CHEMICAL ENGINEERING JOURNAL
·
2020
·
IF 10.652
Zeyou Meng,Yuheng Liu,Xiao Li,Zichuan Ma
Volatile methylsiloxanes (VOSiC) are impurities present in trace amounts in biogas produced by the anaerobic digestion of organic wastes in landfill and sewage plants. Efficient removal of these impurities is required due to the restrictions posed by them on the application of biogas as an alternative energy resource. In this study, methyl-functionalised silica gels (MFS) have been prepared via a hydrolysis and condensation approach using double precursor (TEOS and MTS) in methanol–water medium for achieving effective removal of a model VOSiC - hexamethyldisiloxane (L2). The developed gels have been characterized by N 2 -BET, FTIR, SEM-EDS and XRD. The results reveal that the as-synthesized MFS materials have well-developed micropore structure and superhydrophobicity. Among the developed materials, MFS2 sample obtained with a MTS/TEOS ratio of 1/1 ( v/v ) exhibits the highest specific surface area (1261.3 m 2 g −1 ), micropore volume (0.52 cm 3 g −1 ) and total pore volume (1.03 cm 3 g −1 ), along with superior water contact angle (123.5°). The non-crystalline nature and sponge-like structure of MFS are confirmed by XRD and SEM analyses. The adsorptive performance of MFS materials for L2 siloxane is measured to be 14.9–18.3 times higher than that of the unmodified silica in terms of the breakthrough adsorption capacity ( Q B ). Also, the adsorption capacities of MFS materials are noted to be linearly related to the specific surface area and micropore volume, along with positively affected by the total pore volume and water contact angle. From a series of the experimental results of adsorption of L2 by MFS2, an empirical equation is developed for reflecting the correlation of the breakthrough time and inlet concentration. Use of lower temperature is concluded to result in better overall siloxane adsorption levels. The Q B reaches an optimal value of 346.3 mg L2 g −1 at 0 °C using 83.82 mg L −1 of L2 with N 2 as the carrier gas. The developed MFS adsorbent can be readily regenerated for reuse by heating at 80 °C, and an insignificant fluctuation in the dynamic adsorption behavior is observed even after consecutive 5 adsorption/desorption cycles.
研究领域:
环境科学
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化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Asian Ceramic Societies
·
2022
·
IF 2.546
Ping Yang,Zhenfei Sun,Shengwu Huang,Jun Ou,Qiangguo Jiang,Dichen Li,Shanghua Wu
Due to high light absorption and high refractive index of silicon nitride (Si3N4) ceramic, it is difficult to prepare Si3N4 slurry with favorable curing ability, high solid loading and low viscosity at the same time, and thus the high-quality Si3N4 parts are hard to fabricate via Digital Light Processing (DLP). In this paper, the oxidation process was used to enhance the curing behavior of Si3N4 slurry, and then silane coupling agent (KH560) was used to improve the rheological properties of the oxidized Si3N4 slurry. The effect of Si3N4 slurry with oxidation and modification on its rheological behavior, light absorption, curing ability and stability have been systematically investigated. A Si3N4 slurry with abundant photocuring ability, high solid loading, low viscosity and reliable stability was fabricated by the oxidized (1 h) and KH560 (1 wt.%) modified Si3N4 powders, and the dense Si3N4 ceramic parts were produced by this slurry via DLP 3D printing. Subsequently, the influence of oxidation and modification on microstructure, mechanical properties and thermal conductivity have been investigated. Finally, the microstructure and performances of Si3N4 ceramic were compared between different forming processes (including: DLP and cool isostatic pressing).
研究领域:
材料科学
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3D打印技术
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陶瓷加工
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产品关联
DOI
高影响因子
CEMENT AND CONCRETE RESEARCH
·
2024
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IF 10.9
Binmeng Chen,Xu Fang,Yuyang Zhao,Zongjin Li
In recycling and reusing construction waste, carbonation of recycled concrete fine (RCF) has been successfully applied to produce value-added products, such as silica nanoparticles, via the breaking of calcium silicate hydrate (C-S-H) structure and condensation of silicate chains. However, the intricacies of carbonation of RCF with varying calcium to silicon (C/S) ratios and their implications on the size of generated silica nanoparticles remain unknown. In this work, we developed an optimized carbonation method at high water to solid ratio to fabricate silica nanoparticles from C-S-H with different C/S ratios. The particle size of silica nanoparticles was found to gradually decrease with the increased C/S ratio of C-S-H. Since as C/S ratio increased, silicate in Q 3 state shifted to Q 1 state and the silicate chain became shorter, shifting from long-range, disordered to short-range, ordered. As the disordered self-seeding growth of long silicate chains derived from C-S-H continued, the Si-O-Si network of silica nanoparticles became chaotic, leaving more unreacted Si-OH on its surface. On the contrary, the short silicate chains displayed higher possibility of condensation, making nanoparticles with a smaller diameter.
