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Background and Objective: The updated World Health Organization (WHO) air quality guideline recommends an annual mean concentration of fine particulate matter (PM2.5) not exceeding 5 or 15 μg/m3 in the short‐term (24 h) for no more than 3–4 days annually. However, more than 90% of the global population is currently exposed to daily concentrations surpassing these limits, especially during extreme weather conditions and due to transboundary dust transport influenced by climate change. Herein, the effect of respirable

Superamphiphobic coating with excellent optical transmittance has immense potential for utilization in many fields. However, it is challenging to maintain superamphiphobic surface with high transparency. Herein, a lotus leaf-inspired double-layered coating is proposed. The bottom layer of the coating consisted of fluorosilane-modified epoxy resin, while the top layer was composed of fluorosilane-modified SiO2 and cellulose nanofibers (CNFs). The trends of optical transmittance and oil-water contact angle of the coating at different mass ratios between SiO2 and CNFs were systematically investigated, and the stability of the coating was further studied by means of immersion in water, tape peeling, falling sand abrasion, and ultraviolet radiation. Experimental results showed that the coating exhibited the best comprehensive performance when the mass ratio of SiO2 to CNFs was 1:1. The coating exhibited optical transmittance of 79%, while the contact angles of water, glycerol, glycol, and hexadecane were up to 169°, 163.5°, 155.2°, and 125.4°, respectively. Even after the stability test, the coating still showed a good superamphiphobic performance. This demonstrates that the coating exhibited excellent optical transmittance, good chemical stabilities, and high mechanical stability. [ABSTRACT FROM AUTHOR]

Biomedical analytical applications, as well as the industrial production of high-quality nano- and sub-micrometre particles, require accurate methods to quantify the absolute number concentration of particles. In this context, small-angle x-ray scattering (SAXS) is a powerful tool to determine the particle size and concentration traceable to the Système international d'unités (SI). Therefore, absolute measurements of the scattering cross-section must be performed, which require precise knowledge of all experimental parameters, such as the electron density of solvent and particles, whereas the latter is often unknown. Within the present study, novel SAXS-based approaches to determine the size distribution, density and number concentrations of sub-micron spherical silica particles with narrow size distributions and mean diameters between 160 nm and 430 nm are presented. For the first-time traceable density and number concentration measurements of silica particles are presented and current challenges in SAXS measurements such as beam-smearing, poorly known electron densities and moderately polydisperse samples are addressed. In addition, and for comparison purpose, atomic force microscopy has been used for traceable measurements of the size distribution and single particle inductively coupled plasma mass spectrometry with the dynamic mass flow approach for the accurate quantification of the number concentrations of silica particles. The possibilities and limitations of the current approaches are critically discussed in this study. [ABSTRACT FROM AUTHOR]

Highlights: Aerogels doped with SiO2 particles derived from rice husks are obtained by a freeze-drying method. SiO2 particles provide a reduced-flammability advantage over undoped PUR aerogels. Increasing SiO2 content significantly enhances flame-retardancy in PUR aerogels. In this work, polyurethane (PUR) aerogels doped with different SiO2 particles, derived from a renewable source, were successfully synthesized, and the effects of SiO2 content on the properties of PUR aerogels were investigated. Specifically, three types of SiO2-based particles obtained from rice husk through different procedures were evaluated to enhance the thermal stability of the composites with special attention given to flame-retardant properties. With the optimal SiO2 particles, obtained through acid digestion, the influence of their content between 0.5 and 3 wt.% on the physicochemical characteristics of the synthesized aerogels was thoroughly examined. The results showed that increasing the doping agent content improved the lightness, thermal stability, and flame-retardant properties of the resulting PUR aerogels, with the best performance observed at a 2 wt.% doping level. The doped aerogel samples with non-modified SiO2 particles significantly enhanced the fire safety performance of the material, exhibiting up to an eightfold increase in flame retardancy. However, modification of the SiO2 particles with phytic acid did not slow down the combustion velocity when filling the aerogels. This research highlights the promising potential of doped PUR/SiO2 aerogels in advancing materials science and engineering applications for withstanding high temperatures and improving fire safety. [ABSTRACT FROM AUTHOR]

Atmospheric plasma is used to deposit superhydrophobic fluorine-free thin films onto a substrate. In this process, a suspension of micron size silica particles in a silazane based precursor is deposited in a single step using a dielectric barrier discharge plasma jet moving above the substrate. Thanks to an optimized configuration between the suspension injection and the plasma jet, the silazane precursor can be polymerized on the substrate surface but also, on silica particles to form additional micro size particles. The experimental parameters for optimal deposition are discussed, with emphasis on those leading to the formation of this dual roughness surface caused by the arrangement of both silica particles and particles generated from the precursor plasma polymerization. The combination of these two different length scales for the roughness leads to a decreased wettability of the coated substrate and a water contact angle larger than 150°.

Dialysate fluid is a vital component in hemodialysis therapy. Processing and reusing spent dialysate in hemodialysis significantly reduces costs and produces environmentally friendly hemodialysis. In this research, mixed matrix membrane adsorbers (MMMAs), which have the potential to recycle spent dialysate, have been developed. MMMA is composed of cellulose acetate (CA)-based polymers synthesized from cellulose isolated from oil palm empty fruit bunches (OPEFB) and integrated with silica (Si) bio-adsorbent from rice husk ash waste. The membrane was cast using the phase inversion method to form MMMAs CA-Si. The MMMAs CA-Si has a porous structure with evenly distributed silica particles. The pristine CA membranes had swelling and porosity degrees of 38.89 % and 21.23 %, while the MMMAs CA-Si had swelling and porosity degrees of 41.43 % and 27.81 %, respectively. The pristine CA membrane had a clean water flux of 86.86 L/m2h, while the MMMAs CA-Si membrane had a 96.25 L/m2h clean water flux. The MMMAs CA-Si has a tensile strength of 15.89 (Kgf/mm2) and an elongation of 14.01 %. The pristine CA membrane had a creatinine adsorption capacity of 2.8 mg/g, while the CA-Si MMMAs membrane had a maximum adsorption capacity of 9.98 mg/g. The maximum adsorption capacity (qm) is 9.98 mg/g MMMAs, equivalent to 24.95 mg creatinine/g silica in MMMAs and the dissociation constant (Kd) value is 1.91 mg/L. Creatinine can be removed from the dialysate through a continuous flow dialysis process using MMMAs CA-Si with a total removal of 10.48 mg/g or above 66.45 %. Creatinine can also be filtered by cross-flow circulation, and the total creatinine removal is above 81.0 %. MMMAs CA-Si can be an alternative separation medium to remove creatinine in the dialysate.

