不同结构颗粒对PMMA基复合材料性能影响

采用原位本体聚合法制备PMMA/MCM-41(with template),PMMA/SBA-15(with template),PMMA/SiO2三种复合材料.研究了介孔分子筛MCM-41,SBA-15和SiO2对PMMA复合材料拉伸强度,冲击强度,热稳定性的影响.由于合成介孔分子筛MCM-41,SBA-15时所用的模板剂CTAB和P123分布于孔口处和颗粒表面上,分别与PMMA基体产生物理缠结作用,增加了两者的相容性;且P123(EO20PO70EO20)表面有较大的PO/EO比率,与小分子量的CTAB相比有较强的疏水性,使得PMMA/SBA-15(with template)复合材料的性能要优于PMMA/MCM-41(with template).     

介孔SBA-15的形貌控制合成及负载染料后其光学性能研究

采用水热-组装法、溶剂挥发法等材料合成方法制备了不同形貌(粉末棒状、单块、薄膜)负载染料的介孔SBA-15复合材料, 并开展光学性质研究. 通过TEM, XRD, N₂吸附-脱附表征证明所合成的各种形貌SBA-15材料均具有规则有序介孔结构, 组装染料后复合材料的形貌及结构保持完整|Uv-vis, PL表征表明染料在SBA-15孔道中呈单分散状态, 负载染料后的复合材料具有发光特性.     

(SBA-15)-ZnS主-客体纳米复合材料的制备与表征

本研究在SBA-15分子筛孔道中制备了纳米ZnS。Zn_{2+首先通过离子交换交换到SBA-15中,通过水热法在SBA-15分子筛孔道中制备了纳米ZnS。(SBA-15)-ZnS复合物由粉末X-线衍射,傅立叶变换红外光谱,低温氮气吸附-解析附技术,固体扩散漫反射光谱以及发光研究进行了表征。粉末X-线衍射研究说明在制备主-客体纳米复合材料中分子筛骨架未被制备过程所破坏,保持完整且结晶度仍很高。傅立叶变换红外光谱表明制备的材料骨架完好。77 K低温氮气吸附-解析附研究表明所制备的复合材料孔体积,孔尺寸以及表面积相对于SBA-15分子筛降低,证明客体ZnS已成功地组装入分子筛孔道中。所制备的纳米复合材料固体扩散漫反射吸收光谱相对于体相ZnS显示出蓝移表明,ZnS已限制在分子筛的孔道中且复合材料中分子筛的孔道对ZnS具有明显的立体限域效应,ZnS成功地组装在SBA-15分子筛的孔道中。发光研究表明,(SBA-15)-ZnS样品出现明显发光现象。主-客体复合材料具有良好的发光性能,有望在发光材料领域中获得应用。}     

高介电常数石墨烯/聚酰亚胺复合材料的制备与性能

在原位聚合制备氧化石墨烯/聚酰亚胺复合材料的过程中,加入季铵盐表面活性剂,抑制氧化石墨烯在高温亚胺化时的聚集,同时将氧化石墨烯原位还原,获得高介电常数的石墨烯/聚酰亚胺复合材料.结果表明,采用四丁基溴化铵和四丁基碘化铵作为还原剂,利用原位化学还原方法所制备的石墨烯/聚酰亚胺复合材料的介电常数超过聚酰亚胺薄膜40倍以上,复合材料的热稳定性和机械性能也优于聚酰亚胺薄膜.热重分析结果表明,在复合材料高温亚胺化过程中,季铵盐发生热分解,未残留在复合材料中.     

高负载量LaMnOx/SBA-15的制备及其催化甲苯燃烧性能

采用逐层负载-孔道内氨/水蒸气原位羟化法制备了高负载量的LaMnOx/SBA-15催化剂,并采用X射线衍射、N2吸附-脱附和程序升温还原等技术对催化剂进行了表征,考察了其催化甲苯燃烧的性能.结果表明,孔道内氨/水蒸气原位羟化提高了LaMnOx活性物种在SBA-15孔道内的分散度和还原性,显著改善了高负载量的LaMnOx...     

铑-三苯基膦配合物功能化的聚合物@介孔氧化硅复合材料在1-辛烯氢甲酰化反应中的应用(英文)

通过在介孔氧化硅材料中原位聚合的方法制备了三苯基膦功能化的有机聚合物@介孔氧化硅复合材料PPh3polymer@FDU-12.采用X射线衍射、氮气吸附脱附、透射电镜和热重等手段对其结构和组成进行了表征.该复合材料与金属前驱体Rh(acac)(CO)2配位后得到的固体催化剂,在长链烯烃1-辛烯的氢甲酰化反应中,醛选择性可达92%–96%,并表现出高于聚合物的活性(99%转化率).这主要归因于介孔氧化硅材料的高比表面积和有序的孔结构更有利于反应物和催化活性中心的接触.研究发现,调变复合材料中聚合物的含量或使用不同孔道结构的氧化硅载体(SBA-15,MCM-41和FDU-12)都会影响固体催化剂的反应活性和选择性.该方法得到的多相催化剂具有较好的循环使用性能,在循环使用15次后仍能保持较好的反应活性,但醛选择性有所降低.     