研究领域:
材料科学
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环境工程
✓ 已验证
产品关联
DOI
高影响因子
Materials
·
2024
·Vol. 17
·期 18
·4473
·
IF 3.1
Junlong Luo,Jun Cai,De Gong,Aoping Guo,Jaw-Kai Wang,Jiangtao Zhang
Pursuing improved electrode materials is essential for addressing the challenges associated with large-scale Li-ion battery applications. Specifically, silicon oxide (SiOx) has emerged as a promising alternative to graphite anodes, despite issues related to volume expansion and rapid capacity degradation. In this study, we synthesized carbon-coated SiOxusing diatom biomass derived from artificially cultured diatoms. However, the inherent carbon content from diatoms poses a significant challenge for the electrochemical performance of diatom-based anodes in large-scale applications. Subsequently, we conducted further research and demonstrated excellent performance with a carbon content of 33 wt.% as anodes. Additionally, real-time characterization of the carbonization process was achieved using thermogravimetry coupled with infrared spectroscopy and gas chromatography mass spectrometry (TG-FTIR-GCMS), revealing the emission of CO and C3O2during carbonization. Furthermore, electrochemical tests of the processed diatom and carbon (PD@C) anode exhibited outstanding rate capability (~500 mAh g−1at 2 A g−1), high initial Coulomb efficiency (76.95%), and a DLi+diffusion rate of 1.03 × 10−12cm2s−1. Moreover, structural characterization techniques such as HRTEM-SAED were employed, along with DFT calculations, to demonstrate that the lithium storage process involves not only reversible transport in Li2Si2O5and Li22Si5, but also physical adsorption between the PD and C layers. Exploring the integration of diatom frustules with the intrinsic carbon content in the fabrication of battery anodes may contribute to a deeper understanding of the mechanisms behind their successful application.
研究领域:
材料科学
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电化学
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生物材料
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials Today Energy
·
2021
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IF 7.311
Qiang Ma,Yan Zhao,Zuojun Hu,Jiakang Qu,Zhuqing Zhao,Hongwei Xie,Pengfei Xing,Dihua Wang,Huayi Yin
Low-cost silicon (Si) feedstocks and a facile method to downsize the particle size are two determinants for the application of Si for the lithium-ion battery anode. Among various Si feedstocks, the industrial bulk ferrosilicon (b-Si/FeSi 2 ) alloy is a promising Si resource, but decreasing the particle size and increasing the utilization of Si remain challenging. Herein, we report a self-driven alloying-electrochemical dealloying approach to converting the b-Si/FeSi 2 to nano-sized Si/FeSi (n-Si/FeSi) in molten salts using Mg to extract one Si atom from one FeSi 2 molecule by breaking down the FeSi–Si chemical bond and simultaneously forming Mg 2 Si. Subsequently, the obtained FeSi and Mg 2 Si are converted to nano Si and FeSi by electrochemically removing Mg from the Mg 2 Si anode to the cathode, making a circular use of Mg and increasing the electroactive Si content. Moreover, the polydopamine-coated n-Si/FeSi (n-Si/FeSi@C) anode exhibits a high capacity of 1449.7 mAh g −1 after 500 cycles at 0.4 A g −1 , and an extremely stable reversible capacity of 846.8 mAh g −1 is retained even after 1500 cycles at 2 A g −1 . Overall, this work provides an efficient method to convert industrial bulk Si/FeSi 2 to nano-sized Si/FeSi by leveraging the chemical bonds of Fe–Si and Mg–Si.
