期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
Synthesis of Mesoporous Silica Molecular Sieves via a NovelTemplating Scheme
1
作者 Xiao Ming ZHANG Zhao Rong ZHANG +1 位作者 Ji Shuan SUO Shu Ben LI(State Key Laboratory for Oxo Synthesis and Selective Oxidation, Lanzhou institute of ChemicalPhysics, Chinese Academy of Sciences, Lanzhou 730000) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第11期979-982,共4页
Mesoporous silica molecular sieves have been synthesized under mild conditions by using in situ prepared N,N-dimethyldodecylamine oxide as template.
关键词 mesoporous silica molecular sieves N N-dimethyldodecylamine oxide SYNTHESIS
下载PDF
π-Complexation Mesoporous Adsorbents Cu-MCM-48 for Ethylene-Ethane Separation 被引量:4
2
作者 陈乐 刘晓勤 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第4期570-574,共5页
Copper incorporated MCM-48 molecular sieve adsorbents with different Cu content have been hydrothermally synthesized. The samples have been characterized by various physicochemical methods, including X-ray diffraction... Copper incorporated MCM-48 molecular sieve adsorbents with different Cu content have been hydrothermally synthesized. The samples have been characterized by various physicochemical methods, including X-ray diffraction (XRD), nitrogen adsorption (N2) and X-ray photoelectron spectroscopy (XPS). The results reveal that Cu-MCM-48 with mass fraction of copper up to 10 % can still retain the uniform mesoporous framework of MCM-48. The copper in the framework of MCM-48 was easily auto-reduced to Cu(I) in N2 at high temperature, which did not alter the mesoporous structure of MCM-48. The adsorption equilibrium isotherms of ethylene and ethane on these molecular sieve adsorbents have been measured at 30℃. At 100 kPa, the adsorption capacities of ethylene on 5Cu-MCM-48 and 10Cu-MCM-48 are higher than those on MCM-48. The 10Cu-MCM-48 molecular sieve adsorbent has a higher selective adsorption ratio of ethylene to ethane, the separation factor is 3.8, and the amount of ethylene adsorbed is 11.1 ml·g ^-1. 展开更多
关键词 mesoporous molecular sieve Cu-MCM-48 adsorption separation ETHYLENE ETHANE
下载PDF
ENCAPSULATION OF STRONG SOLID ACID NANOPARTICLES IN MESOPOROUS CHANNEL HOSTS 被引量:1
3
作者 Chen Changlin and Xu Nanping, Mou Chungyuan and Cheng Soofin (College of Chemical Engineering, Naming University of Chemical Technology, Nanjing 210009) (Department of Chemistry, National Taiwan University, Taipei 106) 《化工学报》 EI CAS CSCD 北大核心 2000年第S1期57-60,共4页
Mesoporous molecular sieve with Al-promoted sulfated rirconia (SZA) based strong solid acid nano-particles within its mesoporous channels was synthesized by using a one-step incipient wetness impregnation method with ... Mesoporous molecular sieve with Al-promoted sulfated rirconia (SZA) based strong solid acid nano-particles within its mesoporous channels was synthesized by using a one-step incipient wetness impregnation method with zirconium sulfate and aluminum sulfate as the precursors. The assemblies of SZA/MCM-41 were obtained by thermal decomposition of the precursors in air.The resultant composite was characterized with various techniques such as nitrogen physisorption, X-ray diffraction, SEM and TEM. It was shown that the well-ordered channels of MCM-41 arranged in hexagonal arrays as well as the hollow tubular morphology was retained. The strong solid acid nanoparticles were isolated born each other and highly, dispersed in the channels. Nitrogen sorption showed the expected decrease in pore volume. The catalytic activity of SZA/MCM-41 composite in the isomerization of n-butane was dramatically improved in comparison to bulk SZA or SZA/silica. 展开更多
关键词 mesoporous molecular sieve strong solid acid NANOPARTICLE ENCAPSULATION
下载PDF
Structrue and Characteristics of Mesoporous Silica Synthesized in Acid Medium and Its Reaction Mechanism
4
作者 雷家珩 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2004年第3期58-61,共4页
