Concentration Of Silica Nanoparticles Research Articles

Vibration-triggered spreading of nanofluid drops

This study explores the effects of nanoparticles on the dynamics of drop spreading under external vibration, presenting an advance in the understanding of nanofluid behavior on vibrating substrates. This work introduces insights into nanoparticle-mediated drop spreading, offering implications for improving particulate coatings, mini-mixers, and particle segregation technologies. By employing a twofold approach that combines oscillating drop dynamics with internal flow pattern analysis, we find how even small concentrations of hydrophilic or hydrophobized silica nanoparticles inside water sessile droplets significantly alter the spreading process on silanized glass surfaces. Our study allows distinct drop spreading regimes to be identified based on nanoparticle concentration and vibration amplitude, for both hydrophilic and hydrophobized nanoparticles. Through a comprehensive analysis, we demonstrate that the vibration-triggered spreading of nanofluids can lead to a stable and controlled manipulation of complex liquids.

Double networks hybrid hydrogels of silica nanoparticles/polyacrylamide: Network stiffness, viscoelastic, mechanical and adhesion properties

Today, the challenge of enhancing the strength and adhesion of the polyacrylamide hydrogel network is still a major concern in many applications. This study investigates the effect of silica nanoparticle concentration on the cross-linked polyacrylamide hydrogel’s gelation, viscoelastic, structural, and adhesion properties. The hybrid hydrogels were evaluated using DSC, XRD, SEM, and rheological analysis to determine their enthalpy of cross-linking, crystallinity, morphology, and elastic properties. The results of kinetic analysis confirmed the catalytic effect of silica nanoparticles on the gelation kinetics. A deviation from the elastic behavior of the unfilled hydrogel was found from the rheological studies. Using the Weibull Model to describe the creep test results showed a significant increase in retardation time with increasing silica nanoparticles content up to the percolation threshold of 0.24 wt.%. This confirmed the development of a more viscous behavior due to the formation of a physical network of nano-silica particles. Based on the DSC energy of hydrogels, both chemical and physical tie points (approximately 19 covalent crosslinking points) were calculated. The hydrogel containing 9 wt.% of silica nanoparticles demonstrated significant improvement in density, and adhesion to the metal surface by about 100% and 350%, respectively. As a result of this study, the hydrogel containing 9 wt% of silica nanoparticles (H9) is suggested for various field studies, such as oil well plugging industries.

High-Throughput Silica Nanoparticle Detection for Quality Control of Complex Early Life Nutrition Food Matrices.

The addition of nanomaterials to improve product properties has become a matter of course for many commodities: e.g., detergents, cosmetics, and food products. While this practice improves product characteristics, the increasing exposure and potential impact of nanomaterials (<100 nm) raise concerns regarding both the human body and the environment. Special attention should be taken for vulnerable individuals such as those who are ill, elder, or newborns. But detecting and quantifying nanoparticles in complex food matrices like early life nutrition (ELN) poses a significant challenge due to the presence of additional particles, emulsion-droplets, or micelles. There is a pressing demand for standardized protocols for nanoparticle quantification and the specification of "nanoparticle-free" formulations. To address this, silica nanoparticles (SiNPs), commonly used as anticaking agents (AA) in processed food, were employed as a model system to establish characterization methods with different levels of accuracy and sensitivity versus speed, sample handling, and automatization. Different acid treatments were applied for sample digestion, followed by size exclusion chromatography. Morphology, size, and number of NPs were measured by transmission electron microscopy, and the amount of Si was determined by microwave plasma atomic emission spectrometry. This successfully enabled distinguishing SiNP content in ELN food formulations with 2-4% AA from AA-free formulations and sorting SiNPs with diameters of 20, 50, and 80 nm. Moreover, the study revealed the significant influence of the ELN matrix on sample preparation, separation, and characterization steps, necessitating method adaptations compared to the reference (SiNP in water). In the future, we expect these methods to be implemented in standard quality control of formulation processes, which demand high-throughput analysis and automated evaluation.

An Unprecedented Metal Distribution in Silica Nanoparticles Determined by Single-Particle Inductively Coupled Plasma Mass Spectrometry.

