化学学报 ›› 2003, Vol. 61 ›› Issue (3): 354-358. 上一篇    下一篇

研究论文

纳米沸石胶体化学性质的研究

王兴东;王亚军;杨武利;董安钢;任楠;谢在库;唐颐   

  1. 复旦大学;中国石油化工总公司上海石油化工研究院
  • 发布日期:2003-03-15

Investigation of the Colloidal Properties of Nanozeolites

Wang Xingdong;Wang Yajun;Yang Wuli;Dong Angang;Ren Nan;Xie Zaiku;Tang Yi   

  1. Department of Chemistry & Shangshai Key Laboratory of Molecular Catalysis and Innovative Materials,Fudan University;Department of Macromolecular Science & Key Laboratory of Molecular Engineering of Polymers,Fudan University;Shanghai Research Institute of Petrochemical Technology,SINOPEC
  • Published:2003-03-15

主要考察了MFI和BEA结构纳米沸石的胶体化学性质,对与纳米组装过程直接相 关的纳米沸石的电动性质体现为ξ电势)和自聚集性质进行了研究.考察了pH值、 离子强度和硅铝比对沸石ξ电势的影响.发现纳米沸石表的变化取决于其骨架结构 和组成,而电解质浓度的增大可使沸石胶粒的ξ电势减小;州增大可使ξ电势向负 电性增方向变化.较高的ξ电势是维持沸石胶液稳定的基本条件;而过小的ξ电势 则将导致纳米沸石的聚集或沉降,在毛细作用下纳米沸石可以自组装成沸石纤维, 沸石的粒径是影响该组装的关键因素,沸石粒径越小,越容易组装成致密透明的沸 石纤维.

关键词: 纳米相材料, 沸石, 胶体, 电势, 电解质

In this paper, the colloidal properties of nanosized zeolites with MFI and BEA topology structure were investigated. It is found thatξ potential of nanosized zeolites varied with the change of zeolite structures and composition. The influences of salt concentration and pH value on theξpotential of the nanosized zeolites have been studied. With the increase of the salt concentration, theξ potential gradually decreased and even possessed opposite charges. The effects ofξpotential on the colloidal aggregation and stability are also detected. A cretainξpotential is necessary to stabilize the zeolite colloid, while too lowξpotential may bring on aggregation of the colloid. At stuitabie temperature, nanozeolite can be self- assembled by capillary force to form transparent self-standing fibers. The crystal size significantly influences the character of the products. The zeolites with smaller crystal size are rather apt to form long, dense and transparent zeolite fibers.

Key words: NANOPHASE MATERIALS, ZEOLITE, COLLOID, ELECTRIC POTENTIAL, ELECTROLYTE

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