Formation of ordered macroporous membranes from random copolymers by the breath figure method

In this paper, well-ordered macroporous membranes were fabricated from random poly(styrene-co-acrylonitrile) using tetrahydrofuran as solvent by the breath figure method. Influencing factors were investigated systematically including the relative humidity of atmosphere, the concentration of polymer solutions and the temperature. The pore size and the patterns were affected by these factors. The mechanism of pattern formation was also discussed.     

胶体晶体模板法制备三维有序排列的大孔SiO2材料

将粒径为480 nm的聚苯乙烯微球离心组装为胶体晶体模板,以正硅酸乙酯为硅源配制SiO₂溶胶并填充到模板间隙,原位形成凝胶,最后通过焙烧去除模板,得到三维有序大孔（3DOM）SiO₂。通过SEM检测,大孔以六方有序的方式排列,其孔径及孔径收缩率分别为360 nm和25％。大孔之间由小窗口连通,构成内部三维交联的大孔网络。低温N₂吸附测试表明,大孔孔壁上存在中孔孔隙,其中在3～4 nm有一集中的孔分布。XRD显示,制备的3DOM材料由无定形SiO₂组成。     

三维有序大孔氧化物催化剂的制备及应用

三维有序大孔氧化物具有均匀有序的大孔孔道、较高的孔容以及骨架组成的多样性等。主要介绍了三维有序大孔氧化物的结构、制备过程及应用进展。详细阐述了单分散微球的制备及改性、胶体晶体模板的制备、前驱体的制备及填充以及胶体晶体模板的去除。简单综述了近年来三维有序大孔氧化物在环境催化、石油化工、光催化及生物催化领域的应用研究,并对未来三维有序大孔氧化物的发展做了总结和展望。     

Preparation and characterization of three-dimensionally ordered macroporous syndiotactic poly(p-methylstyrene)

Three-dimensionally ordered macroporous(3DOM) syndiotactic poly(p-methylstyrene) (sPPMS) with pore size 170 nm was fabricated by means of silica templates using (dbm)₂Ti(OPh)₂/MAO catalytic system. The resulting polymers were characterized by SEM, ¹³C NMR, DSC and GPC. The results indicated that the 3DOM sPPMS were highly syndiotactic. GPC curves showed that the 3DOM sPPMS possessed lower Mn and broader MWD compared with bulk one. Meanwhile, DSC results revealed that three 3DOM sPPMS exhibited crystalline form II, and bulk sPPMS form III.     

高比表面积三维有序大孔炭材料的合成与表征

将粒径为540nm的SiO2胶体微球通过自然沉积组装为胶体晶体模板,以葡萄糖的水溶液为前体填充模板间隙,高温炭化后,以HF溶液溶去模板,得到三维有序大孔炭材料。根据SEM检测,大孔以六方有序的方式排列,其孔径及孔径收缩率分别为510nm和5.6%。大孔之间由小窗口连通,构成内部三维交联的大孔网络。低温N2吸附测试表明,大孔孔壁上存在2～10nm为主的中孔孔隙,同时由于前体的表面复制作用,使样品BET比表面积达到948m2/g。XRD表征显示,所制备的3DOM材料由无序石墨结构的炭质组成。     

双模板作用下3DOM ZnO/ZrO2-TiO2（P123）的制备及表征

同时在聚苯乙烯(PS)微球和三嵌段共聚物EO20PO70EO20(P123)双模板剂作用下,经溶胶-凝胶及煅烧后处理的方法制备了三维有序大孔(3DOM)复合材料ZnO/ZrO2-TiO2(P123)。通过X射线衍射(XRD)、傅里叶-红外光谱(FT-IR)、扫描电子显微镜配合X射线能量色散谱仪(SEM-EDS)和N2吸附-脱附测定等测试手段对其元素组成、晶型结构、表面形貌以及表面物理化学性质等进行了表征。结果显示,经PS微球和P123双模板处理后的复合材料3DOM ZnO/ZrO2-TiO2(P123)主要晶型结构为锐钛矿,同时,三维空间的大孔结构排列规则、整齐而有序,其大孔平均直径约为100 nm,且复合材料的BET比表面积高达202.8 m2/g,大孔孔壁的介孔孔径分布也更加均一。     

Ordered macroporous films from self-assembly of two-armed polymer with a crown ether core

Highly ordered honeycomb-like macroporous films were obtained via self-assembly of a two-armed polymer with a crown ether core under controlled conditions. A possible mechanism is speculated, primarily based on the strong affinity between the crown ether cores. The pore size and arrangement are sensitive to the solvent evaporation rate and the solution concentration. Upon spontaneous drying, the pore diameter (D) depends on the concentration (c) by a relation of D=518c^−0.610.     

