材料期刊网

基于长链烯烃/烷烃络合分离的目标,设计构造了AgNO3/MCM-41/NiFe2 O4磁性吸附剂。样品采用X射线衍射( XRD),N2吸附-脱附,红外线光谱分析( FTIR)和振动样品磁强计( VSM)等手段进行表征,结果表明磁性吸附剂中NiFe2 O4呈尖晶石结构,AgNO3最佳负载量为0.2 g/g AgNO3,且单层分散于MCM-41六方孔道内,其比表面积为717.89 m2/g,孔径为2.94 nm。利用磁性吸附剂对C11烯烃/C11烷烃混合物进行液相络合吸附分离研究,实验表明AgNO3/MCM-41/NiFe2 O4对长链烯烃分子具有选择性吸附功能,在100 min内达到吸附平衡,单级平衡吸附量为2.14 g/g。考察了吸附剂重复使用对吸附选择性和磁回收率的影响,使用10次后,吸附剂可保持较高的回收率(98.9%),烯烃吸附选择性略有降低,但仍能实现对烯烃的选择性吸附。

AgNO3/MCM-41/NiFe2 O4 was designed and synthesized via the incipient wetness impregnation. It served as a magnetic complex separation adsorbent and could be used to separate the long-chain olefin/paraffin mixtures. The samples were characterized by powder X-ray diffraction analysis ( XRD ) , nitrogen adsorption-desorption analysis, Fourier transform infrared spectroscopy ( FTIR ) , vibrating sample magnetometer ( VSM) and etc. The tests show that the obtained products are composed of NiFe2 O4 with spinel structure and MCM-41 with hexagonal arrangement of unidimensional mesopores. AgNO3 is dispersed in a monolayer in the channel. The optimal loading amounts of AgNO3 is 0. 2 g/g magnetic carrier. The specific surface area and most probable pore size are 717. 89 m2/g, 2. 94 nm. For the C11 olefin/C11 paraffin mixtures, adsorption behaviours of C11 olefin on magnetic adsorbent were investigated. Results show that adsorbents have preferential adsorption for long-chain olefins. The one-stage equilibrium adsorption capacity and adsorption time are 2. 14 g/g, 100 min respectively. Adsorptive selectivity and magnetic recovery of adsorbents after reuse were studied. After repeated use ten times, the recovery was up to 98. 9% and the selectivity of olefin decreased slightly. But the changes still can satisfied requirements for olefin adsorbed selectively.