JOURNAL OF MOLECULAR CATALYSIS B-ENZYMATIC
·
2015
·
IF 2.128
Chuan-Yang Shang,Wei-Xun Li,Feng Jiang,Rui-Feng Zhang
ZnO nanowires/macroporous SiO 2 composites were used as a new type of microwave absorbing support to immobilize Candida rugosa lipase (CRL). Under microwave irradiation the immobilized lipase was used to catalyze esterification of phytosterol and oleic acid for the synthesis of phytosterol esters. A great improvement of the catalytic activity was found in the systems in which composited ZnO nanowires were present. The microwave absorbing properties of ZnO nanowires have been proved to be helpful for the synergistic effect between microwave irradiation and enzyme catalysis. The immobilized CRL showed higher thermal stability at 55 °C under microwave irradiation than conventional heating. A maximum molar conversion of 95.4% under microwave irradiation was achieved under the optimal condition: 0.1 M phytosterol, 0.2 M oleic acid, water activity ( a w ) of 0.11, reaction temperature at 50 °C and reaction time of 1 h.
研究领域:
生物化学
·
酶工程
·
纳米材料科学
✓ 已验证
产品关联
DOI
高影响因子
SOLAR ENERGY MATERIALS AND SOLAR CELLS
·
2025
·
IF 6.3
Ruishuo Guo,Huijia Wang,Qingwen Wen,Xin Xu,Yanlan Zhou,Xiaoqiang Shao,Ni Li
Phase change capsules effectively address the limitations of leakage and poor stability of phase change materials (PCMs). In this study, SiO 2 @n-Octadecane phase change nanocapsules (PCNCs) with controllable size and structure are prepared by controlling material ratios. When Water-to-EtOH ratio is 2:1 and C 18 -to-TEOS ratio is 3:3 in the reaction system, prepared PCNCs show excellent phase change enthalpy of 152.9 J/g and high encapsulation ratio of 73.77 %, with desirable thermal stability and reliability. After the irradiation of simulating sunlight for 1500 s, the PCNCs achieved a temperature buffer of 6 °C compared with blank cotton fabric, and the cotton fabric with the PU coating containing the PCNCs presents up to 13.2 °C temperature reduction compared with original cotton fabric. The prepared SiO 2 @n-Octadecane PCNCs present excellent heat storage and thermal management performance and effective strategy to develop long-term thermal comfort smart textiles.
研究领域:
材料科学
·
纳米技术
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热工工程
·
智能纺织
✓ 已验证
产品关联
DOI
高影响因子
Russian Journal of Physical Chemistry A
·
2023
·Vol. 97
·期 13
·2966-2975
·
IF 0.7
Liu Kun,Zhu TianHan,Li Feng,Wang Jing,Song Hua
A series of Ni/SiO 2 –Al- x catalysts ( x is the initial mass ratio of SiO 2 to Al(NO 3 ) 3 ) with different aluminum contents was prepared by impregnation method using nickel nitrate as the Ni source. The prepared Ni/SiO 2 –Al- x catalysts were characterized by XRD, BET, TPR, TEM, XPS, NH 3 -TPD, and Py-FTIR methods. Taking m -cresol as a model compound, the effects of aluminum content and reaction conditions on the HDO performance were investigated. Results showed that addition of appropriate amount of aluminum can generate acid sites and improve the metal Ni dispersion by increasing the surface area of catalyst. Furthermore, the selectivity to deoxygenated methyl-cyclohexane product over aluminum modified Ni/SiO 2 –Al- x catalysts increased significantly as compared to that of Ni/SiO 2 , which confirmed the importance of aluminum addition on the dehydration of 3-methyl-cyclohexanol to methyl-cyclohexane. Among the prepared Ni/SiO 2 –Al- x catalysts, the Ni/SiO 2 –Al-5 catalyst exhibits the best HDO performance. A 100% m -cresol conversion with the selectivity to MCH of 100% was achieved under the conditions of T = 250°C, p = 2 MPa, t = 75 min with catalyst (mg)/ m -cresol solution = 2.
