DESALINATION
·
2017
·
IF 5.527
Heiyan Zhang,Bingbing Li,De Sun,Xiaoling Miao,Yunlei Gu
In this study, hydrophobic asymmetric SiO 2 -PDMS-PVDF hollow fiber membranes were prepared for the vacuum membrane distillation (VMD). To make PVDF dope solution, hydrophobic nano-fumed silica (SiO 2 ) and polydimethylsiloxane (PDMS) were used. The effects of SiO 2 concentration on membrane parameters such as membrane morphology, hydrophobicity , porosity, thickness, pore size, liquid entry pressure , burst pressure, Fourier transformed infrared spectroscopy , thermal property, mechanical property and permeability were investigated. With the increasing of nano-particle concentration, membrane hydrophobicity, mechanical property and thermal stability improved. Furthermore, membrane VMD properties under various operation conditions were studied, the membranes showed a stable substantial flux of 44.27 LMH and a stable high salt rejection of over 99.9% under the optimum operation conditions of 75 °C, 35 g/L, 87 kPa, and 50 L/h. The results of our research demonstrated that the prepared hydrophobic asymmetric SiO 2 -PDMS-PVDF hollow fiber membranes not only had high permeability and good anti-wetting property but also exhibited a satisfying stability for the vacuum membrane distillation of desalination .
研究领域:
材料科学
·
环境工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF APPLIED POLYMER SCIENCE
·
2021
·Vol. 139
·期 12
·51810
·
IF 3.125
Songling Chen,Yanyu Han,Chunyu Chen,Hongdou Liu,Hongtao Zou
Nearly 100 million tons of spent mushroom substrates (SMS) are discarded annually in China, which causes a series of environmental pollutants. To improve the nitrogen (N) use efficiency of and to shift dependence away from petroleum-based products, a novel bio-based epoxy coated urea was successfully developed. The bio-based epoxy coating was synthesized from the liquefied SMS and bisphenol-A diglycidyl ether. Subsequently, both nano-SiO 2 and organosilicon were employed to modify the bio-based epoxy and increase its hydrophobicity. Water absorption, ammonium adsorption, and water contact angles of the bio-based epoxy coatings were investigated. The nutrient release behaviors of the bio-based epoxy coated urea in water were also investigated and the modification mechanisms were explored by Fourier transform infrared, scanning electron microscopy–energy-dispersive X-ray spectroscopy and thermogravimetric analysis. The results revealed that the hydrophobic ability of the nano-SiO 2 and organosilicon dual modified bio-based epoxy coated urea coating was significantly enhanced and that its nutrient release longevity was increased to 56 days. Therefore, this work demonstrated that bio-based epoxy coated urea with superior release characteristics exhibited great potential in modern agricultural applications.
研究领域:
环境科学
·
农业科学
✓ 已验证
产品关联
DOI
高影响因子
MATERIALS CHEMISTRY AND PHYSICS
·
2021
·
IF 4.094
Shenghang Xu,Tingting Lu,Kaijie Shen,Junjie Lan,Bin Hu,Huibin Zhang,Yiping Tang,Huazhen Cao,Guoqu Zheng
Ti–5Al–5V–5Mo–3Cr (Ti-5553) metastable β titanium alloy possesses excellent high temperature mechanical properties , however, the oxidation resistance is fairly poor. In this work, a SiO 2 coating was prepared on Ti-5553 alloy by cathodic electro-deposition. The high temperature oxidation resistance of the deposited SiO 2 coating was evaluated at 800 °C. The results show that the optimal current density of deposition is −2.0 mA/cm 2 for 300 s, and the thickness of the compact SiO 2 film reaches 5.5 μm. The SiO 2 film can react with Ti-5553 substrate and form protective Ti 5 Si 3 layer, which inhibits the inward diffusion of oxygen from air, leading to the remarkable improvement of oxidation resistance. The mass gain is only 1.13 mg/cm 2 after oxidation at 800 °C for 80 h. The oxide scale consists of TiO 2 , Al 2 O 3 , V 2 O 5 , Cr 2 O 3 and SiO 2 , but Mo 2 O 5 is absent. The occurrence of Kirkendall voids as well as the cracks induced by internal stress should be responsible for the deterioration of oxidation resistance, which may provide extra channels for oxygen diffusion inwards the substrate.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
STEEL RESEARCH INTERNATIONAL
·
2024
·
IF 1.9
Li Zhang,Hang He,Lei Zhang,Yongqi Sun,Xu Gao,Jie Zeng,Wanlin Wang
Viscosity is an important property for CaO-SiO 2 -Al 2 O 3 -based slag systems, which showcases different scenarios in basic and acid slag systems with temperature change. This article elucidates the mechanism of their difference in viscosity–temperature property from melt structure. Results reveal that basic slag shows a low degree of polymerization (DOP) and a low viscosity of the melt due to an excessive O 2− ions depolymerizing the complex network structures, resulting in more low-polymerized Q 0 (Si) units and less high-polymerized Q 3 (Si) units. With the temperature decreases, the DOP and viscosity do not change significantly. However, the low DOP and viscosity favor crystal precipitation in the melt, leading to a solid–liquid mixed state of the slag, and thus a sharp increase in viscosity when the temperature decreases to 1275 °C. For acid slag, it undergoes a transformation into aluminosilicate structures with the introduction of numerous [AlO 4 ] 5− tetrahedra, accompanied by a significant increase in the relative mole fraction of high-polymerized Q 3 (Si) units. Consequently, the DOP and viscosity are obviously higher than that of the basic slag. Furthermore, the DOP and viscosity of the acid slag increase continuously with the temperature decreasing, thus impeding crystal precipitation and enhancing the glass transition tendency of the molten slag.
