Sheng Lujie, Zhang Xianglong, Hua Kaisheng, Deng Maicun, Ren Jizhong
National Laboratory for Clean Energy, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, 116023, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Small. 2024 May;20(20):e2309409. doi: 10.1002/smll.202309409. Epub 2024 Feb 17.
Translating carbon molecular sieve (CMS) membranes into highly scalable hollow fiber geometry with ultra-thin selective layer (<1 µm) for gas separation remains as great challenge. The porous support layer of precursor hollow fiber membranes is prone to collapse during pyrolysis, which induces thick skin layer (15-50 µm) of CMS hollow fiber membranes. Here, a novel strategy is present to obtain an ultra-thin selective skin layer by carbonization of hollow fiber membranes with porous skin. P84-based defect-free CMS hollow fiber membranes with ultra-thin selective skin layer (0.9 µm) for gas separation are prepared without any coating or complex chemical pretreatment. Compared with the carbon membranes derived from defect-free fibers, the H permeance (93.9 GPU) of CMS membranes derived from the porous fibers increases ≈1353% with comparable selectivity of H/CH (143) and higher H/N (120). Furthermore, the porous fibers are pre-aged near the T in N conditions before carbonization, and the H permeance of the derived CMS hollow fiber membranes reached 147 GPU (increased 2180%). It is a new facile way to prepare CMS hollow fiber membranes with ultra-thin selective layer by porous fibers, demonstrating its versatile potential in gas separation or organic liquids separation.
将碳分子筛（CMS）膜转化为具有用于气体分离的超薄选择层（<1微米）的高度可扩展中空纤维结构仍然是一项巨大挑战。前驱体中空纤维膜的多孔支撑层在热解过程中容易塌陷，这会导致CMS中空纤维膜形成厚皮层（15 - 50微米）。在此，提出了一种新策略，通过对具有多孔皮层的中空纤维膜进行碳化来获得超薄选择皮层。制备了用于气体分离的具有超薄选择皮层（0.9微米）的基于P84的无缺陷CMS中空纤维膜，无需任何涂层或复杂的化学预处理。与源自无缺陷纤维的碳膜相比，源自多孔纤维的CMS膜的H渗透率（93.9 GPU）在H/CH选择性相当（143）且H/N选择性更高（120）的情况下增加了约1353%。此外，多孔纤维在碳化前在N条件下接近T进行预老化，所得CMS中空纤维膜的H渗透率达到147 GPU（增加了2180%）。通过多孔纤维制备具有超薄选择层的CMS中空纤维膜是一种新的简便方法，展示了其在气体分离或有机液体分离中的多种潜力。