研究领域:
材料科学
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电化学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
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2014
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IF 2.086
Ran Liu,Tianyan Xue,Jing Song,Yu Wang,Tao Qi,Jingkui Qu,Ailing Du
The efficiency of silicon removal technology by acid leaching and flocculation during zirconium oxychloride octahydrate (ZrOCl 2 ⋅8 H 2 O) production has been improved. The optimum conditions of acid leaching were found to be as follows: transiton material, 300 g; HCl (6 mol/L), 600 mL; leaching time, 4 h; and leaching temperature, 100 °C. The nonionic polyoxyethylene lauryl ether (AEO9) was adopted as the flocculant. The optimum flocculation conditions were found to be as follows: temperature, 40 °C; flocculant amount, 10 ml (concentration 1%); time, 1 h. The zirconium oxychloride solution after purification contained 36 ppm SiO 2 and 160 g/L ZrOCl 2 . The polymerization and flocculation mechanisms of silicic acid were analyzed. Results of Fourier-transform infrared, scanning electron microscopy, nuclear magnetic resonance, and Brunauer–Emmett–Teller analyses showed the main transformation and properties of the products in the acid leaching and flocculation processes.
研究领域:
化学工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2017
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IF 3.133
Kui Liang,Hailin Yang,Wenxun Guo,Jianlong Du,Lingyun Tian,Xiaofeng Wen
Silicon has been regarded as a promising alternative anode material for next-generation lithium ion batteries (LIBs) due to its high theoretical specific capacity of 3590 mAh g −1 (Li 3.75 Si formed at room temperature). In this work, nanoscale silicon has been synthesized via a simple and effective metathesis reaction in which SiCl 4 is the silicon source and Zn is the reductant and solvent, at a mild temperature of 500 °C. The preparation process is very simple, facile and low-cost. The as-prepared silicon particles are spherical with a diameter of 150–200 nm, and the delithiation capacity of the nanoscale silicon can reach 1747.7 mAh g −1 at a current density of 0.2 A g −1 .
研究领域:
材料科学
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能源存储
✓ 已验证
产品关联
DOI
高影响因子
Crystals
·
2022
·Vol. 12
·期 2
·144
·
IF 2.67
Shun Zhou,Xiaotao Zhang,Han Zhou,Dongxu Li
In the present research work, the ternary effects of varying dosages of graphene oxide encapsulated silica fume (GOSF), nano-silica sol (SS), and fly ash (FA) on the rheological properties, compressive strength, the content and crystal size of calcium hydroxide (CH), porosity, water absorption, and microstructure of cement were studied. The results showed that the incorporation of SF improved the dispersion of GO in the cement matrix. GOSF was prepared through electrostatic attraction between the positively charged SF and negatively charged GO. The ternary mixture of GOSF, SS, and FA had a synergistic effect that improved the performance of cement. When the curing age of cement reached 28 days, the compressive strength reached a peak of 86.5 MPa, the minimum values of content and crystal size of CH were 11.55% and 45.69 nm, respectively, and the minimum values of water absorption and porosity were 0.0011 cm/s0.5and 13.56%, respectively. In terms of microstructure, the denser structure of C-S-H gel and the regular arrangement of CH were noticed.Keywords:silica fume;silica sol;graphene oxide;fly ash;orthogonal experiment
研究领域:
土木工程
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2023
·
IF 8.6
Ye Li,Yong Wang,Honghao Bai,Shishuai Li,Xiaomin Li,Xiaoqing Wang,Libo Li,Jinping Li,Jiangfeng Yang
The economically efficient separation of ethane (C 2 H 6 )/ethylene (C 2 H 4 ) presents challenges in the petrochemical industry, and the use of traditional adsorbents zeolite provides a reliable guarantee for maintaining the economic viability of adsorption separation technology. In this study, we investigate the impact of different silica-alumina ratios (SiO 2 /Al 2 O 3 = 40, 500, and 1500) of high silica zeolites ZSM-11 on the C 2 H 6 /C 2 H 4 separation performance to develop efficient C 2 H 6 selective adsorbents. The results show that the C 2 H 6 adsorption capacity and C 2 H 6 /C 2 H 4 selectivity of ZSM-11 increase as the silica-alumina ratios increases. The pure silica zeolite (ZSM-11(1500)) exhibits the highest adsorption capacity for C 2 H 6 (59.19 cm 3 /g) and the highest selectivity for C 2 H 6 /C 2 H 4 (2.04), which were superior to ultra-high silica sample (ZSM-11(500)) (55.06 cm 3 /g and 1.62, respectively) and high silica sample (ZSM-11(40)) (47.28 cm 3 /g and 1.23, respectively), at 273 K and 1 bar. The mixed gas breakthrough experiments results show that pure silica sample has outstanding C 2 H 6 /C 2 H 4 separation ability. The PSA simulation calculated data demonstrating promising potential for industrial applications. Importantly, this separation performance remains unaffected even in the presence of H 2 O.
