425104 Enhancing CO2 Separation Performance of Composite Membrane By Incorporation of Amino Acid-Functionalized Graphene Oxide

Sunday, November 8, 2015
Exhibit Hall 1 (Salt Palace Convention Center)
Hong Wu, School of Chemical Engineering and Technology, Tianjin University, Key Laboratory for Green Chemical Technology of Ministry of Education, Tianjin, China

Composite membranes composed of polymer phase and filler phase have been extensively studied for energy-efficient gas separation, especially for CO2 separation, gasoline desulfurization, and alcohol dehydration, etc. The multiphase characteristics of composite membranes provide more degree of freedom to manipulate multiple interactions, tailor multiscale structures and integrate multiple functionalities in comparison with unfilled membrane. As the basic unit of protein, amino acid molecules are important in biology for promotion CO2 transport. The composite membranes are fabricated by incorporating amino acid-functionalized graphene oxide nanosheets into sulfonated poly (ether ether ketone) (SPEEK) polymer matrix. Graphene oxide (GO) nanosheets are functionalized with amino acids through a facile two-step method by using dopamine and cysteine in succession. CO2 separation performance of the as-prepared membranes is evaluated for CO2/CH4 and CO2/N2 systems. GO nanosheets increase more tortuous paths for the larger molecules, enhancing diffusivity selectivity. Amino acid with the carboxylic acid groups and primary amine groups simultaneously enhances solubility selectivity and reactivity selectivity. Accordingly, CO2 molecules can transport quickly with the enhanced selectivity. When the content is 8 wt %, the optimum separation performance is achieved with selectivities of 82 and 115 for CO2/CH4 and CO2/N2, respectively, and CO2 permeability of 1247 Barrer, significantly surpassing the Robeson upper bound reported in 2008. Besides, the mechanical and thermal stabilities of the composite membranes are also improved compared with pristine SPEEK membrane.

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See more of this Session: Poster Session: Separations Division
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