Enhanced Gas Separation Properties Performed By Ag+-Containing Mixed Matrix Membrane Utilizing Organic-Inorganic Janus Composite Nanoparticle

Enhanced gas separation properties performed by Ag⁺-containing mixed matrix membrane utilizing organic-inorganic Janus composite nanoparticle

Tiantian Zhou, Liu Luo, Shen Hu, Shaofei Wang, Hong Wu†, Zhongyi Jiang

^aKey Laboratory for Green Chemical Technology, School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China

^bCollaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin 300072, China

wuhong@tju.edu.cn

Abstract: An Ag⁺ containing Janus composite nanoparticle were synthesized by adhering Ag onto as-prepared dopamine nanosphere which was embedded in Pebax^® MH 1657 polymer matrix. The fabricated mixed matrix membrane (MMM) was utilized in CO₂ capture process. Dopamine, acted as bioadhesive, metal chelator as well as reductant, carried Ag⁺ and elemental Ag nanosphere. The high Ag⁺ loading (38.36 wt% of total Ag element) endowed the Janus nanoparticle with CO₂ facilitated transport privilege; while the structural improvement created by Ag-dopamine neighboring bestowed benign interface gap on the membrane nanostructure, ensuring the high gas permeation flux. The membrane separation properties were investigated by two different protocols: dopamine nanofillers with and without silver modification in order to comprehend the role which silver played in MMM. The maximum value of the MMM separation performance could be obtained at Janus nanoparticle loading of 10 wt%, which was 149.89 barrer for CO₂ permeability (82.9% higher), 25.91 for CO₂/CH₄ selectivity (40.04% higher), and 72.48 for CO₂/N₂ selectivity (39.30% higher) compared with that of pure Pebax^® 1657. Effect of both feed pressure and operating temperature on separation properties were investigated through gas separation process with CO₂/CH₄binary system. And results suggested that the Janus particles with composite structure had a great potential merit in MMM utilization.

Keyword: Gas separation; mixed matrix membrane; Janus nanoparticle; facilitated transport; structural improvement