Metal-containing nanoparticles are now common in applications ranging from catalysts to biomarkers. However, little research has focused on per-particle metal content in multicomponent nanoparticles. In this work, we used single-particle inductively coupled plasma mass spectrometry (ICP-MS) to determine the per-particle metal content of silica nanoparticles doped with tris(2,2'-bipyridyl)ruthenium(II). Monodispersed silica nanoparticles with varied Ru doping levels were prepared using a water-in-oil microemulsion method. These nanoparticles were characterized using common bulk-sample methods such as absorbance spectroscopy and conventional ICP-MS, and also with single-particle ICP-MS. The results showed that averaged concentrations of metal dopant measured per-particle by single-particle ICP-MS were consistent with the bulk-sample methods over a wide range of dopant levels. However, the per-particle amount of metal varied greatly and did not adhere to the usual Gaussian distribution encountered with one-component nanoparticles, such as gold or silver. Instead, the amount of metal dopant per silica particle showed an unexpected geometric distribution regardless of the prepared doping levels. The results indicate that an unusual metal dispersal mechanism is taking place during the microemulsion synthesis, and they challenge a common assumption that doped silica nanoparticles have the same metal content as the average measured by bulk-sample methods.

Thermo-rheological improvement of magnetorheological foam with the addition of silica nanoparticles

Magnetorheological (MR) foam has become a potential soft robotic gripper-based material that can provide a better grasping force and handling objects due to its ability in varying stiffness in correspond to applied magnetic fields. However, MR foams are facing degradation issue that may reduce the storage modulus when often exposed to thermal exposure from the operating system of a device. Therefore, this study focuses on improving the storage modulus and simultaneously enhancing the thermal properties of MR foam. Hence, silica nanoparticles were introduced as an additive to achieve the improvement target. MR foams were embedded with different concentrations of silica nanoparticles from 0 to 5 wt.%, and the corresponding rheological properties was examined under different temperature conditions from 25 °C to 65 °C. The results revealed that increasing temperatures have reduced the storage modulus of MR foams, however, the embedded silica has countered the drawbacks by strengthening the interfacial interactions between CIP-polyurethane foam matrix. In addition, the morphological characteristics of MR foams also showed less debris or peel-off PU foam with silica nanoparticles. Besides, the silica nanoparticles have delayed the thermal degradation of MR foam for approximately 30 °C.

Effects of silica nanoparticles on morpho-histological and antioxidant activities of rice seedlings under drought stress

Drought has a direct impact on rice growth performance at various stages. Nevertheless, the impact of nanoparticles on the rice seedlings under drought stress remained limited. Thus, a laboratory experiment was conducted to investigate the effects of different concentrations (300, 600, and 900 mg/L) of silica nanoparticles (SiNPs) on morpho-histological and biochemical features of two rice varieties (UMT-R and MR219) under drought stress (15 % PEG). The findings indicated a substantial reduction due to drought stress in the growth, protein, and antioxidant enzymes, while increasing the proline, malondialdehyde (MDA), and hydrogen peroxide (H2O2) content, and negatively affecting the root histology. Results showed that SiNPs at 600 mg/L were managed to improve plant growth, root vigour, and enzymatic antioxidant levels. Under SiNPs treated plants, among UMT-R and MR219, the proline (1.947 and 1.748 in leaves, 2.010 and 1.890 U/mg protein in roots), peroxidase (POD) (2.850 and 3.512 in leaves, 2.521 and 2.952 U/mg protein in roots), superoxide dismutase (SOD) (3.958 and 4.558 in leaves, 4.296 and 4.606 U/mg protein in roots), and catalase (CAT) (2.171 and 2.289 in leaves, 1.897 and 2.050 U/mg protein in roots) were higher than the drought stress conditions. Meanwhile, the nonenzymatic antioxidant, MDA (0.974 and 0.812 in leaves, 0.842 and 0.778 U/mg Protein in roots), and H2O2 (1.378 and 1.229 in leaves, 1.280 and 1.054 U/mg Protein in roots) showed an opposite trend. SiNPs application noticeably enhanced the histological features of roots under drought conditions. The current findings suggested that SiNPs at 600 mg/L can mitigate the adverse impacts of drought stress and enhance the plant's resistance. Further study should be carried out on the reproductive stage and post-harvest performance of drought-stress rice treated with SiNPs.

