MATERIALS CHEMISTRY AND PHYSICS
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2011
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IF 2.356
Meilan Wang,Tao He,Yanfei Pan,Weiping Liao,Shangzhou Zhang,Wei Du
Hydrolysis of tetrabutyl titanate (TBT) and crystallization from hydrolyzed intermediates were carried out in a simple ternary system including n -octanol, TBT and water. Anatase TiO 2 nanocrystals (NCS) were prepared with precise size control below 10 nm. The hydrolysis rate at different water concentration ( C water ) was evaluated by measuring the induction time before turbidity changing of the synthetic solution. Fourier transform infrared spectrum (FT-IR) and thermogravimetric/differential thermal analysis (TG/DTA) techniques were applied to make clear the composition of hydrolyzed intermediates obtained at different C water . Powder X-ray diffraction (XRD) technique was used to track the crystallization process of TiO 2 NCS. Transmission electron microscopy (TEM), XRD, FT-IR and TG/DTA techniques were used to characterize the particular properties of NCS. The C water controlled mechanism responsible for the slow hydrolysis and crystallization were discussed. Since no other organic capping ligands or rapid injecting techniques were used to limit NCS’ growth and the solvent n -octanol can be easily separated and reused, this simple synthetic process is of green chemistry and has application potential in large-scale preparation of inorganic NCS.
研究领域:
材料科学
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化学工程
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING SCIENCE
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2015
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IF 2.337
Binbin Ding,Chaolin Li,Meng Zhang,Fei Ji,Xiaoqing Dong
A power law relation between the filtration coefficients for straining and flux through small pores is reported. This relation can well explain the large penetration depths of particles. However, the normalized effluent concentrations in the experiment and the exponents estimated from the laboratory tests are inconsistent with those from the 2D network model simulation. This study discusses the effects of pore size distribution , capture scheme, and coordination number on the straining-dominant filtration simulation. The findings are compared with experimental data. The sensitivity studies indicate that the two parameters in pore size distribution particularly scale parameter σ , significantly influence the experimental and simulation power law exponent estimation. Three methods are used to estimate the pore size distribution of packing glass granules to obtain a highly accurate pore size distribution. Two capture schemes are applied to 2D pore network models with periodical boundaries and random walk of particles. The normalized effluent concentrations and exponents increase as the coordination number z increases. This trend is more significant in the minimum capture scheme under the same pore size distribution parameters . The simulated normalized effluent concentrations and exponents are consistent with the experimental data under the appropriate simulated conditions. Highly accurate pore size distribution parameters of the porous medium can be inversely determined from laboratory tests with the use of the power law function.
研究领域:
环境工程
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多孔介质传输
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胶体与界面科学
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地下水污染控制
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颗粒迁移
✓ 已验证
DOI
高影响因子
Applied Materials Today
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2023
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IF 8.3
Chengdong Li,Guihua Zhang
Ambient pressure drying is a mainstream alternative to the supercritical drying process for synthesizing aerogels due to its low cost and high safety, but the problems of time-consuming and low mechanical properties of the synthesized aerogels need to be solved. This work tailored the skeleton of methylsilsesquioxane aerogels by ammonia concentration ( c N H 3 · H 2 O ) and revealed their microstructure evolution mechanism affected by the condensation reactions of methyltrimethoxysilane hydrolysates in the subsequent aging and drying process. The effects of process parameters, including the c NH3·H2O, aging temperature and time, drying temperature and time on the gelation time, macroscopic morphologies, microstructures, and compression properties of as-synthesized methylsilsesquioxane aerogels were investigated. A c NH3·H2O of 4.0 mol/L endowed the methylsilsesquioxane aerogels with a compression strength of 0.171 MPa and a maximum compression strain of 59.5 %. The optimal aging conditions were at 50 °C for 3 h which increased the compression strength and maximum compression strain of as-synthesized aerogels to 0.201 MPa, and 66.2 %, respectively. The synthesis time of methylsilsesquioxane aerogels was reduced to 6.5 h through an optimized step drying process, while further increasing their compression strength and maximum compression strain to 0.359 MPa and 73.5 %, respectively. The process parameters optimization method enables the facile synthesis of methylsilsesquioxane aerogels with mechanically robust texture, providing a theoretical basis for developing next-generation scalable production technologies of aerogels.
