Concentration Of Silica Nanoparticles Research Articles

Synthesis of novel biodegradable silica nanoparticles to improve performance and reduce the emission of CRDI engine fueled with hydrogen-enriched biodiesel blend

Currently, energy poses the most formidable problem globally. Biodiesel has emerged as a viable option for in-depth investigation due to its renewable nature, biodegradability, and reduced emissions. Biodiesel offers potential threats, including low combustion efficiency and high viscosity, which can be managed by enriching hydrogen and fuel additives. Using biocompatible nanoparticles can significantly mitigate the detrimental outcome of metal-enriched nanoparticles on living species. The current study synthesized novel biodegradable silica nanoparticles using waste incense stick ash using a calcination process. The silica nanoparticles were examined using several approaches such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscope (SEM), X-ray diffraction (XRD), and energy dispersive X-ray (EDX). The EDX analysis confirms the synthesized nanoparticles contain silicon (41.91%), oxygen (70.23%), and a small percentage of other elements like potassium (0.43%) and calcium (0.23%). The various concentrations (50, 75, 100, 125, and 150 ppm) of silica nanoparticles were dispersed into B20 (diesel with 20% biodiesel) using a probe sonicator. Hydrogen is supplied to the engine cylinder through the intake manifold, maintaining a constant flow rate of 10 lpm. The finding indicated that the brake thermal efficiency (BTE) improves by 15.58% for hydrogen-enriched B20 fuel blend and 100 ppm nanoparticles (B20HN100). The B20HN100 fuel sample contributes to a significant reduction in harmful emissions.

Preparation and evaluation activity of silica nanoparticles against bacterial oral infections: in vitro study

Background: Oral infections are commonly encountered among populations and frequently result in chronic inflammatory conditions that impact the dental structures (e.g., caries), the gingival tissues surrounding the dental elements (e.g., gingivitis and endodontic lesions), as well as the supporting structures of the teeth (e.g., periodontitis). Objectives: The objective of this study is to ascertain the minimum inhibitory concentrations of silica nanoparticles in order to evaluate the antibacterial efficacy of these nanoparticles against oral pathogens. Materials and Methods: A total of 100 clinical samples were collected from individuals suffering from diverse oral infections. They were diagnosed based on the culture and microscopic characteristics, as well as the diagnosis with Vitek2 device for the purpose of diagnosis for the level of species. Molecular identification of Viridians Streptococci was performed using PCR to detect the 16sRNA gene. The study also involved the synthesis of silica nanoparticles (SiNPs) using the sol-gel technique. Characterization of the SiNPs was conducted through X-ray diffraction (XRD), transmission electron microscopy (TEM), and field emission scanning electron microscopy with energy-dispersive X-ray spectroscopy (FESEM-EDX). The minimum inhibitory concentration (MIC) of the SiNPs against viridans Streptococci was evaluated using a microdilution assay with the blue-resazurin staining method. The agar well diffusion technique was utilized to assess the antibacterial efficacy of biosynthesized silica nanoparticles against Viridans Streptococci in comparison to a standard antibiotic, utilizing the minimum inhibitory concentration (MIC) as a metric. Results: Fifty pathogenic bacterial strains were obtained from clinical specimens, with the genus Streptococcus comprising 27 of these isolates, which corresponds to 54% of the overall total, thereby constituting the highest proportion observed among all species. Molecular identification of Viridans Streptococci in this study, showed that 10/10(100%) isolates were PCR positive for 16sRNA gene has been applied to pathogenic viridians streptococcal only, which include S. mitis, S. oralis and S. sanguinis. Multidrug-resistant isolates showed significant resistance to various antibiotics, including Erythromycin, Cefotaxime, Cefepime, Ceftriaxone, and Penicillin. Clindamycin also showed resistance. Augmentin showed the highest antimicrobial activity, while Trimethoprim-sulfamethoxazole, Ampicillin, and Vancomycin showed commendable activity. The MIC for the synthesized silica nanoparticles against Viridans Streptococci was determined to be 3.13 mg/mL across all bacterial isolates. The study showed that the bio-synthesized silica nanoparticles had a higher inhibition than the standard antibiotic disc Vancomycin (VA) at a concentration of 3.13 mg/ml, as the average diameter of inhibition reached 26.2 mm, respectively. Conclusion: Silica nanoparticles demonstrated significant efficacy in combating Viridans Streptococci, which are implicated in the etiology of oral infections.