Fertigation of NaCl-stressed lentil and soybean plants with silica nanoparticles improves seed yield and nutritional attributes

Lentil (Lens culinaris) and soybean (Glycine max) are proteinaceous legumes susceptible to salinity stress. This study aimed to evaluate the fertigating potential of silica nanoparticles (SiNPs) in improving the physiochemical status, yield parameters, and seed nutritional qualities of the legumes exposed to salinity stress. Characterization of the synthesized SiNPs revealed amorphous, round-shaped particles, a size of 15–40 nm, and a surface charge of −6.18 mV. Different concentrations of SiNPs (0, 1, 5, 10 g/L) were applied to the plants in combination with four different concentrations of NaCl (0, 200, 400, 600 mM) during the reproductive phase of plants. The results indicated that the SiNPs (especially 10 g/L) efficiently reduced the negative impacts of salinity by improving the physiochemical parameters (growth, pigments, primary metabolites, antioxidant enzymes). Similarly, the improvement in yield parameters (pods per plant, pod length, seeds/10 pods, etc.) and seed nutritional attributes (protein, sugar, free amino acids, free fatty acid, polyphenol contents, etc.) were observed irrespective of the NaCl concentrations. Specifically, applying 10 g/L SiNPs enhanced the total pod numbers by 1.70, and 1.57 folds; and the total number of seeds/10 pods by 1.44, and 1.65 in lentil and soybean plants, respectively, compared to the control set (600 mM NaCl). Moreover, the seed protein content was augmented by 3.29, and 1.30 folds compared to the 600 mM NaCl stressed plants (lentil and soybean, respectively) when treated with 10 g/L SiNPs. Therefore, it can be concluded that SiNPs can be used sustainably to improve yield and nutritional attributes under stressed conditions.

Effect of Silica Nanoparticles On Flexural Strength And Surface Hardness Of Heat Polymerized Acrylic Resin.

Statement of problem. Various studies are present to increase the strength and surface hardness of heat polymerized acrylic resin by addition of material or surface treatments. The present study to evaluate an effect of silica nanoparticles on flexural strength and surface hardness of heat polymerized acrylic resin. Purpose. The purpose of this study was effect of silica nanoparticles, incorporated into Polymethyl Methacrylate, on flexural strength and surface hardness. The present study compared the effect of silanated and non silanated silica nanoparticles on the flexural strength and surface hardness of heat polymerized acrylic resin. Material and Methods. A total of 270 acrylic bars were fabricated, in two batches of 135 each, for testing flexural strength by universal testing machine and surface hardness determined using a digital micro Vickers hardness tester. The control group and subgroups had a sample size of 15 each with varied concentrations of nanoparticles by weight. The fabricated samples were tested for flexural strength and surface hardness. Results. Flexural strength was highest for PMMA (Polymethyl methacrylate) with 0.5% silanated silica nano particles as fillers. In both the groups, the flexural strength decreased with increase in filler concentration. Surface hardness was highest in the PMMA group with non-silanated nano particles as fillers at 5% concentration. In both groups the surface hardness improved with an increase in filler concentration. ANOVA and TUKEY’s HSD test were used. P&lt;0.05 was considered statistically significant. Conclusion. Lower concentrations of surface-treated silica nanoparticles should be used as fillers to enhance the flexural strength of commercially available heat polymerized acrylic resin. Bangladesh Journal of Medical Science Vol.23 (Special Issue) 2024 p.S79-S86

Efficient removal of methylene blue dye from wastewater specimen using polystyrene coated nanoparticles of silica