研究领域:
材料科学
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
Food Bioscience
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2024
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IF 4.8
Jingyao Li,Chengguo Sun,Mengli Zhang,Jing He,Zhanyu Shen,Lihua Geng,Liufeng Yuan,Shuo Wang,Chunling Wang
Soybean paste is widely used as a seasoning for authentic Asian cuisine due to its rich and savory sauce flavor. However, the primary components of the soybean paste sauce-flavor compounds and the fermentation regulation mechanisms are still unclear. Therefore, the present study sought to systematically explore the factors affecting the sauce flavor in terms of substrate, external microorganisms, brine concentration, and the alteration in flavor composition and its regulatory mechanisms. The results of the raw material ratios showed that an appropriate increase in the proportion of soybeans (6:4) could significantly enhance the concentration of amino acid metabolites, such as 2-methylbutanal, 3-methylbutanal, and 2-phenylethanal. Delayed addition to Tetragenococcus halophilic significantly enhanced 2-butylfuran, 2-pentylfuran, trans -2-(2-pentenyl) furan, and sauce-flavor perception in soybean paste by modulating the total acid. A suitable brine concentration (10%) could adjust the fermentation process and facilitate the formation of benzaldehyde, 2-ethylfuran, 2-butylfuran, 2-pentylfuran, and other sauce-flavor compounds. Meanwhile, combined results of sensory evaluation and GC-MS analysis demonstrated that the primary components of the sauce-flavor compounds in soybean paste consisted of furans (furfural, 2-methylfuran, 2,5-dimethylfuran, 2-ethylfuran, 2-butylfuran, 2-pentylfuran) and pyrazine (2,6-dimethylpyrazine, 3-ethyl-2,5-dimethylpyrazine). Overall, these results provide a theoretical basis for the targeted enhancement of the sauce-flavor of soybean paste and insights into the industrial production of high-quality soybean paste.
研究领域:
食品科学
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微生物学
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化学
✓ 已验证
产品关联
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
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2015
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IF 3.091
Binbin Ding,Chaolin Li,Xiaoqing Dong
A straining-dominant filtration model based on directed bond percolation is proposed. The infinite cluster structure of this model is relevant to filtration properties. Thus, a direct electrifying algorithm is modified for infinite cluster backbone identification, and the geometrical characteristic of the infinite cluster is analyzed. In addition, the relationship between the normalized effluent concentration and infinite cluster is established. The model is validated by comparing the particle concentrations estimated from analyzing the property of filtration cluster of network model with the normalized effluent concentration obtained from filtration process simulation and the experimental data. The results show that normalized effluent concentrations estimated from cluster analysis are consistent with the experimental data and filtration simulated result. Finally, the sensitivity of pore size distribution (PSD) parameters to normalized effluent concentrations estimation is analyzed. Assuming that the PSD is lognormal, the normalized effluent concentrations increase as the location parameter μ increases and scale parameter σ decreases.
研究领域:
环境工程
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流体力学
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材料科学
✓ 已验证
DOI
高影响因子
COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS
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2020
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IF 3.99
En-Hui Yuan
A series of Beta zeolites has been carefully prepared by the conventional hydrothermal method under various ratios of H 2 O/SiO 2 ranging from 10 to 60. These zeolite materials are thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), nitrogen adsorption-desorption, temperature programmed desorption of ammonia (NH 3 -TPD) and etc. It reflects that the water concentration (H 2 O/SiO 2 ratios) has great impact on the zeolites nucleation and growth rates, resulting in the different crystals morphologies, size distributions and textural properties for the obtained Beta zeolite materials. These primary results are very help for guiding rational design of the zeolite catalysts with different topologies and other related materials for specific applications.
研究领域:
材料科学
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催化
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2020
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IF 7.632
Heng Ban,Youdi Zhang,Shuaibo Chen,Youwei Cheng,Teng Pan,Lijun Wang,Xi Li
In this contribution, readily available 5-methyl furfural (MF) derived from biomass was used as an excellent substitute of the chemically unstable 5-hydroxymethylfurfural (HMF) for preparing the commercial precursor 2,5-furandicarboxylic acid (FDCA). MF was catalytically oxidized by air into FDCA in acetic acid over homogeneous Co/Mn/Br catalysts at 130–170 °C. It was found that both the substitute reactivity and the ring chemical stability have a remarkable impact on the yield of aromatic dicarboxylic acids. The effects of reaction temperature, pressure, catalyst composition and concentration, water concentration in the solvent, and substrate/solvent mass ratio on both the main reaction and the side reaction were investigated systematically and thoroughly using HPLC and an online tail gas monitoring system. Under optimized conditions, the oxidation of MF gave 100% conversion of MF and 75.8% yield of FDCA with 99.6% purity. It was also proven that the addition of 200 ppm cerium could work well at low temperatures (130–140 °C) for enhancing FDCA selectivity via suppressing the side reactions.
研究领域:
化学工程
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催化
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有机化学
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绿色化学
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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）