Structrue and pore characteristics of the mesoporous silica synthesized in acid medium were studied by means of XRD, HRTEM, BET, FT-IR, DSC-TGA, and the reaction mechanism was also investigated deeply. The results sho... Structrue and pore characteristics of the mesoporous silica synthesized in acid medium were studied by means of XRD, HRTEM, BET, FT-IR, DSC-TGA, and the reaction mechanism was also investigated deeply. The results show that mesopores in the sample possess hexagonal arrays obviously, whereas the structure of silica matrix is amorphous. The results also show that the acting mode of silica and CTMA+ inside the mesopores was chemical bonding force. The structure of mesoporous silica was mainly dependent on the aggregational condition of micelle of CTMA+ as well as their liquid-crystallized status. In addition, condensation and dehydration of silicate radicals were accompanied in the process of calcination, which resulted in the mesoporous structure ordered in local range and the pore sizes largening. 展开更多
关键词 porous silica mesoporous molecular sieves isothermal adsorption CTMABr
下载PDF
Large Pore Mesoporous MCM-41 Templated from Cetyltriethylammonium Bromide
5
作者 LeiLIU GaoYongZHANG JinXiangDONG: 《Chinese Chemical Letters》 SCIE CAS CSCD 2004年第6期737-740,共4页
Following hydrothermal synthesis process, MCM-41 was synthesized by using cetyltriethylammonium bromide as templating agent. The experimental results showed that MCM-41 with pore diameter in the range of 4-7 nm can be... Following hydrothermal synthesis process, MCM-41 was synthesized by using cetyltriethylammonium bromide as templating agent. The experimental results showed that MCM-41 with pore diameter in the range of 4-7 nm can be obtained by adjusting nsurf/nsi. It was proved that cetyltriethylammonium bromide is an effective templating agent for increasing pore diameter of molecular sieve MCM-41. 展开更多
关键词 mesoporous molecular sieve MCM-41 synthesis new template.
下载PDF
Synthesis of Mesoporous Molecular Sieve MCM-41 in Extremely Dense System
6
作者 Guang Huan LIU Rui Juan GAO +1 位作者 Hong XU Jin Xiang DONG(Research Institute of special Chemicals. Taiyuan University of Technology, Taiyuan, Shanxi 030024) 《Chinese Chemical Letters》 SCIE CAS CSCD 1997年第7期649-652,共4页
Mesoporous molecular sieve MCM-41 has been synthesized in the extremely dense system (with H2O/Si<10) and characterized by XRD, N-2 adsorption isotherm as well as probe reactions of cracking of cumene and isomeriza... Mesoporous molecular sieve MCM-41 has been synthesized in the extremely dense system (with H2O/Si<10) and characterized by XRD, N-2 adsorption isotherm as well as probe reactions of cracking of cumene and isomerization of o-xylene. 展开更多
关键词 MCM Synthesis of mesoporous Molecular Sieve MCM-41 in Extremely Dense System SIO
下载PDF
Immobilization of Trehalose Synthase on Mesoporous Molecular Sieve
7
作者 Hongli SHANG Ying GU 《Agricultural Biotechnology》 CAS 2012年第2期28-31,共4页
[ Objective] This study aimed to explore the immobitizatian of trehalose synthase on mesoporous molecular sieves. [ Method] With trehalose synthase produced by genetically engineered bacteria as experimental material,... [ Objective] This study aimed to explore the immobitizatian of trehalose synthase on mesoporous molecular sieves. [ Method] With trehalose synthase produced by genetically engineered bacteria as experimental material, rnesoporous molecular sieve MCM-41 was used as a carrier for immobilization of trehalase syn- thase. Properties of trehalose synthase before and after immobilization were compared. [ Result ] Trehalose synthase could be immohihzed on mesoporous molecular sieve MCM-41 by using physical adsorption method. Immobilization of trehalose synthase achieved the best effect at pH 3.0, with enzyme amount of 62.5 mg/g and immobilization duration of 12 h. Compared with the free u, ehalose synthase, immobilized trehalose synthase showed significantly improved pH stability and thermal stability with repeatable operation, which was conducive to the utilization and storage of enzyme. [ Conclusion] This study provided theoretical basis for the devel- opment of new immobilized trehalose synthase. 展开更多
关键词 TREHALOSE Trehalose synthase mesoporous molecular sieve IMMOBILIZATION
下载PDF
Mesoporous molecular sieve confined phase change materials with high absorption,enhanced thermal conductivity,and cooling energy charging/discharging capacity
8
作者 Qi Zhang Chongyang Liu +2 位作者 Xuehong Wu Xueling Zhang Jun Song 《Frontiers of Materials Science》 SCIE CSCD 2024年第1期1-14,共14页
