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Fiberboard (FB) is extensively utilized in heat‐insulating refractory materials owing to its lightweight nature and excellent resistance to high temperatures. Nevertheless, the inadequate mechanical properties and limited dimensional stability of FB hinder its further application. The vacuum filtration was utilized in this study to manufacture inorganically modified insulation FB, incorporating plus fiber/1260 fiber and silica sol as the primary constituents and sepiolite powder (HS) as the modifier. The experimental results show that the fabricated samples exhibited extremely high porosity (75.3%–90.2%) and low thermal conductivity (.063–.15 W m−1 K−1, 200–800°C). The fibers were arranged in a three‐dimensional structure, overlapping with each other, and the silica sol adhered to the fibers, forming a spatial mesh structure through cross‐linking. Importantly, the incorporation of HS was effective in controlling the agglomeration of the silica sol, leading to a more uniform distribution within the fibers. Additionally, the study found that the mechanical properties (high hardness (64–72 HA)) and high‐temperature durability of the FBs were enhanced due to the flocculant modification. This study highlights promising prospects for industrial applications and offers a cost‐effective admixture for modifying and preparing high‐performance FBs, which is expected to see broad adoption in thermal insulation and energy conservation applications. [ABSTRACT FROM AUTHOR]

The effect of CaCO3 particle size on the viscosity of slurry, phase formation, microstructural evolution, and performances of the water‐soluble CaO‐based ceramic core sintered at different temperatures was systematically investigated and discussed, and the particle gradation orthogonal experiments were used to adjust flexural strength, water‐soluble rate, shrinkage rate, apparent porosity, and hygroscopicity rate. The results showed that the finer particle size increased the effective contact area between CaO and SiO2, which promoted the generation of CaO–SiO2 system phase and the dense microstructure in the sintered CaO‐based cores. The higher sintering resulted in dense microstructure. The optimal gradation scheme included 28 wt.%, 56 wt.%, and 16 wt.% CaCO3 powder with D50 = 11.0 µm, 6.17 µm, and 4.62 µm, respectively, and the resulting flexural strength was 9.57 MPa, water‐soluble rate was 65.37 g/h in 60°C water, shrinkage rate was 8.62%, porosity rate was 38.85%, presenting a well‐balanced comprehensive performance, which is significant for the complex internal castings. [ABSTRACT FROM AUTHOR]

In recent years, the service life of building materials has become the focus of attention. Among them, the service life of concrete and steel bars is particularly affected by the corrosion of external ions (such as Cl−) in the environment. To solve this problem, a new type of composite nanocolloid was prepared through a controllable preparation method. The composite nanocolloid is prepared from aluminum chloride sol and silica sol as raw materials. The prepared colloidal particles have a particle size distribution between 10.5 and 17.5 nm, exhibiting excellent stability and dispersibility. In order to verify the improvement effect of the composite nanocolloid on the properties of building materials, the influence of it on the porosity of concrete and the anti-corrosion performance of steel bars was experimentally studied. The results indicate that the moisture absorption and dehumidification speed of concrete treated with composite nano colloids is slower, and the pore size distribution is mainly concentrated in 100–1,000 nm, indicating that the colloids can effectively optimize the pore structure of concrete. In addition, the processed steel plate samples showed high AC impedance values and low corrosion current logarithmic values in electrochemical testing, indicating that composite nanocolloids have a significant protective effect on the corrosion of steel bars, which can effectively improve the performance of building materials and extend their service life.

Silica sol can activate the surface of hollow ceramic microspheres and improve the properties of composite materials by improving the interface between the microspheres and the epoxy resin. The group changes on the surface of microspheres were measured using infrared spectroscopy. The microspheres were observed with a scanning electron microscope. The density, water absorption, and mechanical properties of the materials were tested using scales and mechanical testing machines. The results showed that SiO2 and silane molecules were introduced on the surface of the microspheres after treatments. As the silica sol content increased, the slurry viscosity increased by 34.5%, the composite density increased by 5.8%, and the water absorption decreased by 35.8%. When the silica sol content was 25%, the flexural strength and compressive strength of the composites were 73.49 and 116.27 MPa, respectively, which were 37.8% and 23.6% higher than those of the untreated composites, and the mechanical properties became clearly improved. High mechanical properties enable the materials to be used in deeper ocean areas. Highlights: Nanoparticles are introduced onto the surface of hollow microspheres.The activated microspheres can bind better to the silane coupling agent.Silane coupling agent assisted by silica sol improved interfacial bonding.Surface activation of microspheres improves the properties of composites. [ABSTRACT FROM AUTHOR]

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The low-permeability argillaceous rock mass is an unfavorable geological body commonly found in the construction process of underground engineering conditions such as roadways and tunnels. Due to the compact structure and low permeability of the rock mass, grouting with conventional materials cannot effectively seal the micro-cracks of the rock mass. Based on the low efficiency of high-pressure grouting of nano-silica sol, this paper preliminarily explores the regularities and mechanism of grouting and pore sealing of low-permeability rock mass under the action of silica sol imbibition from the aspects of gelling properties of silica sol, core pore structure, imbibition law, and pore sealing characteristics. The results show the following: (1) The increase in particle size during the gel process reduced the injectability and wettability of the silica sol. The imbibition properties of silica sol were time-varying, and the deterioration inflection points of injectability and wettability appeared at 10 h and 9 h, respectively. (2) Catalyst, temperature, gel process, and rock mass permeability will affect the law of core imbibition, and the injectability and capillary force of the grouting material and rock mass will jointly affect the imbibition process of silica sol. (3) Silica sol imbibition changed the pore size distribution of the core, the pore volume above 50 nm decreased, and the pore volume below 50 nm increased. Silica sol has multiple effects such as filling, adsorption, and percolation in the imbibition process of the micro-pores of rock mass, and the adsorption and percolation of silica are related to the nano micro-pores. [ABSTRACT FROM AUTHOR]

