Addition Of SiO2 Nanoparticles Research Articles

A Janus membrane with silica nanoparticles interlayer for treating coal mine water via membrane distillation

The use of membrane distillation (MD) technology to treat coal mine water content has great potential, and the Janus membrane is very resistant to scaling and wetting during MD. In this work, SiO2 nanoparticles were electrostatically adsorbed onto the surface of a polyvinylidene fluoride (PVDF) membrane, followed by the construction of a polyamide (PA) layer through interfacial polymerization (IP). The intermediate layer of SiO2 nanoparticles can promote the enrichment of amine monomers during the subsequent IP process as well as slow its entry into the organic phase to regulate the PA layer. The addition of SiO2 nanoparticles was increased from 0 to 0.10 %, and the thickness of the polyamide layer was also reduced from 225.1 nm to 102.3 nm. Compared with the original membrane vapor flux of 40.9 ± 1.0LMH, the modified membrane vapor flux slightly increased to 46.2 ± 0.9LMH, but excessive SiO2 nanoparticles blocked the membrane pore, resulting in a decrease in flux. MD experiments show that the Janus membrane is wettability and scaling resistance when passing through the salt solution containing sodium dodecyl sulfate (SDS) surfactant or simulated wastewater as feed. At the same time, the interface thermodynamics of the simulated wastewater and the membrane are calculated to understand the anti-scaling mechanism of the membrane, offering a theoretical foundation for the application of real mine water.

Effects of SiO2 Nanoparticles on Polyvinyl Alcohol/Carboxymethyl Cellulose Polymer Blend Films’ Structural, Wettability, Surface Roughness, and Optical Characteristics

The blend matrix composed of polyvinyl alcohol and carboxymethylcellulose (PVA/CMC) was prepared via the casting method. SiO2 nanoparticles were added as reinforcement in different amounts (SiO2 = 1, 2, 3, and 4 wt.%). The study utilized FTIR to examine the alterations in composition and the interplay between the blend matrix and the inclusion of SiO2. Also, for the first time, the surface roughness and surface wettability of the PVA/CMC blend matrix were investigated with the addition of SiO2 using measurements of contact angle and surface roughness parameters. The surface roughness and wettability of the blend matrix increased as the SiO2 content increased. In addition, the blend matrix optical features were determined by the UV–visible spectrophotometer. Based on the analysis using Tauc’s relation, it was found that the energy bandgap decreases from 5.52 to 5.17 eV (direct transition) and from 4.79 to 4.32 eV (indirect transition) for the PVA/CMC and PVA/CMC/4%SiO2 blend films, respectively. The refractive index increases from 2.009 to about 2.144 for the PVA/CMC and PVA/CMC/4%SiO2 blend films, respectively. Furthermore, optical conductivity and dielectric constants were improved for the PVA/CMC blend film after the addition of SiO2 nanoparticles.

Specific Heat Capacity of Solar Salt-Based Nanofluids: Molecular Dynamics Simulation and Experiment.

In this study, a nanofluid composed of molten solar salt (MSS) and 1.0% SiO2 nanoparticles by mass was created and analyzed using differential scanning calorimetry (DSC) to determine its specific heat capacity (SHC). The SHC of the nanofluid was found to be significantly higher than that of pure MSS. The average increase in SHC of the nanofluid with 1.0% SiO2 nanoparticles (NPs) loading was found to be 15.65% compared with pure MSS. The formation of nanostructures after doping with NPs may increase the SHC of molten salt (MS) nanofluids, according to certain published research that included experimental confirmation. Nevertheless, no thorough theoretical or computational studies have been conducted to verify the experimental findings related to MSS nanofluid. Molecular dynamics (MD) simulations were conducted in various simulation boxes for different cases to verify the experimental findings and investigate the mechanism behind the enhancement of SHC caused by the addition of SiO2 NPs in eutectic MSS. The simulations used pure MSS and mixtures containing NaNO3 nanostructures bonded with SiO2 NPs. The highest SHC increase of 25.03% was observed when the simulation box contained 13.71% NaNO3 nanostructures by weight. The incorporation of NaNO3 nanostructures increased the surface area and total surface energy, leading to a positive effect on the SHC of the MSS nanofluid. However, the decrease in the base molten salt's SHC had a slight negative impact on the overall SHC of the MS nanofluid.