The biggest challenge for organic phase change materials(PCMs)used in cold energy storage is to maintain high heat storage capacity while reducing the leakage risk of PCMs during the phase transition process.This is c... The biggest challenge for organic phase change materials(PCMs)used in cold energy storage is to maintain high heat storage capacity while reducing the leakage risk of PCMs during the phase transition process.This is crucial for expanding their applications in the more demanding cold storage field.In this study,novel formstable low-temperature composite PCMs are prepared with mesoporous materials,namely SBA-15 and CMK-3(which are prepared using the template method),as supporting matrices and dodecane as the PCM.Owing to the combined effects of capillary forces within mesoporous materials and interactions among dodecane molecules,both dodecane/SBA-15 and dodecane/CMK-3 exhibit outstanding shape stability and thermal cycling stability even after 200 heating/cooling cycles.In comparison to those of dodecane/SBA-15,dodecane/CMK-3 exhibits superior cold storage performance and higher thermal conductivity.Specifically,the phase transition temperature of dodecane/CMK-3 is-8.81℃ with a latent heat of 122.4 J·g^(-1).Additionally,it has a thermal conductivity of 1.21 W·m^(-1)·K^(-1),which is 9.45 times that of dodecane alone.All these highlight its significant potential for applications in the area of cold energy storage. 展开更多
关键词 cold energy storage phase change material mesoporous molecular sieve CMK-3 SBA-15 cooling energy charging/discharging capacity
原文传递
Catalytic Synthesis of Geranyl Propionate
9
作者 唐晓红 李保军 +1 位作者 李成未 林钰 《Agricultural Science & Technology》 CAS 2012年第2期251-254,283,共5页
[Objective] The aim was to explore the optimal conditions for the catalytic synthesis of geranyl propionate. [Method] The synthesis of mesoporous molecular sieves Al-MCM-41 was carried out in an open-vessel. The mesop... [Objective] The aim was to explore the optimal conditions for the catalytic synthesis of geranyl propionate. [Method] The synthesis of mesoporous molecular sieves Al-MCM-41 was carried out in an open-vessel. The mesoporous structure of as-synthesized Al-MCM-41 was characterized by X-ray diffraction (XRD) pattern, Fourier transform infrared (FT-IR) spectrum, NH3-Temperature Programmed Desorption (TPD), and N2 adsorption-desorption isotherms. The catalytic performances of Al-MCM-41 for the synthesis of geranyl propionate (GP) with geraniol and propionic acid as reagents also were investigated. [Result] The as-synthesized Al-MCM-41 possesses typical hexagonal mesoporous structure with high long-range order and crystalline degree. Based on the systematic investigation of reaction time, temperature, amount ratio of reagents and regeneration of catalyst, the optimum reaction conditions were obtained with molar ratio of geraniol to propionic acid of 1.0∶1.5, reaction temperature of 120 ℃ and reaction time of 8 h. The high GP selectivity of 70.01% with geraniol conversion of 40.01% was achieved under above optimum conditions. The catalyst inactivation can be observed after five catalytic cycles. The regeneration of inactivated catalyst with high activity and selectivity can be achieved by calcination treatment to remove the carbon deposition, which covers the acid site of catalyst. [Conclusion] The optimal conditions for the synthesis of geranyl propionate were obtained. 展开更多
关键词 mesoporous molecular sieves CATALYST Geranyl propionate
下载PDF
CO2 capture over molecular basket sorbents:Effects of SiO2 supports and PEG additive 被引量:4
10
作者 Lin Zhang Xiaoxing Wang +2 位作者 Mamoru Fujii Linjun Yang Chunshan Song 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第5期1030-1038,共9页
