摘要
采用3种不同碳链长度的季铵盐表面活性剂CnTAB(n=8,12,16)为模板剂,分别合成8-MCM-41、12-MCM-41和16-MCM-41介孔分子筛,并以甲苯、邻二甲苯、均三甲苯为吸附对象,考察了介孔分子筛动态吸附VOCs的性能.结果表明,通过减少表面活性剂的碳链长度,可以成功地把MCM-41分子筛的孔径调变为4.1、3.2和2.4nm.吸附实验结果表明,当MCM-41孔径减小时,其对低浓度甲苯、邻二甲苯的吸附量大幅上升,均三甲苯存在孔道扩散效应,其吸附量增加不明显.吸附等温线表明,在2.4nm孔道内,3种芳烃分子均属于典型的Langmuir单分子层吸附;当孔径大于2.4nm时,芳烃分子出现明显的多层吸附和毛细凝聚现象.
Moleeular sieves 8-MCM-41,12-MCM-41, and 16-MCM-41 were synthesized using alkylammonium salts CnTAB of different alkyl chain lengths （n = 8,12,16 ） as templates. Dynamic adsorption of toluene,o-xylene,and mesitylene on these mesoporous molecular sieves was studied. The results show that the mean pore diameter can be adjust to 4.1 nm,3.2 nm, and 2.4 nm by decreasing the alkyl chain length. The amount of toluene and o-xylene adsorbed increased significantly as the mean pore diameter decreased. There was little increase in mesitylene adsoption due to diffusion. The adsorption isotherms showed that the adsorption of VOCs on molecular sieves with a pore diameter of 2.4 nm followed Langmuir monolayer adsorption ;when the mean pore diameter was larger than 2.4nm,the adsoption appeared to be muhilayer,with capillary condensation observed.
出处
《环境科学学报》
CAS
CSCD
北大核心
2012年第1期123-128,共6页
Acta Scientiae Circumstantiae
基金
浙江省科技厅重大专项资助(No.2007C13042)
浙江省自然科学基金(No.Y5090202)~~
关键词
介孔分子筛
吸附
VOCS
孔径调变
mesoporous molecular sieve
adsorption
VOCs
pore size controlling