Utilization of suitable methodologies for recovery of wastewater and its reuse in various applications is highly stimulated. In agreement with this objective, the current research study presents new adsorbents, composed of silica nanoparticles coated by a polystyrene shell, for use in the purification of wastewater from methylene blue (MB) dye, as a contaminant. Firstly, silica nanoparticles were prepared and covered by a layer of Polystyrene made via the high internal phase emulation (HIPE) polymerization technique. Three composite structures having different contents of silica nanoparticles (by weight %) were designated as adsorbents in this research work. The chemical and structural properties of these adsorbents were verified by X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy while their textural characteristics were acquired by scanning electron microscopy (SEM) and N2 adsorption-desorption surface area analysis. The efficiencies of these adsorbents toward disposal of MB dye from wastewater were next investigated at different operating parameters. The introduced composites of polystyrene@silica nanoparticles revealed promising capacities toward adsorption of MB dye which came up to a maximum of 23.1 mg g−1. The observed removals of MB dye by these composites during the process of water purification are attributed to the presence of both organic and inorganic functional groups within their structures. Thus, various adsorption mechanisms could take place through the elimination of MB particles from the effluent water during the treatment process. Kinetic and isotherm studies for the adsorption of MB species were found to fit the models of pseudo-second-order and Langmuir respectively. Furthermore, the thermodynamics of MB adsorption could indicate the nature of such process as feasible, spontaneous, physisorption, and exothermic.

Electrical characteristics of different concentration of silica nanoparticles embedded in epoxy resin

In this study, modified epoxy nanocomposite was produced by incorporating SiO2 nanoparticles of 15–30 nm in size, with different concentrations ranging from 1 to 20 wt%. The electrical properties of the epoxy nanocomposite were measured at room temperature in the frequency range of 10−2–107 Hz. To determine the impact of nanoparticles on the epoxy composition, scanning electron microscopy-energy dispersive x-ray spectroscopy (SEM-EDS), Fourier transform infrared spectra (FTIR) spectroscopy, and Raman spectroscopy were conducted. With an increase in filler (SiO2 nanoparticles) content, the electrical characteristics of the epoxy nanocomposite exhibited multiple changes. At low concentrations, all electrical properties experienced a notable increase. The epoxy with 15 wt% of SiO2 nanoparticles samples had a lower permittivity, loss number, conductivity, and capacitance than the unfilled epoxy. At medium concentrations (5 to 15 wt%), the formation of immobilized nanolayers has an impact on permittivity, loss number, conductivity, and capacitance, which have decreased; impedance and modulus increased. The initiation of contact between the nanofillers at a concentration of 20 wt% leads to the formation of continuous interfacial conductive pathways, resulting in a dramatic increase in the permittivity, conductivity, and capacitance of the composites, while concurrently reducing impedance.

Performance evaluation of surface-modified silica nanoparticles for enhanced oil recovery in carbonate reservoirs

The purpose was to prepare a (3-glycidoxypropyl)-trimethoxysilane (GPTMS)-SiO2 nanofluid and analyze the effect of nanofluid injection on carbonate reservoirs. GPTMS-modified silica nanoparticles (SNPs) were investigated by Fourier transform infrared spectroscopy (FTIR) and elemental analysis. FTIR spectra of C-H stretching vibrations at 2950 cm−1, indicating silica surface modification with GPTMS, were observed when the GPTMS in the feed was greater than 0.7 mmol/g. Further, a stable nanofluid was obtained when the amount of grafted silane was close to 0.73 mmol/g, the theoretical maximum amount of grafted silanes. To evaluate the performance of surface-modified SNPs for enhanced oil recovery in carbonate reservoirs, wettability alteration tests comprising flotation test and contact angle measurements using powder and plug samples of carbonates, respectively, were performed with different SNP concentrations. Powder samples were successfully changed from oil-wet to water-wet, and the contact angle of the plug sample decreased by up to 62.8% as a result of the reaction of the nanofluid; however, it did not reduce interfacial tension (IFT) as effectively as IFT reducer additives. A coreflooding test was conducted to determine the effective parameters of the enhanced oil recovery with the GPTMS-nanofluid, such as SNP concentration, injection rate, and rock properties. The nanofluid injection increased oil recovery by approximately 20% compared to conventional waterflooding through incremental oil recovery, mainly attributed to wettability alteration. Therefore, we expect the nanofluid to dramatically increase the oil recovery in strongly oil-wet carbonate reservoirs under high-salinity conditions.