研究领域:
材料科学
·
冶金学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2024
·
IF 13.3
Zhuo Ma,Yihui Li,Zheng Li,Ziyin Liu,Xuepeng Wang,Yuan Tan,Xingkun Chen,Wei Lu,Yunjie Ding
Increasing dimethyl oxalate (DMO) hydrogenation activity remains a challenge. A Cu catalyst was designed by creating Cu nanoparticles (NPs) over SiO 2 layer formed on the CeO 2 particles (SiO 2 @CeO 2 ) using the ammonia evaporation method followed by the calcination and reduction step. The optimized 30Cu/SiO 2 @5CeO 2 catalyst shows good performance in the micro-packed bed reactor (100 % DMO conversion, 95.9 % ethylene glycol (EG) selectivity, 200 h stability) under the condition of the ratio of H 2 to DMO (H 2 /DMO) = 30, 190 °C and 2 MPa in the run, and CeO 2 was proved to be effective in the DMO hydrogenation process. The exposed CeO 2 on the surface of catalyst was found to facilitate the formation of Cu + by its interaction between adjacent Cu nanoparticles, resulting in the faster adsorption and dissociation of C=O bond on the catalyst surface, according to the characterization results obtained by the XRD, XPS and in situ FT-IR, etc.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY COMMUNICATIONS
·
2020
·
IF 1.943
Jiuxiao Dong,Peiying Li,Hongyu Guan,Chunhua Ge,Yufeng Bai,Yuhui Zhao,Xiangdong Zhang
We use photosensitive resin as material, and adopt 3D printing and pyrolysis to prepare silica ceramics. HKUST-1 was grown on the ceramic surface by step-by-step in-situ growth method to obtain the HKUST-1/SiO 2 composite material. The HKUST-1/SiO 2 composite material was characterized by X-ray powder diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive spectrometer (EDS), thermogravimetric analysis (TG). The HKUST-1/SiO 2 composite material not only has the characteristics of HKUST-1 and SiO 2 , but also can be designed into different complex shapes. In addition, the composite can be easy to separate from the product without centrifugation or filtration after the reaction is completed. The application of benzyl alcohol oxidation was an example to the performance of composite catalysts.
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
Journal of Inorganic and Organometallic Polymers and Materials
·
2019
·Vol. 29
·期 4
·1192-1197
·
IF 1.637
Zhao YingRui,Yang Chao,Zhang HongYan,Qiang Gen,Fan HuiLing
Two kinds of ZnO/SiO 2 composite (labled as SZ-1 and SZ-2) were synthesized by sol–gel method and characterized by X-ray diffraction (XRD) patterns, XPS (X-ray photoelectron spectroscopy) spectra and Diffuse Reflectance Infrared Fourier Transform (DRIFT) spectra. Water adsorption on the prepared sample was studied by in situ DRIFT. The as-synthesized SZ-1 and SZ-2 sample have different surface property due to the various aging methods in the sample preparation processes, thus showing different results of water adsorption. The adsorption sites (Si atom in Si–O–Si bond) on the surface of SZ-2 for water molecule are occupied by the –OCH 3 group and the hydrophilicity of SZ-2 is weaker, in comparison to SZ-1, which inhibits the formation of water film and ultimately decreases desulfurization performance of SZ-2. So, the desulfurization performance can be changed by altering the hydrophilicity of sorbent.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2019
·
IF 3.45
Zijun Peng,Xudong Luo,Zhipeng Xie,Mengmeng Yang
SiO 2 -MgO ceramics containing different weight fractions (0, 0.5, 1, 2, and 4 wt%) of SiO 2 powder were prepared by mixing nano MgO powder, and the powder mixtures were densified by spark plasma sintering (SPS). The effect of SiO 2 addition and SPS method on the sintering behavior, microstructure and mechanical properties were investigated. Results were compared to specimens obtained by conventional hot pressing (HP) under a similar sintering schedule. The highest relative density, flexural strength and hardness of 2 wt% SiO 2 -MgO ceramics reached 99.98%, 253.99 ± 7.47 MPa and 7.56 ± 0.21 GPa when sintered at 1400 °C by SPS, respectively. The observed improvement in the sintering behavior and mechanical properties are mainly attributed to grain boundary "strengthening" and intragranular "weakening" of the MgO matrix. Furthermore, the spark plasma sintering temperature could be decreased by more than 100 °C as compared with the HP method, SPS favouring enhanced grain boundary sliding , plastic deformation and diffusion in the sintering process.
