum (TRS) of known standard particle was obtained, and the correlation curve of the average peak area per particle (Y) versus particle radius (X) was plotted after optimized blank subtraction. The function Y = aX3 was fitted to the data, demonstrating the validity of the developed method. As a result, the presence of 20 nm SiO2 nanoparticles, much smaller than the size (<80 nm) published in other articles, was confirmed in this work and the correlation curve can be used for on‐line monitoring of nanoparticles present in the process chemicals of the semiconductor industry. [ABSTRACT FROM AUTHOR]

Abundant applications of silica nanoparticles (SiNPs) have motivated many research groups for silica nanoparticles synthesis with tuned properties. Here we show the formation of SiNPs using the top-down method in a wet attrition mill with effective use of surfactants sodium laurylsulfate (SLS) and Tween-80. The attrition milling was facilitated by using zirconium beads as milling media. The effects of surfactant concentration on particle size distribution have been studied with a particle size analyzer using the dynamic light scattering technique (DLS). The optimum conditions for wet milling with surfactant concentration were evaluated experimentally. The field emission scanning electron microscopy (FE-SEM) analysis confirmed particle size and particle shape. The energy-dispersive X-ray spectroscopy (EDX) exhibited the presence of silicon and oxygen as elemental constituents of SiNPs. The FEG - Transmission electron microscope and HR-TEM analysis identified SiNPs of spherical shape in the size range from 21 nm to 46 nm. The X-ray diffraction (XRD) peaks revealed the presence of SiNPs polycrystallite size as 35.54 nm and 40.63 nm for 5 wt % Tween-80 and 5 wt% SLS, respectively. The selected area electron diffraction (SAED) pattern analysis exhibited a polycrystalline structure of SiNPs. Fourier transform infrared spectroscopy (FTIR) peaks confirmed the purity of SiNPs and the presence of Si-O bond. The foam formation and foam stability were analyzed to explore the effects of foam formation on the wet milling process. These experimentations propose the effective use of surfactants in the milling method for the production of SiNPs. Graphical Abstract [ABSTRACT FROM AUTHOR]

In this work, we present two methodologies to prepare nano compounds derived from a mixture of metals oxides supported in biogenic silica nanoparticles. Cobalt, copper, and zinc salts were used to impregnate the silica nanoparticles by two different methods. In the first method, called, Direct method, the rice husks were impregnated with salts solutions of the metals of interest and then thermally treated and sintered to obtain the respective silica nanocomposite, in the second method, the Indirect method, silica nanoparticles were prepared from biogenic materials and then were impregnated with the metal solution and sintered. Samples obtained by both methods were characterized by SEM, DLS, and AFM, the composition was determined by LiBS and their optical properties by Uv–vis, FTIR and the variations in the bandgap of the metal oxides and the effect of the metal oxide's confinement within the nanoparticle structure were studied. The bandgap values obtained for the samples correspond to those of oxide nanoparticles of the corresponding metals, with small variations due to confinement by being embedded in the SiO2 matrix. [ABSTRACT FROM AUTHOR]

Silica nanoparticles (SiO2 NPs) are increasingly investigated for their potential in drug delivery systems. However, the neurotoxicity of SiO2 NPs remains to be fully clarified. Previously SiO2 NPs have been reported to be detected in the central nervous system, especially in the dopaminergic neurons which are deeply involved in Parkinson's disease (PD). In this article, we characterized the effects of SiO2 NPs on inducing PD-like pathology both in vitro and in vivo. Results showed that SiO2 NPs promote more severe hyperphosphorylation and aggregation of α-synuclein, mitochondria impairment, oxidative stress, autophagy dysfunction, and neuronal apoptosis in the α-Syn A53T transgenic mice intranasally administrated with SiO2 NPs compared with the control group. Our findings provide new evidence supporting that SiO2 NPs exposure might have a strong capability of promoting the initiation and development of PD. [ABSTRACT FROM AUTHOR]