Evaluation of Anti-biofilm Activity of Silica nanoparticles against dental Streptococcus mutans: In-Vitro Study

Background: Dental caries is a prevalent chronic infection caused by cariogenic bacteria that cling to teeth, mainly Streptococcus mutans. These bacteria break down sugars into acid over time, demineralizing the tooth structure. Biofilm as an early colonizer and is the most important bacterium in the formation of dental caries . Materials and Methods: The present study concentrates on isolation and identification of the S.mutans pathogen from patients suffering from dental caries. On specific media, the isolates were cultivated. From human teeth, one hundred dental caries samples are gathered. Using MS-agar (Mitis Salivarius agar), only fifty samples are regarded as positive bacterial isolates to identify the S.mutans isolates, their morphological, cultural, biochemical, and VITEK features were examined. . The microtiter plate method was used to detect the development of biofilms by comparing the characteristics of the isolates. In this work, the median values of optical density (OD) at 630 nm were utilised to employ ELISA to distinguish between S. mutans isolates that developed biofilms and those that did not. To confirm the type of bacteria using molecular identification. Objectives: The purpose of this work is to determine the subminimum and minimum inhibitory concentrations of silica nanoparticles that function as anti-biofilm agents, as they have an impact on bacterial growth and details of silica nanoparticle characterization. Results: In this study considered to be S.mutans are twenty isolates the morphological, cultural, biochemical, and VITEK properties of the bacterial isolates were used to identify them . in this study molecular identification to more confirm of S.mutans the result of PCR showed that 20/20(100%) isolates were PCR positive for 16r RNA gene . in this investigation different isolates were evaluated for their capacity to create biofilm; nine (45%) were judged to be strong producers, seven (35%), to be moderate producers, and four (20%) to be weak producers. the sol-gel method was used in this study to synthesis silica nanoparticles, which were then characterised by XRD, FE-SEM, EDX, and TEM. In this study, Si-NPs were tested against isolates of S.mutans by using a resazurin mediated microtiter plate the results have shown that silica nanoparticles has inhibitory action (MIC) against S. mutans with concentration 0,78 mg/ml and sub-MIC with concentration 0.39 mg/ml. .The anti-biofilm effect of silica nanoparticles on isolates of S. mutans in the current investigation revealed that the biofilm mean of control (biofilm development without silica nanoparticles) was 0.583, whereas the findings for anti-biofilm utilizing sub-MIC of NPs, was 0.185 in microtiter plate method when the (p value) less than 0.05 this proves the NPs effected on the biofilm formation by S.murans and inhibition it . Conclusion: Silica nanoparticles' anti-biofilm action on S.mutans isolates demonstrated the importance of biofilm inhibition.

Molecular simulation of liquid-liquid extraction of acetic acid and acetone from water in the presence of nanoparticles based on prediction of solubility parameters

In this work, molecular dynamics simulation (MD) was used for studying the liquid-liquid extraction of acetic acid and acetone from water in the presence of nanoparticles. In the next step, the solubility parameter of acetic acid and acetone were predicted at 1 atm and different temperatures along with the solubility parameter of solvents and water at 25 °C and 1 atm. Three pure systems and three systems with different concentration of nanoparticles were investigated to show the effect of cell size or number of molecules on the solubility parameter. With the addition of SiO2 nanoparticles to the solvents, at low concentrations of nanoparticles (0.01–0.1 vol%), the solubility parameter is increased due to the Brownian motion. With the further increase concentration of the nanoparticles, the solubility parameter decreases due to the accumulation of nanoparticles. The difference between the solubility parameter of benzene and acetone was 0.414 (J/cm3)0.5 and 3.13 (J/cm3)0.5, with and without the presence of SiO2 nanoparticles, respectively. Finally, toluene was found to be the best solvent for acetone and acetic acid at silica nanoparticles concentration of 0.062 vol%.

Polyurethane Nanocomposite Coatings Coupled with Titanium-Based Conversion Layers for Enhanced Anticorrosion, Icephobic Properties, and Surface Protection.

This study examines the efficacy of icephobic polyurethane nanocomposite coatings in mitigating corrosion on an aluminum substrate. A titanium-based conversion coating is applied to modify the substrate, and the research focuses on optimizing the dual functionalities of icephobicity and anticorrosion within the polyurethane coatings while ensuring strong substrate adhesion. The coatings are formulated using fluoropolyol, isocyanate, and silica nanoparticles treated with polydimethylsiloxane. Surface properties are analyzed using contact angles, contact angle hysteresis measurements, and atomic force microscopy, and the coatings' icephobicity is evaluated through differential scanning calorimetry, freezing time delay, ice adhesion under impact and non-impact conditions, and ice accretion tests. The corrosion resistance and adhesive strength of the coatings are assessed using electrochemical impedance spectroscopy and cross-cut tests, respectively. Increasing the concentration of silica nanoparticles to 10 wt.% increases contact angles to 167°, although the 4 wt.% coating produces the lowest contact angle hysteresis (3° ± 0.5°) and ice nucleation temperature (-23 °C). The latter coating is then applied to a substrate pretreated with a titanium/cerium-based conversion coating. This prepared surface maintains an ice adhesion of about 15 kPa after 15 icing/de-icing cycles and provides approximately 90 days of surface protection (|Z|lf = 1.6 × 109 Ω·cm2). Notably, the impedance value exceeds that of untreated substrates, underscoring the effectiveness of the titanium/cerium-based conversion coating in enhancing both corrosion resistance and coating adhesion to the substrate.