The objective of this work is to study the influences of silica supports and PEG additive on the sorption performance of molecular basket sorbent(MBS) for COcapture consisting of polyethylenimine and one of the foll... The objective of this work is to study the influences of silica supports and PEG additive on the sorption performance of molecular basket sorbent(MBS) for COcapture consisting of polyethylenimine and one of the following supports: SBA-15(2-D structure), TUD-1(3-D sponge-like structure) and fumed silica HS-5(3-D disordered structure). Effects of the supports regarding pore structures and pore properties, the PEI loading amount as well as the sorption temperature were examined. Furthermore, polyethylene glycol(PEG) was introduced as an additive into the sorbents and its effect was investigated at different PEI loadings and sorption temperatures. The results suggest that the pore properties of MBS(after PEI loading) play a more important role in the COsorption capacity, rather than those of the supports alone.MBS with 3D pore structure exhibits higher COsorption capacity and amine efficiency than those with 2D-structured support. Among the sorbents studied, fumed silica(HS-5) based MBS showed the highest COsorption capacity in the temperature range of 30-95 °C, probably due to its unique interstitial pores formed by the aggregation of polymer-loaded SiOparticles. It was found that the temperature dependence is directly related to the PEI surface coverage layers. The more PEI surface coverage layers, the higher diffusion barrier for COand the stronger temperature dependence of COcapacity. 3D MBS exceeds 2D MBS at the same PEI coverage layers due to lower diffusion barrier. Adding PEG can significantly enhance the COsorption capacity and improve amine efficiency of all MBS, most likely by alleviating the diffusion barrier within PEI bulk layers through the inter-molecular interaction between PEI and PEG. 展开更多
关键词 CO2 capture Molecular basket sorbents mesoporous molecular sieve Polyethylenimine(PEI) Polyethylene glycol(PEG)
下载PDF
Ti incorporation in MCM-41 mesoporous molecular sieves using hydrothermal synthesis 被引量:1
11
作者 Shengping WANG Changqing MA +1 位作者 Yun SHI Xinbin MA 《Frontiers of Chemical Science and Engineering》 SCIE EI CAS CSCD 2014年第1期95-103,共9页
Abstract Titanium-containing mesoporous materials (Ti-MCM-41) were obtained by hydrothennal synthesis. Such materials are active catalysts for the transesterifica- tion of dimethyl oxalate and phenol to produce diph... Abstract Titanium-containing mesoporous materials (Ti-MCM-41) were obtained by hydrothennal synthesis. Such materials are active catalysts for the transesterifica- tion of dimethyl oxalate and phenol to produce diphenyl oxalate. To understand the role of the Ti in the catalytic process, Ti-MCM-41 samples with different Si/Ti ratios (from 5 to 100) were prepared and the samples were analyzed by Fourier transform infrared spectroscopy, UV- visible spectroscopy, and ammonia temperature pro- grammed desorption. It was concluded that the Ti is incorporated into the framework of the MCM-41 and formed weak Lewis acid sites. In addition, the number of Ti(IV) sites increased as the amount of titanium increased. X-ray powder diffraction, N2 adsorpfion-desorption and transmission electron microscopy results showed that the Ti-MCM-41 samples have a hexagonal arrangement of mono-dimensional pores. A large number of Ti(IV) sites coupled with the mesoporous structure and large pore diameters are favorable for the transesterification catalytic properties of Ti-MCM-41. 展开更多
关键词 TI-MCM-41 mesoporous molecular sieve acid sites TRANSESTERIFICATION hydrothermal synthesis
原文传递
Preparation of Mesoporous Molecular Sieves Al-MSU-S Using Ionic Liquids as Template 被引量:1
12
作者 于心玉 刘彩华 +3 位作者 杨建国 吴海虹 吴鹏 何鸣元 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2006年第10期1282-1284,共3页
Mesoporous molecular sieves Al-MSU-S has been prepared from the precursor of zeolite Y using ionic liquids 1-hexadecane-3-methylimidazolium bromide (CMIMB) as a template in basic medium, which exhibited larger pore ... Mesoporous molecular sieves Al-MSU-S has been prepared from the precursor of zeolite Y using ionic liquids 1-hexadecane-3-methylimidazolium bromide (CMIMB) as a template in basic medium, which exhibited larger pore diameter, pore volume and surface area than that synthesized using cetyl trimethyl ammonium bromide (CTAB) template. 展开更多
关键词 mesoporous molecular sieves Al-MSU-S precursor of zeolite Y ionic liquid
原文传递
Direct Immobilization of Phosphine-Rhodium Complex on MCM-41 for Propene Hydroformylation 被引量:1
13
