Enhancing air-dehumidification performance of polyimide membranes by generating hydrophilic Poly(amic acid) domains using partial hydrolysis
Enhancing air-dehumidification performance of polyimide membranes by generating hydrophilic Poly(amic acid) domains using partial hydrolysis
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DOI：
10.1016/j.memsci.2020.119006
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发表时间：
2021-03
影响因子：
9.5
通讯作者：
Sunghwan Park;Hae‐Kwon Jeong
中科院分区：
文献类型：
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作者：
Sunghwan Park;Hae‐Kwon Jeong
膜基空气过滤器被认为是下一代暖通空调系统最有前途的技术之一。虽然有吸引力，但聚合物膜受到它们的H2O/N2分离性能（即，H_2O/N_2分离因子和H_2O渗透率）和机械稳定性。在此，我们提出了一种简单有效的策略，控制部分水解，以提高聚酰亚胺（PI）膜的H2O/N2分离性能，同时保持其机械稳定性。控制水解PI膜部分变成聚酰胺酸（PAA）/PI膜，表现出不对称的配置与内层水解。有趣的是，在高浓度NaOH溶液中的水解导致形成被水解的局部域（即，PAA结构域）。机械稳定的PI膜的局部水解导致形成嵌入PI中的亲水性PAA通道，从而增强H2O/N2分离性能（即，H2O渗透率从~6400 Barrer到~ 11，000 Barrer，H2O/N2分离因子从~190到~ 320），同时保持膜的机械强度。
Membrane-based air-dehumidification has been considered as one of the most promising technologies for the next-generation heating, ventilation, and air-conditioning (HVAC) systems. Though attractive, polymeric membranes suffer from limitation between their H2O/N2separation performance (i.e., H2O/N2separation factor and H2O permeability) and their mechanical stability. Herein, we propose a facile and effective strategy, controlled partial hydrolysis, to improve the H2O/N2separation performance of polyimide (PI) membranes while maintaining their mechanical stability. Controlled hydrolysis turned the PI membranes partially into poly (amic acid) (PAA)/PI membranes, exhibiting an asymmetric configuration with the inner layers more hydrolyzed. Interestingly, the hydrolysis in a highly concentrated NaOH solution led to formation of localized domains that were hydrolyzed (i.e., PAA domains). The localized hydrolysis of mechanically stable PI membranes led to formation of hydrophilic PAA channels embedded in the PI, thereby enhancing H2O/N2separation performance (i.e., H2O permeability from ~6400 Barrer to ~11,000 Barrer and H2O/N2separation factor from ~190 to ~ 320) while preserving the mechanical strength of the membranes.