The amount of improvement and therapeutic effect of sports health by increasing the viscosity of peach juice through reverse osmosis and polymer membrane

In this study, the performance of polyamide membranes embedded with synthesized silica nanoparticles was evaluated for pomegranate juice concentration using the reverse osmosis (RO) process. The research aims to explore the potential therapeutic benefits and measurable improvements in sports health achieved by employing RO and a polymer membrane to enhance the viscosity of peach juice. The membranes utilized in this study feature a multi-layer structure comprising a non-woven polyester layer for strength, a sulfone polyether polymer sheet, and a polyamide layer synthesized through the copolymerization of m-phenylenediamine and benzene tricarboxylic chloride. To enhance the membrane properties, silica nanoparticles were incorporated into the second layer. The experiment was designed using Design Expert software, considering three parameters: weight percentage of polyether sulfone at three levels (12%, 16%, and 20%), weight percentage of silica nanoparticles at three levels (0%, 0.1%, and 0.2%), and the process pressure at three levels (20, 25, and 30 bar). The optimal membrane configuration obtained from this experimental design consisted of a sulfone polyether polymer content of 16%, silica nanoparticles concentration of 2%, and a working pressure of 23.24 bar. Furthermore, the findings of this study suggest that the application of polymer materials and nanoparticles for membrane modification holds potential benefits for the juice industry in the future. However, it is essential to consider the wide range of factors that can influence the properties of nanocomposite membranes.

Asymmetry-Enhanced Motion of Urease-Powered Micromotors from Double Emulsion-Templated Microcapsules.

Autonomous motion of enzyme-powered motors has important implications for drug delivery, cell-cell communication, and protocell engineering. Although many of these systems are inspired by the motion of biological cells, most of them lack key structural features, like micrometer-sized boundaries and aqueous compartments, and rely on bubble propulsion to generation motion. In this study, we use droplet microfluidics to generate large populations of cell-sized microcapsules with poly(lactic-co-glycolic acid) shells and functionalize their surfaces with the enzyme urease to drive their motion. We adjust the number of surface functional groups for urease conjugation by preparing microcapsules with two different surfactants, poly(vinyl alcohol) (PVA) and poly(ethylene-alt-maleic anhydride) (PEMA). We also tune the surface roughness of the microcapsules by varying the concentration of silica nanoparticles in the droplet middle phase. We find that PEMA plays a crucial role in increasing the grafting density of urease on the surface of smooth microcapsules, leading to active motion in the presence of urea. In addition, rough microcapsules prepared with PEMA and loaded with comparable amounts of urease move up to three times faster than their smooth counterparts, which we believe is due to an asymmetric distribution of urease on the surface, giving rise to a preferred direction of motion. Taken together, these results provide new insights into the role that various stabilizing agents play in the induction of motion by enzymatic motors prepared from microfluidics, which is a potentially powerful tool for future preparation of motile protocells in biomedicine.

Cellophane packaging treated with nano silica is superior to polyethylene in reducing stored irradiated flour from Tribolium confusum infestation

Most packaged food products are attacked and penetrated by insects. Causing reducing food quality. Since, different ways are investigated for controlling stored-product pests without application of chemical methods. So, the present study included laboratory methods to evaluate the effectiveness of two packaging materials, polyethylene and cellophane with silica nano particles to prevent or minimize the insect infestation and grain wastage resulting by the attack of wheat grain by confused flour beetle, Tribolium confusum. Studies made to determine the protecting capacity of the two packaging materials through assessing some parameters, number of adults infested poly ethelene and cellophane bags, percentage weight loss of grains, the results revealed that cellophane was the better packaging material than polyethelene, so polyethylene was the susceptible packaging material because it had maximum number of holes as a result penetrations by insects into them. Also, treatment the two types with packaging materials with different concentrations of nano silica protect the treated packaging materials from insect infestation and the protection increase with the increase of the concentration of silica nano particles

Synergistic effects between anionic surfactant SDS and hydrophilic silica nanoparticles in improving foam performance for foam flooding

