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Theoretical study on the effective thermal conductivity of silica aerogels based on a cross-aligned and cubic pore model
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作者 郑坤灿 李震东 +2 位作者 曹豫通 刘犇 胡君磊 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第6期28-36,共9页
Aerogel nanoporous materials possess high porosity, high specific surface area, and extremely low density due to their unique nanoscale network structure. Moreover, their effective thermal conductivity is very low, ma... Aerogel nanoporous materials possess high porosity, high specific surface area, and extremely low density due to their unique nanoscale network structure. Moreover, their effective thermal conductivity is very low, making them a new type of lightweight and highly efficient nanoscale super-insulating material. However, prediction of their effective thermal conductivity is challenging due to their uneven pore size distribution. To investigate the internal heat transfer mechanism of aerogel nanoporous materials, this study constructed a cross-aligned and cubic pore model(CACPM) based on the actual pore arrangement of SiO_(2) aerogel. Based on the established CACPM, the effective thermal conductivity expression for the aerogel was derived by simultaneously considering gas-phase heat conduction, solid-phase heat conduction, and radiative heat transfer. The derived expression was then compared with available experimental data and the Wei structure model. The results indicate that, according to the model established in this study for the derived thermal conductivity formula of silica aerogel, for powdery silica aerogel under the conditions of T = 298 K, a_(2)= 0.85, D_(1)= 90 μm, ρ = 128 kg/m^(3), within the pressure range of 0–10^(5)Pa, the average deviation between the calculated values and experimental values is 10.51%. In the pressure range of 10^(3)–10^(4)Pa, the deviation between calculated values and experimental values is within 4%. Under these conditions, the model has certain reference value in engineering verification. This study also makes a certain contribution to the research of aerogel thermal conductivity heat transfer models and calculation formulae. 展开更多
关键词 silica aerogel effective thermal conductivity two pore-size structure model porous medium heat transfer
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Nano silica aerogel-induced formation of an organic/alloy biphasic interfacial layer enables construction of stable high-energy lithium metal batteries 被引量:1
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作者 Chengwei Ma Xinyu Zhang +6 位作者 Chengcai Liu Yuanxing Zhang Yuanshen Wang Ling Liu Zhikun Zhao Borong Wu Daobin Mu 《Green Energy & Environment》 SCIE EI CAS CSCD 2023年第4期1071-1080,共10页
Lithium metal batteries represent promising candidates for high-energy-density batteries, however, many challenges must still be overcome,e.g., interface instability and dendrite growth. In this work, nano silica aero... Lithium metal batteries represent promising candidates for high-energy-density batteries, however, many challenges must still be overcome,e.g., interface instability and dendrite growth. In this work, nano silica aerogel was employed to generate a hybrid film with high lithium ion conductivity(0.6 mS cm^(-1)at room temperature) via an in situ crosslinking reaction. TOF-SIMS profile analysis has revealed conversion mechanism of hybrid film to Li–Si alloy/Li F biphasic interface layer, suggesting that the Li–Si alloy and Li F-rich interface layer promoted rapid Li+transport and shielded the Li anodes from corrosive reactions with electrolyte-derived products. When coupled with nickel-cobalt-manganese-based cathodes, the batteries achieve outstanding capacity retention over 1000 cycles at 1 C. Additionally the developed film coated on Li enabled high coulombic efficiency(99.5%) after long-term cycling when coupled with S cathodes. Overall, the results presented herein confirm an effective strategy for the development of high-energy batteries. 展开更多
关键词 Lithium metal batteries Nano silica aerogel In situ crosslinking Biphasic interface layer Li–Si alloy
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Application of Silica Aerogel Carrier via Supercritical Drying for Fragrance Controlled-release
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作者 黄龙 ZHANG Jing +6 位作者 PANG Denghong XIONG Man BIE Xuan DONG Yawei WANG Ben 罗诚浩 黄荣华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS CSCD 2023年第4期807-814,共8页
