Comparative Study On Water Uptake And Ionic Transport Properties Of Pre- And Post Sulfonated Chitosan/PVA polymer Exchange Membrane

International Conference on Process Engineering and Advanced Materials 2018

Wong, Chun Yik^1 ; Wong, Wai Yin^1 ; Loh, Kee Shyuan^1 ; Daud, Wan Ramli Wan^1,2 ; Lim, Kean Long^1 ; Loh, Keh Shyuan^1 ; Walvekar, Rashmi^3 ; Khalid, Mohamad^4

Fuel Cell Institute, Universiti Kebangsaan Malaysia, UKM Bangi, Selangor

43600, Malaysia^1

Department of Chemical and Process Engineering, Faculty of Engineering and Built Environment, Universiti Kebangsaan Malaysia, UKM Bangi, Selangor

43600, Malaysia^2

School of Engineering, Taylor's University Lakeside Campus, Selangor, Subang Jaya

47500, Malaysia^3

Graphene and Advanced 2D Materials Research Group (GAMRG), Research Centre for Nanomaterials and Energy Technology (RCNMET), School of Science and Technology, Sunway University, Selangor, Subang Jaya

47500, Malaysia^4

关键词: Comparative studies;    Fuel cell application;    Functionalisation;    Ion exchange capacity;    Ionic transport properties;    Polymer exchange membranes;    Sulfonated chitosans;    Vinylalcohol;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/458/1/012017/pdf
DOI  :  10.1088/1757-899X/458/1/012017

来源: IOP

【 摘 要 】

Chitosan/poly(vinyl alcohol) (PVA) blend composite was prepared through two strategies of chemical modification, namely pre- and post-sulfonation. The sulfonation was carried out by using 4-sulfopthalic acid (sPTA) as the sulfonating agent. The modified chitosan/PVA blend composite was prepared under a range of chitosan content (10:90, 25:75, 50:50, 75:25 and 90:10). Water uptake and ion exchange capacity (IEC) of modified membranes were evaluated by titration and gravimetry methods respectively. Accordingly, both pre- and post-sulfonated composite showed a decrease in water uptakes and IEC values with an increase in chitosan content from 10 to 50 vol.%, attributed to the greater number of hydrogen bond pairs between the two polymers. At 75 vol.%, the composite was predicted to be dominant by the hydrophilic nature of chitosan, in which IEC values and water uptakes were shown to increase. The composite with 90 wt.% chitosan was found to be excessively hydrophilic with tremendously high water uptake, hence not suitable for fuel cell application. Besides that, the post-sulfonated composite showed a trend of increase in the IEC values and water uptakes with a decrease in chitosan content from 10 to 50 vol.%, and bounced back at 75 vol.%. Despite both pre- and post-sulfonation methods demonstrated similar trends in the results, it was notable that post-sulfonation method emerged with higher water uptake and ionic conductivity was found more favorable, attributed to the possibility that sulfonation took place on both PVA and chitosan which has caused a significant increase in sulfonic groups that purportedly exhibited higher ion transport mobility.