The harmful particles can cause significant health risks and need to be carefully removed from the air before they can pose a threat. One of the most effective methods for separating these particles is a cyclone separator, which can quickly and efficiently remove hazardous particles from the air. In this research, the separation of silica particles using a cyclone separator was investigated and analyzed using artificial neural networks (ANNs) and response surface methodology. The influence of process parameters, including flow rate, particle size, and speed, on cyclone efficiency was investigated. The cyclone experiments were carried out with varying rotation speeds ranging from 0 to 1900 rpm, as well as different particle sizes (15, 25, and 40 μm) and flow rates (30, 50, and 70 m3/hr). Based on the research findings, it was discovered that the ANN model that utilized the multilayer perceptron (MLP) algorithm outperformed the one that used the radial basis function (RBF) algorithm. The findings showed that a neural network with a multilayer perceptron (MLP) architecture performed well in predicting efficiency. Specifically, this MLP had one hidden layer consisting of 10 neurons, and its topology was defined as 3-10-1. The accuracy of the efficiency predictions was high, with a coefficient of determination of 0.998. After analyzing the results, it was concluded that the perceptron multilayer (MLP) model had the highest coefficient of determination value of 0.998 and the lowest error values, with a mean square error of 0.00033838. [ABSTRACT FROM AUTHOR]

In this work, polyurethane (PUR) aerogels doped with different SiO2 particles, derived from a renewable source, were successfully synthesized, and the effects of SiO2 content on the properties of PUR aerogels were investigated. Specifically, three types of SiO2-based particles obtained from rice husk through different procedures were evaluated to enhance the thermal stability of the composites with special attention given to flame-retardant properties. With the optimal SiO2 particles, obtained through acid digestion, the influence of their content between 0.5 and 3 wt.% on the physicochemical characteristics of the synthesized aerogels was thoroughly examined. The results showed that increasing the doping agent content improved the lightness, thermal stability, and flame-retardant properties of the resulting PUR aerogels, with the best performance observed at a 2 wt.% doping level. The doped aerogel samples with non-modified SiO2 particles significantly enhanced the fire safety performance of the material, exhibiting up to an eightfold increase in flame retardancy. However, modification of the SiO2 particles with phytic acid did not slow down the combustion velocity when filling the aerogels. This research highlights the promising potential of doped PUR/SiO2 aerogels in advancing materials science and engineering applications for withstanding high temperatures and improving fire safety.

Ammonia solutions are widely used solvents for CO2 capture. However, a significant disadvantage of these solvents is secondary pollution of the purified gas stream by desorbed ammonia. In this work, α,ω-diols, and colloidal silica have been proposed to reduce this undesired effect. Ammonia solutions with the addition of ethylene glycol (EG), 1,3-propanediol (PRD), 1,4-butanediol (BUD), 1,5-pentanediol (PED), or 1,6-hexanediol (HED) and ammonia solution with the addition of diol and colloidal SiO2 were tested. The concentration of CO2 and NH3 in the exhaust gas was continuously measured during the experiments. Based on the recorded measurements, the number of moles of CO2 absorbed and the number of moles of NH3 lost were calculated. Mass transfer coefficients for CO2 absorption and NH3 desorption were also determined. The studies showed that CO2 absorption occurred faster in ammonia solutions with EG, PRD, BUD, and HED, and the CO2 loading was higher than in pure NH3 solution. The most effective additive improving CO2 absorption was BUD, followed by HED. SiO2 particles improved slightly the absorption efficiency in most of the tested diol solutions. All diols used inhibited the escape of ammonia, with PED having the most effective effect. However, adding silica particles effectively inhibited ammonia escape in all tested systems.

In this study, the separation of silica particles was investigated experimentally and numerically using a cyclone separator. Computational Fluid Dynamics (CFD) simulation was performed using a multi-phase Eulerian-Eulerian model for air-silica powder and k-ε turbulent model. In the experiments, the effects of operating parameters including silica particle size, airflow rate, and rotational speed on cyclone efficiency were examined. The results showed that by increasing the particle size, the flow rate, and the body speed, the cyclone efficiency enhances. Furthermore, body rotation in the opposite direction of the inlet flow decreases cyclone efficiency by around 48% and increasing the flow rate and rotation speed increases tangential velocity, resulting in increased centrifugal force and improved cyclone efficiency. The experimental and simulation performance maximums are about 97 percent and 90 percent, respectively. At a constant flow rate and particle size, a 1900 rpm rotating speed of the current direction of inlet flow increases performance by approximately 10-13 percent compared to a stationary body.

In this study, the separation of silica particles was investigated experimentally and numerically using a cyclone separator. Computational Fluid Dynamics (CFD) simulation was performed using a multi-phase Eulerian-Eulerian model for air-silica powder and a k-ε turbulent model. In the experiments, the effects of operating parameters including silica particle size, airflow rate, and rotational speed on cyclone efficiency were examined. The results showed that by increasing the particle size, the flow rate, and the body speed, the cyclone efficiency enhances. Furthermore, body rotation in the opposite direction of the inlet flow decreases cyclone efficiency by around 48%, and increasing the flow rate and rotation speed increases tangential velocity, resulting in increased centrifugal force and improved cyclone efficiency. The experimental and simulation performance maximums are about 97 percent and 90 percent, respectively. At a constant flow rate and particle size, a 1900 rpm rotating speed of the current direction of inlet flow increases performance by approximately 10-13 percent compared to a stationary body.

In this novel communication, mesoporous silica/poly (amidoamine) generation 5 nanocomposite was synthesized through 3-glycidoxypropyltrimethoxysilane (GPTMS) and its functionality was studied. Successful functionalization of mesoporous silica with PAMAM was studied through Transmission electron microscopy (TEM). N2 adsorption-desorption was indicative of a surface area of 1,321 m2/g and a mean pore diameter of 2 nm. Successful drug loading and optimal release were confirmed using Fourier transform infrared (FTIR) and ultraviolet-visible spectroscopy (UV-Vis), respectively. Furthermore, at 256 μg/mL concentration samples demonstrated antibacterial activity toward Staphylococcus aureus and Escherichia coli bacteria, and cell viability for all samples after 72 h was more than 70%. [ABSTRACT FROM AUTHOR]

Agroindustrial wastes represent a rich and underutilized source of valuable minerals. Because the amount of biomass wastes generated by the agroindustry is increasing and the demand for sustainability is arising, there is a growing need for improving agroindustrial waste utilization and valorization. One of the major industrial interests has been obtaining silica from biomass wastes. The synthesis of silica from agroindustrial waste materials typically involves the use of high energy input for calcination or incineration and chemicals for extraction. To reduce energy consumption and chemical waste generation, we modified a sol-gel method to yield a by-product that can be used as a fertilizer. High purity silica was obtained from rice husk (95.1%), rice straw (91.4%), and corncob (95.9%). The silica particles were amorphous and white in color. The mean diameters of the silica particles obtained from rice husk, rice straw, and corncob were 72.4, 68.1, and 52.9 µm, respectively. The acid waste generated from the process was neutralized to yield potassium chloride. This by-product had mineral contents that could be used for inorganic fertilizer. In addition to supporting sustainability, the development of agroindustrial waste utilization methods is important for the establishment of inexpensive processes that are adaptable for large-scale manufacturing.