Experimental investigation on SiO2 nano particle as additives on performance and emission parameters of diesel engine fueled with castor oil blends


 
 
 
 Introduction: Today, a lot of research work is carried out in the vegetable oil based fuels which are the blended renewable fuels derived from vegetable oils or the oxygenated fuels which could effect in reduced Carbonaceous emissions. This experimental study investigates the impact of Silicon dioxide (SiO2) nanoparticles as additives on the performance and emission parameters of a diesel engine running on castor oil blends.
 
 
 
 
 Materials and methods: Castor oil is a renewable source of biodiesel, but it has limitations such as lower calorific value and higher viscosity compared to conventional diesel. To overcome these limitations, SiO2 nanoparticles were synthesized and characterized. Tests were conducted on a single-cylinder diesel engine under various load conditions using different fuel blends.
 
 
 
 
 Results: Results shows that the addition of SiO2 nanoparticles improved the engine's performance by increasing brake thermal efficiency by 25% and reducing specific fuel consumption by 9%. Carbon monoxide emissions (CO) were decreased by 25%, Hydro Carbon emissions (HC) decreased by 52% with SiO2 nanoparticles while a marginal percentage of NOx was also observed.
 
 
 
 
 Conclusion: This study demonstrates the potential of SiO2 nanoparticles as additives in enhancing the performance and reducing emissions of diesel engines using castor oil blends, contributing to the development of sustainable transportation.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Experimental Study on SiO2 Nanoparticles-Assisted Alpha-Olefin Sulfonate Sodium (AOS) and Hydrolyzed Polyacrylamide (HPAM) Synergistically Enhanced Oil Recovery

The purpose of this study is to investigate the use of SiO2 nanoparticles in assisting with surfactants and polymers for tertiary oil recovery, with the aim of enhancing oil recovery. The article characterizes the performance of SiO2 nanoparticles, including particle size, dispersion stability, and zeta potential, evaluates the synergistic effects of nanoparticles with alpha-olefin sulfonate sodium (AOS) surfactants and hydrolyzed polyacrylamide (HPAM) on reducing interfacial tension and altering wettability, and conducts core flooding experiments in rock cores with varying permeabilities. The findings demonstrate that the particle size decreased from 191 nm to 125 nm upon the addition of SiO2 nanoparticles to AOS surfactant, but increased to 389 nm upon the addition of SiO2 nanoparticles to HPAM. The dispersibility experiment showed that the SiO2 nanoparticle solution did not precipitate over 10 days. After adding 0.05% SiO2 nanoparticles to AOS surfactant, the zeta potential was −40.2 mV, while adding 0.05% SiO2 nanoparticles to 0.1% HPAM resulted in a decrease in the zeta potential to −25.03. The addition of SiO2 nanoparticles to AOS surfactant further reduced the IFT value to 0.19 mN/m, altering the rock wettability from oil-wet to strongly water-wet, with the contact angle decreasing from 110° to 18°. In low-permeability rock core oil displacement experiments, the use of AOS surfactants and HPAM for enhanced oil recovery increased the recovery rate by 24.5% over water flooding. The recovery rate increased by 21.6% over water flooding in low-permeability rock core experiments after SiO2 nanoparticles were added and surfactants and polymers were utilized for oil displacement. This is because the nanoparticles blocked small pore throats, resulting in increased resistance and hindered free fluid flow. The main causes of this plugging are mutual interference and mechanical entrapment, which cause the pressure differential to rise quickly. In high-permeability rock core oil displacement experiments, the use of AOS surfactants and HPAM for oil recovery increased the recovery rate by 34.6% over water flooding. Additionally, the recovery rate increased by 39.4% over water flooding with the addition of SiO2 nanoparticles and the use of AOS surfactants and HPAM for oil displacement. Because SiO2 nanoparticles create wedge-shaped structures inside highly permeable rock cores, they create structural separation pressure, which drives crude oil forward and aids in diffusion. This results in a comparatively small increase in pressure differential. Simultaneously, the nanoparticles change the rock surfaces’ wettability, which lowers the amount of crude oil that adsorbs and improves oil recovery.

