Gels
·
2024
·Vol. 10
·期 2
·118
·
IF 5
Zhi Li,Shengjie Yao,Guichao Wang,Xi Deng,Fang Zhou,Xiaoxu Wu,Qiong Liu
The propensity of foamed concrete to absorb water results in a consequential degradation of its performance attributes. Addressing this issue, the integration of aerogels presents a viable solution; however, their direct incorporation has been observed to compromise mechanical properties, attributable to the effects of the interface transition zone. This study explores the incorporation of MTES-based aerogels into foamed cement via an impregnation technique, examining variations in water–cement ratios. A comprehensive analysis was conducted, evaluating the influences of MTES-based aerogels on the thermal conductivity, compressive strength, density, chemical composition, and microstructure of the resultant composites across different water–cement ratios. Our findings elucidate that an increment in the water–cement ratio engenders a gradual regularization of the pore structure in foamed concrete, culminating in augmented porosity and diminished density. Notably, aerogel-enhanced foamed concrete (AEFC) exhibited a significant reduction in water absorption, quantified at 86% lower than its conventional foamed concrete (FC) counterpart. Furthermore, the softening coefficient of AEFC was observed to surpass 0.75, with peak values reaching approximately 0.9. These results substantiate that the impregnation of MTES-based aerogels into cementitious materials not only circumvents the decline in strength but also bolsters their hydrophobicity and water resistance, indirectly enhancing the serviceability and longevity of foamed concrete. In light of these findings, the impregnation method manifests promising potential for broadening the applications of aerogels in cement-based materials.
研究领域:
建筑材料学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CARBOHYDRATE POLYMERS
·
2024
·
IF 10.7
Wen Liu,Peng Liu,Liang Liu,Huimin Sun,Yimin Fan,Cuiqing Ma,Jia Ouyang,Zhaojuan Zheng
To further enhance the removal efficiency for furanic and phenolic compounds in lignocellulosic hydrolysates, a new detoxification strategy was proposed, which retained fermentable sugars and promoted the growth and metabolism of subsequent bacteria. The best adsorbent (P/M-CCA) was prepared by hybrid chitosan-chitin nanofiber , graft modification with polyethylenimine, and silanization with methyl triethoxylsilane in order. Taken corn cob hydrolysate as object, the removal rates of HMF and furfural were 85.1 % and 99.0 %, respectively. The removal rates of six out of nine phenolic inhibitors were 100 %, and the other three were more than 65 %. Even better, the retention rates of glucose and xylose were both 100 %. In contrast to no growth in undetoxified hydrolysates, Bacillus coagulans grew normally in detoxified hydrolysates, and lactic acid reached 19.1 g/L after 12 h fermentation. P/M-CCA achieves both removal of multiple inhibitors and retain sugars, which would promote the valorization of highly toxic lignocellulosic hydrolysates.
研究领域:
生物技术
·
生化工程
·
环境生物技术
✓ 已验证
DOI
PubMed
高影响因子
MATERIALS SCIENCE FORUM
·
2020
·
IF 0
Zhi Wei He,Hong Xiao Lin,Chun Yan Li,Ashok M. Mahajan,Swati A. Gupta,Mei Zhou
Effect of various silicon sources, such as TEOS, MTES mixed with TEOS and 1,3,5-tris(triethoxymethyl) on SiO2 films was investigated. The synthesized solutions were used as silicon sources to prepare silica-like backbone films. The investigation showed that all precursors can able to produce the flat and uniform films. An FTIR spectrum confirmed the formation of SiO2 in film matrix. The results indicated that the internal microstructure of each film is different. The incorporation of less polar bonds such as F and C was carried out using various Si sources, while the introduction of these sources confirmed through FTIR spectra. Optical properties of the films were carried out by using ellipsometric porosometry (EP) measurement. The leakage current density for the films prepared by using TEOS, MTES and 135TTEB was observed to be 2.8 × 10-7 A/cm2, 2.9 × 10-8 A / cm2, and 4.1 × 10-6 A / cm2, respectively, at 1 MV/cm electric field strength by the IV curves obtained by semiconductor characterization after fabricating MIS devices. The calculated dielectric constants from RI of the deposited SiO2 films were 2.0, 1.9 and 2.5 respectively. When the microstructure of the precursor solution changed, the introduction of atomic morphology or terminal inerted group ratio changed the internal bridging mode of SiO2, and thereby significantly reduced the dielectric constant and improved insulation.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
Functional Materials Letters
·
2025
·
IF 1.1
Min Li,Chongcai Xu,Tianya Li,Guangyi Lin
Use trimethylethoxysilane(MTES) as hydrophobic material, graphene as conductive material, and electrospinning as preparation method to successfully prepare MTES and graphene conductive-hydrophobic composite fiber membranes. A control group was prepared based on the different doping qualities of graphene. And use the composite fiber membrane as microporous layer for proton exchange membrane fuel cell. Polarization curve test results show that with the increase of graphene, voltage loss of composite fiber membrane gradually decreases, and fuel cell performance is significantly better than that of commercial GDL29BC. Electrochemical impedance spectroscopy test results show that material transfer impedance of composite fiber membrane is lower than that of GDL29BC. It also showed that power density difference of the composite fiber membrane was low when humidity was 40% and 60%, indicating that composite fiber membrane has good self humidifying effect.