低介电损耗苯并噁唑复合材料的合成与表征

对介孔二氧化硅SBA-15进行氨基官能团化,制得NH2-SBA-15,通过溶液缩聚合成了一系列具有不同SBA-15质量分数的聚亚苯基苯并二噁唑/SBA-15(PBO/SBA-15)复合材料。利用红外光谱(FT-IR)、扫描电子显微镜(SEM)、热重分析(TG)和矢量网络分析仪(VNA)分别对复合材料的结构、微观形貌、热性能和电磁性能进行了表征与分析,研究了SBA-15对PBO/SBA-15复合材料介电参数的影响。研究表明:经过氨基官能团化之后,SBA-15能够均匀地分散在PBO基体中;当复合材料中SBA-15的质量分数小于8%时,PBO/SBA-15复合材料仍然保持着PBO优异的热稳定性;介孔二氧化硅SBA-15能够有效地降低PBO/SBA-15复合材料的复介电常数和介电损耗角正切,减弱PBO/SBA-15复合材料对电磁波的介电存储和损耗能力,使PBO/SBA-15复合材料表现出低介电损耗的性能。     

温敏性介孔复合材料PNIPAAm/SBA-15的制备与表征

采用自由基引发原位聚合(in situ polymerization)的方法合成了温敏性聚N-异丙基丙烯酰胺(PNIPAAm)/介孔分子筛SBA-15纳米复合物. 用FT-IR、XRD、TEM、低温N₂吸附-脱附、TG和DSC等手段对复合物进行了表征, 结果表明, 单体N-异丙基丙烯酰胺(NIPAAm)在介孔孔内发生了原位聚合, 聚合物PNIPAAm比较均匀地附于孔壁, 含量达24%左右. 这一聚合和孔内填充没有破坏SBA-15的有序六方结构, 但使样品的表面积、孔径、孔容减小. 同时, 这一有机-无机纳米复合物仍然保持PNIPAAm的温度响应性, 最低临界溶解温度(LCST)与纯PNIPAAm相似.     

C60/SBA-15介孔复合材料的合成及其荧光性质的研究

通过对介孔SBA-15孔壁氨基化(SBA-15-NH₂),然后与C₆₀反应形成化学键,成功地将C₆₀组装进入SBA-15孔道中,合成了C₆₀/SBA-15介孔复合材料.通过X射线衍射(XRD)、红外光谱(FTIR)、紫外-可见光谱(UV-V is)和差热-热重分析(TG-DTA)等方法对其进行了表征.同时,对复合材料的荧光性质进行了研究.结果发现,SBA-15-NH₂在575 nm处出现发射峰,C₆₀/SBA-15介孔复合材料在554 nm处出现发射峰,峰位蓝移21 nm.     

石墨烯/还原氧化石墨烯/聚苯胺复合材料的制备及在超级电容器中的应用

本研究以低成本、易规模化的亲水性石墨烯/氧化石墨烯为前驱体,通过原位聚合的方法制备石墨烯/氧化石墨烯/聚苯胺复合材料,经过化学还原后制备得到石墨烯/还原氧化石墨烯/聚苯胺复合材料.采用扫描电子显微镜(SEM)、透射电子显微镜(TEM)和傅里叶红外变化光谱仪(FT-IR)对制备的材料进行了结构和形貌的表征.运用循环伏安法...     

The application of pore size tunable SBA-15 molecular sieves in direct conversion of syngas to ethanol catalyzed by RhCl<Subscript>3</Subscript> and Fe(NO<Subscript>3</Subscript>)<Subscript>3</Subscript>

Four kinds of mesoporous molecular sieve SBA-15 (SBA-15-HCl, SBA-15-HPMo, SBA-15-HPW, and SBA-15-HSiW) were synthesized by different methods or materials. Loaded with RhCl₃ and Fe(NO₃)₃, the SBA-15-HPMo supported catalyst performed well in catalyzing direct conversion of syngas to ethanol.     