Silica aerogel with different hydrophilicities were prepared from tetramethoxysilane,Methymethoxysilane,tetramethoxysilane-propyltrimethoxysilane,or tetramethoxysilane-phenyltrimethoxysilane mixtures via supercritical... Silica aerogel with different hydrophilicities were prepared from tetramethoxysilane,Methymethoxysilane,tetramethoxysilane-propyltrimethoxysilane,or tetramethoxysilane-phenyltrimethoxysilane mixtures via supercritical drying process(labelled as TMOS-AG Me-TMOS-AG,Pr-TMOS-AG,or Ph-TMOS-AG,respectively).Three fragrances,including geraniol,ethyl vanillin,and menthol,were loaded to TMOS-AG.The thermal analysis confirmed all loading fragrances are stable until over 200℃.And among all fragrances,geraniol presented the maximum loading contents(L_(m)).Concentration dependences indicated the geraniol was mono layer absorbed.Py-GC/MS of geraniol in TMOS-AG under both N_(2)and mimic air atmosphere(90%N_(2)and 10%O_(2))confirmed that loaded geraniol could be thermally controlled-released beginning at 200℃.As N_(2)absorption confirmed,even absorption/desorption equilibrium constant(k)was determined mainly by hydrophilicity of silica aerogels,and the maximum loading contents(L_(m))were influenced more by the pore size.Due to mono layered absorption,bigger pores usually give less specific areas and less absorbing sites for geraniol,and then present lower L_(m). 展开更多
关键词 silica aerogel FRAGRANCE CONTROLLED-RELEASE
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Effect of Heat Treatment on Silica Aerogels Prepared via Ambient Drying 被引量:7
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作者 Fei SHI Lijiu WANG +1 位作者 Jingxiao LIU Miao ZENG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2007年第3期402-406,共5页
Silica aerogels were prepared at ambient drying by using ethanol/trimethylchlorosilane (TMCS)/heptane solution as pore water exchange and surface modification of the wet gel before drying. The obtained silica aeroge... Silica aerogels were prepared at ambient drying by using ethanol/trimethylchlorosilane (TMCS)/heptane solution as pore water exchange and surface modification of the wet gel before drying. The obtained silica aerogels exhibit a sponge-like structure with uniform pore size distribution. The effects of heat-treatment on the hydrophobicity, specific surface area and other properties were investigated. The results indicated that the hydrophobicity of silica aerogels could be maintained up to 350℃. With increasing heating temperature, hydrophobicity decreased, and became completely hydrophilic after heat-treatment at 500℃. Brunaueremmitt-teller (BET) surface area results indicated that the specific surface area of silica aerogels increased with increasing heating temperature in the range of 150-500℃. The effects of heat-treatment on the morphology and chemical bonding state of silica aerogels were investigated by scanning electron microscopy (SEM), differential temperature analysis (DTA) and Fourier-transform infrared spectroscopy (FT-IR). 展开更多
关键词 silica aerogel Ambient drying HYDROPHOBICITY Specific surface area Heat-treatment
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Synthesis and Characteristics of Mesoporous Silica Aerogels with One-step Solvent Exchange/Surface Modification 被引量:6
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作者 王立久 赵善宇 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第4期613-618,共6页
The synthesis procedures and physical properties of the ambient dried hydrophobic silica aerogels by using different contents of ethanol (EtOH)/trimethylchlorosilane (TMCS)/n-Hexane as surface modification agent w... The synthesis procedures and physical properties of the ambient dried hydrophobic silica aerogels by using different contents of ethanol (EtOH)/trimethylchlorosilane (TMCS)/n-Hexane as surface modification agent were investigated. One-step solvent exchange and surface modification were simultaneously progressed by immersing silica hydrogels in EtOH/TMCS/n-Hexane solution. It is found that microstructures as well as properties of silica aerogels like porosity, specific density and specific surface area are affected by the contents of surface modification agent in the sol from the results of SEM, TEM morphology, FT-IR chemical structure, BET surface area and BJH pore size analyses. The volume of TMCS is of 10% and 20% of hydrogels, and the final product is hydrophilic xerogels. When TMCS's percent (v/v) is elevated to 75 %-100%, hydrophobic silica aerogels with good performance are synthesized, the porosities of aerogels are in the range of 93.5%-95.8% and the average pore size diameter is less than 20 nm. 展开更多
关键词 silica aerogel surface modification ambient drying synthesis microstructure HYDROPHOBICITY
