Mesoporous zirconium titanium oxides. Part 3. Synthesis and adsorption properties of unfunctionalized and phosphonate-functionalized hierarchical polyacrylonitrile-F-127-templated beads.
Mesoporous zirconium titanium oxides. Part 3. Synthesis and adsorption properties of unfunctionalized and phosphonate-functionalized hierarchical polyacrylonitrile-F-127-templated beads.
复制标题
DOI：
10.1021/la9015299
复制
发表时间：
2009-09
期刊：
影响因子：
--
通讯作者：
G. D. Sizgek;C. S. Griffith;Erden Sizgek;V. Luca
中科院分区：
文献类型：
--
作者：
G. D. Sizgek;C. S. Griffith;Erden Sizgek;V. Luca
提出了一种制备具有分级孔结构的球形钛酸锆复合氧化物的方法。这种方法需要使用预制聚丙烯腈（PAN）聚合物珠和表面活性剂作为模板。通过在低于约500 ℃的温度下煅烧除去模板，得到具有三峰孔径分布和互连孔的混合氧化物珠。使用氮气吸附-脱附测定的孔径分布在4.5和45 nm长度尺度处显示出明显的最大值，并且还显示出微孔性的明显证据。大孔骨架形态是PAN珠的复制品，具有放射状结构。介孔骨架具有约6 nm孔径的虫洞状孔，这与所使用的F-127三嵌段共聚物模板一致。混合氧化物珠粒在500和600 ℃煅烧后表现出215和185 m2/g的表面积。高达650摄氏度的热稳定性对于散装系统来说是前所未有的。的吸附性能，其特征在于使用铀酰作为目标阳离子和质量传输的珠与本层次架构已被证明是例外。用4-氨基，1-羟基，1，1-双膦酸（HABDP）和氨基三亚甲基膦酸（ATMP）对该微球进行了功能化，并考察了其对硫酸铀酰络合物的吸附性能。在研究的两种分子中，ATMP官能化导致最佳的萃取效率，在pH 1和2之间的溶液中约90%的铀的平衡吸收。该珠粒可潜在地用作催化剂、催化剂载体、吸附剂和分离材料。
A method is presented for the preparation of zirconium titanate mixed oxides in bead form having hierarchical pore structure. This method entailed the use of both preformed polyacrylonitrile (PAN) polymer beads and surfactants as templates. The templates were removed by calcination at temperatures below about 500 degrees C, resulting in mixed oxide beads with trimodal pore size distributions and interconnected pores. The pore size distributions as determined using nitrogen adsorption-desorption showed clear maxima at 4.5 and 45 nm length scales and also clear evidence of microporosity. The macroporous framework morphology was a replica of the PAN beads with radial structure. The mesoporous framework possessed wormhole-like pores with pore size of about 6 nm that was consistent with the F-127 triblock copolymer template used. The mixed oxide beads exhibited surface areas of 215 and 185 m2/g after calcination at 500 and 600 degrees C. Thermal stability up to 650 degrees C is unprecedented for bulk systems. The adsorption properties were characterized using uranyl as the target cation and the mass transport in the beads with the present hierarchical architectures has been shown to be exceptional. The beads were functionalized with 4-amino,1-hydroxy,1,1-bis-phosphonic acid (HABDP) and amino-tris-methylene phosphonic acid (ATMP) and the adsorption properties for the extraction of uranyl sulfate complexes from acidic solution examined. Of the two molecules investigated, ATMP functionalization resulted in the best extraction efficiency with equilibrium uptake of about 90% of uranium available in solution between pH 1 and 2. The beads could potentially be utilized as catalysts, catalyst supports, adsorbents, and separation materials.