Porous MOFs-based self-assembled membrane with specific rebinding nanocages for selective recognition and separation at molecular level

We present the design and fabrication of high-performance molecularly imprinted membranes (MIMs) using a UiO-66@PDA framework with densely imprinted sites for the targeted adsorption of artemisinin (ATSN). UiO-66@PDA was synthesized by modifying polydopamine with metal-organic frame (MOF) that contain Zr(IV) ions. The unique UiO-66@PDA structure exhibits an excellent specific surface area and strong binding abilities towards ATSN due to the abundant phenolic, quinone, and amino functional groups. The addition of SiO2 nanoparticles further enhanced the stability of the hybrid membrane during the adsorption process, and the preparation of inorganic-organic hybrid membranes (k-SUPCP-IMs) involves the use of a click chemistry-based imprinted polymer that takes advantage of the heterogeneous structure of the material. This process highlights the importance of different building blocks and functional reactions in controlling the morphology and porosity of porous organic polymers. The results showed satisfactory rebinding ability (40.07 mg g−1) and superselective (βATMT/ATSN = 7.87, βDDTM/ATSN = 8.26, βATST/ATSN = 6.40). It was noteworthy that the unique electrostatic interaction between SiO2 and the imprinted molecules provides optimal conditions for the formation of high-affinity binding sites, thereinto, the creation of additional active sites played a critical role in improving the sensitivity of MIMs.

Investigating the effect of SiO2 nanoparticle addition and thickness of face-coverings on COVID-19 protection using molecular dynamics approach

This study investigates the penetration of coronavirus (COVID-19) and oxygen (O2) in different commercial face coverings like surgical and N-95 masks using a molecular dynamics approach. For this purpose, the effects of the thickness of the masks and the addition of SiO2 nanoparticles are studied. We could demonstrate quantitatively the advantages of N-95 masks over surgical masks for coronavirus protection. The temperature (T) in all the simulated structures converges to 300 K after 20 ns. By increasing the thickness and decreasing the concentration of the coronavirus, the stability of the coronavirus was reduced. For the surgical mask, the atomic ratio of O2 molecules that penetrated was 73 %, and for the N-95 mask, it was 78 %. With the increase in mask thickness from 15 nm to 1000 nm, the atomic ratio of O2 molecules in surgical masks decreased from 73 % to 67 %. Furthermore, the atomic ratio of the coronavirus in this mask decreased from 11 % to 5 %. The atomic ratio of O2 molecules decreased from 78 % to 71 % as thickness increased. Also, the atomic ratio of coronavirus decreased from 6 % to 3 % in the N-95 mask. For the surgical mask, with the increase of SiO2 from 1 % to 10 %, the atomic ratio of O2 increased from 78 % to 80 %. Also, the atomic ratio of the coronavirus remained constant with the addition of carrier particles. For the N-95 mask, with the increase of SiO2 from 1 % to 10 %, the atomic ratio of O2 increased from 83% to 85%. Additionally, the atomic ratio of the coronavirus increased from 9 % to 8 % by adding nanoparticles.

SiO2-Based Nanofluids for the Inhibition of Wax Precipitation in Production Pipelines.

