Spatiotemporally resolved characterization for analyzing the interfacial behaviors of gelation in aqueous phase separation

Li，Shengzhe1; Zhang，Kexin1; Li，Zhuo1; Liu，Jie1,2; Liu，Xin1; Li，Weiyi1

2024-02-01

10.1016/j.memsci.2023.122299

Journal of Membrane Science   影响因子和分区

0376-7388

1873-3123

Precipitating polymer in a completely aqueous environment is conceptualized as a process of aqueous phase separation (APS) and lends itself to the environmentally friendly fabrication of membranes. In an effort to effectively regulate the morphological formation in APS, it is of fundamental concern to elucidate how asymmetry can be developed in the absence of an unbalanced exchange of the ‘nonsolvent’ and solvent. Therefore, technical modifications were made by this study to essentially improve the in-situ characterization based on optical coherence tomography (OCT). In particular, a process of APS was modeled by passively contacting an acidic aqueous dope of chitosan with another aqueous solution of sodium hydroxide in a mini-coagulation bath, where the OCT scan was implemented in a high speed mode to capture the onset and evolution of gelation at the coagulant-dope interface with a temporal resolution of 6.25 ms. The quantitative analysis indicated that the gelation could be initiated at the interface in a period shorter than ∼10 ms and evolved in an oscillating way; a skin layer with a smaller critical size would be formed by damping the interfacial oscillations. This study not only sheds light on the APS-based fabrication of membranes, but also establishes a novel paradigm for in-situ characterizing the film formation via an OCT-based approach.

Aqueous phase separation Asymmetric structures Chitosan membranes In-situ characterization Optical coherence tomography

SCI ; EI

英语

第一 ; 通讯

CHEMISTRY

2-s2.0-85178149232

Scopus

1.School of Environmental Science and Engineering,Southern University of Science and Technology,China
2.Guangdong Nantian Institute of Forensic Science,China

Li，Shengzhe,Zhang，Kexin,Li，Zhuo,et al. Spatiotemporally resolved characterization for analyzing the interfacial behaviors of gelation in aqueous phase separation[J]. Journal of Membrane Science,2024,692.

Li，Shengzhe,Zhang，Kexin,Li，Zhuo,Liu，Jie,Liu，Xin,&Li，Weiyi.(2024).Spatiotemporally resolved characterization for analyzing the interfacial behaviors of gelation in aqueous phase separation.Journal of Membrane Science,692.

Li，Shengzhe,et al."Spatiotemporally resolved characterization for analyzing the interfacial behaviors of gelation in aqueous phase separation".Journal of Membrane Science 692(2024).