溶胶-凝胶模板法制备三维有序大孔TiO_2微球

采用无皂乳液聚合方法自制的单分散聚苯乙烯(PS)微球乳液为原料,并以PS微球自组装制备了有序胶体晶体模板("蛋白石"),采用溶胶-凝胶模板法制备了三维有序大孔TiO2微球("反蛋白石"),其孔呈六边形,孔径分布均一,约为200 nm,运用SEM,XRD对其形貌特征及晶型进行表征。结果表明,采用表面含有羧基的单分散聚苯乙烯微球及高的硅油粘度制得的模板有序度高;控制煅烧温度可以改变有序大孔TiO2微球的晶型,当煅烧温度为500℃时,其晶型为锐钛型,当煅烧温度为700℃时,其晶型则为金红石型。     

致孔法制备新型CMCTS-g-PAA大孔高吸水树脂

在过硫酸铵的引发下,使丙烯酸在羧甲基壳聚糖的分子链上接枝聚合,以N,N’-亚甲基双丙烯酰胺为交联剂,并加入NaHCO₃为致孔剂,制得具有大孔结构的羧甲基壳聚糖接枝聚丙烯酸（CMCTS-g-PAA）高吸水性树脂。采用Voigt模型成功地对树脂的溶胀动力学进行了模拟,并确定了模型中的各参数在高吸水树脂溶胀过程中的意义。通过溶胀动力学及SEM的表征,研究讨论了致孔剂的加入量,致孔剂加入时间与聚合物的凝胶过程的配合等因素对所合成树脂的表面形貌和吸水速率的影响。     

Preparation of novel three-dimensionally ordered macroporous molecularly imprinted microspheres and its recognition for proteins

A novel protein molecularly imprinted microsphere with three-dimensionally ordered macroporous (3DOM) structure has been successfully prepared with a combination of colloidal crystal template method and molecular imprinting technique by using bovine serum albumin as template, acrylamide as functional monomer, and N,N′-methylenebisacrylamide as crosslinker, respectively. SEM shows that the polymeric microspheres have a highly ordered three-dimensional interconnected macroporous structure with typical face-centered cubic lattice. The isothermal and kinetic adsorption behaviors of the polymer were investigated. Compared with the traditional bulk polymer, the 3DOM imprinted microspheres show higher binding rate constant, adsorption capability and specificity to template molecules.     

Preparation of ordered macroporous platinum and palladium powders

Ordered macroporous platinum and palladium metal powders were prepared with a combination of silica template and hydrogen reduction methods. The effects of species of metal precursor and calcination of silica templates on the structure of final metal powders were investigated. Precursor of platinum or palladium was infiltrated into closely packed silica templates prepared from tetraethyl orthosilicate and vacuum dried at room temperature following hydrogen reduction to obtain metal–silica complexes. After the removal of the silica templates from the complexes by hydrofluoric acid treatment, metal powders were obtained. Ordered macroporous platinum and palladium powders were obtained by using hydrogen hexachloroplatinate (IV) hexahydrate with uncalcined silica template and palladium (II) chloride with calcined templates, respectively. Composition analyses indicated that silica templates were completely removed from the ordered metal powder. Sizes of the voids in the ordered macroporous metal powders were controlled in the range of 240–520 nm corresponding to those of the silica spheres used.     

三维有序大孔炭材料的制备及其应用

综述了三维有序大孔(3DOM)炭材料的制备及应用.3DOM炭材料的制备方法主要有胶晶模板法、炭气凝胶法、聚合物热解法,其中胶晶模板法是最有效的方法.还归纳了3DOM炭材料在光子晶体、电极材料、催化剂及催化剂载体、生物材料以及模板等方面的应用研究.     

三维有序介孔和大孔过渡金属氧化物的硬模板制备及催化应用

总结了课题组以硬模板法制备三维有序介孔Cr2O3(3DOMeso-Cr2O3)、Co3O4(3DOMeso-Co3O4)、MnO2(3DOMeso-MnO2)、Fe2O3(3DOMeso-Fe2O3)和三维有序大孔Fe2O3(3DOMacro-Fe2O3)及其催化氧化挥发性有机物的研究进展。以三维有序介孔二氧化硅KIT-6为硬模板,可制备出3DOMeso-Cr2O3-1、3DOMeso-Cr2O3-2、3DOMeso-Co3O4-1和3DOMeso-Fe2O3,比表面积分别为106、124、121、113 m2/g;以三维有序介孔二氧化硅SBA-16为硬模板,可制备出3DOMeso-Co3O4-2、3DOMeso-Co3O4-3和3DOMeso-MnO2,比表面积分别为118、313、266 m2/g;以规整排列的聚甲基丙烯酸甲酯微球为硬模板,可获得3DOMacro-Fe2O3,比表面积为42 m2/g。这些三维有序介孔或大孔结构的过渡金属氧化物对典型挥发性有机物(甲苯、甲醛、甲醇、丙酮和乙酸乙酯)氧化反应显示出优异的催化性能。     

Preparation of three-dimensional ordered macroporous SiCN ceramic using sacrificing template method

Three-dimensional (3D) long range well ordered macroporous SiCN ceramics were prepared by infiltrating sacrificial colloidal silica templates with the low molecular weight preceramic polymer, polysilazane. This was followed by a thermal curing step, pyrolysis at 1250 °C in a N₂ atmosphere, and finally the removal of the templates by etching with dilute HF. The produced macroporous SiCN ceramics showed high BET surface areas (pore volume) in the range 455 m²/g (0.31 cm³/g)–250 m²/g (0.16 cm³/g) with the pore sizes of 98–578 nm, which could be tailored by controlling the sizes of the sacrificial silica spheres in the range 112–650 nm. The sphere-inversed macropores were interconnected by 50 ± 30 nm windows and 3–5 nm mesopores embedded in the porous SiCN ceramic frameworks, which resulted in a trimodal pore size distribution. The surface of the achieved porous SiCN ceramic was then modified by Pt–Ru nanoparticle depositing under mild chemical conditions.     