In this study, the separation of silica particles was investigated experimentally and numerically using a cyclone separator. Computational Fluid Dynamics (CFD) simulation was performed using a multi-phase Eulerian-Eulerian model for air-silica powder and a k-e turbulent model. In the experiments, the effects of operating parameters including silica particle size, airflow rate, and rotational speed on cyclone efficiency were examined. The results showed that by increasing the particle size, the flow rate, and the body speed, the cyclone efficiency enhances. Furthermore, body rotation in the opposite direction of the inlet flow decreases cyclone efficiency by around 48%, and increasing the flow rate and rotation speed increases tangential velocity, resulting in increased centrifugal force and improved cyclone efficiency. The experimental and simulation performance maximums are about 97 percent and 90 percent, respectively. At a constant flow rate and particle size, a 1900 rpm rotating speed of the current direction of inlet flow increases performance by approximately 10-13 percent compared to a stationary body. [ABSTRACT FROM AUTHOR]

Nanomotors that use polymers to gain locomotion is an upcoming concept. Here, we made use of self‐immolative polymers (SIP), i. e. polymers that disintegrate in a domino‐like fashion, to initiate motion in 500 nm silica particles. We selected a BSA‐triggered SIP and assessed its degradation both in solution and when deposited onto the silica particles. A 1.5‐fold increase of monomer was found in the solution compared to the controls, suggesting the SIP disintegration. The locomotion of the SIP‐coated motors was shown to have an average velocity of up to ∼3 μm s−1 when incubated with BSA. These proof of concept findings illustrate an alternative polymer‐powered motor design, which benefits from modern polymer chemistry concepts. [ABSTRACT FROM AUTHOR]

Environmental exposure to crystalline silica particles can lead to silicosis, which is one of the most serious pulmonary interstitial fibrosis around the world. Unfortunately, the exact mechanism on silicosis is unclear, and the effective treatments are lacking to date. In this study, we aim to explore the molecular mechanism by which interleukin-11 (IL-11) affects silica particles-induced lung inflammation and fibrosis. We observed that IL-11 expressions in mouse lungs were significantly increased after silica exposure, and maintained at high levels across both inflammation and fibrosis phase. Immunofluorescent dual staining further revealed that the overexpression of IL-11 mainly located in mouse lung epithelial cells and fibroblasts. Using neutralizing anti-IL-11 antibody could effectively alleviate the overexpression of pro-inflammatory cytokines (i.e., interleukin-6 and tumor necrosis factor-α) and fibrotic proteins (i.e., collagen type I and matrix metalloproteinase-2) induced by silica particles. Most importantly, the expressions of IL-11 receptor subunit α (IL-11Rα), Glycoprotein 130 (GP130), and phosphorylated extracellular signal-regulated kinase (p-ERK) were significantly increased in response to silica, whereas blocking of IL-11 markedly reduced their levels. All findings suggested that the overexpression of IL-11 was involved in the pathological of silicosis, while neutralizing IL-11 antibody could effectively alleviate the silica-induced lung inflammation and fibrosis by inhibiting the IL-11Rα/GP130/ERK signaling pathway. IL-11 might be a promising therapeutic target for lung inflammation and fibrosis caused by silica particles exposure. [Display omitted] [ABSTRACT FROM AUTHOR]

Microbial food safety of raw or minimally processed fresh produce is a significant challenge. The current sanitation processes are effective for inactivation of bacteria in wash water but have limited efficacy (5-log reduction) in the presence of relatively high organic content (chemical oxygen demand of 500 mg/liter), demonstrating a potential to address a significant unmet need to improve fresh produce sanitation. The particle-based sanitizer had no significant effect on the quality of fresh lettuce.IMPORTANCE The limitation of current sanitation processes for inactivation of microbes on the surfaces of fresh produce is due to nonspecific consumption of sanitizers by reactions with the food matrix and complexity of surface chemistries and structural features of produce surfaces. This study demonstrates a novel approach to enhance sanitation effectiveness of fresh produce using a particle-based sanitizer. The particle-based sanitizer concept provides localized high concentration delivery of chlorine to the surfaces of fresh produce and enables more than 5 logs of inactivation of inoculated bacteria on fresh produce surfaces without significant changes in produce quality. The results of this study illustrate the potential of this approach to address the unmet need for improving sanitation of fresh produce. Further validation of this approach using a scaled-up produce washing system will enable commercialization of this novel concept.

Ferronickel slag is a by-product of nickel smelting that provides an abundant silica source. Based on data, every ton of nickel production is equal to eight tons of ferronickel slag production, increasing without any recycling process. It is essential to create an end-to-end process for nickel production and its by-products because this would be a problem in the future and is relevant for many industrialized countries. This study describes a strategy to process ferronickel slag to produce silica. A pyrometallurgy–hydrometallurgy process and ferronickel slag were used to increase the silica content. The process was conducted through alkali fusion; the ferronickel slag was mixed with sodium carbonate at a temperature of 1000 °C for an hour and continued via leaching, precipitation, and cleaning processes. The leaching process was conducted with four concentrations (4 M, 6 M, 8 M, and 10 M) of sodium hydroxide and three different leaching durations (2 h, 4 h, and 6 h). Using hydrochloric acid (HCl) at pH 2 and deionized (DI) water cleaning, the precipitation process was adopted to synthesize a silica powder with the lowest agglomeration and enhance its purity. Characterization was carried out using X-ray Diffraction (XRD), Scanning Electron Microscopy–Energy-Dispersive Emission (SEM-EDS), X-ray Fluorescence (XRF), and Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES). This study highlighted silica characteristics that indicate high recovery by 85% through alkali fusion, HCl leaching, precipitation, and deionized water cleaning. [ABSTRACT FROM AUTHOR]

Nature offers a wide range of evolutionary optimized materials that combine unique properties with intrinsic biocompatibility and that can be exploited as biomimetic materials. The R5 and RRIL peptides employed here are derived from silaffin proteins that play a crucial role in the biomineralization of marine diatom silica shells and are also able to form silica materials in vitro. Here, we demonstrate the application of biomimetic silica particles as a vaccine delivery and adjuvant platform by linking the precipitating peptides R5 and the RRIL motif to a variety of peptide antigens. The resulting antigen-loaded silica particles combine the advantages of biomaterial-based vaccines with the proven intracellular uptake of silica particles. These particles induce NETosis in human neutrophils as well as IL-6 and TNF-α secretion in murine bone marrow-derived dendritic cells. [ABSTRACT FROM AUTHOR]

