Crosslinked inter penetrating network of sulfonated styrene and sulfonated PVdF-co-HFP as electrolytic membrane in a single chamber microbial fuel cell Vikash Kumar, Piyush Kumar, Arpita Nandy and Patit Paban Kundu * In the present study, semi-IPN membranes of sulfonated styrene (SS) and sulfonated PVdF-co-HFP membranes have been analyzed as a polymer electrolyte membrane in single chamber microbial fuel cells (MFCs). 5%, 10%, 20% and 30% sulfonated styrene (SS) with varying concentrations of divinyl benzene (DVB) have been polymerized in the presence of sulfonated PVdF-co-HFP to prepare SPS- 0 (0% SS), SPS-5 (5% SS), SPS-10 (10% SS), SPS-20 (20% SS) and SPS-30 (30% SS) membranes, respectively. Progressive improvements in membrane properties were observed with increasing SS and DVB concentrations, where excess DVB (<0.8 wt% of SS) resulted in increased crosslinks within the membrane structure. This eventually impeded the membrane properties and altered their rigidity. The membranes were characterized for their ion exchange capacity (IEC) and proton conductivity; IEC value of 0.39 meq g 1 , 0.42 meq g 1 , 0.47 meq g 1 , 0.54 meq g 1 and 0.63 meq g 1 and proton conductivity of 3.23 10 3 , 1.06 10 2 , 1.87 10 2 , 2.47 10 2 and 1.61 10 2 S cm 1 were observed for SPS- 0 (0% SS), SPS-5 (5% SS), SPS-10 (10% SS), SPS-20 (20% SS) and SPS-30 (30% SS) membranes. The membranes were sandwiched as membrane electrode assemblies (MEA) and employed in single chamber MFCs with open air cathode to analyze their overall performance outputs. It was observed that amongst these membranes, the MFC with SPS-20 membrane showed the maximum power and current density of 447.42 22 mW m 2 and 1729.63 87 mA m 2 with an overall 91.27% COD removal in 28 days of operation, using electrogenic mixed rmicutes as biocatalysts. Overall, this study reveals the relevance of semi-IPN membranes of sulfonated styrene (SS) and sulfonated PVdF-co-HFP in MFC applications for harvesting bio-energy. 1. Introduction The vast majority of the advances made in MFCs have occurred in the last 5 to 10 years. Bennetto et al. were one of the rst groups which consistently pursued MFC research in the 1980s and 1990s. 1,2 In addition several studies on alternative polymer electrolyte membranes (PEMs) and their optimization have been conducted. A suitable replacement for the high cost per- uorinated membranes as PEM has always been a requisite in fuel cell technology. Some polymeric materials like polystyrene, polyether ether ketone (PEEK), poly (arylene ether sulfone), phenylated poly sulfone, polyphosphazenes, polyimides, poly(4- phenoxybenzoyl-1,4-phenylene), polybenzimidazole (PBI), low density polyethylene (LDPE), high density polyethylene (HDPE) and polypropylene (PP) have been widely studied. 36 Fundamentally, any ion permeable material can function as a barrier and serve as a PEM in fuel cells; for comparison, Kim et al. equated cation-exchange, anion exchange, and ultra ltration (molecular cut-os of 0.5, 1, and 3 kilodaltons) membranes to determine their eects in MFC performance. 79 Similarly, other PEMs using dierent catholytes e.g.; ferricya- nides have been analyzed in dual chamber MFCs. 1012 Recently, a group led by S. Ayyaru developed a sulfonated polystyrene ethylenebutylenepolystyrene (SPSEBS) membrane as an alternative of Naon membrane. 13 SPSEBS membranes were found to be butylenepolystyrene (SPSEBS) membrane as an alternative of Naon membrane. 13 SPSEBS membranes were found to be producing 106.9% higher power density and lower internal resistance in comparison to Naon 117 in a single chamber MFC (SCMFC). S. Ayyaru and S. Dharmalingam also carried out the sulfonation of polyether ether ketone (PEEK) and used it as a proton exchange membrane (PEM) in a single chamber MFC (SCMFC). 14 MFC with the SPEEK membrane were found to produce approximately 55.2% higher power density than Naon-117. In another study, the performance of an anion Advanced Polymer Laboratory, Department of Polymer Science & Technology, University of Calcutta, 92 A. P. C. Road, Kolkata-700009, India. E-mail: ppk923@ yahoo.com; Fax: +91-33-2352-510; Tel: +91-33-2352-510 Electronic supplementary information (ESI) available. See DOI: 10.1039/c5ra03411f Cite this: RSC Adv. , 2015, 5, 30758 Received 24th February 2015 Accepted 20th March 2015 DOI: 10.1039/c5ra03411f www.rsc.org/advances 30758 | RSC Adv. , 2015, 5, 3075830767 This journal is © The Royal Society of Chemistry 2015 RSC Advances PAPER Published on 20 March 2015. Downloaded by Indian Institute of Science on 02/04/2015 04:48:05. View Article Online View Journal | View Issue