Inorganic binders have become a research hotspot in the field of anti-corrosive coatings due to their advantages in economy, environmental friendliness and practicality. In this paper, the preparation and properties of three commonly used inorganic binder anti-corrosive coatings, namely phosphate, silicate and silica sol, were reviewed. Firstly, the bonding mechanisms and adhesion film formation mechanisms of the three binders were clarified. Then, the synthesis, anti-corrosive properties and existing problems of three kinds of inorganic binder-based anti-corrosive coatings were discussed. Finally, the development trends and application prospects of inorganic binder anti-corrosive coatings were examined.

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The application of fast-growing Chinese fir (Cunninghamia lanceolata) is limited due to low dimensional stability and weak mechanical strength. Silica sol can effectively improve fast-growing fir wood's physical and mechanical properties. In order to clarify the influence of impregnation process parameters on the modification effect, the effect of the vacuum impregnation variants (e.g., pre-vacuum time, pre-vacuum pressure, pressurization time, and pressurization pressure) was discussed using the orthogonal test approach. The optimal modification process was determined by comparing the water absorption and nail-holding power under different modification processes. The range analysis and variance analysis methods were used to study the correlation between process factors and the performance of the modified wood. The results showed that the water absorption and nail-holding power of fast-growing fir wood were significantly improved via vacuum impregnating with silica sol. The optimum process parameters for water absorption and nail-holding power of fast-growing fir as the pre-vacuum time was 30 min, the pre-vacuum pressure was −0.08 MPa, the pressurization time was 3 h, and the pressurization pressure was 1.2 MPa. [ABSTRACT FROM AUTHOR]

The organosilicon modified silica sol sealant was prepared by modifying silica sol with methyltrimethoxysilane and dimethyldimethoxysilane, and the porous Al2 O3 ceramic sheets were sealed by impregnation and heating curing. The effects of curing temperature and time on the insulation properties of porous Al2 O3 ceramics sheets were studied, and the microstructure of porous Al2 O3 ceramic sheets before and after sealing was characterized. The results show that the optimal conditions are that curing temperature of 120 and curing time of 60 min, at which the DC and AC breakdown voltage of the Al2 O3 ceramic sheets reach the maximum values of 10. 76 kV and 6. 01 kV respectively, and the insulation resistance of 1,000 V reaches more than 9,999 MΩ. The surface of the Al2 O3 ceramic sheet is a modified silica sol coating, which is compact, non-porous and tightly bound to the matrix. The coating thickness is about 25 mm, the surface water contact angle is increased to 86. 93°, and the depth of the layer is about 10 μm. [ABSTRACT FROM AUTHOR]

In this study, a composite modifier for wood impregnation is prepared, which is functional and environmentally friendly. The surface of silica sol was modified by using KH-560. The modified silica sol, melamine, and glyoxal were used as raw materials. The silica sol/melamine glyoxal resin (from now on referred to as Silica sol/MG) composite modifier was prepared based on in-situ polymerization. The physicochemical properties (viscosity, solid content and etc.) of the composite modifier were evaluated. The structural and thermal properties were characterized and analyzed by FTIR spectroscopy, particle size distribution, TG and DSC. The results showed that the viscosity and solid content of the composite modifier decreased with the increase in the mass of the silica sol. The FTIR spectroscopy showed peaks at 473 cm−1 and 1101 cm−1, which were assigned to bending and stretching vibrations of the Si-O-Si bond, respectively, indicating that the modified silica sol was successfully introduced into the MG resin. When the modified silica sol mass fraction was 30%-40%, the particle size distribution of the composite modifier was relatively uniform. TG analysis found that the thermal stability of the composite modifier was significantly improved compared with the unmodified resin. DSC analysis showed that adding the modified silica sol reduced the curing temperature of the modifier from 115.5 °C to 107.9 °C.

This work aims to improve the thermal stability and flame retardancy of cotton fabrics treated just by a single SiO2, a single B2O3 and their binary composite sol–gel systems. Tetraethyl orthosilicate (TEOS) and tributyl borate were used as precursors. The sols were coated onto cotton fabrics via dipping-baking processes. Techniques including Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), Scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), thermogravimetric analysis (TGA), limiting oxygen index (LOI) and vertical burning test (VBT) were used to investigate the surface functional groups, elemental compositions, crystal structures, surface morphologies, elemental contents, thermal stability and flame retardancy levels of original and sols-treated cotton fabrics, respectively. The results show that the sols converted gel coatings are successfully deposited on the cotton fabric surfaces. SiO2-B2O3 sol finishing cotton fabric shows the best flame retardancy. It shows the highest char residue rate (43.82%), the highest LOI (25.7%) and ΔLOI/Δm (7.0%/g), the lowest after-flame time (10.0 s) and after-glow time (0.0 s without a smoldering process), a relatively complete and continuous char residue after a VBT. The SiO2 and B2O3 sol–gel systems play more synergistic effects than competitive effects in flame retarding a cotton fabric. A SiO2 gel shows effects of a high melting point, a structural support and dimensional stability, while a B2O3 gel shows a fusing capability and a longer pyrolysis process. [ABSTRACT FROM AUTHOR]

[Display omitted] • A Ca2+ modified diatom biosilica-based hemostat (DBp-Ca2+) with a full scale hierarchical porous structure (pore sizes range from micrometers to nanometers) was prepared. • Provided new insights to the study of the procoagulant mechanism of porous inorganic materials through the adsorption of pores with hierarchical porous structure on water, blood, and plasma proteins. • The DBp-Ca2+ exhibited efficient water absorption (the time to complete water exchange was <80 ms), extensive scale protein absorption (the absorption range: 1–500 nm), enhanced hemocyte aggregation capacity, in situ prothrombin activation and rapid hemostasis (clotting time was 15 %–20 % shorter than that of Quikclot®). Here, we developed a Ca2+ modified diatom biosilica-based hemostat (DBp-Ca2+) with a full scale hierarchical porous structure (pore sizes range from micrometers to nanometers). The unique porous size in stepped arrangement of DBp-Ca2+give it selective adsorption capacity during coagulation process, resulted in rapid hemorrhage control. Based on in vitro and in vivo studies, it was confirmed that the primary micropores of DBp-Ca2+gave it high porosity to hold water (water absorption: 78.46 ± 1.12 %) and protein (protein absorption: 83.7 ± 1.33 mg/g). Its secondary mesopores to macropores could reduce of water diffusion length to accelerate blood exchange (complete within 300 ms). The tertiary stacking pores of DBp-Ca2+ could absorb platelets and erythrocytes to reduce more than 50 % of thrombosis time, and provided enough contact between Ca active site and coagulation factors for triggering clotting cascade reaction. This work not only developed a novel DBs based hemostat with efficient hemorrhage control, but also provided new insights to study procoagulant mechanism of inorganic hemostat with hierarchical porous structure from selective adsorption to rapid hemostasis. [ABSTRACT FROM AUTHOR]

Duplex oxide ceramic fibers have excellent high temperature properties. However, controlling the microstructure of duplex oxide ceramic fibers is difficult and complexed. In this work, the effect of silica sols affecting the interaction of precursor sol-gel particles on the high-temperature phase transition and microstructure of alumina-mullite fibers was investigated. The results show that the silica sol affects the particle interactions and distribution in the mixed sol. Alumina-mullite fibers prepared from non-homogeneous precursor sols generated α-Al 2 O 3 at 1400 °C, while fibers prepared from homogeneous precursor sols required higher temperatures. In addition, mullite (3Al 2 O 3 :2SiO 2) with an orthogonal structure is more likely to be generated in the non-homogeneous Al 2 O 3 -SiO 2 precursor sol. The prepared alumina-mullite fibers have a tensile strength of up to 1.68 GPa. Finally, the mechanism of the influence of silica-sol properties on the final organization of the alumina-mullite fiber was further discussed. [ABSTRACT FROM AUTHOR]

Phenolic resin(PF) is commonly used as a binder in Al 2 O 3 -SiC-C bricks; however, it reduces the strength and accelerates the damage after carbonisation under temperatures of 300–800 °C. To improve the medium-temperature mechanical properties of Al 2 O 3 -SiC-C bricks, the mechanism of silica sol modify PF was analyzed, and silica sol modified phenolic resin (PFS) was introduced into Al 2 O 3 -SiC-C bricks to explore the effect of PFS on the mechanical properties of Al 2 O 3 -SiC-C bricks. The results showed that the silanol groups (Si-OH) in the silica sol can react with the hydroxyl groups (-OH) in the PF to form a Si-O-C bond, which makes PFS have a higher residual carbon rate and greater thermal stability. Overall, the introduction of PFS enhances the mechanical properties of the Al 2 O 3 -SiC-C bricks. When the content of silica sol in PFS is 10 wt%, the cold modulus of rupture and compressive strengths increased by 62.6% and 22.1%, respectively. [ABSTRACT FROM AUTHOR]

In this study, a composite modifier for wood impregnation is prepared, which is functional and environmentally friendly. The surface of silica sol was modified by using KH-560. The modified silica sol, melamine, and glyoxal were used as raw materials. The silica sol/melamine glyoxal resin (from now on referred to as Silica sol/MG) composite modifier was prepared based on in-situ polymerization. The physicochemical properties (viscosity, solid content and etc.) of the composite modifier were evaluated. The structural and thermal properties were characterized and analyzed by FTIR spectroscopy, particle size distribution, TG and DSC. The results showed that the viscosity and solid content of the composite modifier decreased with the increase in the mass of the silica sol. The FTIR spectroscopy showed peaks at 473 cm−1 and 1101 cm−1, which were assigned to bending and stretching vibrations of the Si-O-Si bond, respectively, indicating that the modified silica sol was successfully introduced into the MG resin. When the modified silica sol mass fraction was 30%-40%, the particle size distribution of the composite modifier was relatively uniform. TG analysis found that the thermal stability of the composite modifier was significantly improved compared with the unmodified resin. DSC analysis showed that adding the modified silica sol reduced the curing temperature of the modifier from 115.5 °C to 107.9 °C. [ABSTRACT FROM AUTHOR]

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Stain resistance is one of the important characteristics of exterior wall latex coatings in cities. Adding silica sol to the coating can increase its stain resistance. However, there is currently limited research on the long-term natural exposure test of latex coatings. This paper first investigates the influence of different amounts of silica sol on the elongation, water absorption, and stain resistance of coatings and obtains a better percentage of silica sol addition. Then, heat storage tests were conducted to obtain the viscosity and pH changes of the coating. Afterwards, outdoor natural exposure tests were conducted for up to 12 months to obtain the stain resistance of the coating with the addition of silica sol. The results indicate that the stain resistance value of the coating with added silica sol was significantly better than that without added silica sol after 12 months of natural exposure to sunlight, increasing by 65.8%. The formation of a network structure of Si O-Si bonds in the silica sol enhances the hardness and rigidity of the coating while also allowing it to enter the capillary tubes of the coating caused by prolonged exposure to sunlight, avoiding cracking of the coating and preventing the entry of dust and impurities. Therefore, the stain resistance of the coating is improved. These research results will contribute to the better application of exterior wall latex coatings in architecture. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The application of fast-growing Chinese fir (Cunninghamia lanceolata) is limited due to low dimensional stability and weak mechanical strength. Silica sol can effectively improve fast-growing fir wood’s physical and mechanical properties. In order to clarify the influence of impregnation process parameters on the modification effect, the effect of the vacuum impregnation variants (e.g., pre-vacuum time, pre-vacuum pressure, pressurization time, and pressurization pressure) was discussed using the orthogonal test approach. The optimal modification process was determined by comparing the water absorption and nail-holding power under different modification processes. The range analysis and variance analysis methods were used to study the correlation between process factors and the performance of the modified wood. The results showed that the water absorption and nail-holding power of fast-growing fir wood were significantly improved via vacuum impregnating with silica sol. The optimum process parameters for water absorption and nail-holding power of fast-growing fir as the pre-vacuum time was 30 min, the pre-vacuum pressure was −0.08 MPa, the pressurization time was 3 h, and the pressurization pressure was 1.2 MPa.

In this paper, quartz fiber‐reinforced silica matrix SiO2f/SiO2 composites were prepared by the precursor impregnation‐heat treatment method using quartz fiber needle felt as the reinforcement and silica sol as the precursor. The effects of particle size in silica sol (10, 50, and 100 nm) on the density, apparent porosity, mechanical properties, and thermal properties of SiO2f/SiO2 composites were investigated. The phase composition and microstructure of the composites were characterized by X‐ray diffraction and scanning electron microscopy, respectively. The thermal expansion coefficient and thermal conductivity of composites were measured by a push rod method and the laser method. The results show that the density, apparent porosity, and mechanical strength of the specimens firstly increase and then decrease with the increase in the particle size in silica sol. The sample using silica sol with particle size 50 nm has the optimum overall performances (i.e., the flexural strength of 13.7 MPa and the compressive strength of 59.8 MPa), and shows a ductile fracture behavior. At 300°C–700°C, the average thermal expansion coefficient of the optimal sample is.783 × 10−6/°C. And the thermal conductivity of the samples increases with the increase in temperature, and it reached the highest value of.810 W/(m·K) at 700°C. The SiO2f/SiO2 composites show obvious advantages in the application of load‐bearing and thermal insulation integration, and they are expected to meet the demanding requirements of hot‐pressing sintering and non‐ferrous metallurgy industries. [ABSTRACT FROM AUTHOR]

Copyright of Electroplating & Finishing is the property of Electroplating & Finishing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

It’s a universal engineering problem to seal micro-cracks of low-permeability argillaceous rock mass by grouting in the fields of civil engineering and mining. This paper achieved the grouting sealing of low- permeability artificial rocks with the permeability of 0.1–40 mD by adopting silica sol imbibition grouting. The variation characteristics of particle size, viscosity, and contact angle of silica sol during solidification and the pore size distribution of low-permeability artificial rocks were measured, and spontaneous imbibition tests of the artificial rocks were carried out. Finally, combined with the imbibition theory, percolation theory, and fracture medium grouting principle, the silica sol imbibition mechanism of low-permeability rocks and soil was discussed. The results show that: (1) Silica sol can be injected into artificial rocks with the minimum permeability of 0.1 mD through spontaneous imbibition; (2) The particle size increase of silica sol leads to decreased wettability, affinity, and injectability in grouting materials; and (3) In the range of 0.1–40 mD, the grout absorption first increases and then decreases with increased permeability. The number of large pores and fractures in the rock mass is related to injectability, and the number of small and medium pores is related to the internal driving force of imbibition. This study provides a theoretical basis for silica sol grouting sealing of low-permeability argillaceous rocks and is, therefore, an important reference for application.

To improve hydrophobicity and thermal stability, polydimethysiloxane (PDMS) emulsion and silica sol were used for depositing organic/inorganic hybrid coatings in wood. PDMS emulsion could provide the hydrophobic film to improve the hydrophobicity and dimensional stability owing to its low-surface-energy. Silica sol could significantly enhance the surface hardness and thermal stability due to its penetration in cell walls, indicating the pore-filling effect in wood. Moreover, in the hybrid system, silica incorporation in PDMS emulsion helped to form integrate coatings in wood via Si-O-Si cross-linked networks. The hydrophobicity, surface hardness and thermal stability of treated wood were related to the loadings of silica sol in the PDMS. Stiff silica could compensate the negative effect on thermal stability caused by PDMS, and synergistically improve the surface hydrophobicity and hardness of wood. This work opens a facile method to produce bio-based materials with satisfied hydrophobicity and thermal stability to be used in humid environments. [ABSTRACT FROM AUTHOR]

The present work aims to synthesize silica sol from the acidification of sulfuric acid plus sodium silicate. Three solutions of sodium silicate were prepared at different concentrations; these were mixed with a 17% diluted sulfuric acid solution until a whitish colloidal suspension was obtained. The pH of the final solutions obtained was determined. The colloidal suspensions obtained and the gel formed were analyzed in an infrared spectrophotometer to compare the functional groups they present with those of conventional chromium salt. Finally, tanning tests were carried out with the silica sol obtained plus an aldehyde, where the typical quality parameters of leather were analyzed: dry rubbing abrasion, elongation percentage, temperature shrinkage and tensile strength. These results were compared with the data of leather tanned with chromium salts. For the comparison, statistical tests such as multiple ranges, anova, and determination of means were carried out. It is obtained as a result that the process should be carried out at room temperature up to a pH of 2.5; the infrared spectrum reveals that the functional groups of sodium silicate are similar to the chromium salts used for the tanning process. The statistical analysis shows that the silica sol obtained from a 1/5 solution of sodium silicate presents quality parameters statistically similar to those obtained from conventional chrome salt tanning. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Pharmaceutical Negative Results is the property of ResearchTrentz and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Ceramic filter elements (FE) based on aluminosilicate fibers are produced by vacuum forming, using various drying methods. Microwave drying and freezing followed by drying are used as methods to reduce binder migration. FE microstructure, tensile strength, and aerodynamic resistance are analyzed. The characteristics obtained are compared with FE prepared using convective drying. [ABSTRACT FROM AUTHOR]

Copyright of Tekstilec is the property of University of Ljubljana, Faculty of Natural Sciences & Engineering, Department of Textiles and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

As the silicon - oxygen bond of silica sol is too rigid, it is easy to form microcracks during the film - forming cross - linking process. To overcome this problem, modified silica sol solution was prepared by sol - gel method using silane coupling agent and silica sol as raw materials, and coated on the surface of aluminum plate. The effects of pH value of silica sol, pH regulator type and reaction time on the properties of the above - mentioned silica sol and coating were studied, and the properties of such coating were characterized through Fourier transform infrared (FT - IR) spectroscopy, thermogravimetry (TG) and contact angle analyzer. Results showed that the modified silica sol had stable properties and the coating had a smooth surface, a pencil hardness up to 6 H, a temperature resistance of 500 ℃, a contact angle of 91°, and a good thermal stability.

A hydrophobic surface with an antibacterial property has numerous uses, including self-cleaning, anti-sticking, anti-contamination, sports apparel, and wound healing/implant materials. The durability of the coating in an aquas media (pH 7.4) is a vital requirement for use in technical textile sectors, particularly in medical applications. In this study, we used silica sol, chitosan and hexadecyltrimethoxysilane (HDTMS) to create exceptionally hydrophobic surfaces with antibacterial properties on cotton fabrics. First, cotton fabric was treated with silica sol, which was produced by the hydrolysis and condensation of tetraethoxysilane (TEOS) in an alkaline environment. After that, chitosan was applied on the silica sol-treated fabric to add an antibacterial characteristic. The silica sol-chitosan-treated fabric was then given a hydrolysed HDTMS treatment to give a highly hydrophobic property. The hydrophobicity was assessed by measuring the water contact angle, while the AATCC-147 test protocol was used to assess the antibacterial property. The developed fabric exhibited a strong hydrophobic property. The fabric samples were immersed in an aquas media for 30 days to assess the coating durability by observing changes in hydrophobicity and anti-bacterial activity in terms of the zone of inhibition (ZOI). After 30 days of immersion in the aquas media, it was observed that the contact angle decreased from 151.7° to 129.5°, and the ZOI increased from 1 mm to 5 mm, which indicates an increase in anti-bacterial activity in relation to time of immersion. The wicking characteristics of coated and uncoated fabrics were also measured to determine how coating affects the wicking behaviour of fabric. EDS was performed to observe the coating stability for coated-dipped fabric samples after 30 days. SEM analysis was performed to examine the surface morphology, while FTIR was used to determine the surface functional groups after coating and changes after dipping in the aquas media. The developed hydrophobic cotton fabrics with anti-bacterial properties may help in the fabrication of natural biomaterials and other technical textile products.

Silica sol is widely used in the preparation of mullite-based fiber porous ceramics (MFPCs), but it aggregates at the top surface of MFPCs during the drying process. This leads to the decrease in mechanical strength and porosity. To overcome the problem and fabricate homogeneous MFPCs, the sodium silicate solution and glass fibers were applied in the fabrication process of MFPCs. The effects of concentrations of sodium silicate solution and silica sol, amounts of glass fibers and sintering temperatures on the properties of prepared MFPCs were studied. The sodium silicate solution consolidated the silica sol and mullite fibers, forming a homogeneous structure and ensuring the even distribution of silica sol. Compared with other reported MFPCs, this process required low sintering temperature while maintaining high compressive strength (2.14 MPa) and porosity (75.93%). This study provides an effective method for preparing MFPCs with high strength, uniformity and porosity. • Mullite-based fiber porous ceramics (MFPCs) with high performances were fabricated. • Sodium silicate solution and glass fibers were applied for the preparation of MFPCs. • Sodium silicate solution consolidated silica sol and ensured even distribution. • Interlaced mullite fibers and glass fibers formed 3D structures and improved strength. • The fabrication process in this study required a low sintering temperature. [ABSTRACT FROM AUTHOR]

Copyright of Refractories / Naihuo Cailiao is the property of Naihuo Cailia (Refractories) Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

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In this study, nanosilica particles were prepared from self-made silica gel under the protection of citric acid in situ complexation and ethyl acetate as the latent acid reagent. The effects of ethyl acetate, citric acid, reaction temperature, and reaction time on the particle size of nanosilica were studied. The optimum process parameters were determined as follows: Vethyl acetate: Vsilica sol = 9:50, citric acid addition amount 3.64%, reaction time 8 h, and reaction temperature 70 °C. The products were characterized by IR, XRD, SEM and TEM analyses. The results show that the nano-silica particles prepared by complexation precipitation method employing silica sol as silicon source has good dispersion with average particle size controlled about 19.44 nm. The method has numerous advantages over the conventional inverse extraction method under colloid protection, and is expected to achieve industrial production. [ABSTRACT FROM AUTHOR]

BACKGROUND Through visiting the jadeite market, the existence of inorganic material-filled jadeite is known, but there is a lack of identification basis due to rare references. OBJECTIVES To understand the identification characteristics of inorganic material-filled jadeite. METHODS Two types of inorganic materials, water glass and silica sol, were used to fill low-grade jadeite in the simulation experiment. Conventional gemological tests, fluorescence image observation with DiamondViewTM, Fourier transform infrared (FTIR) spectroscopy, and laser-induced breakdown spectroscopy (LIBS) were used to test the inorganic filled jadeite samples. RESULTS The transparency, color, density and structure of jadeite were improved after filling. Under the DiamondViewTM, the jadeite particles in the sample showed green fluorescence, and the filling around the cracks and between the particles displayed blue fluorescence with non-uniform distribution. Mid-infrared reflectance spectrum analysis showed that the spectra of silica sol and water-glass were slightly different from each other. The absorption peaks of the samples filled with inorganic materials at 1162cm-1, 1070cm-1, 949cm-1, 579cm-1, 529cm-1 and 470cm-1 gradually weakened, and the peak shape gradually became smooth or disappeared. In addition, the differences between the jadeite and inorganic filled jadeite can be determined by the near-infrared spectral morphology and the shape of the absorption peak changed in the range of 7062cm-1, 5204cm-1 and 4537cm-1. The laser-induced breakdown spectroscopy demonstrated that the content of the silicon in the jadeite filled with silicon sol or sodium and potassium water-glass was higher. The high potassium content was an important feature for the jadeite filled by sodium and potassium water-glass. CONCLUSIONS The samples effect of the simulation experiment needs to be improved, but the identification characteristics of the filled jadeite with inorganic materials are recognized, which has caused a further breakthrough in the enhancement and treatment of jadeite identification.

Antioxidants, which are effective in reducing the color change in the material by the effect of visible light and oxygen, were applied to linen fabric by an innovative finishing process, sol-gel technique. Antioxidants and silica sols were combined to make the color of the fabric more stable to light. The silica sol was obtained using TEOS (tetraethyl ortosilicate) and GPTS [(3-glycidyloxypropyl)trimethoxysilane] as precursor and combined with aqueous solutions of gallic acid and L-ascorbic acid. When the images obtained by SEM analysis were examined, it was found that antioxidant added silica sol solutions have changed the surface morphology of the flax fibers. It has been found that gallic acid added silica sol solution was effective on improving the light fastness of the blue fabrics. Wear resistance results indicated that the addition of cross-linker in SiO2 containing solution made xerogel a protective coat for linen fabrics.

Herein, a silica sol was firstly prepared and coated on the glass substrate, followed by a co-deposition of tannic acid (TA) and 3-aminopropyltriethoxysilane (APTES) to form a hydrophilic layer. Subsequently, the zwitterionic polymer PEIS (polyethylenimine-quaternized derivative) was grafted onto the glass surface via Schiff-base reaction and/or Michael addition between the amino of PEIS and phenolic hydroxyl groups of TA, resulting in the formation of zwitterionic polymer PEIS-functionalized glass substrate (Glass@Silica Sol-PEIS). The thickness and surface roughness of the as-prepared Glass@Silica Sol-PEIS coating was 0.71 μm and 60.2 nm measured by AFM, respectively. Compared with the unmodified glass substrate, the Glass@Silica Sol-PEIS effectively prevented the adhesion of over 96 % of microalgae and 80 % of bacteria on its surface. The excellent antibacterial and antifouling ability can be attributed to the bactericidal activity of quaternary amine groups in PEIS and strong surface hydration effect of zwitterionic polymer PEIS. In addition to glass substrate, the novel coatings demonstrate versatility by being applicable to various substrates such as metal, fabric and plastic, showing a promising prospects for widespread application. [Display omitted] • A tannic acid-based zwitterionic polymer PEIS-functionalized coating was successfully prepared. • The PEIS-functionalized coating (Glass@Silica Sol-PEIS) exhibits outstanding hydrophilicity and lubrication performance. • The introduction of zwitterionic PEIS endows the coating with effective antibacterial and anti-biofouling properties. [ABSTRACT FROM AUTHOR]

The dispersibility of silica sol particles modified by γ-methacryloxy propyl trimethoxyl silane (γ-MPS) in an ethanol–water mixed solvent was investigated. In the modification process, the hydrolysate of γ-MPS condensed to form oligomers, which further formed hydrogen bonds with the hydroxyl groups on the surface of the silica sol particles to cause agglomeration. Increasing the ethanol concentration inhibited the hydrolysis of γ-MPS and the formation of oligomers, thus inhibiting the agglomeration of silica sol particles. When the ethanol concentration was above 74 wt%, the γ-MPS-modified silica sol slurry was transparent and with a TEM image in a single-particle dispersed state. The dispersibility of the silica sol particles was determined by a double electric layer repulsion mechanism before modification and a steric hindrance mechanism by organic molecules grafted on the surface of the particles after modification. The grafting density of γ-MPS on the surface of silica sol particles affected the hydrophobicity of the modified particles, which can be effectively controlled. [Display omitted] • High ethanol concentration facilitates high dispersibility of particles. • High ethanol concentration inhibits γ-MPS hydrolysis and particle agglomeration. • Modified particles are single-particle dispersed by steric-hindrance. • Particle hydrophobicity has a positive correlation with γ-MPS grafting density. [ABSTRACT FROM AUTHOR]

Using 3D printing technology to prepare ceramic shell used for precision investment casting can realize short process and efficient preparation of the ceramic shell, which has a great application potential in the casting field. However, the 3D printed ceramic shells often have the problems of low strength and accuracy. In this paper, a silica sol room temperature dip coating treatment combined with high temperature sintering method was proposed to improve the strength and surface precision of the ceramic shell prepared by the binder jetting. The effects of silica sol concentration and dip coating time on performance and surface precision of the alumina ceramic shell were studied. The mechanical properties and surface precision of the alumina ceramic shell prepared by the binder jetting were improved significantly with the increases of the sol concentration and dip coating time. With the dip coating time of 90 s and sol concentration of 30%, the maximum bending strength of the alumina ceramic reached 44.8 MPa, which was 18.9 times higher than that of the untreated alumina ceramic. The top surface roughness and side roughness of the alumina ceramic decreased from 6.87 μm to 5.70 μm and 7.55 μm–6.46 μm, respectively, compared to those of the untreated alumina ceramic. [ABSTRACT FROM AUTHOR]

A creative approach for fabricating porous magnesia materials with improved mechanical and thermal properties using walnut shell powders as pore-forming agent combined with self-created porous magnesia aggregates is reported in the present work. The work focused on the microstructure and binding mechanism of the novel walnut shell powders (WSP), which treated by silica sol, aluminum sol, and oleic acid, and the properties and microstructure of porous magnesia materials. The results showed that the surface of the sols-treated walnut shell powders was spherical and significantly dispersed. The oleic acid-treated walnut shell powder (OWS) did not differ much from the original state; the surface was rough and agglomeration. The porous magnesia material with the addition of SWS has excellent properties, forms closed pores and low conductivity. When the SWS was added at 10%, the bulk density, porosity, compressive strength, and thermal conductivity of samples were 1.64 g·cm−3, 53.97%, 22 MPa, and 0.447 W/(m·K), respectively. [ABSTRACT FROM AUTHOR]

This article summarizes data on the influence of various factors on the crystallization of quartz ceramic products during their heat treatment. The formation of silica gel during the oven drying of billets and its effect on the heat treatment and quality of the final product were assumed. [ABSTRACT FROM AUTHOR]

The application of scientific and technological studies prior to the repair of historic and ancient ceramics can provide a more complete understanding of glazes to aid the conservator's decision-making process before undertaking the conservation of ceramics. There are two categories of Chinese glaze morphology for general high-temperature single-color glazes, calcium glazes (smooth glazes), and calcium alkali glazes (glazes containing more bubbles or crystals and multiple glazes). High-temperature colored glazes can be divided into four types: on-glazed, in-glazed, diffused, and under-glazed pigments. The subdivision of high-temperature glaze types has significance as a guiding factor in the repair of historic and ancient ceramic glazes. Optical coherence tomography (OCT) is discussed as a non-invasive way to understand glaze structure and as a tool to aid the conservator in the treatment of ceramics. Moreover, a silica sol-acrylic composite coating was studied as a possible material to use in the replication of ceramic glazes on areas of restoration. A small amount of acrylic resin can improve the reversibility of the synthetic coating. On the macro level, this coating exhibits natural glaze bubbles and craquelure similar to historic and ancient ceramics; in addition, on the micro level, it can imitate the clean calcium glaze and crystallization calcium alkali glaze of such ceramics. The silicon oxide content in this glaze-like material is found to be similar to that of historic and ancient ceramics. [ABSTRACT FROM AUTHOR]

Porous alumina ceramics were prepared by using calcined α-Al2O3 as raw material,nano silica sol as high temperature binder and carboxymethy cellulose as molding binder with processes of mixing,aging,molding and sintering.The effect of silica sol addition on sintering properties was investigated by test method of SEM and XRD. The linear shrinkage,volume density,porosity and flexural strength were also tested.The results show that the quartz silicon dioxide which is pyrolysed product from silica sol could bond the alumina particles together to form porous ceramics and improve the mechanical properties.The essence of silica sol bonding is physical bonding.The silicon dioxide in the sol begins to react with alumina to form mullite when the sintering temperature reaches 1500 ℃,and the porous ceramics tend to be compact with excellence mechanical properties.The flexural strength is about (105.5±8.0) MPa.The content of mullite phase increases with sintering temperature.However,with much higher content of mullite generation,the porosity increases and the mechanical performance degrades.The porous alumina ceramics with excellence performance can be obtained when the sintering temperature is between 1400 ℃ and 1500 ℃.

BACKGROUND: Through visiting the jadeite market, the existence of inorganic material-filled jadeite is known, but there is a lack of identification basis due to rare references. OBJECTIVES: To understand the identification characteristics of inorganic material-filled jadeite. METHODS: Two types of inorganic materials, water glass and silica sol, were used to fill low-grade jadeite in the simulation experiment. Conventional gemological tests, fluorescence image observation with DiamondViewTM, Fourier transform infrared (FTIR) spectroscopy, and laser-induced breakdown spectroscopy (LIBS) were used to test the inorganic filled jadeite samples. RESULTS: The transparency, color, density and structure of jadeite were improved after filling. Under the DiamondViewTM, the jadeite particles in the sample showed green fluorescence, and the filling around the cracks and between the particles displayed blue fluorescence with non-uniform distribution. Mid-infrared reflectance spectrum analysis showed that the spectra of silica sol and water-glass were slightly different from each other. The absorption peaks of the samples filled with inorganic materials at 1162 cm-1, 1070 cm-1, 949 cm-1, 579 cm-1, 529 cm-1 and 470 cm-1 gradually weakened, and the peak shape gradually became smooth or disappeared. In addition, the differences between the jadeite and inorganic filled jadeite can be determined by the near-infrared spectral morphology and the shape of the absorption peak changed in the range of 7062 cm-1, 5204 cm-1 and 4537 cm-1. The laser-induced breakdown spectroscopy demonstrated that the content of the silicon in the jadeite filled with silicon sol or sodium and potassium water-glass was higher. The high potassium content was an important feature for the jadeite filled by sodium and potassium water-glass. CONCLUSIONS: The samples effect of the simulation experiment needs to be improved, but the identification characteristics of the filled jadeite with inorganic materials are recognized, which has caused a further breakthrough in the enhancement and treatment of jadeite identification. [ABSTRACT FROM AUTHOR]

Thermal modification could act as pretreatment for promoting silica sol impregnation in wood. It could create extra available channels and spaces for silica transportation and deposition owing to the presence of micro-cracks and enlarged pore size. The significant improvements on anti-hygroscopicity, hydrophobicity, and dimensional stability of treated wood were attributed to the degradation of cell wall polymer (hemicellulose, cellulose, and lignin) and filling effect of silica in wood. The synergistic effect contained the reduction on –OH concentration owing to thermal degradation, and consumption of –OH groups via the interaction (Si–O–Si cross linked networks and Si–O–C covalent bonds) between silica and wood matrix. Furthermore, the degradation of cell wall polymers resulted in the increase of crystallinity in wood. However, the crystallinity turned to decrease due to the amorphous silica impregnation. The silica impregnation could compensate the mass loss caused by thermal degradation, leading to various weight percentage gains (WPGs) that depended on treatment temperature. Moreover, owing to the coverage and penetration of mineral silica in wood, acting as a thermal barrier, the thermal stability and surface hardness of treated wood improved prominently. [ABSTRACT FROM AUTHOR]

Antioxidants, which are effective in reducing the color change in the material by the effect of visible light and oxygen, were applied to linen fabric by an innovative finishing process, sol-gel technique. Antioxidants and silica sols were combined to make the color of the fabric more stable to light. The silica sol was obtained using TEOS (tetraethyl ortosilicate) and GPTS [(3-glycidyloxypropyl)trimethoxysilane] as precursor and combined with aqueous solutions of gallic acid and L-ascorbic acid. When the images obtained by SEM analysis were examined, it was found that antioxidant added silica sol solutions have changed the surface morphology of the flax fibers. It has been found that gallic acid added silica sol solution was effective on improving the light fastness of the blue fabrics. Wear resistance results indicated that the addition of cross-linker in SiO2 containing solution made xerogel a protective coat for linen fabrics. [ABSTRACT FROM AUTHOR]