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Mechanism of low thermal conductivity of xonotlite-silica aerogel nanoporous super insulation material 被引量:8
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作者 Hailong Yang Wen Ni Deping Chen Guoqiang Xu Tao Liang Li Xu 《Journal of University of Science and Technology Beijing》 CSCD 2008年第5期649-653,共5页
In an effort to incorporate the low thermal conductivity of the silica aerogel and the superior structure strength of the xonotlite,a composite material of these two was produced. It was synthesized under vacuum condi... In an effort to incorporate the low thermal conductivity of the silica aerogel and the superior structure strength of the xonotlite,a composite material of these two was produced. It was synthesized under vacuum condition and dried by supercritical drying technique. The thermal conductivity of the new material,which is at 298K with the gas pressure ranging from 1.01×10^5 to 1×10^-2 Pa,was measured using the transient hot-strip method. The mechanism of the low thermal conductivity was studied. The results indicate that the low thermal conductivity mainly results from the significant decrease of gaseous thermal conductivity of the new material due to the restriction of the motion of gas molecules in its fine structures. The formation of the fine structures is because the new material takes the pore structure of the silica aerogel which consists of mainly nanometer-sized pores. 展开更多
关键词 silica aerogel XONOTLITE nanometer-sized pore super insulation thermal conductivity
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Synthesis and Thermal Insulation Performance of Silica Aerogel from Recycled Coal Gangue by Means of Ambient Pressure Drying 被引量:5
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作者 朱平华 ZHENG Meng +2 位作者 赵善宇 WU Junyong 徐海珣 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2015年第5期908-913,共6页
Silica aerogel materials are well recognized for their superinsulation performance and are regarded as one of the hot candidates to revolutionize building insulation. To date, high production cost related to exorbitan... Silica aerogel materials are well recognized for their superinsulation performance and are regarded as one of the hot candidates to revolutionize building insulation. To date, high production cost related to exorbitant precursors as well as cumbrous multi-step hydrophobization process has often narrowed the field of applications. In this work, granular silica aerogel materials were synthesized by extracting Si O2 from recycled rich silicon coal gangue, followed by one-step hydrophobization and ambient pressure drying. Lightweight(about 0.16 g/cm3) and nanostructural aerogels were obtained through this route. They exhibit a 3D open porous microstructure with around 600 cm2/g surface area and 20 nm of the average pore diameter, thermal conductivity of 4-5 mm packed granules is 20-25 m W/(m·K), which was proved by both guarded hot plate and hot-wire transient methods. This study offers a new facile route for the synthesis of silica aerogel from recycled solid waste coal gangue and suggests a method, which may lead to a cost reduction in terms of industrial production. 展开更多
关键词 silica aerogel coal gangue thermal insulation one-step hydrophobization
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Preparation and Characterization of Silica Aerogels Derived from Ambient Pressure 被引量:4
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作者 Jun SHEN Zhihua ZHANG Guangming WU Bin ZHOU Xingyuan NI Jue WANG 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2006年第6期798-802,共5页
Silica aerogels were prepared by sol-gel technique from industrial silicon derivatives (polyethoxydisiloxanes, E40), followed by silylation and drying under ambient pressure. The specific surface area, pore size dis... Silica aerogels were prepared by sol-gel technique from industrial silicon derivatives (polyethoxydisiloxanes, E40), followed by silylation and drying under ambient pressure. The specific surface area, pore size distribution and thermal conductivity of the silica aerogels were investigated and the results showed that the diameter of the silica particles is about 6 nm and the average pore size of the silica aerogels is 14.7 nm. The specific surface area of which is about 1000 m^2.g^-1 and the thermal conductivity is about 0.014 wm^-l.K^-1 at room temperature and pressure of 1.01×10^5 Pa. The Si-CH3 groups were also detected on the internal surface of the silica aerogels, which show hydrophobic. Silica aerogels derived by this technique is low cost and have wide applications. 展开更多
关键词 silica aerogel SOL-GEL NANO-STRUCTURE Ambient pressure drying
