层叠层技术组装纳米沸石—沸石涂饰纤维和沸石空心纤维

Layer- by- layer Assembly of Nanozeolite Zeolite Coated Fibers and Hollow Zeolite Fibers

以纳米沸石为基元构件,通过层叠层(1ayer-by-layer)组装技术在碳纤维模板上成功地制备了纳米沸石涂饰纤维(zeolite coated fibers),焙烧除去碳纤维模板后,制得了完整的沸石空心纤维(hollow zeolite fibers),并系统研究了它们的制备条件和材料结构.发现纳米沸石胶体溶液的pH值是制备沸石涂饰纤维和空心沸石纤维的关键因素,其它条件,诸如吸附液的离子强度,每层吸附后的干燥以及每次干燥前是否用PDDA溶液预浸泡,对纤维的完美性也有影响.通过改变吸附纳米沸石的类型和层数可以调变沸石层的组成和厚度,而交替吸附不同的纳米沸石可以制备复合沸石涂饰纤维及复合空心沸石纤维.

Zeolite coated fibers (abbreviated as ZCF) were successfully fabricated using carbon fibers as templates and nanozeolite as building block, through layer - by - layer assembly technique. After removal of the templates by calcination, intact hollow fibers of zeolite (abbreviated as HFZ) were also obtained. The optimum performance conditions for obtaining these types of materials were systematically studied. The pH value of the zeolite colloidal solution was a key factor affecting the fabrication of these zeolite coated fibers and hollow zeolite fibers. Other conditions, such as ionic strength of the dipping solution, drying the samples after every layer of zeolite nanocrystals deposited and adsorbing a PDDA layer on the silicalite - 1 coated carbon fibers before drying also bad influence on fabricating intact fibers. The wall thickness and composition of these novel materials could be readily tailored by varying the number of nanozeolite/PDDA [poly(diallyldimethyl ammonium chloride)] deposition cycles and zeolite types used, respectively. The hollow zeolite fibers with hybrid walls were also fabricated through stepwise deposition of different kinds of nanozeolites.