Wax deposition in high-wax (waxy) crude oil has been an important challenge in the oil and gas industry due to the repercussions in flow assurance during oil extraction and transportation. However, the nanotechnology has emerged as a potential solution for the optimization of conventional wax removal and/or inhibition processes due to its exceptional performance in the alteration of wax morphology and co-crystallization behavior. In this sense, this study aims to study the performance of two commercial wax inhibitor treatments (WT1 and WT2) on the wax formation and crystallization due to the addition of SiO2 nanoparticles. Differential scanning calorimetry experiments and cold finger tests were carried out to study the effect of the WT on wax appearance temperature (WAT) and the wax inhibition efficiency (WIE) in a scenario with an initial temperature difference. In the first stage, the behavior of both WT in the inhibition of wax deposition was achieved, ranging in the concentration of the WT in the waxy crude (WC) oil from 5000 to 50,000 mg·L-1. Then, NanoWT was prepared by the addition of SiO2 nanoparticles on WT1 and WT2 for concentrations between 1000 and 500 mg·L-1, and the performance of the prepared NanoWT was studied at the best concentration of WIT in the absence of nanoparticles. Finally, the role of the nanofluid concentration in wax inhibition was accomplished for the best NanoWT. Selected NanoWT with nanoparticle dosage of 100 mg·L-1 added to WC oil at 5000 mg·L-1 displays reductions in WAT and WIE of 15.3 and 71.6 for NanoWT1 and -2.2 and 42.5% for NanoWT2. In flow loop experiments for the crude oil at temperatures above (30 °C) and below (16 °C), the WAT value indicates an increase of 8.3 times the pressure drops when the crude oil is flowing at a temperature below the WAT value. Therefore, when NanoWT1 is added to the crude oil, a reduction of 31.8% was found in the pressure drop in comparison with the scenario below the WAT value, ensuring the flow assurance in the pipeline in an unfavorable environment. Based on the pressure-drop method, a reduction greater than 5% in the wax deposit thickness confirms the wax deposition inhibitory character of the designed NanoWT.

Taguchi design and optimization of the PLA/PCL composite filament with plasticizer and compatibilizer additives for optimal 3D printing

Abstract3D printing (3DP) has brought endless possibilities to the manufacturing industry. Biodegradable high‐polymer materials such as polylactic acid (PLA) and polycaprolactone (PCL) have attracted widespread attention. However, to optimize printing performance, this study prepared six PLA/PCL composite materials with ratios of 4:6, 5:5, and 6:4, by adding Polyethylene Glycol 4000 (PEG 4000) as a plasticizer and nano silica as a reinforcing agent. Parameters that can affect printing quality, including formulation, printing temperature (150, 170, and 190°C), filling density (305, 40%, and 50%), and printing speed (20, 30, and 40 mm/s), were examined and optimized. The optimal factor level combination determined by Taguchi fractional factorial design were silica addition 0.6 g, PLA content 60 wt%, printing temperature 190°C, infill density 50%, and printing speed 20 mm/s. The obtained minimum error value was 0.338 mm. Analysis of variance revealed the statistical significance of PLA content and printing temperature. A general linear model was established for result prediction, showing a difference of 9.25% from the actual error values. SEM results indicated poor compatibility between PLA and PCL in the melt‐blended mixture, while the addition of SiO2 nanoparticles facilitated PCL and PLA crystallization. DSC analysis demonstrated that the incorporation of PLC and SiO2 led to an increase in crystallinity, with 5PLA/5PCL/SiO2 exhibiting the highest crystallinity at 51.4%. Tensile testing results showed that the addition of 50 wt% PCL to PLA significantly improved the fracture elongation of the PLA/PCL material with a 5:5 formulation, averaging about 4 times higher than that of pure PLA, while the tensile strength decreased by 1.5 times. This study not only expands the research on PLA/PCL blends but also provides process guidance for 3D printing of the materials.

Molecular dynamics investigation of thermo-physical properties of molten salt with nanoparticles for solar energy application