硅烷偶联剂改性SBA-15固载Keggin型杂多酸催化合成柠檬酸三丁酯

以3-(甲基丙烯酰氧)丙基三甲氧基硅烷(MEMO)表面改性的介孔分子筛SBA-15为载体,制备了一系列介孔分子筛/硅烷偶联剂@杂多酸复合催化剂SBA-15/MEMO@HnXW12O40(X=P⁵+,Si⁴⁺,B³⁺;n=3,4,5),并利用FTIR、P-XRD、TEM、N2吸附-脱附对其结构进行表征。以SBA-15/MEMO@HnXW12O40(X=P⁵⁺,Si⁴⁺,B³⁺;n=3,4,5)为负载型杂多酸催化剂对柠檬酸三丁酯的催化合成进行研究,分别考察了酸醇摩尔比、催化剂用量、反应温度、反应时间对催化合成柠檬酸三丁酯酯化率的影响,并获得合成柠檬酸三丁酯的最佳工艺条件。结果表明:当负载型硅钨酸催化剂的负载量为50%、催化剂用量为3.8%、酸醇摩尔比为1∶4、反应温度为140℃、反应时间为6 h、环己烷用量为5 mL时酯化率可达97.56%,重复使用7次后酯化率仍可达62.67%。     

Copolymers with fluorescence properties in mesoporous silica SBA-15:Synthesis and characterization

A novel copolymer with fluorescence properties in mesoporous silica SBA-15 was prepared via a combination of surface-initiated reversible addition-fragmentation chain transfer(RAFT) polymerization and "click" chemistry.A sufficient amount of peroxide groups were introduced into mesoporous silica SBA-15 channel pores and were further used to initiate the RAFT polymerization of styrene and 4-vinylbenzyl azide,resulting in SBA-15 supported polystyrene-co-poly(4-vinylbenzyl azide) copolymer(PS-co-PVBA/SBA-15) hybrid material.The samples were characterized by Fourier transform infrared spectroscopy(FT-IR),transmission electron microscopy(TEM),thermogravimetry analysis(TGA),N_2 adsorption-desorption isotherms and X-ray diffraction(XRD),respectively.The results show that the styrene and 4-vinylbenzyl azide had copolymerized inside mesoporous silica SBA-15.Subsequently,Npropargyl-carbazole(PC) was connected to PS-co-PVBA/SBA-15 hybrid material via "click" reaction,resulting in PS-co-PVBC/SBA-15 with carbazole side groups hybrid material.The fluorescence spectrum is dominated by a broad band from 350 nm to 400 nm in narrow region and the maximum peak is 362 nm,indicating the characteristic absorption of the carbazole group of PS-co-PVBC/SBA-15 hybrid material.     

甲基丙烯酸甲酯在改性介孔分子筛SBA-15孔道中的溶液聚合

水热法合成了介孔分子筛SBA-15,分别用硅烷偶联剂KH-151,KH-560和KH-570对SBA-15进行了改性,将不同类型的改性介孔分子筛(M-SBA-15)作为"微反应器",把含MMA的甲苯溶液载入到"微反应器"中,通过溶液聚合法使得MMA在孔道内部形成聚合物.通过XRD,FTIR,N2吸附/脱附,GPC,1H-NMR,TG和DSC测试手段对M-SBA-15和PMMA/M-SBA-15复合材料以及孔道内PMMA进行了分析测试.研究表明,改性介孔分子筛仍保留了有序介孔材料的基本特性,M-SBA-15和相应的复合材料的比表面积、孔径以及孔容降低,表明PMMA载入到介孔分子筛的孔道中.与传统的溶液聚合所得的PMMA相比,介孔孔道内所得的PMMA的分子链的间规立构度有所提高,其分子量约为传统溶液聚合的十几倍,初始热稳定性明显提高,玻璃化转变温度提高9～11℃.此外,KH-151改性SBA-15载入最多的PMMA,所得的PMMA的分子量和玻璃化转变温度最高.     

Preparation, Characterization and Catalytic Performance of La-SO42-/SBA-15 in Esterification of Acetic Acid with n-Butanol

La-SO42-/SBA-15 was synthesized with various amounts of lanthanum via incipient-wetness impregnation.Characterization was done by X-ray diffraction(XRD), transmission electron micrographs(TEM), nitrogen adsorption,FTIR spectroscopic analysis, thermogravimetric analysis, and the total amount of acidity of catalyst was estimated by TPD of NH3. The results indicate that lanthanum has been incorporated into SBA-15 molecular sieve. The prepared materials(La-SO42-/SBA-15) keep the highly ordered mesoporous two-dimensional hexagonal structure and do not change the mesoporous channel structure of the support SBA-15. The catalyst showed best catalytic activity in the synthesis of n-butyl acetate. The optimum conditions of the esterification by orthogonal experiments were studied: the molar ratio of n-butanol to acetic acid 1:1.2, the amount of catalyst 7.5%, reaction time 80 min. The yield of n-butyl acetate could reach 93.2% under the optimum conditions. The catalyst was recyclable, cost effective and environmental friendly.     

