SiO2 Nanoparticles Research Articles

Sol–gel synthesis of silicon oxide (SiO2) nanoparticles: exploring gas sensing and photocatalytic applications

In this research, silicon oxide (SiO2) nanoparticles (NPs) were synthesized using the sol–gel method. The synthesized materials were characterized through various techniques. Fourier transform infrared spectroscopy (FTIR) revealed the absorption band corresponding to Si–O–Si bonds. Ultraviolet–visible (UV–Vis) spectroscopy analysis indicated a band gap energy of 5 eV. X-ray diffraction (XRD) analysis displayed a broad peak, confirming the amorphous nature of the material. Field emission scanning electron microscopy (FESEM) further demonstrated a spherical morphology of the SiO2 NPs. The photocatalytic degradation of MB dye using SiO2 NPs has been examined, revealing promising and improved degradation properties. Even a small amount of SiO2 NPs achieved around 69.20% degradation of MB within 240 min, with the rate constant for the material being 0.001 min−1. The gas sensing properties of the SiO2 NPs were tested on domestic gas sensor units for different gases, including ethanol, methanol, CO2, LPG, H2S, NH3, O2, and Cl2, at temperatures ranging from room temperature to 300 °C. Among these materials, SiO₂ NPs displayed the strongest response to H₂S gas, showing outstanding gas-sensing performance at a concentration of 100 ppm. The response time was 18 S, with a quick recovery time of approximately 22 S.Graphical

Innovative Hygroscopic Material for Humidity Regulation: Diatomaceous Earth Composite Porous Ceramic

Urbanization in hot and humid regions such as southern China has increased the demand for comfortable indoor environments. In order to design a material for efficient passive indoor humidity regulation, this study investigates a composite material that combines the hygroscopic properties of salt and the adsorption capacity of diatomaceous earth (DE). Firstly, we prepared DE and boehmite into moisture-absorbing porous materials. Then, the initial DE-based sample was innovatively doped with SiO2 nanomaterials and loaded with LiCl to enhance the humidity regulation ability of the composite, especially in the adsorption and desorption ability of water vapour. The microstructure and phase composition of the composite samples were analysed, and we observed an increase in porosity, filling performance and capillary condensation upon the introduction of SiO2 nanoparticles. The hygroscopic salt loaded into the pores can absorb more water when exposed to the ambient humidity. This synergic effect can effectively improve the hygroscopic performance of the composite material while maintaining the stability of the physical and chemical properties. The optimized samples showed a moisture absorption rate of 28% in high-humidity environments, meeting moisture buffer value evaluation standards. The study’s findings lay the foundation for the future integration of these materials through advanced manufacturing technologies.

Binder-free SiO2 nanoparticles coated polypropylene separator for high performance lithium-ion battery

Binder-free SiO2 nanoparticles coated polypropylene separator for high performance lithium-ion battery

Optimizing the electrocatalytic hydrogen production with vanadyl porphyrin impregnated on mesoporous SiO2 nanoparticles

Optimizing the electrocatalytic hydrogen production with vanadyl porphyrin impregnated on mesoporous SiO2 nanoparticles

Antibacterial UV-Curable Gel with Hydroxyapatite Nanoparticles for Regenerative Medicine in the Field of Orthopedics

The development and analysis of the properties of a new material based on UV-curable acrylate monomers with silicon-containing hydroxyapatite and zinc oxide nanoparticles as an antibacterial component and gelatin was carried out. Using this material in orthopedics and dentistry is very convenient because it covers any surface geometry of metal implants and hardens under ultraviolet light. In this work, sorption properties, changes in porosity, and mechanical properties of the material were investigated. The conditions for obtaining hydroxyapatite (HA) nanoparticles and the presence of silicon oxide nanoparticles and organic for the shell in an aqueous medium were studied for the pH of the medium, the sequence of administration and concentration of the material components, as well as antibacterial properties. This polymer material is partially resorbable. That supports not only the growth of bone cells but also serves as a protective layer. It reduces friction between organic tissues and a metal implant and can be a solution to the problem of the aseptic instability of metal implants. The material can also be used to repair damaged bones and cartilage tissues, especially in cases where the application and curing procedure is performed using laparoscopic methods. In this work, the authors propose a simple and quite cheap method for obtaining material based on photopolymerizable acrylates and natural gelatin with nanoparticles of HA, zinc oxide, and silicon oxide. The method allows one to obtain a composite material with different nanoparticles in a polymer matrix which retain the requisite properties needed such as active-sized HA, antibacterial ZnO, and structure-forming and stability-improving SiO2 nanoparticles.