作者 CAI Yang LI Zhi hua +1 位作者 YANG Yi quan YUAN You zhu 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2002年第3期311-315,共5页
MCM 41 molecular sieve supported Rh PPh 3 catalysts were prepared by the in situ assembling of the metal complex from smaller moieties of Rh(acac)(CO) 2 and ligand of PPh 3. The resulted guest/host materials(Rh PPh 3/... MCM 41 molecular sieve supported Rh PPh 3 catalysts were prepared by the in situ assembling of the metal complex from smaller moieties of Rh(acac)(CO) 2 and ligand of PPh 3. The resulted guest/host materials(Rh PPh 3/MCM 41) were characterized by X ray powder diffraction, FTIR and 31 P( 1H) NMR, and served as catalysts for propene hydroformylation. The results showed negligible change in MCM 41 framework after propene hydroformylation at 393 K. Higher hydroformylation activities were obtained on Rh PPh 3/MCM 41 catalysts compared to that on Rh PPh 3/SiO 2. 展开更多
关键词 MCM 41 mesoporous molecular sieve HYDROFORMYLATION PROPENE Rh phopshine complex
下载PDF
Mesoporous molecular sieve-based materials for catalytic oxidation of VOC: A review 被引量:6
14
作者 Wei Gao Xiaolong Tang +4 位作者 Honghong Yi Shanxue Jiang Qingjun Yu Xizhou Xie Ruijie Zhuang 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2023年第3期112-134,共23页
As the main contributor of the formation of particulate matter as well as ozone, volatile organic compounds(VOCs) greatly affect human health and the environmental quality. Catalytic combustion/oxidation has been view... As the main contributor of the formation of particulate matter as well as ozone, volatile organic compounds(VOCs) greatly affect human health and the environmental quality. Catalytic combustion/oxidation has been viewed as an efficient, economically feasible and environmentally friendly way for the elimination of VOCs. Supported metal catalyst is the preferred type of catalysts applied for VOCs catalytic combustion because of the synergy between active components and support as well as its flexibility in the composition. The presence of support not only plays the role of keeping the catalyst with good stability and mechanical strength, but also provides a large specific surface for the good dispersion of active components, which could effectively improve the performance of catalyst as well as decrease the usage of active components, especially the noble metal amount. Mesoporous molecular sieves, owing to their large surface area, unique porous structures, large pore size as well as uniform pore-size distribution, were viewed as superior support for dispersing active components. This review focuses on the recent development of mesoporous molecular sieve supported metal catalysts and their application in catalytic oxidation of VOCs. The effect of active component types, support structure, preparation method, precursors, etc. on the valence state, dispersion as well as the loading of active species were also discussed and summarized. Moreover, the corresponding conversion route of VOCs was also addressed.This review aims to provide some enlightment for designing the supported metal catalysts with superior activity and stability for VOCs removal. 展开更多
关键词 Volatile organic compound mesoporous molecular sieves Supported catalyst Catalytic oxidation Reaction mechanism Influencing factors
原文传递
MCM-41 Prepared with Ionic Liquid and Cethytrimethylammonium Bromide as Co-templates
15
作者 张光旭 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2009年第1期25-29,共5页
The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid (RTIL) synthesized in laboratory and cethytrimethylammonium bromide (CTAB) as compound templates for the first time. They w... The mesoporous molecular sieves MCM-41 were prepared using room tempera-ture ionic liquid (RTIL) synthesized in laboratory and cethytrimethylammonium bromide (CTAB) as compound templates for the first time. They were prepared under low aging temperature and short aging time. Via characterizing by XRD and nitrogen adsorption instrument, MCM-41 synthesized by this new method exhibited good crystal structure and narrow pore distribution. The following pre-paratory conditions was optimal: the molar ratio of RTIL to CTAB was 1.0∶1.0, aging at 80 ℃, for 40 h and calcined at 540 ℃. It is found that the acidified MCM-41 improves its activity as catalyst over the unmodified ones. 展开更多