研究领域:
催化化学
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能源化学
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材料化学
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工业催化
·
绿色化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Fu Yang,Xu Hu,Shuying Gao,Xianfeng Liu,Shijian Zhou,Yan Kong
Herein, we report a facile synthetic method enabling the synchronously activated decoration of the inner core and mesoporous outer shell of monodispersed Fe 3 O 4 @meso-silica using in situ implanted MnO x . This approach can maintain the catalytic activity of the internal core without loss of its inherent magnetic properties even when undergoing calcination . The developed catalyst exhibits a well-defined core-shell configuration with a MnO x coating on an Fe 3 O 4 internal core and a MnO x -modified mesoporous outer shell, obtained via only a one-pot output cycle. The thin MnO x coating layer prevents excess oxidation of the unoxidized Fe 3 O 4 core during the annealing process. Additionally, the mesopores in the coated silica were synchronously functionalized by the assistance of dodecylamine (DDA) as surfactant because of the coordination effect of Mn 2+ and DDA molecules. The optimal nanocatalyst exhibits improved catalytic activity for styrene oxidation and recoverability due to its magnetic-responsive properties, in contrast to postsynthesized and shell-only functionalized catalysts.
研究领域:
材料科学
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催化化学
✓ 已验证
DOI
高影响因子
PROGRESS IN ORGANIC COATINGS
·
2024
·
IF 6.5
Chuanjin Lin,Guoquan Suo,Rongrong Mu,Jiarong Li,Laraib Habib,Xiaojiang Hou,Shukai Ding,Jianfeng Zhu
Water-induced degradation threatens sandstone cultural relics, highlighting the need for effective protection. This study applies a nano-coating of PFDTS-modified TiO 2 /SiO 2 to sandstone, optimizing PFDTS concentration, coating penetration depth, and hydrophobicity. A TiO 2 -to-SiO 2 ratio of 75:25 with 80 μL of PFDTS achieved high water and oil contact angles of 152.7° and 145.7°, respectively. After 210 h of UV exposure, contact angles showed minimal reduction, confirming the coating's durability. Additionally, air permeability is preserved to maintain sandstone breathability. These findings provide valuable insights for safeguarding sandstone heritage sites against weathering.
研究领域:
材料科学
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文物保护
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纳米技术
✓ 已验证
DOI
高影响因子
CARBOHYDRATE POLYMERS
·
2021
·
IF 9.381
Xinyu Zhao,Furui He,Gaobo Yu,Yuhong Feng,Jiacheng Li
The separation of crude oil from oily water and collection of the emulsion constituents has attracted significant attention. We demonstrate that the relationships between inherent dynamic factors and the performance of a Pickering emulsion stabilized by SiO 2 particles with adsorbed hydrophobically modified sodium alginate derivatives (HMSA), a natural pH-sensitive polysaccharide , can be clarified via a multi-scale methodology. Functionalization of the silica surface with HMSA controls particle dispersibility, as verified by turbidity and stability analyses, the zeta potential , and transmission electron microscopy measurements. The interaction mechanism between HMSA and SiO 2 nanoparticles was elucidated by both experimental adsorption measurements and computer simulations, which showed qualitative consistency. The aggregation/disaggregation of HMSA/SiO 2 particles achieved by tuning the pH of the solution facilitated reversible dispersibility/collectability behavior. Overall, a high-viscosity Pickering emulsion system based on particle-particle and droplet-droplet interactions, which can be filtered for the recovery of spilled crude oil, was demonstrated.
研究领域:
材料科学
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环境科学
·
化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
·
2021
·
IF 6.953
Jumin Hou,Xiaoxia Yan
The ultrasonic treatment could decrease the particles size of chitosan-SiO 2 particles. The EDS of samples with ultrasonic treatment for 0 min and 10 min indicated that the SiO 2 was present in prepared chitosan-SiO 2 particles. When the ultrasonic time reached 10 min, the chitosan-SiO 2 nanoparticles formed and the mean size was 506.7 ± 3.42 nm and the Zeta potential of the chitosan-SiO 2 nanoparticles was greater than 30 mV, showing the suspension was a stable dispersed liquid. The chitosan-SiO 2 nanoparticles were used as reinforcement in thermoplastic starch films to further verify their performance in enhanced films. The water contact angle of thermoplastic starch film reinforced with chitosan-SiO 2 nanoparticles was 44.13 ± 5.02° and had a good mechanical property with tensile strength of 8.91 ± 0.49 MPa. This study indicates that chitosan-SiO 2 nanoparticles could be used as a reinforcement to prepare thermoplastic starch films and promote the application of chitosan nanoparticles in nanocomposite films.