In foam flooding, foams stabilized by conventional anionic surfactants are usually raptured in contacting with crude oil, which behaves as a strong defoamer. In this article the synergistic effects between anionic surfactant SDS and negatively charged hydrophilic silica nanoparticles in stabilization of aqueous foams were examined. The results show that in either deionized (DI) water at 25 °C or Daqing simulated connate (SC) water with a total salinity of 6,778 mg/L at 45 °C, in absence of oil adding low concentration of silica nanoparticles into the SDS aqueous solutions can improve the foam performance of SDS mainly by increasing foam stability, as indicated by a synergistic effect index Se(d/s) (ratio of the composite foaming index of dispersion to that of solution) of 2.7 to 2.8. In presence of oil the foam performance of SDS in SC water at 45 °C can still be improved as indicated by an increased Se(d/s) of 3.7, but the maximum composite forming index is catastrophically reduced from 3222 Ls in absence of oil to 470 Ls in presence of oil. As similarly charged nanoparticles the silica nanoparticles do not adsorb at gas/liquid or oil/water interface to stabilize Pickering foams or Pickering emulsions but can improve emulsification of the oil, and the emulsified oil droplets together with the silica nanoparticles distribute in aqueous lamellae enhancing liquid viscosity and slowing down the liquid drainage in the foams. However, this effect weakens at high surfactant concentration, and addition of silica nanoparticles does not significantly reduce the interfacial tensions involved. The Enter (E), Spreading (S) and Bridging (B) coefficients of the oil in the foam systems are therefore still positive. The defoaming action of the oil in this system is not eliminated by only partially inhibited by addition of silica nanoparticles.

Combined toxicity of fluorescent silica nanoparticles with cadmium in Ceriodaphnia dubia: Interactive effects of natural organic matter and green algae feeding

The environmental risks of silica nanoparticles (SiNP) reported in the literature are contradictory and bring into question its safety for use in consumer applications. Organisms are never exposed to NPs alone in the real environment, while studies of the combined toxicity of SiNP are limited. To address this, we compared the acute toxicity of fluorescent core-shell SiNPs alone and in mixtures with Cd2+ to Ceriodaphnia dubia in the absence and presence of NOM. We identified biodistribution and feeding behaviour in addition to the traditional endpoints. NOM increased the colloidal stability of SiNPs in reconstituted water. In immobility tests, no significant effects were observed from Cd2+ exposure with NOM and varying concentrations of SiNPs. A similar pattern of curve dose-response was observed for varying concentrations of SiNPs and increasing Cd2+ concentration and constant NOM. Fluorescence microscopy verified a dose-dependent bioaccumulation of SiNPs in C. dubia. Co-exposure to 10 mg L−1 SiNP with NOM and Cd2+ resulted in a stimulated stress feeding response at the lower Cd2+ concentrations which declined at the higher dose due to a functional impairment of the digestive tract. Alterations in feeding behaviour and the increasing bioaccumulation of SiNP indicate a potential ecological risk for Ceriodaphnia dubia from the mixture exposure.

Smart Emulsions Stabilized by a Multi-headgroup Surfactant Tolerant to High Concentrations of Acids and Salts.

Retaining emulsions stable at high acidity and salinity is still a great challenge. Here, we report a novel multi-headgroup surfactant (C3 H7 -NH+ (C10 COOH)2 , di-UAPAc) which can be reversibly transformed among cationic, anionic and zwitterionic forms upon pH variation. Stable oil-in-dispersion (OID) emulsions in strong acidity (pH=2) can be co-stabilized by low concentrations of di-UAPAc and silica nanoparticles. High salinity at pH=2 improves the adsorption of di-UAPAc on silica particles through hydrogen bonding, resulting in the transformation of OID emulsions into Pickering emulsions. Moreover, emulsification/demulsification and interconversion between OID and Pickering emulsions together with control of the viscosity and droplet size can be triggered by pH. The present work provides a new protocol for designing surfactants for various applications in harsh aqueous media, such as strong acidity and high salinity, involved in oil recovery and sewerage treatments.

Preparation of ethanol-gels as hand sanitizers formed from chitosan and silica nanoparticles