关键词 mesoporous molecular sieve hydrothermal crystallization co-templates IONICLIQUID MCM-41
下载PDF
Effect of synthesis conditions on particle size of HMS
16
作者 李浩 刘红 何世强 《Journal of Shanghai University(English Edition)》 CAS 2009年第1期76-80,共5页
HMS mesoporous molecular sieve was synthesized hydrothermally by using dodecylamine (DDA) as template and tetethylorthosilicalite (TEOS) as silicon source. The influence of the hydrothermal synthesis conditions on... HMS mesoporous molecular sieve was synthesized hydrothermally by using dodecylamine (DDA) as template and tetethylorthosilicalite (TEOS) as silicon source. The influence of the hydrothermal synthesis conditions on HMS particle size was studied systematically. The results showed that the smaller particle was obtained under the condition of DDA/SiO2=0.27, H2O/SiO2=66.7, EtOH/SiO2=6.5 mol and synthesis time of 18 h. The presences of additives (TW20, TW60, SP60 and Neopelex) also helped to the reduction of particle size. The HMS mesoporous molecular sieve with particle size around 60-100 nm was obtained by using TW20 or TW60 as an additive. In addition, TEM image showed that HMS mesoporous molecular sieve with pariticle size about 20-100 nm was synthesized in microemulsion. 展开更多
关键词 HMS mesoporous molecular sieve SYNTHESIS ADDITIVE NANOSIZED MICROEMULSION
下载PDF
Effect of Templates on the Structure and Stability of Ti-TMS
17
作者 Qing DAI Nong Yue HE +3 位作者 Xing Li WANG Xun Wei SHEN Yan GUO Chun Wei YUANI(National Laboratory of Molecular and Biomolecular Electronics)(Department of Chemistry and Chemical Engineering, Southeast University, Naming 210096) 《Chinese Chemical Letters》 SCIE CAS CSCD 1999年第3期267-268,共2页
Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution. The XRD ... Pure Mesoporous TiO2 molecular sieves (Ti-TMS) were synthesized with different templates for the first time and the templates can be successfully removed by refluxing the samples in the EtOH/H2O/KOH solution. The XRD pattern and TEM confirm that the uniformity and stability of Ti-TMS2 synthesized with dodecylamine as template is obviously inferior to that of Ti-TMS1 prepared with dodecylphosphate and hexadecylphosphate as templates. Furthermore, after the templates were removed, the mesostructure of Ti-TMS1 was preserved to a great degree than that of Ti-TMS2. 展开更多
关键词 TIO2 mesoporous molecular sieves TEMPLATE
下载PDF
Immobilization of acetylcholinesterase on functionalized SBA-15 mesoporous molecular sieve for detection of organophosphorus and carbamate pesticide 被引量:2
18
作者 Yin Rui Xiaomei Wu +1 位作者 Baodi Ma Yi Xu 《Chinese Chemical Letters》 SCIE CAS CSCD 2018年第9期1387-1390,共4页
The immobilization of acetylcholinesterase (ACHE) on amino functionalized SBA-15 mesoporous sieves (NH2-SBA-15) was explored for detection of organophosphorus and carhamate pesticides. Several methods have been st... The immobilization of acetylcholinesterase (ACHE) on amino functionalized SBA-15 mesoporous sieves (NH2-SBA-15) was explored for detection of organophosphorus and carhamate pesticides. Several methods have been studied and the "adsorption-crosslinking" is found to be the best one. Firstly, AChE and bovine serum albumin (BSA) were adsorbed in turn on the surface of NH2-SBA-15 by electrostatic adsorption, and then glutaraldehyde was added for cross-linking the amino group of AChE. The NH2-SBA- 15 showed around 95% immobilization efficiency and the specific activity of immobilized AChE (ACHE- NH2-SBA-15) reached 130% relative to free AChE under optimal immobilization conditions. It was found AChE-NH2-SBA-15 retained 94.0% and 82.8% of its initial activity after 60days at 4℃ and 25℃, respectively. It remained 55.0% of its initial activity after 6 times recycling. During the detection of pesticide, the AChE-NH2-SBA-15 showed wider linear range and much lower limit of detection compared with free ACHE. The current method showed good recovery (93.8%-109.3%) and low RSD (〈5%) for both standard solution and real vegetable samples of Carbaryl and Trichlorfon. It was believed that AChE-NH2- SBA- 15 could be exploited as a fast, sensitive and low-cost biocatalyst towards the detection of pesticides residues which could be stored at room temperature for a long time. 展开更多