Improving the surface roughness of cotton fabric is one of the main strategies to prepare superhydrophobic cotton fabric. To improve the surface roughness of fabric, it is advisable to immobilize inorganic/organic particles on the surface of cotton fabric. However, the durability of the superhydrophobic cotton fabric is very poor due to the inorganic/organic particles are easily detachable from the fabric surface. In this work, a mild eutectic solvent prepared by choline chloride and oxalic acid was used to etch the cotton fabric, making the surface of the cotton fabric have many ravines. These ravines on the cotton fabric can be used the embedded the silica particles, thus making the silica particles firmly immobilized on the cotton fibers. Then, the treated cotton fabric was coated with polydimethylsiloxane (PDMS). As a result, the water contact angle of the finished fabric was reached at 156.9°. In addition, the superhydrophobic cotton fabric constructed by silica particles and PDMS via "Mosaic Mode" showed excellent mechanical and chemical stability. Therefore, the finished fabric has great potential application in the self-cleaning and oil–water separation fields. [ABSTRACT FROM AUTHOR]

• Green tea polyphenol (TP) significantly alleviated silica-induced lung injury. • Improved inflammatory response mediated TP's improvement of lung injury. • TP downregulated IL-17/NF-κB p65 signaling pathway and thus reduced inflammation. • TP shows promise as a natural agent in controlling lung inflammation and fibrosis. Silicosis, an interstitial lung disease caused by inhalation of silica particles, poses a significant health concern globally. Green tea polyphenol (TP) stands out as a promising therapeutic candidate, yet its specific protective effects and in-depth mechanisms against silicosis have not been thoroughly investigated. This study aimed to systematically assess the protective potential of TP against silicosis and to elucidate the underlying mechanisms of its action. A combination of physiological, transcriptomic, molecular, and computational techniques was employed. HPLC was used to identify the components of TP, and its antioxidant properties were tested with DPPH and ABTS assays. The effects of TP on lung injury were assessed in silicosis mice using histopathology, qRT-PCR, and western blot. Transcriptomic analysis was applied to explore the differentially expressed genes and pathways in response to TP intervention. In vitro studies with mouse alveolar macrophages (MH-S) examined TP's effects on cell viability, proliferation, apoptosis, and inflammation responses. Integrated qRT-PCR, western blot, immunohistochemistry, and molecular docking were performed to confirm the molecular mechanism underlying the protective effects of TP against silicosis. TP effectively attenuated pulmonary inflammation and fibrosis in silicosis mice, as evidenced by significant reductions in inflammation and fibrotic markers. Moreover, TP's therapeutic benefits were linked to its cytoprotective effects on alveolar macrophages, notably its ability to protect MH-S cells from silica particle-induced apoptosis, inhibition of proliferation, and inflammatory response, underscoring its targeted protective effects at the cellular level. Mechanistically, TP exerted its anti-silicosis activity by targeting key pathways implicated in inflammatory responses, notably through the inhibition of the IL-17/NF-κB p65 signaling cascade. Molecular docking simulations corroborated these findings, demonstrating favorable binding affinities between TP's bioactive components (EGC, ECG, and EGCG) and crucial proteins (IL-17A, IL-17F, p65, TNF-α, IL-6, and IL-1β) involved in the IL-17/NF-κB p65 signaling pathway. This pathway inhibition led to a significant decrease in the production of pro-inflammatory cytokines, such as TNF-α, IL-6, and IL-1β, thus mitigated silicosis. TP demonstrates efficacy in alleviating silica particle-induced lung injury by suppressing inflammation through the IL-17/NF-κB p65 signaling pathway, underscoring its potential as a valuable natural compound for silicosis management. [Display omitted] [ABSTRACT FROM AUTHOR]

Mesoporous silica particles (MSP) have received increasing interest for various applications because of their unique features such as controlled pore size, low density, high chemical and thermal stability, and high surface area. In this study, MSP was applied as an additive in water-based drilling fluids (WBMs). The effect of MSP on the rheological, thermal, filtration, and structural properties of WBMs was investigated. The results were compared with those of analogous fluids containing conventional nonporous silica particles (SSP). Rheological assays showed shear-thinning and viscoelastic behavior, which were more noticeable for fluids including MSP. It was observed that low concentrations of MSP (0.25 %wt) can achieve the same rheological properties as the fluids with higher SSP content (up to 0.5 %wt). The rheological properties of SSP-containing fluids were not significantly affected by the presence of NaCl or aging tests. The theoretical Herschel–Bulkley model represents the rheological behavior of WBMs. The MSP-based WBMs exhibited better filtration properties before aging. The microstructures of the WBMs were analyzed using Scanning Electron Microscopy (SEM). A homogeneous distribution of SSP in the WBMs was observed, while particle agglomeration was observed in WBMs containing MSP. In addition, surface interactions were studied to elucidate the interactions between particles and fluid constituents. The surface interaction, assessed through ζ -potential and FTIR analysis, revealed that the binding affinities of BT, PAC, and XGD with MSP were augmented compared to their individual values. Based on the experimental results, MSP constitutes a promising alternative as an additive for the design of WBMs. [Display omitted] • The effect of silica particles type on water-based drilling fluids (WBMs) performance was investigated. • Lower concentrations of MSP were required to achieve the same rheological properties of the fluids containing SSP. • The physicochemical properties of SSP and MSP had a different effect on the performance of WBMs. • The surface interactions mainly governed the rheological properties of WBMs. [ABSTRACT FROM AUTHOR]

Superhydrophobic surfaces are receiving increasing attention due to their real-world applications. However, these surfaces suffer from a lack of durability and complicated synthetic processes. This research uses a combination of a simple in-situ coating process between oxygen-activated polypropylene films and unreacted silane monomers. The in-situ process uses a modified Stöber method with the addition of the surfactant cetyltrimethylammonium bromide (CTAB) which aggregates silica (SiO 2) particles in a basic aqueous solution. This resulted in a layer of covalently bonded hierarchical coating of individual and aggregated SiO 2 “flakes” and particles. These coatings were found to have at least double the surface roughness than samples prepared without CTAB with superhydrophilic properties due to their high surface roughness and hydrophilic surface chemical groups. A second layer of fluorocarbon silane monomers was reacted with the hydroxyl groups on the hierarchical SiO 2 coating resulting in films with excellent superhydrophobic and self-cleaning properties. The sample containing aggregated SiO 2 particle structures exhibited higher chemical and physical durability against external irritations including adhesion, different pH levels, detergent, abrasion and UV radiation by retaining high contact angles and low rolling angles. Samples coated with flake structures were negatively affected by mechanical irritations. This simple in-situ SiO 2 coating process in combination with different concentrations of CTAB has not been investigated and has promising potential for many practical applications such as superhydrophilic, superhydrophobic and self-cleaning surfaces.