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Preparation and Properties of PMMA Modified Silica Aerogels from Diatomite 被引量:2
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作者 马海楠 王宝民 +1 位作者 ZHAO Lei YUNA Dawei 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第5期877-884,共8页
Diatomite was used as raw material to prepare sodium silicate with a modulus of 3.1 by alkali dissolution method and the resulted sodium silicate solution was employed as a precursor. Methyl methaerylate monomers were... Diatomite was used as raw material to prepare sodium silicate with a modulus of 3.1 by alkali dissolution method and the resulted sodium silicate solution was employed as a precursor. Methyl methaerylate monomers were introduced in wet gels through solution-immersion, and upon heating at 70 ℃, the mesoporous surfaces throughout the skeletal framework were coated with the polymer layer. PMMA modified silica aerogels were successfully synthesized via ambient pressure drying. The properties were investigated by FT- IR, NMR, TGA, nitrogen adsorption-desorption, FESEM and nano-indentation, etc. Results indicate that with the increasing of PMMA incorporated into silica aerogels, the bulk density and the BET surface area increase, the porosity decreases. Through the observation of FESEM, it is found that the interconnecting pores and the big pores add, the pore size distribution expands from 5-17 to 28-150 urn. By comparison, the PMMA modified silica aerogels achieve a 52-fold increase in hardness and a 10-fold increase in modulus. 展开更多
关键词 silica aerogels PMMA DIATOMITE ambient pressure drying mechanical properties
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Adsorption of cationic dyes from aqueous solution using hydrophilic silica aerogel via ambient pressure drying 被引量:2
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作者 Qun Liu Yuan Liu +2 位作者 Zhihua Zhang Xiaodong Wang Jun Shen 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2020年第9期2467-2473,共7页
In order to remove the organic dyes of textile waste water,the silica aerogel was successfully prepared by using E-40 as a novel precursor and then dried in ambient pressure.The synthesized sample was verified by Scan... In order to remove the organic dyes of textile waste water,the silica aerogel was successfully prepared by using E-40 as a novel precursor and then dried in ambient pressure.The synthesized sample was verified by Scanning Electron Microscopy(SEM)and Fourier Transform Infrared Spectroscopy(FTIR).After calcining,the hydrophilic silica aerogel(HSA)was used as adsorbent to remove Methylene Blue(MB),Malachite Green(MG),and Gentian Violet(GV)from aqueous solution.The effects of initial concentration of dyes and adsorbent dosage on the adsorption process were examined.It was found that HSA showed excellent adsorption capacities,the maximum percentage of removal dyes could reach 98%.Herein,the Langmuir,Freundlich and de Boer-Zwikker isotherm modes were employed to discuss the adsorption behavior.The results indicated that the de Boer–Zwikker model can effectively describe the adsorption behavior.Besides,the HSA could be utilized as the recyclable adsorbent in degradation experiment,after five cycles,no obvious loss of adsorption capacity was found.As an efficient,low-cost,environmental friendly and recyclable adsorbent,silica aerogel is expected to be used for dyes removal. 展开更多
关键词 silica aerogel Adsorbents E-40 Waste water ADSORPTION Cationic dyes
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Mechanical Properties of Silica Aerogels Prepared from a Mixture of TEOS and Organo-alkoxysilanes of Type R_1SiX_3 被引量:1
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作者 杨海龙 孔祥明 +2 位作者 ZHANG Yanrong WU Chunchao CAO Enxiang 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第1期201-207,共7页
Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility ... Silica aerogels were prepared from a mixture of tetraethylorthosilicate and organo- alkoxysilanes. The effects of organo-alkoxysilanes on the mechanical properties of the silica aerogels were studied. The flexibility of silica aerogels was significantly improved by incorporation of organo-alkoxysilanes. When MTES and TEOS were combined as precursors of silica areogels, with the increased amount of MTES, the apparent elastic modulus and apparent compressive strength monotonously rose. At the same organo- alkoxysilanes to TEOS ratio, the size of alkyl groups of the organo-alkoxysilanes had little effect on the mechanical properties. In series of MTES and TEOS, the lowest elastic modulus of silica skeleton and the highest compressive strength of silica skeleton were observed at MTES to TEOS ratio of around 50:50. At a certain organo-alkoxysilanes to TEOS ratio, the elastic modulus of silica skeleton increased and the compressive strength of silica skeleton decreased with the size increase of the alkvl grouns. 展开更多