The main goal of this study is to investigate the influence of functionalization of silica nanoparticles on the structural properties and gas separation performance of the poly (etherblock-amide) based mixed matrix membranes containing silica nanoparticles. For this purpose, first silica nanoparticles were modified by carboxylic functional groups and used for the preparation of mixed matrix membranes. The prepared membranes were analysed using the XRD, DSC, FTIR, SEM and gas permeation tests. The results showed that the chemical modification of silica nanoparticles and the incorporating of carboxyl groups on its surface had a strong interaction with the polymer matrix and improved the filler distribution in the membrane matrix. It was observed that by loading 4%wt of silica nanoparticles functionalized with carboxyl groups in the polymer matrix increases the gas permeability at different pressures. The membranes containing 4%wt modified silica nanoparticles had the permeability of CO2, O2 and N2 equal 43.1, 2.8 and 0.42 Barrer, respectively, and the selectivity of O2/N2 (6.71) and CO2/N2 (103.3) at the pressure of 3 bar. [ABSTRACT FROM AUTHOR]

Forward osmosis (FO) is the most promising upcoming desalination technique which requires more detailed researches to reduce its challenges like low pure water flux and high reverse solute flux. This paper represents the fabrication of thin-film nanocomposite polyethersulfone membrane with 0.005 wt% of silica nanoparticle (SiNPs) loading and analysis of FO performance of the fabricated TFN membrane. The nanoparticle was incorporated into the polyamide active rejection layer by interfacial polymerization. Membrane characterizations like ATR-FTIR, SEM, and wettability analysis were done. Successful nanoparticle incorporation was confirmed by ATR-FTIR analysis. Rise in hydrophilicity of TFN membrane was confirmed surface wettability measurements. The effect on draw solution concentration as well as cross-flow rate on membrane performance was analyzed. Comparison of forward osmosis performance with various inorganic draw solutes was also tested. The draw solutes considered were KCl, NaCl, and CaCl2 due to its various applications in fertigation and desalination. The filtration parameters of the fabricated membranes are analyzed and enlisted. The membrane FO performance under AL-FS and AL-DS modes of operation was tested. Results show that fabricated TFN membrane obtains a maximum flux of 23.93LMH in AL-DS mode, and salt rejection was 91%. [ABSTRACT FROM AUTHOR]

Mixed matrix membranes (MMMs) owing to the tunable characteristics and functionalization ability can effectively substitute the highly intensive conventional membranes for industrial‐scale CO2 separation. Further, to strengthen the interfacial polymer‐filler interaction, an interfacial design strategy incorporating active functional groups in the filler surface can be demonstrated. In this study, as‐synthesized silica nanoparticles (SNPs) was surface functionalized by (3‐aminopropyl) trimethoxysilane silica modifier (AFSNP). The CO2 separation of poly (vinyl alcohol)/polyethylene glycol based MMM infused with surface‐functionalized SNP (AFSNP) was conducted. The comparative study highlighted in‐depth analysis of intrinsic physicochemical properties of as‐synthesized membranes and nanoparticles. Detailed characterization such as advanced microscopic analysis, X‐ray photoelectron spectroscopy (XPS) analysis and ninhydrin assay validated the successful grafting of amino groups onto the silica surface. The morphological inspection corroborated the consistent dispersion ability of the nanoparticles in the membrane matrix. The effect of the operating conditions on the membrane selectivity and CO2 permeance were statistically analyzed by ANOVA. The CO2 permeation result (CO2 permeance and CO2/N2 selectivity) exhibited many fold increment with surface functionalization of SNPs compared to undoped silica MMM. The defect‐free, performance‐oriented CO2‐selective membrane thus opened up the possibility of this combination as a prospective contender for large‐scale carbon capture studies. [ABSTRACT FROM AUTHOR]