Previous reports have shown that colloidal crystal (CC) films with visible Bragg reflection characteristics can be fabricated by the surface modification of monodisperse silica particles (SiPs) with poly(methyl methacrylate) (PMMA) chains, followed by hot-pressing at 150 °C. However, the reflection bands of the CC films were very broad due to their relative disordering of SiPs. In this report, we attempted to fabricate the CC films using SiPs surface-modified with poly(n-octyl acrylate) (POA) chains by hot-pressing. When the cast films of POA-grafted SiPs were prepared by hot-pressing at 100 °C, the reflection bands were narrow rather than those of CC films of PMMA-grafted SiPs. This can be ascribed to easy disentanglement of POA chains during the hot-pressing process, thereby enabling the formation of well-ordered CC structures. Moreover, the reflection colors of CC films could be easily tuned by controlling the molecular weight of POA chains grafted on the SiP surface. [ABSTRACT FROM AUTHOR]

The SiO2 particles system is one of the most common ways to protect colloidal metal systems, such as gold nanoparticles, from aggregation and activity loss due to their high chemical stability and low reactivity. In this study, silica green gold nanoparticles (AuNPs synthesized with mullein extract) were fabricated using two different sol–gel methods. The nanoparticles were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Fourier Transformed Infrared (FTIR), and the antibacterial activity against pathogens (Staphylococcus aureus, Listeria monocytogenes, Escherichia coli, and Salmonella enterica). Synthesis-1 nanoparticles had a kidney-shaped form and uniform distribution, while synthesis-2 nanoparticles had a spherical and non-uniform form. Characterization showed that temperature is an important factor in the distribution of AuNPs in silica; a decrease allowed the formation of Janus-type, and an increase showed a higher concentration of gold in energy-dispersive spectroscopy (EDS) analysis. Overall, similar bands of the two synthesis silica nanoparticles were observed in FTIR, while XRD spectra showed differences in the preferential growth in AuNPs depending on the synthesis. Higher antibacterial activity was observed against S. aureus, which was followed by L. monocytogenes. No differences were observed in the antibacterial activity between the two different sol–gel methods. [ABSTRACT FROM AUTHOR]

[Display omitted] Alcohols can strongly reduce the interfacial tension between immiscible liquids, thus facilitating the formation of emulsions. By combining non-surface-active hydrophobic particles with medium-chain alcohols, stable water-in-oil (w/o) high internal phase Pickering emulsions (HIPPEs) can be easily prepared without high-energy emulsification methods. The emulsions containing acrylate monomer as the oil phase were prepared at different pH values in the presence of hydrophobic silica particles. Further, by replacing monomer oil with organic solvents (e.g., toluene) and a certain concentration of alcohol, the promoted particle adsorption at the oil–water interface has been systematically investigated. The morphology and interfacial structure of HIPPEs were visualized by confocal laser scanning microscopy (CLSM). At high pH, stable water-in-acrylate monomer HIPPEs can be formed using commercial fumed silica nanoparticles alone with simple stirring or vortexing. The hydrolysis of the acrylate group at high pH can generate alcohols in situ which adsorb at the oil–water interface to reduce the interfacial tension and promote particle adsorption to hinder droplet coalescence. The novel strategy for forming stable and processable HIPPEs can be universally applied to different hydrophobic silica particles with the help of various alcohols as the co-stabilizer, which provides a flexible approach for the fabrication of lightweight, closed-cell solid foams for a range of applications. [ABSTRACT FROM AUTHOR]

Our previously reported exploration (Journal of Membrane Science 565 (2018) 241–253) on the differences between fouling in reverse osmosis (RO) and forward osmosis (FO), used alginate as a foulant with initial conditions that ensured that the starting fluxes were the same. That study found that for a cellulose triacetate (CTA) membrane the extent of fouling, based on the analysis of foulant resistance, was greater when the membrane was part of a FO system. Herein, using the same methodology, results for a thin film composite membrane with alginate as the foulant are presented and these confirm the same general conclusion namely that the extent of foulant accumulation in FO mode is more severe than in RO mode. Furthermore the specific fouling resistance with alginate fouling in FO is more than for RO. However examining the overall operation including cleaning as well as fouling, this study suggests that FO operation is potentially less sensitive to fouling phenomena than RO for similar feed materials. This is due to the driving force compensation coming from a changing level of ICP. Some preliminary work including that with silica particles is also reported. [ABSTRACT FROM AUTHOR]

The purpose of this work was to evaluate the efficiency of oil sorption of silica particles modified by three different types of cationic polymers and a cationic surfactant. Low-molecular-weight polyethyleneimine (LPEI), high-molecular-weight polyethyleneimine (HPEI), polydiallyldimethylammonium chloride (PDM), and cetyltrimethylammonium bromide (CTAB) were used to modify the silica particles and then compared their performances for oil removal. The scanning electron microscope and zeta potential measurements were used to analyze the surface characteristics of unmodified and modified silica particles. Adsorptions of motor oil and palm oil on the modified silica particles have been investigated under various parameters such as the silica particle size, the oil concentration, the polymer/surfactant concentrations, and the pH. The results have shown that the modified silica particles enhanced the oil sorption ability by approximately 10–20 times depending on the size of silica particles, pH, and the type of polymer/surfactant used when compared with the unmodified silica particles. The highest palm oil adsorption values of LPEI-silica, HPEI-silica, PDM-silica, CTAB-silica, and unmodified silica were 2.40, 2.10, 1.95, 1.50, and 0.15 g/gsilica, respectively. Moreover, the oil sorption of the modified silica particles was increased by approximately 30–50% for the smallest-sized silica particles. HIGHLIGHTS Cationic polymers/surfactant-modified silica particles can enhance the oil sorption by approximately 10–20 times.; Polymer/surfactant-modified silica can be used to remove both fresh and used oil.; Low molecular weight of the cationic polymer performed the outstanding oil sorption performance.; Oil sorption on small particles was 30–50% higher than that of the large particles.;

The natural occurrence of precious opals, consisting of highly organized silica particles, has prompted interest in the synthesis and formation of these structures. Previous research has shown that a highly organized photonic crystal (PhC) array is only possible when it is based on a low polydispersity index (PDI) sample of particles. In this study, a solvent-only variation method is used to synthesize different sizes of silica particles (SiPs) by following the traditional sol-gel Stöber approach. The controlled rate of the addition of the reagents promoted the homogeneity of the nucleation and growth of the spherical silica particles, which in turn yielded a low PDI. The opalescent PhC were obtained via self-assembly of these particles using a solvent evaporation method. Analysis of the spatial statistics, using Voronoi tessellations, pair correlation functions, and bond order analysis showed that the successfully formed arrays showed a high degree of quasi-hexagonal (hexatic) organization, with both global and local order. Highly organized PhC show potential for developing future materials with tunable structural reflective properties, such as solar cells, sensing materials, and coatings, among others. [ABSTRACT FROM AUTHOR]