Molten salt is an important medium for thermal storage, which is widely used in concentrating solar power plants. The addition of nanomaterials becomes an effective way to overcome the unsatisfactory thermo-physical properties of pure molten salt. In the present study, molecular dynamics simulations are performed to investigate the influence of SiO2 nanoparticle on the thermo-physical properties of solar salt. Two kinds of models of solar salt nanofluids, i.e., different sizes of boxes with the same size of nanoparticles and the same size of boxes with different sizes of nanoparticles, at the mass fractions of nanoparticles of 1%, 2%, 3%, 4%, 5%, and 6% are built to analyze the size effects on the simulation results. The effects of SiO2 nanoparticles on the specific heat capacity, viscosity and thermal conductivity of the composited thermal energy storage (CTES) materials are studied extensively. The microscopic mechanism of the thermo-physical properties variation is revealed by calculating the mean square displacement (MSD), diffusion coefficient, Radial distribution function (RDF) and energy of systems. It is proved that the calculations of shear viscosity, specific heat capacity and MSD do not have size effect. An enhancement as large as 2.05% in the specific heat capacity of the CTES materials has been found with 2 wt% addition of nanoparticles. The presence of the compressed layer on the surface of the nanoparticles might be responsible for the enhancement of the specific heat capacity according to the calculation of RDF. It is also found that with the increase of mass fraction of nanoparticles, the viscosity of the CTES materials increases due to the enhancement of interaction between ions in the base fluid. Therefore, in order to avoid the negative effects caused by excessive viscosity of solar salt in thermal energy storage system, it is suggested to consider the appropriate amount of nanoparticles. The addition of SiO2 nanoparticles enhances the thermal conductivity of the CTES materials with the increase of mass fraction of nanoparticles. It is demonstrated that the enhancement of ion collision frequency in the base fluid is the main factor for the enhancement of thermal conductivity by the addition of SiO2 nanoparticles.

Effects of TiO2, CuO, and SiO2 nanoparticles addition on the microstructure and mechanical properties of Al-10 wt% Zn alloy

This paper presents the effects of adding TiO2, CuO, and SiO2 (1 wt%) nanoparticles on the microstructure and mechanical properties of Al-10 wt% Zn alloy. A set of composite alloys was produced by incorporating SiO2, CuO, and TiO2 nanoparticles to the Al-10 wt% Zn alloy. Optical microscope (OM), scanning electron microscope (SEM) fitted with an Energy Dispersive Spectroscope (EDS), and X-ray diffraction (XRD) were used to investigate the microstructure of these alloys. The mechanical properties of the composite solders were assessed using the Vickers hardness tests. After a solution heat treatment at 500 K for 2 h, samples were immediately aged at 373 to 473 K for 2 h, followed by water quenching at 300 K. The experimental data indicated that Al-10 wt% Zn-1wt% SiO2 samples had the highest hardness values among all investigated composite alloys. The calculated porosity percentages of the composite alloys revealed that the Al-10 wt% Zn-1 wt% SiO2 samples had the lowest percentage. This finding can be attributed to the fact that these samples demonstrated the highest hardness values. The hardness of all composite alloys decreased with increasing the aging temperature with anomalous behavior at 443 K, where they had abnormally high values. The observed differences in the mean crystallite size, lattice strain, and dislocation density of the composite alloys, calculated from XRD data with increasing aging temperature, are attributed to the precipitation in Al-Zn alloys. The calculated values of the stress exponent and activation energy of composite alloys may be associated with grain boundary diffusion (GBD) as the dominant operating mechanism.

Electrochemical Study of an ASTM A36 Steel with an Epoxy Coating Reinforced with SiO2 Nanoparticles.

The ASTM A36 structural steel was evaluated with the electrochemical techniques, Linear Polarization Resistance (LPR), Electrochemical Impedance Spectroscopy (EIS) and Electrochemical Noise (EN). The techniques were applied to the bare steel substrate, coated, and coated with the addition of SiO2 nanoparticles (NP). The applied coating was a commercial epoxy of two layers. Stöber method was used to obtain the NP and were characterized with X-Ray Diffraction. A coating improved was obtained in the first day of immersion, according to EIS results, that it shows higher impedance compared with the coating without NP. Moreover, with the RE it was possible to observe that the NP reinforced coating showed a better anticorrosive performance, having a localized and mixed corrosion morphology.