研究领域:
材料科学
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食品科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
·
2021
·Vol. 168
·期 2
·022504
·
IF 4.316
Shahid Khan,Chaoyan Fang,Yecheng Ma,Mahmood ul Haq,Mohammad Nisar,Gang Xu,Yong Liu,Gaorong Han
The aim of the study was to determine the effect of inorganic core-shell SiO2 nanoparticles modified with polymethyl methacrylate (PMMA) layer, on the optical and electrochemical properties of poly vinylidenefluoride-co-hexafluoropropylene (PVDF-HFP) gel polymer electrolyte (GPE). The core-shell SiO2 nanoparticles were first modified with PMMA to improve its dispersibility and compatibility in the polymer matrix. The morphology and structural properties of the core-shell SiO2 nanoparticles before and after modification were characterized by XRD, FTIR and SEM analysis. Then the modified SiO2 nanoparticles were used to prepare the composite GPE, composed of chemically modified core-shell structured SiO2-PMMA and PVDF-HFP polymer matrix. The transformation of nano-silica to SiO2-PMMA nanoparticles shows the better compatibility of PMMA and PVDF-HFP that favours the silica to be well dispersed in the organic matrix and significantly improve the doping effect. Various concentrations of modified SiO2-PMMA were used to dope PVDF-HFP GPEs. The results indicate that the 10% doping shows the highest ionic conductivity i.e. 2.22 × 10−3 s cm−1. In addition, the composite GPEs show the high transmittance and good thermal stability; therefore it can add important insight into developing high-performance materials for electrochromic devices.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
FUEL
·
2018
·
IF 4.908
Xin Li,Yilin Xu,Chen Zhang,Hong Wang,Yongji Song,Wei Zhang,Cuiqing Li
Photocatalytic-adsorptive desulfurization of model fuel by the H 2 O 2 -assisted synthesized TiO 2 -SiO 2 (TiO 2 -SiO 2 -H) was investigated using air as the oxidant under UV irradiation. TiO 2 -SiO 2 -H was synthesized hydrothermally in the presence of H 2 O 2 and characterized by scanning electron microscopy (SEM), N 2 adsorption, X-ray diffraction (XRD), UV–vis diffuse reflectance spectroscopy (UV–vis DRS) and photoluminescence spectrum (PL). Compared to TiO 2 -SiO 2 synthesized in the absence of H 2 O 2 , Ti 0.25 SiO y -H showed greatly enhanced photocatalytic-adsorptive desulfurization performance due to its increased surface area, greatly increased UV absorption and decreased recombination of photogenerated hole/electron pairs. The Ti/Si molar ratio was optimized to 0.3 with the sulfur removal of 100% after reaction for 1 h at the fuel-to-Ti 0.3 SiO y -H weight ratio of 20, and the sulfur content could still be reduced to be <1 ppmw when the fuel-to-Ti 0.3 SiO y -H weight ratio was increased to 80. Moreover, TiO 2 -SiO 2 -H based photocatalytic-adsorptive process bears high selectivity for removing organosulfur in the toluene-containing fuel. The sulfur removal for model fuel containing 25 wt% toluene could reach 98.4% after reaction for 5 h. The photocatalytic-adsorptive selectivity of Ti 0.3 SiO y -H for organosulfur compounds in model diesel fuels followed the order of dibenzothiophene > 4,6-dimethyldibenzothiophene > benzothiophene. The desulfurization performance of TiO 2 -SiO 2 -H was basically stable after four consecutive desulfurization-regeneration cycles.
