以多孔钛片为载体的氧化铝膜的制备和表征

γ-alumine membranes supported by porous titanium plate were prepared by sol-gel techniqe with alumina isopropoxide. The factors, which influenced membrane per formance, in the membrane preparing process were investigated. A dynamic flow-weighted active pore size distribution apparatus for inorganic membrane were set-up on the basis of Kelvine equation. The results showed that for composite porous membrane the active pore size distribution is about 6-8nm, the most probable pore size is about 7nm and nitrogen permeability is 7.1×10-6mol﹒m-2﹒Pa-1﹒s-2.     

A novel porous supramolecular complex constructed by the co-crystallization of melamine and sulfate via hydrogen bonds and aromatic π-π interaction

Co-crystallization of melamine(MA) and sulfate results in crystalline product [(C₃H₇N₆⁺)₂(SO₄²⁻)] · 2H₂O. The novel supramolecular complex has been characterized by elemental analysis, thermal analysis (TGA and DSC), nuclear magnetic resonance (NMR), and single crystal X-ray diffraction. X-ray crystallographic studies of the complex reveal that the title complex has a 3-D microporous structure which is linked by intense intermolecular hydrogen-bonding interactions (N–H······O, N–H······N, O–H······O) and aromatic π-π interaction, which stabilize the whole crystal framework. The TGA curve shows that the complex is stable up to 500 °C, above which its structure begins to collapse.     

泡压-滤速法研究聚丙烯微孔膜的孔径及其分布

膜科学与膜技术作为新兴的材料科学分支之一,在国民经济中发挥着越来越重要的作用．近年来,高分子微孔膜的研究与应用正引起人们日益增长的关注．采用双轴拉伸方法制备的聚丙烯微孔膜同时具备了良好的力学性能和透过性能［１］,克服了单轴拉伸方法各向异性的缺点,是一...     

Membrane extraction through cross-flow rectangular modules

The mass transfer for membrane extraction through a cross-flow parallel-plate module has been studied both theoretically and experimentally. Theoretical analysis of mass transfer in cross-flow membrane extractors was analogous to heat transfer in cross-flow heat exchangers with the assumption that the concentration variation in the cross-sections of flow channel was negligible. Experiments were carried out with the use of membrane sheet made of microporous polypropylene coated with polytetrafluoroethylene as a permeable barrier to extract acetic acid from aqueous solution by methyl isobutyl ketone. Theoretical predictions are in agreement with the experimental results. The simpler but still precise equation for predicting the total mass transfer rate might be more powerful than the exact solution obtained in the previous work to overcome the mathematical difficulties in device design.     

Preparation and Photocatalytic Application of the Microporous Decatungstate, Na4W10O32/SiO

The photochemical behavior of polyoxometalates（POMs）have been studied extensivelyIn homogeneous solutions［1-3]．However,the major drawback to the practical applications ofthe homogeneous systems is the high water solubility of POMs,which impedes the readyrecovery and the reuse of the photocatalysts．Therefore,the preparation of insoluble POMs Isconsidered．More recently,we haveprepared insoluble POMs,i．e,Keggin－type microporousPOMs,H3PW12O40／SiO2 or H4SiW12O40／SiO2,and paratungstate A－containing pillaredcompound,Mg12Al6（OH）36（W7O24）·4H2O,for the purpose of photo－oxidation of aqueous     

Synthesis,Structure, and Clathration Ability of the Microporous Three‐Dimensional Coordination Polymer [{CuCN(4,4′‐bpy)} · 2(4,4′‐bpy)]

The respectively yellow and red coordination polymers [(CuCN)₂(μ‐4,4′‐bpy)] ( 1 ) and [{CuCN(μ‐4,4′‐bpy)} · 2(4,4′‐bpy)] ( 2 ) (4,4′‐bpy = 4,4′‐bipyridine) may be prepared by self‐assembly of CuCN and 4,4′‐bpy at the appropriate molar ratio in acetonitrile solution at 100 °C. In 1 infinite CuCN chains are linked by 4,4′‐bpy ligands into lamellar polymers which exhibit short Cu…C(N) contacts of 2.41(1) Å between one of the crystallographically independent copper atoms and cyanide carbon atoms of a neighbouring corrugated sheet. At a molar ratio of CuCN : 4,4′‐bpy below 2 : 3, the heteroaromatic ligands also adopt a structure‐directing role to afford 3 , in which [(CuCN)₂(μ‐4,4′‐bpy)] sheets are now joined by additional bridging 4,4′‐bpy spacer molecules to provide a three‐dimensional framework, whose nanometer‐sized channels (12.76 × 13.12 Å) accomodate two noncoordinated 4,4′‐bpy guest molecules. A DTA/TGA trace demonstrates that these can be removed in two steps at 150 and 176 °C.     