Fabrication and characterization of PVDF-CTFE/SiO2 electrospun nanofibrous membranes with micro and nano-rough structures for efficient oil-water separation

A crucial step in the purification and recycling of industrial waste oil is the separation and removal of trace water from emulsified oil. After optimizing the polymer content, solvent composition, and SiO2 nanoparticle addition amount of the spinning precursor solution, a Polyvinylidene fluoride-co-trifluoroethylene chloride (PVDF-CTFE)/SiO2 nanofibrous membrane with micro and nano-rough structure was prepared by electrospinning. Using scanning electron microscopy, a pore size analyzer, a contact angle tester, a single-fiber strength tester, and a gravity separation experiment, the influence of SiO2 addition on the morphology, pore size distribution, wettability, mechanical, and separation properties of the modified membranes was characterized. The results demonstrated that the water contact angle of the nanofibrous membrane was increased to 151.3° of superhydrophobic when SiO2 was added at a concentration of 2.5 wt%. The nanofibrous membranes exhibited outstanding separation performance (>99%) for water-in-oil mixtures and emulsions, as well as for various oil-water systems. Moreover, the PVDF-CTFE/SiO2 nanofibrous membranes exhibited superior multi-cycle performance and consistent chemical resistance. This research yielded a novel material and a straightforward method for fabricating superhydrophobic nanofibrous membranes, which demonstrated greater application potential in oil-water separation.

Elucidating the role of nanoparticles on photosynthetic biogas upgrading: Influence of biogas type, nanoparticle concentration and light source

Three different nanoparticles, namely Fe2O3, carbon coated zero valent iron (CACOI) and SiO2, were added to a mixed microalgae culture in order to improve photosynthetic biogas upgrading. Fe2O3 and CACOI nanoparticles at 10 mg/L supported higher CO2 consumptions compared to their respective controls. The addition of Fe2O3 nanoparticles at 70 mg/L resulted in a 38 % enhanced biomass productivity, and 20 % higher CO2 consumption but delayed exponential growth. The CACOI nanoparticles at 70 mg/L resulted in a shorter lag phase, enhanced CO2 consumption by 13 %, and carbohydrate content enhancement by 64 %, while the addition of SiO2 nanoparticles at this concentration induced an enhanced lipid and carbohydrates production by 47 % and 68 %, respectively. Interestingly, UV light exposure reduced the beneficial effects of nanoparticles, although CACOI nanoparticles still supported a shorter lag phase and higher carbohydrates production at 70 mg/L. In brief, CACOI nanoparticles hold an untapped potential to promote the metabolism of microalgae during photosynthetic biogas upgrading.

Facile preparation of superhydrophobic/superoleophilic diatomite porous ceramics for efficient oil-water separation

In this work, a superhydrophobic diatomite porous ceramic was successfully prepared via a straightforward impregnation and heat-treatment way using isobutylene-maleic anhydride copolymer and SiO2 nanoparticles (NPs) as co-modifier. Due to the removal of the hydroxyl group after 1 h heating at 573 K in a 5 % H2/Ar atmosphere, the amide group in the original isobutylene-maleic anhydride copolymer was transformed to imide group, endowing the porous ceramics with excellent hydrophobic property. Furthermore, the addition of SiO2 NPs which enhanced the surface roughness resulted in the superhydrophobic properties of the final products. The continuous oil-water separation test of as-prepared superhydrophobic diatomite porous ceramics exhibited an initial separation flux of over 205.5 kg·min−1·m−2 with a separation selectivity of over 93 % for various oil-water mixtures. Moreover, their oil-adsorption tests demonstrated an 1.6–57 times adsorption capacity as high as these of other traditional inorganic sorbent materials.

Addition of SiO2 to the operation of a polyimide cathode in a sodium battery

The effect of the addition of SiO2 nanoparticles on the properties of a polyimide cathode was explored by CV, XPS, and galvanostatic cycling methods. The capacity and average cycling potential of the cell increased in the presence of SiO2. By quantum chemical modeling, it was shown that SiO2 nanoparticles served as a framework for polyimide, which retained its fixed structure upon metalation with sodium.

Stability mechanism of SiO2/SDS dispersion for foam flooding in hydrocarbon reservoirs: experimental research and molecular simulation.