Synthesis and comprehensive investigation of ZnCoFe2O4 nanoferrite: unveiling SiO2 nanoparticle substitution effects on structural, morphological, and magnetic properties

Synthesis and comprehensive investigation of ZnCoFe2O4 nanoferrite: unveiling SiO2 nanoparticle substitution effects on structural, morphological, and magnetic properties

Organic-Inorganic Hybrid One-Dimensional Photonic Crystals with Blue and NIR Dual Bandgaps for Light Protection.

Planar 1D photonic crystals (1DPhCs), owing to their photonic bandgaps (PBGs) formed by unique structural interference, are widely utilized in light protection applications. Multifunctional coatings that integrate various light management functions are highly desired. In this study, we present the fabrication of dual-PBG 1DPhCs with high reflectance in both the blue and near-infrared (NIR) regions. The 1DPhCs were constructed through the alternating stacking of hollow SiO2 (HS) nanoparticles hybridized with poly(vinyl alcohol) (PVA), referred to as PHS, and TiO2 layers. The 1DPhC with 7 bilayers demonstrated remarkable reflectance of 98.2% and 93.4% in the blue and NIR spectra, respectively, with shielding efficiencies of 93.9% and 85.6%. Compared to bare PC, the temperature was observed to be 10.6 °C lower, achieving a thermal insulation efficiency of 44.8% in the 900 nm near-infrared range. Additionally, spectral fitting using the transfer matrix method (TMM) and optimization of process parameters, including PHS concentration and spin-coating speed, enabled the fabrication of 1DPhCs with tunable optical thickness ratios. The fabricated films demonstrated a smooth surface morphology with flat and uniform interfaces, as well as excellent environmental stability. These features make the 1DPhCs highly promising for applications in light protection and thermal management. This study provides a novel approach for the development of dual-PBG 1DPhCs with enhanced protective capabilities.

Use of SiO2 nanoparticles preparation in carp feeding

A series of studies were performed to evaluate the biological properties and productive action of a silicon dioxide nanoparticle preparation (NPS SiO2) on a carp model. The NPS SiO2 preparation obtained by plasma-chemical synthesis was used (d=126.5±9.7 nm, Z-potential - 29±0.1 mV). The NPS SiO2 preparation was characterized by the absence of toxicity in the range from 1.5•10-5 to 5•10-1 g/l (Escherichia coli K12 TG1 biosensor model). The effect of NPS SiO2 in three dosages (100, 200, 300 mg/kg of feed) on the productivity and metabolism in the carp body was studied. The optimal dosage of NPS SiO2 was established, amounting to 200 mg/kg. When including NPS SiO2 in a complete feed with a crude protein content of 23%, the fact of increasing the intensity of carp growth by 10.2 - 14.1% was established. At the same time, an increase in the content of total protein in the blood serum of fish and an increase in the content of a number of amino acids in the liver of carp were established. In the second experiment, the productivity and metabolism of mineral substances in carp were studied with joint feeding of NPS SiO2 and amino acids (lysine, mytheonine, arginine).

Superhydrophobic coatings on meta-aramid papers enabled by mechanical interlocking for anti-thermal aging applications

Abstract The durability of superhydrophobic coatings has emerged as a pivotal consideration for their practical applications. Conventional methods for preparing robust superhydrophobic coatings often incorporate chemical binders. However, these binders are susceptible to melting and embrittlement under high temperatures, greatly limiting their stable service life, particularly in complex outdoor environments. Herein, the meta-aramid papers are treated with superhydrophobic modification using the surface-embedded spray coating technique. Benefiting from the unique deprotonation and reprotonation features of meta-aramid fibers, the paper surface morphology is reconstructed into a porous micro-nano structure. Given the comparable dimensions between the hydrophobic nano-SiO2 particles and the surface pores, the SiO2 particles become surface-embedded within the pores, resulting in a firmly bonded superhydrophobic coating. Furthermore, additional hydrogen bonds are formed between the SiO2 particles and meta-aramid fibers, further strengthening their adhesion. The as-prepared paper can endure temperatures up to 260℃, preserving a contact angle >150° and a sliding angle <5°. It also exhibits exceptional abrasion durability even after thermal aging. Additionally, the DC wet flashover voltage maintains over 95% of its original value. Our surface-embedded strategy offers an innovative alternative to chemical binders and enhances the viability of superhydrophobic coatings for applications in high-temperature environments.