关键词 silica aerogels mechanical properties organo-alkoxysilanes silica skeleton FLEXIBILITY SOL-GEL
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Influence of Drying Methods on Fractal Geometric Characteristics of Mesoporous Silica Aerogels
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作者 赵善宇 XU Haixun +1 位作者 WANG Lijiu J William Suggs 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第3期476-482,共7页
Chemical modification/ambient drying method and freeze drying method were introduced to research the synthesis of mesoporous silica aerogels. By analyzing N2 gas adsorption/desorption isotherms, the fractal geometric ... Chemical modification/ambient drying method and freeze drying method were introduced to research the synthesis of mesoporous silica aerogels. By analyzing N2 gas adsorption/desorption isotherms, the fractal geometric characteristics of gels were focused. The overall surface fractal dimensions were determined by analyzing N2 gas adsorption branch and a Frenkel-Halsey-Hill (FHH) equation was empolyed to determine surface fractal dimension Df It is found that, during ambient drying process, VTMCS/VWetgel ratio plays a crucial role in the changes of geometric feature, the key point is 50%, when the ratio is lower, and surface roughness increases with the ratio, when it exceeds 50%, the surface is almost unaffected by the modification. While freeze drying always tends to get larger Df freeze drying process could cause a rough surface of the gels. Compared with traditional porosity and specific surface area analyses, fractal geometry may be expected to be favorable for mesoporous structural analyses of materials. 展开更多
关键词 silica aerogel N2 gas adsorption surface fractal dimension mesoporous structure
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Synthesis and Characterization of Multi-walled Carbon Nanotube Doped Silica Aerogels
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作者 王宝民 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2012年第3期512-515,共4页
Multi-walled carbon nanotube doped silica aerogels(MWCNT-SAs) were synthesized from a wet gel of well-dispersed MWCNT by one-step solvent exchange/surface modification and ambient pressure drying(APD). Waterglass ... Multi-walled carbon nanotube doped silica aerogels(MWCNT-SAs) were synthesized from a wet gel of well-dispersed MWCNT by one-step solvent exchange/surface modification and ambient pressure drying(APD). Waterglass was employed as a precursor to prepare wet gel. The content of MWCNT varied from 0 to 15% volume by wet gel. The surface group, thermal stability and microstructure of pure silica aerogel and MWCNT-SAs were investigated by FTIR, DTA, and TEM. Experimental results show that MWCNT-SAs are hydrophobic when the temperature is below 400 ℃, MWCNT-SAs exhibit a mesoporous network structure, and they achieve the largest scale with least shrinkage and lowest density when doped with 5 vol% MWCNT. 展开更多
关键词 multi-walled carbon nanotubes(MWCNT) silica aerogels ambient pressure drying(APD)
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Reaction parameters influence on the catalytic performance of copper-silica aerogel in the methanol steam reforming 被引量:1
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作者 Taher Yousefi Amiri Jafarsadegh Moghaddas 《燃料化学学报》 EI CAS CSCD 北大核心 2016年第1期84-90,共7页
Steam reforming of methanol was carried out on the copper-silica aerogel catalyst.The effects of reaction temperature,feed rate,water to methanol molar ratio and carrier gas flowrate on the H_2 production rate and CO ... Steam reforming of methanol was carried out on the copper-silica aerogel catalyst.The effects of reaction temperature,feed rate,water to methanol molar ratio and carrier gas flowrate on the H_2 production rate and CO selectivity were investigated.M ethanol conversion was increased considerably in the range of about 240-300,after which it increased at a slightly lower rate.The used feed flowrate,steam to methanol molar ratio and carrier gas flowwere 1.2-9.0 m L/h,1.2-5.0 and 20-80 m L/min,respectively.Reducing the feed flowrate increased the H_2 production rate.It was found that an increase in the water to methanol ratio and decreasing the carrier gas flowrate slightly increases the H2production rate.Increasing the water to methanol ratio causes the lowest temperature in which CO formation was observed to rise,so that for the ratio of 5.0 no CO formation was detected in temperatures lower than 375℃.In all conditions,by approaching the complete conversion,increasing the main product concentration,increasing the temperature and contact time,and decreasing the steam to methanol ratio,the CO selectivity was increased.These results suggested that CO was formed as a secondary product through reverse water-gas shift reaction and did not participate in the methanol steam reforming reaction mechanism. 展开更多