三维无机-有机杂化骨架微孔化合物[Co3(BDC)3(EG)4]·2DMF的合成与结构

传统的微孔晶体材料是以硅酸盐、硅铝酸盐、磷铝酸盐和无机金属磷酸盐等作为结构的骨架[1,2]. 近几年来, 出现了一类新型的无机-有机杂化微孔晶体材料, 这类晶体材料是用刚性和热稳定性较好的有机分子(如芳香多酸和多碱)和金属离子作为骨架的结构单元. 它们能够在去除孔道中的溶剂分子后仍然保持骨架的完整性, 而且其孔道的直径在0.4～1.0 nm之间, 比表面积远大于相似孔道的分子筛. 因此, 这类材料具有许多潜在的特殊性能, 在选择性催化、分子识别和可逆性主客体分子(离子)交换等方面具有诱人的应用前景. Yaghi等[3～11]利用不同的有机分子和各种金属制备出了许多这类晶体材料. 对苯二酸是常见的有机配体, 以它和金属离子为结构骨架所形成的无机-有机杂化微孔晶体有Zn3(BDC)3*(CH3OH),Zn(BDC)*(DMF)(H2O),(TPT)(Py)Cd和Zn4O(BDC)3*(DMF)8(C6H5Cl)等[12～15], 但在对苯二酸与金属构成的骨架中, 由于有多个乙二醇分子配位, 很少形成稳定的三维骨架结构的无机-有机杂化微孔晶体.     

漆酚醛胺聚合物多孔膜的制备

以漆酚醛胺聚合物(UFDP)为成膜材料,利用水辅助自组装的固体基板展开法和水面展开法制备了漆酚醛胺聚合物多孔膜.研究了在静态(即不在聚合物表面吹扫氮气)高湿度环境下聚合物溶液浓度、环境湿度和固体基板等因素对多孔膜形貌的影响.结果表明,水面展开法更有利于形成单层的多孔膜而固体基板展开法得到的是多层的多孔膜.当UFDP聚合物浓度为6.0 mg/mL,环境相对湿度为90%时,用水面展开法制得的单层多孔膜的孔径分布较均匀.     

多孔材料的研究进展

本文总结了2010~2013国际和国内在无机微孔材料领域的研究进展和亮点,比较了国内外研究的进展,展望了本领域的发展趋势。全文共引用参考文献87篇。     

Effects of sulfone/ketone in poly(phthalazinone ether sulfone ketone) on the gas permeation of their derived carbon membranes

A series of copolymer, poly(phthalazinone ether sulfone ketone)s (PPESKs) with the sulfone over ketone unit (S/K) ratio varying from 20/80, 50/50 to 80/20, were used as precursors to prepare carbon membranes. The effects of chemical structure as S/K ratio of PPESKs on the microstructure and gas separation performance of their derived carbon membranes were mainly investigated. The properties of PPESKs were detected in terms of density, fractional free volume, char yield, interlayer distance and glass transition temperature. During the formation process of carbon membranes (i.e., stabilization and pyrolysis), the changes in functional groups, microstructural parameters and gas permeation were monitored by FTIR, X-ray diffraction, TEM and single gas permeation techniques. The results have shown that the microstructure and gas permeation of obtained carbon membranes are significantly affected by the S/K ratio in precursor PPESKs. Carbon membranes exhibit higher selectivity and lower permeability when prepared at low pyrolytic temperature (i.e., 650 °C and 800 °C) and from PPESKs with S/K ratio equaling 50/50, followed with 20/80 and 80/20. As for carbon membranes prepared at high pyrolytic temperature (i.e., 950 °C), the selectivity order of them is well in accordance with S/K mole ratio in precursor PPESKs: 20/80 > 50/50 > 80/20, and vice versa for permeability.