Improved performance of PDMS/silicalite-1 pervaporation membranes via designing new silicalite-1 particles
Improved performance of PDMS/silicalite-1 pervaporation membranes via designing new silicalite-1 particles
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DOI：
10.1016/j.memsci.2015.06.043
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发表时间：
2015-11
影响因子：
9.5
通讯作者：
Xiaojie Zhuang;Xiangrong Chen;Yi Su;Jianquan Luo;Weifeng Cao;Y. Wan
中科院分区：
文献类型：
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作者：
Xiaojie Zhuang;Xiangrong Chen;Yi Su;Jianquan Luo;Weifeng Cao;Y. Wan
为了改善渗透汽化(PV)膜的分离性能，在氟化物(F)和碱性(OH)介质中用水热合成法制备了不同的Silicalite-1粒子，并将其与聚二甲基硅氧烷(PDMS)复合，制备了PDMS/Silicalite-1 PV膜。用扫描电子显微镜、傅立叶变换红外光谱、核磁共振、X射线衍射仪、比表面积法和免疫吸附分析等手段对其进行了表征。结果表明，与Silicalite-1(OH)相比，Silicalite-1(F)具有更少的硅醇基团和更多的疏水基团，表现出更高的乙醇选择性。因此，在相同的Silicalite-1负载量下，PDMS/Silicalite-1(F)膜的分离因子(乙醇/水)远高于PDMS/Silicalite-1(OH)膜。对于PDMS/Silicalite-1(OH)膜，当Silicalite-1负载量为60wt%时，分离系数达到最大(23.0)，而在Silicalite-1(F)负载量为40wt%时，分离系数为23.8。然而，由于Silicalite-1(F)粒子的尺寸较大，其在PDMS中的最大负载量(40wt%)低于Silicalite-1(OH)粒子的最大负载量(60%)。为了利用Silicalite-1(F)粒子的高选择性和Silicalite-1(OH)的高负载量，将这两种Silicalite-1粒子混合并入到PDMS中。采用这种新策略，Silicalite-1粒子的总负载量可达60wt%，当Silicalite-1(F)的部分负载量为30wt%时，膜的分离系数提高到28.9。考察了进料温度和乙醇浓度对新型PDMS/Silicalite-1(F)-Silicalite-1(OH)膜性能的影响。结果表明，将Silicalite-1(F)和Silicalite-1(OH)混合粒子引入到PDMS中是一种很有前途的制备高性能PV膜的方法。
In order to improve the separation performance of pervaporation (PV) membranes, different silicalite-1 particles were prepared by hydrothermal synthesis in fluoride (F) or alkaline (OH) media, and then incorporated into polydimethysiloxane (PDMS) to prepare PDMS/silicalite-1 PV membranes. These silicalite-1 particles were characterized by SEM, FT-IR, NMR, XRD, BET and IGA. The results indicated that, compared with the silicalite-1(OH), the silicalite-1(F) particles had much less silanol groups and were more hydrophobic, thus showing higher selectivity to ethanol. Accordingly, the separation factor (ethanol/water) of the PDMS/silicalite-1(F) membrane was much higher than that of PDMS/silicalite-1(OH) membrane at the same silicalite-1 loading. For the PDMS/silicalite-1(OH) membrane, the highest separation factor (23.0) was obtained at 60 wt% silicalite-1 loading, while it was found to be 23.8 at 40 wt% silicalite-1 loading for the PDMS/silicalite-1(F) membrane. However, due to the larger size of the silicalite-1(F) particles, its maximal loading (40 wt%) in PDMS was lower than that of the silicalite-1(OH) particles (60 wt%). In order to take advantage of the higher selectivity of silicalite-1(F) particles and the higher loading of silicalite-1(OH), these two kinds of silicalite-1 particles were mixed and incorporated into PDMS. Using this new strategy, the total loading of the silicalite-1 particles could be up to 60 wt%, and the separation factor of such membrane increased to 28.9 when the partial loading of silicalite-1(F) was 30 wt%. The effects of feed temperature and ethanol concentration on this new PDMS/silicalite-1(F)-silicalite-1(OH) membrane were also investigated. The results demonstrated that the incorporation of the mixed silicalite-1(F) and silicalite-1(OH) particles into PDMS could be a promising method for the preparation of high performance PV membranes.