关键词 copper-silica aerogel activity CO SELECTIVITY reaction parameters METHANOL steam REFORMING
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Mechanical Properties of Weft-Knitted Spacer Fabrics Integrated with Silica Aerogels 被引量:1
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作者 SYED Rashedul Islam YU Weidong +1 位作者 JIANG Jinhua MOHAMMAD Abu Nasir Rakib 《Journal of Donghua University(English Edition)》 EI CAS 2019年第6期559-563,共5页
The work investigated surface and mechanical properties of untreated and treated three-layered weftknitted spacer fabrics.In order to optimize the mechanical properties of weft-knitted spacer fabrics,silica aerogels(S... The work investigated surface and mechanical properties of untreated and treated three-layered weftknitted spacer fabrics.In order to optimize the mechanical properties of weft-knitted spacer fabrics,silica aerogels(SAs)coating was employed.Scanning electron microscopy(SEM)images of untreated and treated spacer fabrics were analyzed to ensure the presence of SAs on the coated spacer fabrics.The basic properties of uncoated and coated weftknitted spacer fabrics were studied and compared.Tensile strength and initial modulus were studied according to the GB/T3923 test standard YG026 MB-250 by testing machine.Moreover,compression properties of spacer fabrics were also tested by HD026 G test instrument.In this testing,work of compression,the linearity of compression,recovery work of compression and other parameters were calculated from stress and strain curves.It was found that SAs coating has a significant influence on the mechanical properties of weftknitted spacer fabrics.The statistical analysis also verified the significant performance(P value smaller than 0.05)of treated fabric samples at the 0.05 level. 展开更多
关键词 3D weft-knitted SPACER FABRICS silica aerogels(SAs)coating tensile strength initial MODULUS compression properties
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Review: Silica Aerogel as a Viable Absorbent for Oil Spill Remediation 被引量:2
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作者 Abiodun Paul Olalekan Adewunmi Oluwasogo Dada Olusola Adedayo Adesina 《Journal of Encapsulation and Adsorption Sciences》 2014年第4期122-131,共10页
The review article reflects on the potential of silica aerogel as viable absorbents for spilled crude oil. Reported oil absorption capacity of silica aerogel shows it has a future in polluted site clean-up. The review... The review article reflects on the potential of silica aerogel as viable absorbents for spilled crude oil. Reported oil absorption capacity of silica aerogel shows it has a future in polluted site clean-up. The review presents the various dynamics of oil spill, conventional clean-up technologies and silica aerogel synthesis techniques. It also highlights some investigations of oil spill sorption using aerogels. The future prospect of rice husk as a cheaper source silica aerogel is also considered. 展开更多
关键词 Oil SPILL REMEDIATION ABSORBENT silica aerogel Rice Husk DRYING
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Silica Aerogel as Super Thermal and Acoustic Insulation Materials
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作者 Yanru Lu Xiaodong Li +3 位作者 Xijiang Yin Handojo Djati Utomo Neng Fu Tao Hai Huang 《Journal of Environmental Protection》 2018年第4期295-308,共14页
Silica aerogels are light weight, nanostructured, and highly porous materials with an open pore structure. Due to their excellent characteristics, such as extremely low thermal conductivity, low density and high poros... Silica aerogels are light weight, nanostructured, and highly porous materials with an open pore structure. Due to their excellent characteristics, such as extremely low thermal conductivity, low density and high porosity, the silica aerogels become promising potential adsorbents, catalysts, thermal insulation, and acoustic absorption materials for environmental purposes. This paper presents the synthesis of a highly flexible polymer modified silica aerogel with the use of a cellulose-methyltriethoxysilane (MTES) precursor in a two-step acid-base catalyzed sol-gel process. The physical properties of the resulting aerogels were characterized by thermogravimetry, scanning electron microscopy, nitrogen