Cyanidin‐3‐galactoside (C3G), the most abundant anthocyanin in Aronia melanocarpa, has many beneficial health effects, such as antioxidation. C3G was extracted from A. melanocarpa and applied (100, 200, and 400 mg/kg body weight) to 50‐μl silica particles (SP) solution‐exposed mice to research its antifibrotic properties using histological analysis, hydroxyproline assay, quantitative real‐time polymerase chain reaction, and western blot analysis. The results showed that C3G treatment significantly ameliorated pulmonary fibrosis and cell infiltration into the lungs of mice. It also relieved SP‐induced epithelial–mesenchymal transition (EMT), 400 mg/kg C3G treatment increasing epithelial‐cadherin mRNA expression and decreasing α‐smooth muscle actin mRNA expression to the level of that in the control group. Western blot analysis showed that exposure to SP increased the production of transforming growth factor‐β1 (TGF‐β1) and phosphorylated mammalian target of rapamycin (mTOR) by 4.71‐ and 4.15‐fold, respectively, in the lungs of mice, which were significantly inhibited by C3G treatment. Moreover, 400 mg/kg C3G treatment up‐regulated two important antioxidant mediators, nuclear factor erythroid‐2‐related factor 2 (NRF2; 4.91‐fold) and heme oxygenase‐1 (HO‐1; 4.81‐fold). The mechanism study indicated that C3G might inhibit the TGF‐β/mTOR signaling via the NRF2/HO‐1 pathway and that SP‐induced pulmonary EMT was ameliorated by inhibiting the TGF‐β/mTOR signaling pathway. Our findings could provide new avenues for C3G as a functional food for preventing or mediating the progression of SP‐induced pulmonary fibrosis. [ABSTRACT FROM AUTHOR]

Tetraethyl-orthosilicate (TEOS)-based nanoparticles are most extensively used as a silica-based hemoglobin carrier system. However, TEOS-based nanoparticles induce adverse effects on the hemoglobin structure. Therefore, a heulandite-calcium-based carrier was investigated as a novel silica-based hemoglobin carrier system. The heulandite-calcium mesoporous aluminosilicate particles (MSPs) were fabricated by a patented tribo-mechanical activation process, according to the manufacturer, and its structure was assessed by X-ray diffraction analysis. Upon hemoglobin encapsulation, alternation in the secondary and tertiary structure was observed. The hemoglobin-particle interactions do not cause heme degradation or decreased activity. Once encapsulated inside the particle pores, the hemoglobin shows increased thermal stability, and higher loading capacity per gram of particles (by a factor of >1.4) when compared to TEOS-based nanoparticles. Futhermore, we introduced a PEGlyted lipid bilayer which significantly decreases the premature hemoglobin release and increases the colloidal stability. The newly developed hemoglobin carrier shows no cytotoxicity to human umbilical vein endothelial cells (HUVEC). [ABSTRACT FROM AUTHOR]

Polymerization induced surface self-assembly (PISSA) technology is a state-of-the-art method in the fabrication of the hierarchical surface nanostructures. Previously, we demonstrated that reversible addition−fragmentation chain transfer (RAFT) polymerization-based PISSA could be used to construct hierarchical surface nanostructures on the silica particles. Atom transfer radical polymerization (ATRP) has many advantages, especially in the synthesis of the macroinitiator. In this research initiators for continuous activator regeneration (ICAR) ATRP-induced PISSA approach is used to fabricate surface nanostructures. Poly(ethylene glycol) (PEG) macroinitiator and poly(oligo(ethylene glycol) monomethyl ether methacrylate-co-2-(2-bromoisobutyrnyloxy) ethyl methacrylate) (P(OEGMA-co-BIEM)) polymer brush macroinitiator on silica particles are used to initiate ATRP of styrene in methanol/water mixture. With the chain extensions, POEGMA-g-PS graft copolymer brushes and “free” PEG-b-PS block copolymer chains make surface coassembly into surface nanostructures. With an increase in monomer feeding ratio, the surface morphology gradually changes from small-sized spherical surface micelles (s-micelles), to big-sized s-micelles, and to asymmetric layered structures. Kinetics studies indicate that with an increase in monomer conversion there is a transition from homogeneous to heterogeneous polymerization.

[Display omitted] • Thermo-responsive Si-PM-PN particles are engineered to tailor coffee-ring effect. • Si-PM-PN particles move inward along the droplet interface above the LCST of PNIPAM. • Coffee-ring effect is effectively mitigated by utilizing thermo-responsive polymers. Silica (Si) particles coated with poly(methyl methacrylate- b - N -isopropylacrylamide) (PMMA- b -PNIPAM) block copolymers (Si-PM-PN particles) were engineered to mitigate the coffee-ring effect (CRE) frequently encountered during the drying process of particulate suspensions. Leveraging the thermo-responsive transition between the hydrophilic and hydrophobic states of PNIPAM, with its lower critical solution temperature (LCST) around 32 °C, enabled precise adjustment of the CRE. Through microrheological analysis using multi-speckle diffusing wave spectroscopy and observation under an optical microscope, the dynamic behaviors of Si-PM-PN particles in sessile suspension droplets during drying were scrutinized both below and above the LCST. Above the LCST, the Si-PM-PN particles exhibited hydrophobic characteristics, with some migrating toward the center along the droplet interface, resulting in a more uniform particle distribution post-drying. Conversely, below the LCST, the homogeneously dispersed Si-PM-PN particles displayed rapid Brownian motion, contributing to a pronounced CRE. This approach, involving the surface treatment of particles with thermo-responsive polymers, effectively altered the droplet pattern by modulating particle interactions with the air–water interface. [ABSTRACT FROM AUTHOR]

Silica submicronic particles doped with Dy and Gd paramagnetic ions were successfully synthesized by using chemical synthesis based on the modified Stöber method, having potential applications as contrast agents for magnetic resonance imaging (MRI).Structural characterization analyses show an amorphous character of the particles (XRD), good thermal stability (DTA), and spheroid shape (SEM). The integration of paramagnetic ions into the silica network was demonstrated by the TEM, EPR and FTIR spectroscopies.The magnetic resonance (MR) relaxivity examinations of the samples show a high rate of relaxivity for the particles doped with Dy, making them suitable as T2 contrast agent for magnetic resonance imaging. This is in contrast to the results obtained on the particles doped with Gd, which are an effective T1-weighted MRI contrast agent. Notably, if the silica structure incorporates both Gd and Dy the particles are suitable for contrast enhancement in both T1 and T2 weighted images. These characteristics of the samples are also supported by the value of the relaxivity ratio (r2/r1) for the three samples doped with paramagnetic ions. The results confirm the sustainability of MRI contrast agent applications for all three synthesized samples.