研究领域:
材料科学
·
陶瓷工程
✓ 已验证
产品关联
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2021
·
IF 5.161
Yi Wu,Kai Yan,Guilin Xu,Chenguang Yang,Dong Wang
Re-entrant geometries can effectively trap air pockets, increase air/liquid interface fraction, prevent the penetration of low surface tension organic liquids, and achieve super-oleophobic performance. However, the creation of re-entrant geometries usually involving expensive lithographic tools, or complicated chemical procedures, and cannot be applied on a large scale, such super-oleophobic surfaces are unsuitable for practical application. Constructing hierarchical micro/nanostructure on substrates is a feasible solution to achieve super-oleophobicity through facile spraying method. Herein, we report a super-oleophobic TiO 2 /SiO 2 composite coatings by taking advantage of an exceedingly simple spraying method. The dendritic structures produced by spraying the TiO 2 /SiO 2 mixture play the critical role in obtaining the re-entrant geometry required for oleophobic surface, and the introduction of micron-scale TiO 2 particles and nano-scale SiO 2 particles provide an enough dual-scale rough structure for the coating. The TiO 2 /SiO 2 composite coatings exhibit superior repellence to high and low surface tension liquids as well long-term durability. This design strategy may provide useful guidelines for the fabrication of particle-based spray-coated super-oleophobic surfaces.
研究领域:
材料科学
·
表面工程
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2014
·Vol. 4
·期 50
·26309-26315
·
IF 3.708
Zheng-Yong Chen,Ya-Yuan He,Hong-Wen Gao
A “dissolving and rebuilding” method was applied to prepare a diatomiteethyleneimine–polymer (PEI) hybrid composite, and its structure and topography were characterized by XRD, SEM, TEM, FTIR, DTG, elemental analysis and ζ-potential. The results indicated that the PEI was efficiently assembled into the SiO2 framework formed from diatomite. Attempts were made to use the composite to remove phenolic pollutants, e.g. phenol, o-chlorophenol and bisphenol A (BPA), from aqueous solution. These adsorptions were to be in accordance with lipid–water-partition law, and their Kaw values were calculated to be 79.1 L kg−1 for phenol, 37.3 L kg−1 for o-chlorophenol and 24.2 L kg−1 for BPA.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
FUEL PROCESSING TECHNOLOGY
·
2024
·
IF 7.2
Xiequan Chen,Qi Zhang,Song Li,Haiyong Wang,Xinghua Zhang,Lungang Chen,Longlong Ma,Jianguo Liu
Acidic promoters are significant in the hydrodeoxygenation (HDO) of bioderived furans into alkanes over metal-acid bifunctional catalysts. Here, a supported Pd/HPW-SiO 2 catalyst was prepared to investigate the promotion effect of phosphotungstic acid (HPW) on the HDO of HMF-acetone adduct (H-Ac). Characterizations suggested that an intimate contact between Pd and HPW was established in Pd/HPW-SiO 2 . HPW promoters significantly reduced the reduction temperature of Pd oxides with enhanced hydrogenation and HDO capability. Particularly, in-situ DRIFTS confirmed that Pd-HPW sites significantly weakened the π CO η 2 adsorption mode (ν 3 (C=O)) of C=O group on Pd surfaces. Thereby, the HDO efficiency was synergistically improved through releasing more Pd metal sites to activate hydrogen for hydrogenation and HDO with HPW promoters. Eventually, >90% yield of nonane was efficiently achieved at 160 °C. This work is applicable to explore the structure-activity relationship of bifunctional catalysts in the efficient HDO of complicated oxygenated bioderived furans.
研究领域:
化学工程
·
催化科学
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Peijun Liu,Wenjie Zhang,Da Chen,Lili Yang
Lanthanum doped MgTiO 3 (La–MgTiO 3 ; n (La): n (Mg) = 0.05:0.95) was synthesized using a sol–gel method, and a layer of this material was supported on quartz microspheres to produce La–MgTiO 3 ( x% )/SiO 2 microspheres (LMTO( x% )/SiO 2 ; where x% represents the weight fraction of La–MgTiO 3 in the microspheres). The crystal size of MgTiO 3 decreased from 43.4 nm in La–MgTiO 3 to 29.2 nm in LMTO( 20 % )/SiO 2 , and the bandgap energies increased from 3.34 eV (La–MgTiO 3 ) to 3.91 eV (LMTO( 20 % )/SiO 2 ). The supported La–MgTiO 3 contributed the most to the total surface area of the LMTO( x% )/SiO 2 microspheres; further, the specific surface area of the microspheres decreased with decreasing La–MgTiO 3 content. The photoluminescence intensity of the microspheres was significantly lower than that of La–MgTiO 3 . The activity of La–MgTiO 3 was enhanced after loading onto the quartz microspheres. The maximum photocatalytic activity was obtained using LMTO( 40 % )/SiO 2 , while the azophloxine degradation efficiency slightly decreased after five reaction cycles.
CAS / MDL:
研究领域:
材料科学
·
环境科学
✓ 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）