adsorption-desorption, contact angle, thermal conductivity measurements, compression testing and Fourier transform infrared spectroscopy. The fabricated aerogel exhibited high flexibility with a Young’s modulus of compression of 0.33 MPa and the density of 0.132 g/cm3. They were hydrophobic in nature and had low thermal conductivity. Preparation of aerogel with solid waste (fly ash/bottom ash) is also discussed. The preliminary results showed that the materials have great potential for environmental application, i.e. enhancement of solid waste recycling rate by converting waste to high value-added materials, super thermal and acoustic insulation materials in green building and removal of oil spilled into surface drainage. 展开更多
关键词 silica aerogelS Polymer Modified High Flexible Low THERMAL CONDUCTIVITY FLY ASH BOTTOM ASH and Environmental Protection
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Study on Dispersion Polymerization Process of Silica Aerogel/Polystyrene Core-Shell Composite Particles
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作者 Gangqiang Geng Suqing Wen Huan Wang 《材料科学研究(中英文版)》 2013年第2期16-22,共7页
关键词 二氧化硅气凝胶 聚合工艺 复合颗粒 聚苯乙烯 核壳 分散 扫描电子显微镜 苯乙烯单体
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Potential Application of Silica Aerogel Granules for Cleanup of Accidental Spillage of Various Organic Liquids
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作者 Vinayak G. Parale Dinesh B. Mahadik +3 位作者 Mahendra S. Kavale A. Venkateswara Rao Pratap B. Wagh Satish C. Gupta 《Soft Nanoscience Letters》 2011年第4期97-104,共8页
The experimental work has been carried out to study the absorption-desorption properties of the silica aerogels, for their use in oil spill cleanup application. For these studies, silica aerogel granules were prepared... The experimental work has been carried out to study the absorption-desorption properties of the silica aerogels, for their use in oil spill cleanup application. For these studies, silica aerogel granules were prepared by two step acid– base catalyzed sol–gel process, involving ambient pressure drying of alcogels, were made use for absorption & desorption studies of different organic liquids. The optimal molar ratio of precursors tetraethoxysilane (TEOS):Methanol (MeOH):Oxalic acid:NH4OH:NH4F:trimethylchlorosilane (TMCS) was kept constant at 1:16.5:0.71:0.58:0.60:0.98, respectively. In all, four alkanes, four aromatic compounds, four alcohols and three oils were used for absorption and desorption studies of organic liquids. The absorption capacity of aerogel sample was quantified by measuring the mass of the organic liquid absorbed by unit mass of the aerogel sample. The hydrophobic aerogel granules showed a very high uptake capacity and high rate of uptake. The desorption of solvents and oils was studied by keeping the liquid absorbed aerogel granules at various temperatures and weighing them at regular time intervals until all the absorbed liquid got totally desorbed. The Fourier transform infrared spectroscopy analysis showed that the aerogel structure was not much affected by the solvent absorption, while the oil absorption led to the shrinkage, resulting in a dense structure after desorption. 展开更多
关键词 Oil SPILL CLEANUP Ambient Pressure Drying HYDROPHOBIC silica aerogelS
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Preparation and Characterization of Mullite-Silica Aerogel Composite Material
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作者 Zhaofeng Song Haiquan Zhao 《Open Journal of Organic Polymer Materials》 2018年第4期43-52,共10页
Silica aerogel due to the high specific surface area, nanometer level pores and low density of the micro structure, had excellent heat-insulating properties. But the characteristics of silica aerogel with low density ... Silica aerogel due to the high specific surface area, nanometer level pores and low density of the micro structure, had excellent heat-insulating properties. But the characteristics of silica aerogel with low density and high voidage resulted in poor mechanical properties. In order to improve the strength of materials and meet the actual needs, in this paper the heat-insulating composite material was made from the silica aerogel and mullite fiber. This kind of composite material mainly contented of mullite fiber, formed macro block structure, that gas gel is coated and filled with mullite fiber. Furthermore, the composite material had good strength and kept excellent thermal stability at 600&deg;C. In addition the density of composite decreased with the increasing of the gas gel content. 展开更多
关键词 silica aerogel MULLITE COMPOSITE Materials
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