Synthesis and performance analysis of novel SiO2 Janus nanoparticles for enhancing gas foam injection in oil reservoirs

Gas foam injection offers a viable solution to challenges faced in oil reservoirs, yet ensuring optimal foamability and stability remains a pivotal hurdle in practical field operations. This study presents a novel synthesis procedure to create silica (SiO2) Janus nanoparticles (JNPs) and examines their potential to enhance gas foam stability for enhanced oil recovery (EOR) applications. Two variations of SiO2 JNPs were synthesized via a masking procedure, employing oleic acid and ascorbic acid within a Pickering emulsion, marking a pioneering approach. These nanoparticles underwent comprehensive analysis for a deeper understanding. The investigation sought to unravel the mechanisms behind these JNPs’ performance in the foam injection process, probing various operational parameters such as JNP type, concentration, and gas medium (air, CO2, and CH4) impact on surface tension reduction, foamability, and stability through static tests. Results uncovered remarkable efficiency in SiO2-oleic acid JNPs, showcasing a substantial edge in reducing surface tension compared to bare SiO2 nanoparticles. Specifically, at a concentration of 15,000 ppm, SiO2-oleic acid JNPs demonstrated a 25 mN/m greater reduction in surface tension than bare SiO2 within a CH4 medium. Notably, while the gas type had limited influence on surface tension under standard pressure, the synthesized JNPs showed superior foam stabilization in air compared to CO2 and CH4 environments. SiO2-oleic JNPs exhibited outstanding foamability, stabilizing 80% of the foam generator cell’s height and remaining stable for 122 min during the EOR process. Conversely, ascorbic acid-SiO2-oleic acid JNPs displayed elevated foamability but reduced stability compared to SiO2-oleic acid JNPs. Despite achieving full height in the foam generator cell, stability was limited to 26 min in the CO2 medium.

Uptake and transpiration of solid and hollow SiO2 nanoparticles by terrestrial plant (Apium Graveolens var. secalinum).

Recent studies have raised concerns about the potential toxicity of amorphous silica (SiO2) nanoparticles (NPs). This investigation explores the uptake, transport, and transpiration of silica NPs in Apium graveolens var. secalinum. The study reveals that SiO2 NPs can infiltrate the plant cell wall, translocate from roots to stems and leaves, leading to elevated silicon levels and posing ingestion exposure risks. Furthermore, the release of these NPs through transpiration droplets (481±205mg·m-2day-1 for 10nm SiO2 NPs and 367±22mg·m-2day-1for 20nm SiO2 NPs) presents significant health and environmental hazards. Modeling silica-coated NPs with thin-shelled hollow silica (h-SiO2) NPs demonstrate in vitro and in vivo toxicity. Exposure of mice to these NPs (10mg·Kg-1day-1) over four weeks induces oxidative stress, inflammation, and apoptosis, along with observed tissue damage in the brain, liver, and kidneys. These findings necessitate additional research into the neurobehavioral impacts of nanoparticles on mice.

Superhydrophobic Nanocoatings Fabricated by Materials with Low Young's Contact Angle.

To achieve superhydrophobicity with an apparent contact angle (θ*) greater than 150° on rough surfaces, materials with a high Young's contact angle (θY > 90°) are commonly utilized. However, achieving superhydrophobicity with θY < 90° materials without specific auxiliary designs faces unknown challenges. Here, we develop a novel superhydrophobic nanocoating with θ* of ∼155° sprayed by an ethanol suspension only composed of bisphenol A epoxy resin (EPA) with a low θY of ∼70° and hydrophilic SiO2 nanoparticles. Additionally, we also show more superhydrophobic nanocoatings created by low θY resins that even down to 58°. This superhydrophobicity results from sustained three-dimensional hydrogen bonding equilibrium on the droplet surface postcontact with the rough surface, despite low θY. We also constructed a wetting transition model to quantify the impact of surface energy on the stability of droplet surface structures and revealed how the concentration of EPA can regulate the wetting behavior of the coating.