关键词 ACETYLCHOLINESTERASE IMMOBILIZATION Adsorption-crosslinking mesoporous SBA-15 molecular sieve Pesticide residues detection
原文传递
Synthesis of nano SnO2-coupled mesoporous molecular sieve titanium phosphate as a recyclable photocatalyst for efficient decomposition of 2,4-dichlorophenol
19
作者 Yanduo Liu Ning Sun +5 位作者 Shuangying Chen Rui Yan Peng Li Yang Qu Yichun Qu Liqiang Jing 《Nano Research》 SCIE EI CAS CSCD 2018年第3期1612-1624,共13页
It is essential to develop a cheap, recyclable, and efficient photocatalyst to help degrade pollutants contaminating the environment. Herein, mesoporous molecular sieve titanium phosphate (MMS-TiP) was used as an ef... It is essential to develop a cheap, recyclable, and efficient photocatalyst to help degrade pollutants contaminating the environment. Herein, mesoporous molecular sieve titanium phosphate (MMS-TiP) was used as an efficient nano-photocatalyst to degrade 2,4-dichlorophenol (2,4-DCP) and to oxidize CO. The catalyst was successfully synthesized by a simple and convenient hydrothermal method in the presence of a tri-block copolymer surfactant. Exceptional photoactivity of the optimized MMS-TiP mainly depends on its porous structure, with a large surface area by means of O2 temperature-programmed desorption curves and fluorescence spectra related to the amounts of produced hydroxyl radical. Interestingly, the photocatalytic activity of the prepared MMS-TiP could be greatly improved by coupling with nanocrystalline SnO2. This is likely due to the increase in the lifetime and separation of photogenerated charges by transferring electrons to SnO2 and was observed by steady-state surface photovoltage spectra and time-resolved surface photovoltage responses. The SnOa-coupled MMS-TiP exhibits better photocatalytic performance for 2,4-DCP degradation and better self-settlement than those of the commercial catalyst P25 TiO2. Moreover, it was confirmed by radical-trapping experiments that ·O2^- is the main activated species for the photocatalytic degradation of 2,4-DCP, and is photogenerated by electron transfer from MMS-TiP to SnO2. Furthermore, the main intermediates in the degradation of 2,4-DCP, like parachlorophenol superoxide and 1,2-benzenediol superoxide radicals, were detected, and a possible decomposition pathway related to ·O2^- attack is proposed. These experimental results provide new strategies for developing a recyclable molecular sieve- based nano-photocatalyst with high photocatalytic activity for environmental remediation. 展开更多
关键词 mesoporous molecular sieve titanium phosphate coupling SnO2 charge separation photocatalysis 2 4-dichlorophenol DECOMPOSITION
原文传递
Thermal decomposition of poly(ethylene terephthalate)/mesoporous molecular sieve composites
20
作者 RUN Mingtao ZHANG Dayu +1 位作者 WU Sizhu WU Gang 《Frontiers of Chemical Science and Engineering》 SCIE EI CSCD 2007年第1期50-54,共5页
The nonisothermal and isothermal degradation processes of poly(ethylene terephthalate)/mesoporous molecular sieve(PET/MMS)composites synthesized by in-situ polymerization were studied by using thermogravimetric analys... The nonisothermal and isothermal degradation processes of poly(ethylene terephthalate)/mesoporous molecular sieve(PET/MMS)composites synthesized by in-situ polymerization were studied by using thermogravimetric analysis in nitrogen.The nonisothermal degradation of the composite is found to be the first-order reaction.An iso-conversional procedure developed by Ozawa is used to calcu-late the apparent activation energy(E),which is an average value of about 260 kJ/mol with the weight conversion from 0%to 30%,and is higher than that of neat PET.Isothermal degradation results are confirmed with the nonisothermal process,in which PET/MMS showed higher thermal stability than neat PET.The polymer in mesoporous channels has more stability due to the protection of the inorganic pore-wall.These results indicate that mesoporous MMS in PET/MMS composites improve the stability of the polymer. 展开更多
关键词 poly(ethylene terephthalate) mesoporous molecular sieve thermal degradation kinetics
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部