The dispersion of silica dioxide (SiO2)/sodium lauryl sulfate (SDS) has been widely used in hydrocarbon reservoirs, but its instability is still a problem in practical engineering applications. The dispersion morphology of SiO2 nanoparticles before and after modification was studied by TEM, and the thermal stability of different foam dispersions was evaluated by FoamScan. In this paper, the mechanism of foam stability was investigated by combining the measurement of interfacial energy of nanoparticles at the gas-liquid interface with dynamics simulation of molecular diffusion. The results showed that SiO2/SDS dispersions had good thermal stability due to the synergistic effect of SiO2 nanoparticles and SDS. The addition of SiO2 nanoparticles improved the interfacial energy and interfacial activity at the gas-liquid interface, meanwhile limited the movement of SDS molecules and water molecules, which was beneficial for foam stability. Notably, the addition of modified SiO2 nanoparticles further enhanced the interfacial energy at the gas-liquid interface and strengthened the restriction of water/SDS molecular movement, thereby slowing down the drainage and decay of the foam dispersions. The mechanism investigation of SiO2/SDS dispersions was of benefit to foam flooding in hydrocarbon reservoirs.

Friction and wear characteristics of chemically modified mahua (madhuca indica) oil based lubricant with SiO2 nanoparticles as additives

There is a tremendous increase in global warming due to the pollution enhanced by petroleum product utilization. Lubrication of the machinery parts is the main requirement for the industries, but conventional lubricants are having major problems related to their drainage. So, providing an eco-friendly oil and having better lubricity is a major task in recent research activities. This work performed tribological characteristics of epoxidized Madhuca indica oil while considering SiO2 nanoparticles as additives. According to the evaluation, the Madhuca indica oil contains more unsaturated fatty acids by means of Gas Chromatography-Mass Spectrometry (GC-MS). The unsaturated fatty acid in the oil was chemically improved by the epoxidation technique to make it more acceptable, and varying quantities of silicon dioxide (SiO2) were added. The thermo-physical properties of the material, such as kinematic viscosity, viscosity index, pour point, and flash point, as well as its tribological performance, were assessed. An optical microscope was utilized to examine the worn surfaces. The tribological characterization was carried out on a pin on disc wear testing machine. At 100 °C, nanoparticles addition to chemically treated oil results rise in kinematic viscosity of 1.2 wt percent. The addition of SiO2 nanoparticles resulted in a flash point rise, but the pour point decreased. The presence of SiO2 in the epoxidized oil improves the consistency of distribution. The addition of 0.8 wt%SiO2 nanoparticles reduced the coefficient of friction & wear rate. The improved surface wear was observed up to 0.8 wt% concentration of nanoparticles and the same has been verified by worn surface images.

Development of robust and high-performance polysilsesquioxane reverse osmosis membranes modified by SiO2 nanoparticles for water desalination

Robust and highly water permeable organically bridged polysilsesquioxane (PSQ) reverse osmosis (RO) membranes were prepared by introducing SiO2 nanoparticles into bis[3-(triethoxysilyl)propyl]amine (BTESPA)-based RO membrane by the sol–gel process. Nitrogen adsorption/desorption isotherm measurements revealed that BET surface areas are significantly increased by introduction of SiO2 nanoparticles. RO experiments using a 2000 ppm NaCl aqueous solution indicate that the addition of SiO2 nanoparticles improves membrane RO performance; water permeability was 1.2 × 10-12 m3/m2sPa and salt rejection was approximately 98%. It was also found that these membranes exhibited high thermal stability, i.e., after heat treatment at 95 ℃ for 180 min, the membranes showed a salt rejection decrease of less than 2.5%. In addition, the membranes manifested favorable resistance to chlorine exposure, namely, salt rejection decrease was less than 2% after 10,000 ppm⋅h NaOCl exposure.

Radiation stability of optical properties of Wollastonite powder with SiO2 nanoparticle addition

We studied the phase composition, diffuse reflectance spectra (ρλ), and integral absorption coefficient (аs) and their variations after a 30 keV electron irradiation of wollastonite powder with added silicon dioxide nanoparticles.It was found that after heating and nanoparticle addition, the reflectivity of wollastonite decreases in the UV and visible ranges, and increases in the near-IR range. The addition of 0.5 and 1 wt% SiO2 nanoparticles increases the radiation stability of the wollastonite powder by 255 and 233%, respectively.Such nanoparticle-micro powder systems can be used in high-performance spacecraft thermal control coatings and other applications where optical properties should be resistant to radiation.