BiVO_4/SBA-15催化剂的制备及其光催化氧化脱硫性能

采用水热后合成法制备了BiVO_4/SBA-15催化剂,利用XRD、SEM-EDS和N2吸附-脱附等手段对其进行表征分析,并在自制的光催化反应装置中对其静态光催化氧化脱硫性能进行了研究。结果表明,BiVO_4/SBA-15催化剂具有SBA-15分子筛的介孔孔道结构,BiVO_4均匀分布在SBA-15分子筛表面。BiVO_4/SBA-15催化剂具有良好的催化氧化脱硫性能,在BiVO_4负载量为15%、水热合成时间为18 h、530℃下焙烧3 h制备的BiVO_4/SBA-15催化剂,对模拟柴油的脱硫率可达95.6%。     

Electrocatalytic oxidation of carbon monoxide and methanol at Pt nanoparticles confined in SBA-15: voltammetric and in situ infrared spectroscopic studies

Electrocatalytic oxidation of carbon monoxide and methanol at Pt nanoparticles confined in mesoporous molecular sieve SBA-15 was studied by using cyclic voltammetry and in situ FTIR spectroscopy. Cyclic voltammetric studies revealed that the Pt nanoparticles confined in SBA-15 exhibit a high activity in the presence of hydrated phase consisting of SiO₂ in the SBA-15. In situ FTIR spectroscopy results discovered that IR absorption of CO adsorbed on Pt nanoparticles confined in SBA-15 has been enhanced 11-fold, and the full-width at half-maximum of the CO band is significantly increased, in comparison with IR feature of CO adsorbed on a bulk Pt electrode. The linearly adsorbed CO species is the only intermediate derived from dissociative adsorption of methanol, which is more readily oxidized to form CO₂ in the aid of the active oxide in SBA-15.This paper is dedicated to Professor G. Horanyi on the occasion of his 70th birthday and in recognition of his outstanding contribution to electrochemistry     

MCM-41 and SBA-15 supported Cp2ZrCl2 catalysts for the preparation of nano-polyethylene fibres via in situ ethylene extrusion polymerization

Under atmospheric pressure, nano-polyethylene fibres were prepared via in situ ethylene extrusion polymerization, with MCM-41 and SBA-15 supported zirconocene dichloride (Cp₂ZrCl₂) catalytic systems, respectively. The effects of the geometrical structures and surface properties of MCM-41 and SBA-15 on the morphology of the resultant polyethylene, catalytic activity and polymerization rate were investigated and compared in various polymerization conditions. The possible formation mechanism of nano-polyethylene fibres with MCM-41 and SBA-15 supported Cp₂ZrCl₂ as catalyst was discussed.     

微孔-介孔复合分子筛HY-SBA-15的表征及应用

用后合成法制备了微孔-介孔复合分子筛HY-SBA-15(y) (y表示HY与SBA-15的质量比)。并用XRD、FT-IR、N₂吸脱附及NH₃-TPD等技术对HY-SBA-15进行表征。结果表明,HY-SBA-15既具有微孔结构又具有介孔结构,当y=0.10时,微孔与介孔混合晶相显著,且HY-SBA-15(0.10)复合分子筛具有B酸和L酸,酸性强于HY。用浸渍法将Ni-W活性组分担载在HY-SBA-15(0.10)载体上,制备加氢脱芳烃催化剂Ni-W/HY-SBA-15(0.10),选用茂名石化FCC柴油为原料,考察了催化剂的加氢脱芳烃性能。实验结果表明,Ni-W/HY-SBA-15(0.10)催化剂具有良好的芳烃加氢饱和性能和开环活性。     

Preparation and application of nanocatalysts via surface functionalization of mesoporous materials

Surface immobilization of active species onto mesoporous materials is gaining importance, especially in the design of functionalized mesoporous materials as a nanocatalyst through heterogenization of homogeneous catalytic systems. This article summarizes recent work on the synthesis, characterization and catalytic performance of the functionalized mesoporous catalysts performed by the present authors. A cationic rhenium(I) complex was encapsulated into mesoporous Al-MCM-41 molecular sieve using a ion-exchange method, yielding a new photocatalyst to be active for photocatalytic reduction of CO₂. Surface functionalization of mesoporous silica SBA-15 with sulfonic acid groups was investigated to give a solid acid catalyst. The chemically modified Fe-containing mesoporous materials, which are active for hydroxylation of phenol, were prepared by a surface-grafting method that iron salts are immobilized onto mesoporous Si-MCM-41 with the help of 3-aminopropyltrimethoxysilane as a linker. A cobalt(III) complex was heterogenized onto mesoporous silica SBA-15 containing carboxylic groups in order to utilize as a solid catalyst for the liquid-phase oxidation of aromatic hydrocarbons.