摘要
Natural gas and biogas are important resources.The enrichment of CH4 is necessary for increasing the caloric value of feed gas[1-3].Membrane-based gas separation technology is more energyefficient with continuous operation and more environmentally friendly than conventional gas separation technologies,and it has strong application prospects in the field of industrial separation[1,4].Metal-organic frameworks(MOFs)have high porosity,adjustable aperture,highly diversified structures and satisfactory chemical stability,which inspire many researchers to explore their applications in membrane fabrication for gas separation[2,3,5].Pure MOF membranes that are fabricated on porous substrates can realize high gas permeance and satisfactory selectivity simultaneously and have been attracted substantial attention[6,7].
通过原位界面剥离法在聚合物支撑体表面制备了超薄二维ZIF-L膜.聚乙烯醇和六水合硝酸锌络合物作为中间层改性支撑体表面,同时提供ZIF-L膜生长所需的晶核.反应溶液中的自由晶核和界面上的铆钉晶核对溶液中的有限配体产生竞争吸附力,从而形成亚纳米的限域空间.在限域空间内,超薄ZIF-L纳米片能够形成并自组装成超薄ZIF-L膜.通过调控溶液中配体的浓度,ZIF-L膜的厚度可在微米至亚纳米级进行调节,其最薄可达27nm.对于CO2/CH4混合气,超薄ZIF-L膜的CO2渗透速率可达4600 GPU,CO2/CH4分离因子可达21.此方法首次实现了超薄ZIF-L膜在聚合物支撑体表面的原位生长,有望进一步推动MOF膜的应用,也为其他二维膜的制备提供了有效策略.
作者
Yueyao Liang
Caijiao Yu
Jingge Ju
Zhihua Qiao
Chongli Zhong
梁跃耀;于彩娇;鞠敬鸽;乔志华;仲崇立(State Key Laboratory of Separation Membranes and Membrane Processes, Tiangong University;School of Materials Science and Engineering, Tiangong University;School of Chemistry and Chemical Engineering, Tiangong University)
基金
supported by the National Natural Science Foundation of China(21536001,21878229,and 21908163)
the Science and Technology Plans of Tianjin(18PTSYJC00180 and 19PTSYJC00020)。