The application of chitosan as a gelling agent in hydro-alcoholic hand sanitizers has rarely been studied due to its insolubility in ethanol. In this study, high-ethanol-content gels were prepared with chitosan in combination with silica nanoparticles. The properties of the gels were investigated by FTIR, XRD, SEM, rheological measurement and the zone of inhibition test against bacteria. The results showed that the adsorption of silica nanoparticles on the chitosan inhibited the precipitation of chitosan in ethanol. The chitosan/silica fibres entangled with each other, and gelation occurred in the solvent with high ethanol concentration due to the solvent-driven effect. The gelation process was related to the concentrations of ethanol, chitosan, and silica nanoparticles. A stable gel could be formed at a chitosan concentration as low as 0.5%, with an ethanol concentration up to 80%. All the gels exhibited pseudoplastic behaviour and had frequency-dependent profiles in the viscoelastic spectrum of non-Newtonian liquids, behaving in a solid-like manner. The limited linear viscoelastic region of all samples was<1%. The optimal silica concentrations (OSCs) for various chitosan concentrations in 75% ethanol were proposed by rheological analysis as a reference to optimize the sensory and textural properties of gels. These gels showed antibacterial activity, which introduced a potential application as hand sanitizers. This research provides a method of preparing novel high-ethanol-content gels, highlights the application of solvent-driven effects in gelation, and identified some suggestions for future research.

Silica nanoparticles induce pulmonary damage in rats via VEGFC/D–VEGFR3 signaling-mediated lymphangiogenesis and remodeling

Silica nanoparticles (SiNPs) are widely used as drug carriers for improving drug delivery and retention. The lungs are highly sensitive to the toxicity of SiNPs entering the respiratory tract. Furthermore, pulmonary lymphangiogenesis, which is the growth of lymphatic vessels observed during multiple pulmonary diseases, plays a vital role in promoting the lymphatic transport of silica in the lungs. However, more research is required on the effects of SiNPs on pulmonary lymphangiogenesis. We investigated the effect of SiNP-induced pulmonary toxicity on lymphatic vessel formation in rats and evaluated the toxicity and possible molecular mechanisms of 20-nm SiNPs. Saline containing 3.0, 6.0, and 12.0 mg/kg of SiNPs was instilled intrathecally into female Wistar rats once a day for five days, then sacrificed on day seven. Lung histopathology, pulmonary permeability, pulmonary lymphatic vessel density changes, and the ultrastructure of the lymph trunk were investigated using light microscopy, spectrophotometry, immunofluorescence, and transmission electron microscopy. CD45 expression in lung tissues was determined using immunohistochemical staining, and protein expression in the lung and lymph trunk was quantified using western blotting. We observed increased pulmonary inflammation and permeability, lymphatic endothelial cell damage, pulmonary lymphangiogenesis, and remodeling with increasing SiNP concentration. Moreover, SiNPs activated the VEGFC/D–VEGFR3 signaling pathway in the lung and lymphatic vessel tissues. SiNPs caused pulmonary damage, increased permeability and resulted in inflammation-associated lymphangiogenesis and remodeling by activating VEGFC/D–VEGFR3 signaling. Our findings provide evidence for SiNP-induced pulmonary damage and a new perspective for the prevention and treatment of occupational exposure to SiNPs.

Determination of mechanical properties of nanocomposites reinforced with spherical silica nanoparticles using experiments, micromechanical model and finite elements method

In this research, experimental, numerical, and micromechanical methods are used to determine the effects of silica nanoparticle content on the elastic modulus of polymer matrix nanocomposites in tension and compression. The direct mixing method was used to prepare experimental samples containing 0.1, 0.25, and 0.5 volume fractions of silica nanoparticles. The elastic modulus of the nanocomposites is evaluated by the Einstein, Guth, Mori-Tanaka, Halpin-Tsai, Kerner, and Ji et al. micromechanical models. In addition, the elastic modulus of the nanocomposites is evaluated using the RVE method in ABAQUS software. The effects of volume fraction and diameter of silica nanoparticles, thickness, and adhesion exponent of the interphase on the elastic modulus of polymeric nanocomposite are extensively examined. Stiffer elastic modulus behavior is found in the presence of interphase region. The results indicate that the elastic modulus of nanocomposites reinforced with spherical silica nanoparticles is improved with increasing nanoparticle volume fraction, decreasing the nanoparticle diameter, increasing the interphase thickness, and decreasing the interphase adhesion exponent. The validity of the results of numerical and micromechanical models has been checked with experimental results. It can be seen that the results obtained from the experiments with 1 hour of ultrasonic waves in the tensile samples with volume fractions of 0.1, 0.25, and 0.5, compared to the pure sample, have increased by 5.4, 10.3, and 9.7 percent, respectively. Similarly, for compression samples with the same volume fractions, the results have increased by 7, 13, and 11 percent, respectively.