Impact assessment of polymer, cross-linker, and nanoparticles on gelation kinetics and properties of silica nanocomposite hydrogel for water shut-off treatment in harsh reservoir conditions

The study presented the impacts of various parameters like compositional combinations of PHPA (partially hydrolyzed polyacrylamide), organic cross-linker (hydroquinone-HQ and hexamethylenetetramine-HX), and silica nanoparticles (SNP) in addition to the degree of hydrolysis and molecular weight of PHPA on the efficacy of hydrogel for water shut-off jobs. The investigation indicated that the gelation time, gel strength of the gel, tolerance against salinity, and temperature were tuned as required by the field conditions by changing the variables mentioned above. The gelation time was found to vary inversely with the concentration of polymer, cross-linkers, and silica nanoparticles, whereas the gel strength and temperature tolerance followed the reverse trend. SNP was observed to control the gel properties significantly, even at the lower polymer and cross-linker compositions, as evidenced by the stronger network in FESEM, rheological, and other related properties. The hydrogels prepared with the PHPA-LM (low molecular wt) and PHPA-HM (high molecular wt) polymers and HX-HQ cross-linkers showed improved temperature tolerance from 126.49 °C to 131.78 °C and 99.88 °C to 164.34 °C, respectively when improvised with SNP. The gel’s microstructure (FE-SEM image) exhibited significant silica nanoparticle aggregation and evenly distributed compact three-dimensional network structure. The prepared nanohydrogel with optimized composition maintained its stability even at a salinity of 60000 ppm and 120 °C for more than two years. Sand-pack flooding with the nanohydrogel proved very effective, with a permeability reduction of ∼ 90 %. Thus, the prepared nano-hydrogel could be effectively used for high temperature and high salinity conditions with preferred resistance to water flow.

Vat photopolymerization of silica reinforced styrene-butadiene rubber elastomeric nanocomposites

Compared to their unfilled counterparts, elastomeric nanocomposites offer tailorable combinations of properties, including improved mechanical properties, increased durability, and enhanced thermal and electrical conductivity. However, the high viscosity caused by the presence of both the high molecular weight elastomer and the inclusion of fillers complicates additive manufacturing (AM) of elastomeric nanocomposites. This is especially challenging in vat photopolymerization (VP) AM, which requires resins that possess low viscosity (< 10 Pa·s) and exhibit sufficient storage modulus (∼ 104 Pa) when photocured. To address this process limitation, the authors have previously demonstrated decoupling the relationship between viscosity and molecular weight via VP of a photocurable composite latex resin. In this approach, a photocurable matrix is photocured as a scaffold around the latex particles, which provides sufficient modulus for the printed "green" part. Following a dehydration post-processing step, the latex particles coalesce to provide the final elastomeric mechanical properties without compromising feature resolution.In this work, the authors explore the effects of the addition of silica nanoparticles (10, 15, and 20 wt.%) on (i) the printability of photocurable styrene-butadiene rubber (SBR) latex resin and (ii) the mechanical properties of the resultant printed composites. The printable photocurable silica-SBR colloidal resin is realized by balancing the viscosity of the resin, the modulus of the cured green body, the silica nanoparticles content for reinforcement, and the high SBR content for elastomeric behavior. Specifically, the photocurable colloidal resin's viscosity is controlled by formulation design, while high silica nanoparticle content in the final part is achieved through evaporation of unreactive diluent. Characterization of the printed SBR nanocomposites with 20 wt.% silica reinforcement elucidated significant enhancements in the tensile strength (53 % increase), Young's modulus (671 % increase), and Shore A hardness (108 % increase) compared to printed SBR without filler reinforcement. To the authors' knowledge, this is the first report of 3D printing rubber nanocomposite using VP.

Bio-inspired stretchable and self-healable nanocomposite gelatin hydrogel with low silica nanoparticle content and brilliant angle/strain-independent structural colors

Stretchable and self-healable structural-colored nanocomposite gelatin hydrogel with photonic structure of random dense/loose regions of non-close-packed silica nanoparticles (SiO2 NPs) is developed via convenient and scalable polymer-mediated assembly. The formation of the special photonic structure with overall low SiO2 NP content is characterized by transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The small-angle X-ray scattering test indicates the existence of short-range order, which is consistent with the TEM and SEM results. The dense photonic structure consisting of SiO2 NP chains and domains, and the loose structure consisting of abundant solitary SiO2 NPs, accounts for pronounced and uniform structural colors via combined effects of coherent scattering of light by dense structure, and Mie scattering of solitary NPs. These structural colors are independent of viewing angles and large mechanical strains. The dynamic physical and chemical bonding of the gelatin hydrogel network matrix enables self-healing functions and good deformability. Moreover, salt treatment of the structural-colored gelatin hydrogel networks enhances physical crosslinking and the mechanical strength of the hydrogel. The resilient, flexible and self-healable structural-colored nanocomposite hydrogel with low SiO2 NP content has great potential in wearable photonics, cosmetics, and various other color-related fields. This work also sheds light on enhancing non-iridescent structural colors through advanced photonic design.

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.