Enhancing hepatocellular carcinoma therapy with DOX-loaded SiO2 nanoparticles via mTOR-TFEB pathway autophagic flux inhibition

Chemotherapeutic drugs often fail to provide long-term efficacy due to their lack of specificity and high toxicity. To enhance the biosafety and reduce the side effects of these drugs, various nanocarrier delivery systems have been developed. In this study, we loaded the anticancer drug doxorubicin (DOX) and an MRI contrast agent into silica nanoparticles, coating them with pH-responsive and tumor cell-targeting polymers. These polymers enable the carrier to achieve targeted delivery and controlled drug release in acidic environments. This integrated diagnostic and therapeutic strategy successfully achieved both the diagnosis and treatment of liver cancer. Additionally, we demonstrated that the nanocarrier inhibits autophagic flux in liver cancer cells by targeting the autophagy-lysosome pathway and regulating the nuclear translocation of TFEB, thereby promoting tumor cell death. This novel diagnostic-integrated nanocarrier is expected to be a promising tool for targeted liver cancer treatment.

Sonochemical Functionalization of SiO2 Nanoparticles with Citric Acid and Monoethanolamine and Its Remarkable Effect on Antibacterial Activity.

Nanoparticles (NPs) are excellent antibacterial agents due to their ability to interact with microorganisms at the cellular level. However, their antimicrobial capacity can be limited by their tendency to agglomerate. Functionalizing NPs with suitable ligands improves their stability and dispersion in different media and enhances their antibacterial activity. The present work studied the functionalization of SiO2 NPs using the sonochemical method and the Influence of organic ligands on antimicrobial activity (AA). The organic ligands studied were citric acid (CA) and monoethanolamine (MEA). X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) results confirmed the amorphous structure of SiO2 NPs and their functionalization. Thermogravimetric analysis (TGA) and X-ray photoelectron spectroscopy (XPS) showed that functionalization with MEA (SiO2-MEA NPs) is more favored compared to AC (SiO2-CA NPs), and the organic ligand content was 34.42% and 28.0%, respectively. Fourier-transform infrared spectroscopy (FTIR) and RAMAN spectroscopy results confirmed the functionalization of NPs through the presence of carboxyl and amino groups. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), and zeta potential results showed that functionalization of SiO2 NPs helped to improve their dispersion and prevent their agglomeration. Furthermore, the results of antibacterial activity against Staphylococcus aureus and Escherichia coli showed that the functionalization provided a significant improvement in the antibacterial activity (AA) of the SiO2 NPs, where the SiO2-CA NPs showed the highest activity, with a 99.99% inhibition percentage at concentrations of 200 ppm against both E. coli and S. aureus strains. The AA is maintained at high concentrations of 1200 ppm, which is essential in applications requiring high percentages of biocidal NPs, such as marine coatings.

Enhancing the morphological and mechanical performances of basalt/glass fiber/polymer composites modified with hybrid MWCNTs and SiO2 nanoparticles

Enhancing the morphological and mechanical performances of basalt/glass fiber/polymer composites modified with hybrid MWCNTs and SiO2 nanoparticles

Robust, Fluorine-Free Superhydrophobic Films on Glass via Epoxysilane Pretreatment.

Durable and fluorine-free superhydrophobic films were fabricated by a simple two-step process involving the pretreatment of glass substrates with an epoxysilane, which acted as an adhesive. The next step involved the aerosol-assisted chemical vapor deposition of a simple mixture of polydimethylsiloxane (PDMS) and SiO2 nanoparticles (NPs). Various parameters were studied, such as deposition time as well as PDMS and SiO2 loadings. The optimum film generated was with a 1:1 loading of PDMS and SiO2, deposited at 360 °C for 40 min. The resultant film demonstrated excellent water repellency with a water contact angle of 165 ± 3° and a sliding angle of 2°. The epoxysilane underlayer provided the adhesion between the film and substrate. The films maintained superhydrophobicity and durability after being exposed to solvents such as diethyl ether, toluene, and ethanol for up to 5 h, 400 tape peel cycles, UV exposure, and heat exposure at 400 °C. The robustness results indicated enhanced durability relative to the superhydrophobic film without the epoxysilane underlayer.

