SULFONATED NATA DE COCO AS POLYMER ELECTROLYTE MEMBRANE FOR DIRECT METHANOL FUEL CELLS

• Main Author: HIMAWAN (NIM : 10510005) ; Pembimbing Prof. Dr. Ing Cynthia Linaya Radiman, HENDRY
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18627
• Institution: Institut Teknologi Bandung

Polymer membrane electrolyte is one of the most important components of fuel cells. