MOLECULES
·
2021
·Vol. 26
·期 7
·1960
·
IF 4.412
Xingzhong Guo,Zixiao Li,Wei Lei,Ronghua Ding,Yun Zhang,Hui Yang
Microwave heating technology is known as an alternative to traditional gas and electric heating sources. In this work, mesoporous methylsilsesquioxane (MSQ) aerogels were prepared via a sol–gel process accompanied by microwave heating technology, and microwave heating was used in the gelation of sol and the drying of wet gels, respectively. The effects of hexadecyltrimethylammonium chloride (CTAC) as a surfactant and template, hydrochloric acid (HCl) as a catalyst, ethanol as a solvent, sodium hydroxide (NaOH) as a gelation agent, and microwave power on the pore structure of as-prepared MSQ aerogels were investigated in detail. Microwave heating at low power results in the acceleration of sol–gel transition and achieves the gelation within a few minutes. Appropriate amounts of chemical reagents and microwave heating at high power allow the preparation of mesoporous MSQ aerogels with a BET-specific surface area of 681.6 m2·g−1and a mesopore size of 19 nm, and the resultant MSQ aerogel still has a BET specific surface area as high as 134 m2·g−1after heat treatment at 600 °C for 2 h, showing high thermal stability. The MSQ aerogels/fibre composite possesses a low thermal conductivity of 0.039 W/(m·k)−1, displaying good thermal insulation. Microwave heating technology is a promising heating method for the preparation of other aerogels.Keywords:MSQ aerogels;microwave drying;sol–gel
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED OPTICS
·
2024
·Vol. 63
·期 10
·A70
·
IF 1.7
FengHong Chu,Dan Pei,ZhengLan Bian,YiSheng Sun,AnDuo Hu,GuiLin Zhang,Liang Xue,JiaWen Han,JiaMeng Zhang
Tungsten oxide (${{\rm WO}_3}$) has been widely used in hydrogen sensing due to its stable chemical properties and high oxygen vacancy diffusion coefficient. However, the response of pure ${{\rm WO}_3}$ to hydrogen is slow, and doping is an effective way to improve the hydrogen sensing performance of ${{\rm WO}_3}$ materials. In this paper, ${{\rm WO}_3}/{\rm Pt}/{\rm PEG}/{{\rm SiO}_2}$ porous film was prepared by the sol-gel method using tungsten powder, ${{\rm H}_2}{{\rm O}_2}$ and ${{\rm C}_2}{{\rm H}_5}{\rm OH}$ as precursors, polyethylene glycol (PEG) as the pore-forming agent, and tetraethyl orthosilicate (TEOS) as the ${{\rm SiO}_2}$ source material. The sensing properties of the ${{\rm WO}_3}$ composite for hydrogen were characterized by a transmission optical fiber hydrogen sensing system made at home. The process parameters such as water bath time, aging time, W:PEG ratio, and W:TEOS ratio were optimized to improve the sensitivity and response time of the sensing film. The experimental results indicate that the sensitivity is 15.68%, the average response time is 45 s, and the repeatability is up to 98.74% in 16 consecutive tests. The linearity index ${{\rm R}^2}$ is 0.9946 within the hydrogen concentration range of 5000 ppm to 50,000 ppm. The film responds only to ${{\rm H}_2}$ when the concentration of interfering gases (${{\rm CH}_4}$, CO, ${{\rm CO}_2}$) is 2000 ppm. The hydrogen sensing performance of the optimized film is significantly improved compared with that of the undoped film.
研究领域:
材料科学
·
传感器技术
✓ 已验证
DOI
PubMed
高影响因子
Coatings
·
2020
·Vol. 10
·期 7
·690
·
IF 2.436
Xiaolin Liu,Yansong Wang,Tao Bai
SiO2/ZrO2and SiO2/ZrO2/Al2O3composite organic–inorganic coatings were prepared by the sol-gel technology. The structure of the coating was characterized by IR, particle size analyzer, SEM, and AFM, respectively. The results showed that ZrO2, SiO2(inorganic component), and siloxane had undergone a hydrolytic condensation reaction, and the composite organic–inorganic coatings were formed with -O-M-O- (M is Si, Zr) as molecular skeleton network structure. Adding an appropriate ratio of ZrO2sol, no agglomeration and phase separation occurred, which could significantly improve the refractive index, hardness, and light transmittance of the coatings. Al2O3sol could greatly improve the friction resistance of the composite organic–inorganic coatings, and the Bayer ratio of the composite coatings could reach 7.86. By adjusting the proportioning of composite sol solution, the refractive index of the composite transparent coatings could be controlled from 1.52 to 1.65.Keywords:sol-gel technology;refractive index;ZrO2;Al2O3;coating
研究领域:
材料科学
·
化学工程
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Coatings
·
2023
·Vol. 13
·期 6
·1085
·
IF 3.4
Zhenchuan Lu,Kamale Tuokedaerhan,Haotian Cai,Hongguo Du,Renjia Zhang
This article presents the sol-gel method for depositing La2O3thin films on n-type Si substrates and quartz substrates, and investigates the impact of annealing temperature on the microcomposition, surface morphology, optical properties, and band characteristics of the films. X-ray diffraction (XRD) analysis indicates that the films are amorphous below 500 °C, with annealing resulting in a hexagonal-phase La2O3(h-a2O3) and new non-hydrated impurities. Fourier-transform infrared (FTIR) analysis reveals that the prepared La2O3film is unaffected by moisture. Atomic force microscopy (AFM) and scanning electron microscopy (SEM) provide evidence that the La2O3film has a smooth, uniform surface without cracks. The roughness increases from 0.426 nm to 1.200 nm, and the film thins from 54.85 nm to 49.80 nm as the annealing temperature rises. The film’s transmittance is above 75%, as measured by UV-Vis, and the calculated optical bandgap increases from 5.11 eV to 5.75 eV. The calculated band offset of the La2O3film is greater than 1 eV, which meets the minimum requirements for MOS devices, thus providing promising prospects for La2O3films in MOS applications.Keywords:high k gate dielectric;sol-gel;La2O3;thin film
研究领域:
材料科学
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
MOLECULES
·
2024
·Vol. 29
·期 8
·1834
·
IF 4.2
Mengruo Wu,Le Mu,Zhiyue Zhang,Xiangna Han,Hong Guo,Liuyang Han
Tetraethoxysilane (TEOS) is the most commonly used silicon-based reinforcement agent for conserving art relics due to its cost-effectiveness and commercial maturity. However, the resulting silica gel phase is prone to developing cracks as the gel shrinks during the sol–gel process, potentially causing severe damage to the objects being treated. In this study, dodecyltrimethoxysilane (DTMS) was introduced into TEOS to minimize this shrinkage by adding elastic long chains to weaken the capillary forces. The gel formed from the DTMS/TEOS hybrid material was transparent and crack-free, featuring a dense microstructure without mesopores or micropores. It exhibited excellent thermal stability, with a glass transition temperature of up to 109.64 °C. Evaluation experiments were conducted on artificially aged, handmade bamboo paper. The TEOS-based hybrid material effectively combined with the paper fibers through the sol–gel process, polymerizing into a network structure that enveloped the paper surface or penetrated between the fibers. The surface of the treated paper displayed excellent hydrophobic properties, with no significant changes in appearance, color, or air permeability. The mechanical properties of the treated bamboo paper improved significantly, with longitudinal and transverse tensile strengths increasing by up to 36.63% and 44.25%, respectively. These research findings demonstrate the promising potential for the application of DTMS/TEOS hybrid materials in reinforcing paper relics.
研究领域:
文物保护
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Batteries-Basel
·
2025
·Vol. 11
·期 4
·142
·
IF 4.8
Pengqing Hou,Qi Sun,Shengxue Yan,Guanglong Li,Yingdong Qu,Shaohua Luo
The development of a simple and reliable strategy to synthesize cathode materials is crucial for achieving the overall high performance of rechargeable lithium batteries, which has proved to be quite challenging. Herein, we report a simple sol–gel method for the synthesis of Li2FeTiO4cathode materials. The reaction mechanism of Li2FeTiO4crystals can be divided into five stages: including the breakage of the coordination bond; the thermal decomposition of citric acid; the thermal decomposition of metal salts and the reduction of trivalent iron and the formation of Li2FeTiO4crystals. Finally, the optimum calcination temperature for the preparation of Li2FeTiO4cathode materials was explored. The Li2FeTiO4cathode material prepared at 700 °C provides a discharge-specific capacity of 121.3 mAh/g in the first cycle and capacity retention of 89.2%. Our results provide new insights into the application of Li2FeTiO4cathode materials.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2018
·Vol. 11
·期 3
·350
·
IF 2.467
Guangyuan Yang,Zhixiong Huang,Xu Wang,Bo Wang
The paper proposed a method to improve the anti-oxidation performance of carbon fibers (CF) at high temperature environment by coating silicon dioxide (SiO2) and silicon carbide (SiC). The modified sol-gel method had been used to ensure the proper interface between fibers and coating. We used polydimethylsiloxane and ethyl orthosilicate to make stable emulsion to uniformly disperse SiC nanoparticles. The modified SiO2/SiC coating had been coated on CF successfully. Compared with the untreated CF, the coated fibers started to be oxidized around 900 °C and the residual weight was 57% at 1400 °C. The oxidation mechanism had been discussed. The structure of SiC/SiO2coated CF had been characterized by scanning electron microscope and X-ray diffraction analysis. Thermal gravimetric analysis was used to test the anti-oxidation ability of CF with different coatings.Keywords:carbon fiber;oxidation resistance;coating;characterization
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF NANOSCIENCE AND NANOTECHNOLOGY
·
2013
·Vol. 13
·期 10
·6953-6960
·
IF 1.149
Shi Haowei,Huang Yan,Cheng Chao,Ji Guoyuan,Yang Yuxiang,Yuan Hongming
The size- and shape-controlled Fe3O4@SiO2 nanocomposites were successfully synthesized via the sol–gel method. The results showed that the size, shape, and property of the products were directly influenced by the amount of TEOS, and the concentration
of water-based magnetic fluid in the coating process. The morphology and properties of the products were characterized by TEM, SEM, X-ray powder diffraction, IR and EDS. The Fe3O4@SiO2 composites with easily-controlled size arranged from 58 to 835 nm could
be synthesized by adjusting the experimental parameters. When TEOS amount is 1 mL and the concentration of magnetic fluid were 30.0 and 10.0 mg/mL respectively, chain-like and peanuts-like well-dispersed Fe3O4@SiO2 particles with clear core–shell structure
were obtained. These size- and shape-controlled Fe3O4@SiO2 composites may have potential application in the field of targeted drug delivery and MRI contrast agent.
研究领域:
材料科学
·
纳米医学
✓ 已验证
DOI
PubMed
高影响因子
CLAYS AND CLAY MINERALS
·
2024
·Vol. 66
·期 5
·466-473
·
IF 2
Jingyi Liu,Rui Chen,Yuru Li,Jiajia Chen,Lihui Chen,Jing Gao,Guohua Li
The elimination of Pb2+ and recovery of lead metal during the treatment of industrial sewage is an important research topic. Montmorillonite (Mnt) is a promising material in this regard. The purpose of the present study was to improve the Pb2+ adsorption ability of Na-containing Mnt (Na-Mnt) by pillaring titania (anatase) into its interlayer spaces using a sol-gel method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The ratio of Ti to Mnt affected the crystal phase of titania-pillared Na-Mnt (Ti-Mnt), and changed the interlayer spacing of the (001) plane of Ti-Mnt and the growth of anatase. The Pb2+-adsorption capabilities of Ti-Mnt were tested using an aqueous solution of lead nitrate as a wastewater model. The Ti-Mnt prepared adsorbed >99.99% of the Pb2+; leached and activated Ti-Mnt adsorbed >95.7% of the Pb2+, indicating that Ti-Mnt could be recycled effectively. Furthermore, the Pb2+-adsorption capability of Ti- Mnt was related to the interlayer spacing of Mnt, the distribution of anatase particles pillared in Mnt, and the specific surface area, especially with respect to the relationship between the anatase particles and the interlayer spacing of the (001) plane.
研究领域:
环境科学
·
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
FIBERS AND POLYMERS
·
2018
·Vol. 19
·期 2
·340-349
·
IF 1.353
Wang Yixi,Wang Hao,Peng Huili,Wang Zhicun,Wu Jianning,Liu Zhiyong
A novel eco-friendly porous adsorbent of cellulose (CE)/chitosan (CS) aerogel was prepared through sol-gel process and freeze-drying to remove Congo Red (CR). A series of aerogels were prepared by adjusting the mass ratios of CE and CS. Composite aerogels were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and X-ray diffraction (XRD). SEM images showed that it was possible to change the structure of the aerogel by adjusting the amount of chitosan. The effects of dosage of chitosan, initial pH, temperature, adsorbent dosage, contact time, and initial dye concentration on adsorption capacities for CR were studied in detail. Batch adsorption studies showed that aerogel exhibited maximum removal efficiency to CR at a composite ratio of 1:3 and dosage of 2.5 g/ l . CE/CS aerogel had excellent adsorption capacities for CR at a pH range of 3-11, which indicated stability of the aerogel in both acidic and alkaline conditions. CR adsorption on the composite aerogel fitted pseudo-second-order kinetics and Langmuir isotherm. The Langmuir isotherm model revealed that the maximum theoretical adsorption capacity of this material for CR was 381.7 mg/g at pH 7.0 at 303 K for 24 h. The adsorption mechanism included electrostatic and chemical interactions. The results indicated that the adsorption capacity of CE/CS aerogels was higher than the other chitosan composites adsorbents.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
SURFACE & COATINGS TECHNOLOGY
·
2022
·
IF 4.865
Linbo Zhang,Weihong Wan,Xianyu Jiang,Bo Wang,Liangjun Yin,Simeon Agathopoulos,Jiangliang Xie,Li Zhang,Haipeng Lu,Longjiang Deng
The popular magnetic material of flaky carbonyl iron (FCI) is unfortunately vulnerable to electrochemical corrosion when exposed to a salty and foggy environment. This work reports on a sol-gel method that successfully modifies FCI particles, using lithium silicate (Li 2 SiO 3 ), poly dimethyl siloxane (PDMS), and γ-(2,3-epoxypropoxy) propytrimethoxysilane (KH560), to synthesize Fe@SiO 2 @KH560@PDMS hybrid composite, related to its organic–inorganic hybrid coatings. The favorable hydrophobicity of organic–inorganic hybrid coatings with the static contact angle of 120° impeded the contact between corrosive medium and FCI core. The results of electrochemical experiments also confirmed its excellent corrosion resistance , since the corrosion potential E corr was positively shifted to 0.01 V, and the corrosion current I corr was three orders of magnitude lower than that of the unmodified FCI particles. Thermogravimetric (TG) analysis indicates that the presence of hybrid coatings also improved the thermal stability of the produced material towards oxidation . Furthermore, the results of molecular dynamics simulation reveal that the hybrid layer inhibits the diffusion of corrosive medium.
研究领域:
材料科学
·
电化学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2014
·
IF 4.058
Hong-Tao Fan,Qi Tang,Yang Sun,Zhi-Gang Zhang,Wen-Xiu Li
A Sb(III)-imprinted iodole-functionalized organic–inorganic hybrid sorbent was synthesized by combination of surface imprinting technique with sol–gel process for the selective removal of Sb(III) from aqueous media. The material was characterized by Fourier-transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis and nitrogen adsorption–desorption isotherms. Compared to the non-imprinted sorbent, the imprinted hybrid sorbent had higher selectivity and adsorption capacity for Sb(III) ion. The static adsorption capacity of the imprinted and non-imprinted sorbents for Sb(III) was 32.4 and 11.1 mg g −1 , respectively. The relative selectivity coefficients of the imprinted hybrid sorbent for Sb(III)/Cr(III) Sb(III)/Fe(III) and Sb(III)/As(III) were 13.2, 10.4 and 11.8, respectively. The imprinted hybrid sorbent possessed fast kinetics for the removal of Sb(III) from aqueous solution with a saturation time of 30 min, had a stable binding capacity in the range of pH 4–6, and could be used repeatedly. Both the pseudo-second-order kinetic model and the Langmuir model fit the experimental data well. It could be concluded from the thermodynamic parameters that the adsorption of Sb(III) on the imprinted hybrid sorbents was an exothermic and spontaneous process.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）