Nanoparticles are termed as kinetic promoters with great application potential whose promotion effect exceeding that of surfactants in some cases. However, the effects on hydrate dissociation in nanoparticle system have been studied rarely. In the presence of nanoparticles, there are differences in the heat conduction of different systems, which may cause different hydrate dissociation behaviors. Herein, the dissociation kinetics under different systems were quantitatively characterized using gas production and activity energy. It was found that silica nanoparticle promotes the CO2 hydrate dissociation and the gas production increases with the increase of nanoparticle mass fraction. The activation energy in different silica nanoparticle systems of 50 nm 0.05–1.00 wt% increases with the decrease of nanoparticle concentration with the value changing from 72.05 ± 4.21 kJ·mol−1 to 122.25 ± 11.46 kJ·mol−1. Compared with pure carbon dioxide hydrate, the thermal conductivity of CO2 hydrate-silica nanoparticle systems increase by 2.4 % to 5.5 %. The thermal conductivity increases with the increase in concentration or the decrease in particle size. There is an approximately linear negative correlation between activation energy and thermal conductivity, that is, as the thermal conductivity increases, the activation energy decreases. The law of fluctuation and dissipation is the internal mechanism of hydrate dissociation and that was analyzed firstly in macroscopic experimental investigation. It was found that the fluctuation and dissipation of gas production in the near-equilibrium region can be used to predict the hydrate dissociation kinetics under non-equilibrium conditions. [ABSTRACT FROM AUTHOR]

We report a quick and simple method to fabricate transparent superhydrophobic polydimethylsiloxane (PDMS) using partial combustion of PDMS by thermal convection. The fabrication process only uses PDMS as an ingredient and does not require harmful, expensive materials such as organic solvent or fluoropolymer. To make PDMS superhydrophobic, combustion reaction was used to create hierarchical structures with micro- to nano-scale roughness with low surface energy required for the fabrication of superhydrophobic surface. Combustion of PDMS surface created hydrophobic silica-containing nanoparticles. These nanoparticles are deposited on the PDMS surface, creating hierarchical nano-structures required for superhydrophobic surface. To minimize the damage from excessive heat and flame, thermal convection was used to control the degree of combustion during the fabrication process. The fabricated superhydrophobic surface showed static water contact angle of 155.6°, and contact angle hysteresis of 5°. The fabricated surface also maintained light transmittance greater than 70% of the maximum transmittance of pristine PDMS in visible light region. [ABSTRACT FROM AUTHOR]

The rapid development of nanotechnology has greatly benefited modern science and engineering and also led to an increased environmental exposure to nanoparticles (NPs). While recent research has established a correlation between the exposure of NPs and cardiovascular diseases, the intrinsic mechanisms of such a connection remain unclear. Inhaled NPs can penetrate the air–blood barrier from the lung to systemic circulation, thereby intruding the cardiovascular system and generating cardiotoxic effects. In this study, on-site cardiovascular damage was observed in mice upon respiratory exposure of silica nanoparticles (SiNPs), and the corresponding mechanism was investigated by focusing on the interaction of SiNPs and their encountered biomacromolecules en route. SiNPs were found to collect a significant amount of apolipoprotein A-I (Apo A-I) from the blood, in particular when the SiNPs were preadsorbed with pulmonary surfactants. While the adsorbed Apo A-I ameliorated the cytotoxic and proinflammatory effects of SiNPs, the protein was eliminated from the blood upon clearance of the NPs. However, supplementation of Apo A-I mimic peptide mitigated the atherosclerotic lesion induced by SiNPs. In addition, we found a further declined plasma Apo A-I level in clinical silicosis patients than coronary heart disease patients, suggesting clearance of SiNPs sequestered Apo A-I to compromise the coronal protein’s regular biological functions. Together, this study has provided evidence that the protein corona of SiNPs acquired in the blood depletes Apo A-I, a biomarker for prediction of cardiovascular diseases, which gives rise to unexpected toxic effects of the nanoparticles. [ABSTRACT FROM AUTHOR]

We investigated the effects of silica nanoparticles (SiNPs) on the rheological properties and microstructures of polyvinyl alcohol (PVA)/silver nanowire (AgNW) suspensions. For PVA/AgNW suspensions without SiNPs, rheological percolation threshold was calculated using storage modulus determined by small amplitude oscillatory shear (SAOS) tests. Results from SAOS tests revealed that PVA/AgNW suspensions had two transition concentrations, which led to different structure developments. Storage modulus from large amplitude oscillatory shear (LAOS) tests showed double-step strain softening behavior at all AgNW concentrations tested, and elastic stress components, also obtained by LAOS tests, exhibited trends similar to storage modulus development. Furthermore, two distinguishable structures were observed when large strain amplitude shear was applied. When SiNPs were added to PVA/AgNW suspensions, the rheological properties of PVA/AgNW suspensions from SAOS tests increased. LAOS results showed storage modulus and elastic stress components of PVA/AgNW suspensions were dependent on AgNW concentration. Doublestep strain softening disappeared for PVA/AgNW suspensions containing SiNPs at low AgNW concentrations, whereas at high AgNW concentrations double-step strain softening behavior was observed. [ABSTRACT FROM AUTHOR]