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
JOURNAL OF NANOPARTICLE RESEARCH
·
2014
·Vol. 16
·期 11
·1-10
·
IF 2.278
Yao Yang Rong,Huang Wan Zhen,Zhou Huan,Cui Xia,Zheng Yi Fan,Song Xu Chun
A core–shell nanostructured magnetic photocatalyst Fe 3 O 4 @SiO 2 @Ag 3 PO 4 with a grain size ranging from 200 to 400 nm was prepared via a facile and effective method. The as-prepared products were characterized using X-ray diffraction, high-angle annular dark field-scanning transmission electron microscopy, energy-dispersive spectroscopy, and UV–Vis diffuse reflectance spectra. The photocatalytic activity was evaluated by the degradation of 10 −5 M RhB solution under visible light irradiation with a cut-off filter ( λ ≥ 420 nm). The results showed that nearly 100 % color removal efficiency was achieved in 45 min with the presence of Fe 3 O 4 @SiO 2 @Ag 3 PO 4 photocatalyst. Furthermore, it can be easily recollected from the solution by magnetic separation and efficiently recycled without major loss of activity due to its superior magnetic responsibility and extremely high reusability, exhibiting highly potential applications in water purification avoiding the secondary pollution.
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
International Journal of Minerals Metallurgy and Materials
·
2023
·Vol. 30
·期 9
·1740-1747
·
IF 4.8
Cai Dawei,Zhang Li,Wang Wanlin,Zhang Lei,Sohn Il
Mold flux serves the crucial metallurgical function of absorbing inclusions, directly impacting the smoothness of the casting process as well as the cast slab quality. In this study, the dissolution behavior and mechanism of TiO 2 and TiN inclusions in molten CaO–SiO 2– B 2 O 3 -based fluorine-free mold flux were explored by in situ single hot thermocouple technology combined with X-ray photoelectron spectroscopy. The results showed that TiO 2 inclusions are effectively dissolved by the molten slag within 76 s, during which the original octahedral [TiO 6 ] 8− structures are destroyed and convert to the networker tetrahedral [TiO 4 ] 4− structures. However, the dissolution rate is much lower for TiN inclusions than for TiO 2 inclusions. This can be attributed to the fact that the TiN particles need to be oxidized and then dissolved in the molten slag to form tetrahedral [TiO 4 ] 4− and octahedral [TiO 6 ] 8− structures during the TiN inclusion dissolution process, which is accompanied by the generation of a large amount of N 2 gas. Moreover, CaTiO 3 crystals tend to nucleate and grow on bubble surfaces with sufficient octahedral [TiO 6 ] 8− structures and Ca 2+ ions, eventually resulting in the molten slag being in a solid–liquid mixed state.
研究领域:
冶金学
·
材料科学
·
铸造过程
✓ 已验证
DOI
高影响因子
RUSSIAN JOURNAL OF APPLIED CHEMISTRY
·
2017
·Vol. 89
·期 10
·1681-1693
·
IF 0.375
Lai Nanjun,Wu Tao,Ye Zhongbin,Zhou Ning,Xu Qian,Zeng Fanhua
A novel water-soluble hyperbranched polymer (AA/AM/SMNS) consisting of functionalized Nano-SiO 2 as the core was synthesized by free-radical polymerization for low-moderate permeability reservoirs. The AA/AM/SMNS was carefully characterized by spectroscopic and electronic technologies. It was found that the microscopic structures of AA/AM/SMNS was denser and more regular in comparison to the linear polymer HPAM. The hydrodynamic radius of AA/AM/SMNS was 197 nm, less than the HPAM radius of 244 nm with similar molecular weight, so that the AA/AM/SMNS had a good matching relationship with pore throat in midpermeability reservoirs (100–500 mD). Besides, the introduction of Nano-SiO 2 endowed the AA/AM/SMNS remarkable thermal stability, shear resistance and viscoelasticity. Based on core flooding experiments, the AA/AM/SMNS could build high resistance factor and residual resistance factor in the corresponding porous medium. Furthermore, the sheared AA/AM/SMNS solution of 1500 mg L–1 performed excellent oil recovery of 15.47% in the 300 mD porous medium, which suggested the hyperbranched polymer based on modified Nano-SiO 2 have a valuable prospect for enhancing oil recovery in low-moderate permeability reservoirs.
研究领域:
材料科学
·
石油工程
·
化学工程
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）