Reducing the length of the conical geothermal heat exchanger by using variable pitch and hybrid nanoparticles of Al2O3 and SiO2

Reducing the length of the conical geothermal heat exchanger by using variable pitch and hybrid nanoparticles of Al2O3 and SiO2

Superhydrophobic Coatings Based on PMMA-Siloxane-Silica and Modified Silica Nanoparticles Deposited on AA2024-T3.

The study aimed to develop a superhydrophobic coating on the aluminium alloy 2024-T3 surface. The desired surface roughness and low surface energy were achieved with SiO2 nanoparticles, synthesised via the Stöber method and modified with alkyl silane (AS) or perfluoroalkyl silane (FAS). To enhance particle adhesion to the alloy substrate, nanoparticles were incorporated into a hybrid sol-gel coating composed of tetraethyl orthosilicate, methyl methacrylate, and 3-methacryloxypropyl trimethoxysilane. The coated substrates were characterised using field emission scanning and transmission electron microscopy with energy-dispersive spectroscopy for surface topography, nanoparticle size distribution, composition, and coating thickness. The corrosion resistance of the coatings on AA2024-T3 was evaluated in a 0.1 M NaCl solution using electrochemical impedance spectroscopy. The synthesised SiO2 nanoparticles had an average size between 25 and 35 nm. The water contact angles on coated aluminium surfaces reached 135° for SiO2 + AS and 151° for SiO2 + FAS. SiO2 + FAS, indicating superhydrophobic properties, showed the most uniform surface with the most consistent size distribution of the SiO2 nanoparticles. Incorporation of nanoparticles into the hybrid sol-gel coating further improved particle adhesion. The ~2 µm-thick coating also demonstrated efficient barrier properties, significantly enhancing corrosion resistance for over two months under the test conditions.

Preparation and initial condensation characteristics of superhydrophobic coating based on nano-SiO2 particles

Superhydrophobic surfaces can effectively inhibit the growth of droplets and reduce attachment, thus inhibiting the formation of frost. In this paper, using dimethyldimethoxysilane-modified silica nanoparticles, a superhydrophobic coating with a contact angle of 165.73 ± 1° and a rolling angle of 2 ± 1° was successfully prepared by the secondary spraying method, and the chemical composition of the substrate and the surface morphology of the coating were characterized by means of FT-IR, EDS, and SEM. A visualization test rig was constructed to investigate the condensation droplet growth characteristics on the superhydrophobic surface across various tilt angles (0°to 90°), cold surface temperatures (-1 ℃ to 5 ℃), and humidity levels (45% to 75%). The experimental results revealed that as the tilt angle increases, the forces acting on the condensed droplets change, resulting in a higher frequency of droplet merging, jumping, and slipping. Furthermore, a decrease in cold surface temperature accelerates the growth of condensed droplets. Under varying humidity conditions, droplets on the superhydrophobic surface nucleate and grow more rapidly in high humidity environments, where they exhibit a larger coverage area despite having a relatively small mean radius.

Durable, Transparent, and Superhydrophobic Film Design for Flexible Substrate

Transparent superhydrophobic films/coatings have recently gained significant attention in the solar energy field due to their ease of preparation, low cost, self‐cleaning process, and high effectiveness in reducing dust adhesion to the surface. Compared to the rigid glass cover, the organic one has an advantage of flexibility and light weight, but the dust deposition impact is more serious. The aim of the present study is to design a transparent and superhydrophobic film with good durability on the organic glass surface, to recover the module efficiency reduction caused by dust deposition. Based on a soft photolithography and hot‐pressing process, periodic microcavities are prepared on the organic glass surface as an armor structure, and hydrophobic SiO2 nanoparticles are sprayed into the microcavities to achieve anti‐reflection and superhydrophobicity. The experimental test results show that the designed film possesses a large contact angle around 160°, a sliding angle of 3°, and a high visible transmittance over 90%. The unique armor structure design greatly improves the wear resistance of the film, and after encountering harsh conditions such as sandpaper friction, water flow impact, acid immersion, UV exposure, and repeatable bending, it still maintains excellent superhydrophobicity.