Ferronickel slag is a by-product of nickel smelting that provides an abundant silica source. Based on data, every ton of nickel production is equal to eight tons of ferronickel slag production, increasing without any recycling process. It is essential to create an end-to-end process for nickel production and its by-products because this would be a problem in the future and is relevant for many industrialized countries. This study describes a strategy to process ferronickel slag to produce silica. A pyrometallurgy–hydrometallurgy process and ferronickel slag were used to increase the silica content. The process was conducted through alkali fusion; the ferronickel slag was mixed with sodium carbonate at a temperature of 1000 °C for an hour and continued via leaching, precipitation, and cleaning processes. The leaching process was conducted with four concentrations (4 M, 6 M, 8 M, and 10 M) of sodium hydroxide and three different leaching durations (2 h, 4 h, and 6 h). Using hydrochloric acid (HCl) at pH 2 and deionized (DI) water cleaning, the precipitation process was adopted to synthesize a silica powder with the lowest agglomeration and enhance its purity. Characterization was carried out using X-ray Diffraction (XRD), Scanning Electron Microscopy–Energy-Dispersive Emission (SEM-EDS), X-ray Fluorescence (XRF), and Inductively Coupled Plasma–Optical Emission Spectroscopy (ICP-OES). This study highlighted silica characteristics that indicate high recovery by 85% through alkali fusion, HCl leaching, precipitation, and deionized water cleaning.

Background: Solubility is a common feature of allergens. However, the causative relationship between this protein-intrinsic feature and sensitization capacity of allergens is not fully understood. This study aimed to proof the concept of solubility as a protein intrinsic feature of allergens., Methods: The soluble birch pollen allergen Bet v 1 was covalently coupled to 1 μm silica particles. IgE-binding and -cross-linking capacity was assessed by inhibition ELISA and mediator release assay, respectively. Alterations in adjuvanticity by particle-loading were investigated by activation of dendritic cells, mast cells and the Toll-like receptor 4 pathway as well as by Th2 polarization in an IL-4 reporter mouse model. In BALB/c mice, particle-loaded and soluble Bet v 1 were compared in a model of allergic sensitization. Antigen uptake and presentation was analysed by restimulating human Bet v 1-specific T cell lines., Results: Covalent coupling of Bet v 1 to silica particles resulted in an insoluble antigen with retained IgE-binding and -cross-linking capacity and no increase in adjuvanticity. In vivo, particle-loaded Bet v 1 induced significantly lower Bet v 1-specific (s)IgE, whereas sIgG1 and sIgG2a levels remained unaffected. The ratio of Th2 to Th1 cells was significantly lower in mice sensitized with particle-loaded Bet v 1. Particle-loading of Bet v 1 resulted in a 24-fold higher T cell activation capacity in Bet v 1-specific T cell lines, indicating more efficient uptake and presentation than of soluble Bet v 1., Conclusions: Our results show that solubility is a decisive factor contributing to the sensitization capacity of allergens. The reduction in sensitization capacity of insoluble, particle-loaded antigens results from enhanced antigen uptake and presentation compared to soluble allergens., (Copyright © 2024 Japanese Society of Allergology. Published by Elsevier B.V. All rights reserved.)

Biomedical analytical applications, as well as the industrial production of high-quality nano- and sub-micrometre particles, require accurate methods to quantify the absolute number concentration of particles. In this context, small-angle x-ray scattering (SAXS) is a powerful tool to determine the particle size and concentration traceable to the Système international d'unités (SI). Therefore, absolute measurements of the scattering cross-section must be performed, which require precise knowledge of all experimental parameters, such as the electron density of solvent and particles, whereas the latter is often unknown. Within the present study, novel SAXS-based approaches to determine the size distribution, density and number concentrations of sub-micron spherical silica particles with narrow size distributions and mean diameters between 160 nm and 430 nm are presented. For the first-time traceable density and number concentration measurements of silica particles are presented and current challenges in SAXS measurements such as beam-smearing, poorly known electron densities and moderately polydisperse samples are addressed. In addition, and for comparison purpose, atomic force microscopy has been used for traceable measurements of the size distribution and single particle inductively coupled plasma mass spectrometry with the dynamic mass flow approach for the accurate quantification of the number concentrations of silica particles. The possibilities and limitations of the current approaches are critically discussed in this study., (Creative Commons Attribution license.)

To overcome the aggregation-caused quenching of carbon dots (CDs) in the solid state, this work presented a facile approach for in situ synthesis of N-doped CDs (N-CDs) in silica particles with the assistance of a bifunctional organic base, tetramethylammonium hydroxide (TMAOH). In this approach, TMAOH first acted as a basic catalyst, which can dissociate into TMA+ and OH–, to direct the growth of TMA+-embedded SiO2 particles. The TMA+ in silica particles was then used as the precursor for in situ synthesis of N-CDs via pyrolysis, resulting in the formation of N-CD-embedded SiO2 (N-CDs/SiO2) particles. The N-CDs/SiO2 particles presented tunable emission color from blue to green and yellow, depending on the amounts of TMAOH used in the reactions. More importantly, the resulting N-CDs/SiO2 particles exhibited bright and stable emission in both solution and solid states, making them potentially useful in the fabrication of anti-counterfeiting labels and light-emitting devices. [ABSTRACT FROM AUTHOR]

Low cost and high quality composite foams were successfully produced by using inexpensive materials and manufacturing method. 7075 Al alloy based composite foams were prepared by using recycled beverage aluminum cans and silica waste particles as reinforcements and thickening agent. The effects of processing parameters such as silica particles volume fraction as well as the foaming agent amount, temperature and time on the structures, relative densities and impact energy values of the produced composite foams were investigated. It was found that as the foaming agent and SiO2 content increased, the foam relative density increased, but, the relative density was reduced with increasing foaming temperature. The structures of the 7075 Al foams revealed some heterogeneities and imperfections. However, uniform cell distribution and size with almost regular equiaxed closed cells were observed in the macrostructures of the 7075 Al based composite foams. Impact energy absorption testes showed that the composite foam containing 10 vol % of SiO2 particles and 6 wt % of foaming agent exhibited the highest impact energy among all the composite foams produced in the current work. [ABSTRACT FROM AUTHOR]

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The purpose of this study was to assess the antimicrobial activity of root canal sealers modified with novel highly loaded antimicrobial drug-silica coassembled particles (DSPs) on Enterococcus faecalis –infected root canal dentin. DSPs were synthesized through coassembly of silica and octenidine dihydrochloride (OCT) surfactant drug (35% w/w OCT). DSPs (1% wt of the total mass of the sealer) were mixed homogenously with either epoxy resin sealer (AH Plus [AH]; Dentsply Sirona, Tulsa, OK) or calcium silicate–based sealer (EndoSequence BC Sealer [BC]; Brasseler, Savannah, GA). To assess the antimicrobial activity of DSP-loaded sealers, the apical third of single-rooted teeth was obtained and infected with E. faecalis for 3 weeks followed by the application of experimental (DSP-loaded) sealers or corresponding controls for up to 28 days. Microbiological analysis and laser scanning confocal and scanning electron microscopy were used to determine the colony-forming unit (CFU)/mL, the percentage of live bacteria, and the intratubular bacterial and sealer penetrations. Factorial analysis of variance and Tukey post hoc tests were used to assess the antimicrobial effect of DSPs on different sealers. All experimental groups showed significant reductions in CFUs at all-time points compared with positive controls (P <.05). The addition of DSPs to BC significantly reduced the CFUs (2.11 ± 0.13, 2.22 ± 0.19, and 2.25 ± 0.17 at 1, 7, and 28 days, respectively) compared with the unmodified sealer (3.21 ± 0.11, 4.3 ± 0.15, and 4.2 ± 0.2 at 0, 7, and 28 days). DSPs enhanced the antimicrobial performance of AH only at 1 day (4.21 ± 0.17 vs 5.19 ± 0.12, P <.05). AH and AH + DSPs showed higher bacterial viability compared with BC and BC + DSPs at all incubation periods (P <.05). Loading endodontic sealers with DSPs had a material-dependent effect on the antimicrobial properties and could reduce the incidence of secondary infections. [ABSTRACT FROM AUTHOR]