In this work, we have observed change in different physical properties and glucose sensing capability of Chitosan-Silica nanoparticle composite membranes (CSNCM) with pore diameter variation. For a particular mixture percentage of chitosan and SiNp dust, successful fabrication of deformation free, free-standing membrane formation was possible. Silica nanoparticles of three different sizes (NP1 ~ 100 nm, NP2 ~ 300 nm & NP3 ~ 500 nm) were prepared to produce CSNCM of corresponding pore sizes (CM1, CM2 and CM3 respectively). Hot NaOH etching was performed to induce surface pore in CSNCM matrix by dissolving Silica nanoparticles from the top layer. We have found that pore distribution, surface morphology, optical properties and dielectric properties are very much dependent on pore size of the membranes. For glucose sensing characterization, we have focussed on multi-parametric optical sensitivity of the membranes in presence of glucose molecules and found that, though all three membranes show response in one or more parameters, only CM2 membranes hold the capability to perform as a multi-parametric sensor in our optical sensing arrangement. [ABSTRACT FROM AUTHOR]

A hyperbranched hybrid curing agent (CSD) for epoxidized novolac resin (ENR) was prepared by grafting silica nanoparticles modified with poly(amidoamine) (PAMAM) dendritic structure (SD) to carbon nanotube (CNT) using an esterification reaction between the amino functional groups of SD and carboxylic acid functionalities of oxidized CNT. ENR was prepared by a reaction between novolac resin and epichlorohydrin. Curing of ENR was carried out with two different contents of CSD as the hyperbranched hybrid curing component of the epoxidized matrix. The amino-rich structure of CSD could result in its high dispersion in the ENR matrix and consequently high thermal stability of the hybrid composites. Fourier-transform infrared spectroscopy and thermal gravimetric analysis (TGA) showed successful modification of silica nanoparticles and CNT with the PAMAM dendritic structure and SD, respectively. Structure of the resulting hybrid curing agents (SD and CSD) was investigated by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. Thermal investigation of the resulted composites by TGA showed that the cured ENR with higher content of CSD has high thermal properties with a char residue of 44.4% among the other hybrid composites. [ABSTRACT FROM AUTHOR]

Background: As the application of silica nanomaterials continues to expand, increasing chances of its exposure to the human body and potential harm are anticipated. Although the toxicity of silica nanomaterials is assumed to be affected by their physio-chemical properties, including size and surface functionalization, its molecular mechanisms remain unclear. We hypothesized that analysis of intracellular localization of the particles and subsequent intracellular signaling could reveal a novel determinant of inflammatory response against silica particles with different physico-chemical properties. Results: We employed a murine intratracheal instillation model of amorphous silica nanoparticles (NPs) exposure to compare their in vivo toxicities in the respiratory system. Pristine silica-NPs of 50 nm diameters (50 nm-plain) induced airway-centered lung injury with marked neutrophilic infiltration. By contrast, instillation of pristine silica particles of a larger diameter (3 μm; 3 μm-plain) significantly reduced the severity of lung injury and neutrophilic infiltration, possibly through attenuated induction of neutrophil chemotactic chemokines including MIP2. Ex vivo analysis of alveolar macrophages as well as in vitro assessment using RAW264.7 cells revealed a remarkably lower cellular uptake of 3 μm-plain particles compared with 50 nm-plain, which is assumed to be the underlying mechanism of attenuated immune response. The severity of lung injury and neutrophilic infiltration was also significantly reduced after intratracheal instillation of silica NPs with an amine surface modification (50 nm-NH2) when compared with 50 nm-plain. Despite unchanged efficacy in cellular uptake, treatment with 50 nm-NH2 induced a significantly attenuated immune response in RAW264.7 cells. Assessment of intracellular redox signaling revealed increased reactive oxygen species (ROS) in endosomal compartments of RAW264.7 cells treated with 50 nm-plain when compared with vehicle-treated control. In contrast, augmentation of endosomal ROS signals in cells treated with 50 nm-NH2 was significantly lower. Moreover, selective inhibition of NADPH oxidase 2 (NOX2) was sufficient to inhibit endosomal ROS bursts and induction of chemokine expressions in cells treated with silica NPs, suggesting the central role of endosomal ROS generated by NOX2 in the regulation of the inflammatory response in macrophages that endocytosed silica NPs. Conclusions: Our murine model suggested that the pulmonary toxicity of silica NPs depended on their physico-chemical properties through distinct mechanisms. Cellular uptake of larger particles by macrophages decreased, while surface amine modification modulated endosomal ROS signaling via NOX2, both of which are assumed to be involved in mitigating immune response in macrophages and resulting lung injury. [ABSTRACT FROM AUTHOR]