研究领域:
材料科学
·
燃料电池技术
·
纳米材料
·
电化学
✓ 已验证
DOI
高影响因子
POWDER TECHNOLOGY
·
2023
·
IF 5.2
Chengdong Li,Qingsong Liu,Guihua Zhang,Liangliang Lin,Kostya (Ken) Ostrikov
Polymethylsilsesquioxane (PMSQ) aerogels are silica aerogels that contain dangling methyl groups and exhibit high strength and flexibility. Common silica precursors trialkoxysilanes have difficulty to form networks in sol-gel processes, preventing monolith formation. Here crack-free PMSQ monolithic aerogels are synthesized from methyltriethoxysilane (MTES) at ambient conditions. The concentrations of cetyltrimethylammonium bromide (CTAB) surfactant in the sol were optimized to delay the phase separation of MTES. Crack-free aerogel monoliths with flat surfaces were obtained from silica sols with a CTAB of 0.692–1.039 mmol/L, while pits, wrinkles, cracks, or complete breakage appeared beyond this range. The Si-CH 3 groups on the aerogel skeleton made them hydrophobic up to 400 °C for 1 h in air conditions while oxidized into Si-O-Si bonds at 565.0–751.2 °C under N 2 conditions, making them hydrophilic. The new synthesis method is 1.3–31.8 times faster than conventional processes and contributes to developing next-generation green and scalable production technologies of silica aerogels.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
JOURNAL OF SOL-GEL SCIENCE AND TECHNOLOGY
·
2021
·Vol. 100
·期 3
·477-488
·
IF 2.326
Deng Xi,Wu Liling,Deng Yunmeng,Huang Siqi,Sun Mengtian,Wang Xiaowu,Liu Qiong,Li Ming,Li Zhi
This work presents a facile synthesis approach of methyltriethoxysilane (MTES) based aerogels using pure water as the only solvent, and the effects of precursor concentration on the physicochemical properties are investigated in detail. Therein, the precursor concentration has no effect on the chemical composition but causes the denser and slenderer skeletons at the lower precursor concentration and vice versa. At the 14.4 vol% precursor concentration, the MTES based aerogels are made up of slender skeletons, having the minimum density (0.057 g/cm 3 ), the maximum porosity (97.5%), and the low thermal conductivity (29.4 mW/m/K). It further finds the denser and slenderer silica skeletons cause higher compressive strength and higher Young’s modulus. The TG-DSC results indicate the nice thermal stability of MTES based aerogels. In short, this research demonstrates the great competitive advantages of MTES based aerogels in the field of thermal insulation from the view of preparation method, thermal conductivity, and thermal stability.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry C
·
2017
·Vol. 5
·期 12
·3088-3096
·
IF 5.256
Xinmin Cui,Ruimin Ding,Mengchao Wang,Conghui Wang,Jing Zhang,Jing Wang,Wensheng Dong,Yao Xu
An ultralow-index top layer is a prerequisite to preparing high-performance broadband AR coatings. When coupled with hydrophobicity and the abrasion-resistance required in practical applications, the challenge becomes even greater. In this work, a MgF2 AR coating was studied because of the low refractive index of MgF2 and its easily realized strong adhesion through low-temperature heat treatment. In order to obtain an ultralow refractive index and endow the coating with hydrophobicity, we designed several experimental routes and finally adopted MTES/TEOS co-precursors to direct MgF2 particles to form a honeycomb-like network structure without a template. A final refractive index of 1.15 and good hydrophobicity, with a water contact angle of 122°, were obtained using the MgF2–SiO2(CH3) coating. These superior properties were attributed to the incorporation of methyl groups, which not only endowed the coating with hydrophobicity, but also changed the original linear assembly of MgF2 particles to a circular assembly. Using this hydrophobic ultralow-index coating as a top layer, a high-performance double-layer AR coating was fabricated with a high average transmittance of 99.43% in the wavelength range of 400–1000 nm, good abrasion-resistance, and damp heat resistance after a low-temperature heat treatment of 250 °C. This MgF2 double-layer AR coating may be used in display devices or lenses.
研究领域:
材料科学
·
光学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
POLYMER TESTING
·
2019
·
IF 2.943
Di Yang,Junkai Ren,Jiwei Li,Qinglin Wang,Qiu Wang,Zheng Xie,Xiaozhong Qu
Herein we report on a biluminophore fast-responding pressure sensitive coating with a bi-layer structure prepared by a non-sensitive reference base paint and subsequently a classic polymer-ceramic pressure sensitive paint (PSP). The coating procedure is fully sprayable and allows the separation of the two luminophores in each layer to prevent their interference that may affect the pressure responsibility. The major advance is the use of sol-gel process of tetraethoxysilane (TEOS) and methyltriethoxysilane (MTES) to make the bottom reference layer which ensures the spreading and affinity of the top PSP, composed of a room-temperature vulcanizing silicone rubber (RTV), so that very thin PSP layer, i.e. less than 5 μm, was achieved. Besides, silane-functionalized carbon dots (CDs) was selected as the reference probe, for it could be well-incorporated with the TEOS/MTES matrix, and gained high loading level and hence strong luminescence of the basecoat to overcome the attenuation effect of the top PSP layer. The resultant biluminophore bi-layer fast-responding PSP (denoted as Fast bi-PSP) showed two completed separated emissions with λ max at 430 and 600 nm for the incorporated CDs and the oxygen sensitive ruthenium complex dye, which enables the utility of intensity ratio from blue and red luminescence for the measurement of surface pressure by following Stern-Volmer relationship. Using a shock tube , the response time of the Fast bi-PSP coating was determined to be 0.4–0.6 ms according to the chemical composition . The ability of the coating for monitoring the dynamic evolution of full-field surface pressure was demonstrated on sample plates at attack angles of 0° and 5°. Our work suggests a facile but efficient way for the future design of self-referenced photoluminescent non-contact surface pressure sensing systems.
研究领域:
航空航天工程
·
材料科学
·
光学传感
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）