Nature offers a wide range of evolutionary optimized materials that combine unique properties with intrinsic biocompatibility and that can be exploited as biomimetic materials. The R5 and RRIL peptides employed here are derived from silaffin proteins that play a crucial role in the biomineralization of marine diatom silica shells and are also able to form silica materials in vitro. Here, we demonstrate the application of biomimetic silica particles as a vaccine delivery and adjuvant platform by linking the precipitating peptides R5 and the RRIL motif to a variety of peptide antigens. The resulting antigen-loaded silica particles combine the advantages of biomaterial-based vaccines with the proven intracellular uptake of silica particles. These particles induce NETosis in human neutrophils as well as IL-6 and TNF-α secretion in murine bone marrow-derived dendritic cells.

Silica particles were used as a filler to produce silica-epoxy composite. Silica particles with two mean diameters of 1 \im and 37 u.m and filler content of 20, 30, 40, and 60 wt.% were used to investigate the effect of particle size and filler content on the fracture behavior of epoxy resin composite, respectively. The fractural behavior of composites was characterized by linear elastic fracture mechanics according to standard of ASTM-D5045 in which three-point bending test procedure was used to investigate plane-strain fracture toughness (KI) and strain energy release rate (G1C) of the composite specimens. Glass transient temperatures of the samples were evaluated by using differential scanning calorimetry (DSC). Fracture surfaces of the produced specimens were examined by SEM. The highest Young's modulus value was 10.48 GPa for the sample produced with 37 Km particle size and 60 wt.% filler content and it was found that a considerable increase was obtained according to the 3.05 MPa values of the unfilled epoxy. Experimental results show that fracture toughness value of the silica filled epoxy composite was improved by 98% compared to unfilled epoxy. [ABSTRACT FROM AUTHOR]

The purpose of this study is to describe the enhancement of molecular‐shape selectivity and grafted polymer characteristics by altering the particle size, pore size, and polymer chains of polymer‐silica hybrid materials used in reversed‐phase liquid chromatography. The poly(octadecyl acrylate‐alt‐N‐octadecylmaleimide)‐grafted silica hybrid materials were prepared with 3 and 5 μm particle size silica, respectively. The alternating copolymerisations were conducted with 3‐mercaptopropyltrimethoxysilane‐modified silica via surface‐initiated radical chain transfer reactions. The polymer‐silica hybrid materials were characterised by elemental analyses, diffuse reflectance FTIR spectroscopy, solid‐state 13C and 29Si cross‐polarisation–magic‐angle spinning and suspended‐state 1H NMR spectroscopy. The NMR spectroscopy results revealed that the alkyl chains of 3 μm particle size phase are more ordered than those of 5 μm particle size phase at lower temperatures and vice versa at higher temperatures. After detailed characterisation, the hybrid materials were packed into a stainless‐steel column, and their chromatographic performance with polycyclic aromatic hydrocarbons was compared. Regardless of the grafting‐density, ordering of the alkyl chains, and column temperature, differences in molecular‐planarity selectivity molecular‐linearity were observed. Aspects of molecular‐shape selectivity were also evaluated using the standard reference material for priority pollutant polycyclic aromatic hydrocarbons. [ABSTRACT FROM AUTHOR]

Positive effect of silica reinforcement in bentonite clay based geopolymer has been observed in the present investigation. In this research, heat treated bentonite clay with varying percentages of silica reinforcing particles (low, medium and high concentration) were used to prepare geopolymer mortars. While a constant quantity (25%) of sodium hydroxide and sodium silicate mixture was used. The effect of reinforcing silica particles on the physical and mechanical integrity of heat treated bentonite clay based geopolymer mortar has been elaborated in this research. After geopolymerization and de-hydroxylation, density (bulk and apparent) and porosity were measured for the all geopolymeric samples. Various techniques like FTIR (to confirm degree of geopolymerization), XRD (to determine the mineral phases), TGA (to measure the weight loss), and SEM (to study the microstructure) were used for the characterization of samples. The sample with low percentage of silica particles showed higher degree of polymerization. A compressive strength upto 57 MPa was achieved for the sample having high concentration (90%) of silica. The evaluation of various samples demonstrated that heat-treated bentonite-silica particles reinforced geopolymers were viable and eco-friendly alternative to fly ash geopolymers. [ABSTRACT FROM AUTHOR]

The cytotoxicities of silica (SiO2s) particles against cancers are still controversial. In this study, the purchased submicron silica particles (SM-SiO2s) were identified by transmission electron microscopy and energy dispersive spectrometer, and it showed potent cytotoxicities on hepatocellular carcinoma (HCC), non-small cell lung cancer (NSCLC) and breast cancer (BC), which ranked the top in the incidence among the tumor types. Through the microarray assay on long noncoding RNAs (lncRNAs) from the SM-SiO2s-treated HCC, NSCLC and BC cells, followed by Venn analysis, we found that a series of lncRNAs were significantly regulated by SM-SiO2s, among of which XLOC_001659 was mostly decreased. Quantitative reverse transcription-polymerase chain reaction (qRT-PCR) assay confirmed that XLOC_001659 could be decreased in all the SM-SiO2s-treated HCC, NSCLC and BC cells, coupled to inhibited cell proliferation. Further, XLOC_001659 was recognized as a miR-98-5p sponge and therefore modulates the "pro-inflammatory tumor promoter" MAP3K2 expressions. The XLOC_001659/miR-98-5p/MAP3K2 axis uniformly mediated the regulation of SM-SiO2s on proliferation of HCC, NSCLC and BC cells. Further clinical experiments demonstrated that XLOC_001659 was negatively correlated with miR-98-5p level and positively correlated with MAP3K2 level, and XLOC_001659/miR-98-5p/MAP3K2 axis was significantly associated with progressions and prognosis in HCC, NSCLC and BC patients. These results provide a new clue for the anti-tumor mechanism of SM-SiO2s and a new way for drug development by using SM-SiO2s. [ABSTRACT FROM AUTHOR]