研究领域:
化学工程
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Mingwei Liang,Weijing Wang,Yi Jiang,Chenyang Liao,Qin Long,Xuefei Lai,Li Liao
The commercial application of silicon is still impeded by poor conductivity and significant volume change. In this work, a C@Si@G composite was synthesized by a facile chemical solution reaction and carbonization procedure with cocoon silk as a natural carbon source. This composite has a sandwich structure, where Si nanoparticles as a sandwich middle layer and graphene (G) as an out layer. And it possesses the advantages of flexible, nitrogen-doped and is environmentally friendly. The optimized C@Si@G-15 composite is used as a self-supporting anode without a current collector, and it shows a reversible discharge capacity of 972 mAh g −1 after 120 cycles at 1 A g −1 and a relatively high capacity of 1070 mAh g −1 after 300 cycles at 200 mA g −1 , demonstrating the effect of coating the N-doped carbonized silk and the graphene synergistically to improve electrical connectivity and to constrain the pulverization of Si nanoparticles. Hence, it delivers great potential for application on wearable devices .
研究领域:
材料科学
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能源技术
✓ 已验证
产品关联
DOI
高影响因子
POLYMER
·
2024
·
IF 4.1
Shengqiang Wang,Zhenbo Peng,Yanhua Huang,Mingquan Zhu,Yayun Liu,Yong Zhang
Phenyl-containing polysiloxanes have better thermal stability, low-temperature flexibility, and room-temperature damping performance than polydimethylsiloxanes. Poly [dimethylsiloxane- co -methyl (phenyl)siloxane] and poly (dimethylsiloxane- co -diphenylsiloxane) were synthesized through a bulk copolymerization of octamethylcyclotetrasiloxane and methylphenylcyclosiloxane mixture or octaphenylcyclotetrasiloxane, and the structure and properties of the copolysiloxanes were comparatively studied. The phenyl content in poly [dimethylsiloxane- co -methyl (phenyl)siloxane] can be as high as 50 mol%. With the increment of the phenyl content, the thermal stability of the copolysiloxanes is dramatically improved as evaluated by thermal gravimetric analysis. At a given phenyl content, poly [dimethylsiloxane- co -methyl (phenyl)siloxane] has higher thermal stability than poly (dimethylsiloxane- co -diphenylsiloxane). The former is more difficult to crystalline at low temperatures and has lower room temperature viscosity than the latter as confirmed by differential scanning calorimetry and rotational rheometer. The copolysiloxanes is mixed with hydrogen-containing polysiloxane and silica, and vulcanized at elevated temperature to get copolysiloxane composites with good damping properties, oil resistance, and low-temperature resistance. This study not only enriches the fundamental academic research on functional polysiloxanes, but also provides useful technical references for practical applications of phenyl silicone rubber.
研究领域:
高分子科学
·
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF WUHAN UNIVERSITY OF TECHNOLOGY-MATERIALS SCIENCE EDITION
·
2018
·Vol. 33
·期 1
·233-241
·
IF 0.524
Cai Qi,Huang Jiemin,Weng Rui,Liu Shichen
In order to prepare hydrophobic waterborne polyurethane coatings with better performances, the silicon-containing waterborne polyurethane (SiWPU) with functional chain extender hydroxyethyl acrylate (HEA) was prepared first, and then a series of silicon&fluorine-containing polyurethane/acrylate (FSiPUA) emulsions were obtained with flourine containing acrylic monomer by seed emulsion polymerization, introducing micro-nano SiO 2 into FSiPUA emulsion to make the final hybrid emulsion. The properties of SiWPU, FSiPUA and SiO 2 /FSiPUA were investigated by fourier transform infrared spectra (FTIR), transmission electron microscope (TEM), Scanning Electron Microscope (SEM) and some other analytical methods. The results revealed that FSiPUA emulsion particles possessed composite core-shell structure and FSiPUA films with suitable ratio performed better than SiWPU films in hardness, water resistance and solvent resistance. The SiO 2 /FSiPUA films with micro-nano dual roughness structure showed a water contact angle of 136° with good resistance to acid and alkali.
研究领域:
材料科学
·
表面化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）