Keggin结构三维有序大孔PMo_(12)-SiO_2材料的制备与表征

以三维有序大孔SiO2为载体,采用等体积浸渍法将Keggin结构的12-磷钼酸(PMo12)固载化,制备了三维有序大孔PMo12-SiO2材料,利用IR、TG-DTA、XRD、SEM及低温N2吸附等测试手段对制备的样品进行了表征。结果表明,负载后磷钼酸的热稳定性显著提高,经500℃焙烧后,其Keggin结构依然保持;负载后,样品具有三维有序的大孔结构;磷钼酸以微晶形式高度分散在载体的孔隙中,其对孔隙的填充作用使载体的比表面积由125.4 m2/g下降到24.4 m2/g。     

简述胶晶模板法制备三维有序大孔炭材料

三维有序大孔炭(3DOM)材料是近年来刚刚兴起的多孔材料领域一项重要研究课题。3DOM大孔炭材料不仅具有多孔材料的一般特点,还具有孔结构排列周期性强、孔径分布窄、大孔尺寸均匀可调,且具有较大的孔径、较高的表面积等一系列特点,在新型催化、吸附分离、电极材料等方面都具有潜在的应用价值。本文总结了近年来胶晶模板法制备三维有序大孔炭材料,分别从模板的制备、碳源的选择以及到最终大孔炭的制备三个方面加以总结概述。     

Effect of the precursor and the preparation method on copper based activated carbon catalysts for methanol decomposition to hydrogen and carbon monoxide

Copper oxide supported on activated carbon catalysts, obtained by various preparation techniques, are compared in methanol decomposition to hydrogen and carbon monoxide. The favourable role of copper deposition from ammonia solution of copper carbonate is proved. The effect of the preparation conditions on the catalysts activity and stability as well as on the nature of the catalytic active complexes is studied.     

Synthesis of ordered polymers by direct polycondensation

A series of ordered polymers can be prepared by direct polycondensation of nonsymmetric monomers using diphenyl(2,3-dihydro-2-oxo-3-benzothiazolyl)phosphonate (1) as a condensing agent. The methodology and requirements for the preparation of ordered polymer are first presented. Then, the following ordered polymer syntheses are described: (1) ordered polyamides (head-to-head or tail-to-tail) from a symmetric monomer and a nonsymmetric monomer. (2) the ordered polyamide (head-to-tail) from a symmetric monomer and a nonsymmetric monomer. (3) the ordered (-abcd-) polymer from a pair of two symmetric monomers and a nonsymmetric monomer. (4) the ordered (-abcdef-) polymer from nonsymmetric monomers, XabX, YcdY, and ZefZ.     

New redox deposition-precipitation method for preparation of supported manganese oxide catalysts

A new preparation method has been developed to produce homogeneous coatings of manganese compounds on alumina-coated monoliths by redox deposition-precipitation using acetone as solvent. The deposition is produced by reduction of manganese permanganate with ethanol. The Lewis acid sites on the alumina catalyze this reaction. Thus, the precipitation is produced preferentially on the surface of the monolith and not in the bulk of the solution. Monoliths prepared by this method are very active for the complete oxidation of oxygenated volatile organic compounds (VOCs). These monoliths consist of a mixture of complex phases including aluminum, sulfated alumina, potassium sulfate and manganese oxide.     

三维有序大孔钙钛矿金属氧化物作为高效燃烧催化剂的研究进展

三维有序大孔（3DOM）材料因为具有独特的结构、可调的组成、高稳定性、高电子传递能力以及高比表面积而引起很多学者的研究兴趣。本文主要介绍了3DOM钙钛矿材料作为催化剂或载体在催化碳烟、挥发性有机物和甲烷燃烧方面取得的成果,分析了制备条件、结构特征对催化性能的影响;指出了3DOM钙钛矿材料具有优异的催化燃烧稳定性、高分子吸附和扩散能力以及高氧迁移率,能够显著降低氧化还原温度和表观活化能,因此可以作为高效燃烧催化剂。最后提出了未来研究重点和发展方向,在未来的研究中应该开发出更多可以与贵金属相媲美的廉价的新型3DOM材料以拓展3DOM材料应用范围。另外,3DOM 材料表面性能的提升以及用于催化燃烧的作用机理需进一步深入研究。