A high‐performance interdigitated electrode (IDE) biosensing surface was reported here by utilizing self‐assembled silica nanoparticle (SiNP). The modified surface was used to evaluate the complementation of hairpin forming region from Mitoxantrone resistance gene 7 (MXR7; liver cancer‐related short gene). The conjugated SiNPs on 3‐aminopropyl triethoxysilane functionalization were captured with probe sequence on IDE biosensing surface. The physical and chemically modified surface was used to quantify MXR7 and an increment in the current response upon complementation was noticed. Limit of target DNA detection was calculated (1–10 fM) and this label‐free detection is at the comparable level to the fluorescent‐based sensing. A linear regression was calculated [y = 0.243x − 0.0773; R² = 0.9336] and the sensitivity was 1 fM on the linear range of 1 fM to 10 pM. With the strong attachment of capture DNA on IDE through SiNP, the surface clearly discriminates the specificity (complementary) versus nonspecificity (complete‐, single‐, and triple‐mismatched sequences). This detection strategy helps to determine liver cancer progression and the similar strategy can be followed for other gene sequence complementation. [ABSTRACT FROM AUTHOR]

Multidrug resistance (MDR) of chemotherapy is one of the significant concerns in cancer therapy. Here in our study, cisplatin (DDP) and oleanolic acid (OA) were co‐loaded in mesoporous silica nanoparticles (Nsi) to construct DDP/OA‐Nsi and solve the DDP‐resistance in lung cancer therapy. The cytotoxicity and apoptosis assays demonstrated that in DDP‐resistant A549/DDP cells, the cytotoxicity of DDP/OA‐Nsi was significantly higher than that of free DDP or DDP single delivery system (DDP‐Nsi). The intracellular drug accumulation study revealed that the intracellular DDP concentration in the DDP/OA‐Nsi group was also higher than that in free DDP and DDP‐Nsi groups. In the A549/DDP xenograft tumor model, DDP/OA‐Nsi showed the best anticancer effect. In summary, DDP/OA‐Nsi was a promising drug delivery system to solve MDR in lung cancer therapy. [ABSTRACT FROM AUTHOR]

Enhanced oil recovery (EOR) processes are applied to recover trapped or residual oil in the reservoir rocks after primary and secondary recovery methods. Changing the wettability of the rock from oil-wet to water-wet is named wettability alteration. It is an important factor for EOR. Due to their unique properties, nanoparticles have gained great attention for improving oil recovery. Despite the promising results, the main challenges of applying nanoparticles are related to the colloidal stability of the nanofluids in the harsh conditions of the reservoirs. In recent years, polymer-grafted nanoparticles have been considered as novel promising materials for EOR. The obtained results showed that adding a hydrophobic agent trimethoxy (propyl) silane on the surface of modified silica nanoparticles with polyethylene glycol methyl ether has an effective role in improving retention and wettability alteration, especially in the oil-wet substrate due to hydrophobic interaction. The modified silica nanoparticle by mixed polyethylene glycol methyl ether (Mn ~ 5000) and trimethoxy (propyl) silane showed a proper performance at a concentration of 1000 ppm and a salinity range of 2000–40,000 ppm. The obtained findings can help for a better understanding of the silica nanofluid modification with both hydrophilic and hydrophobic agents for the EOR application of near-wellbore. [ABSTRACT FROM AUTHOR]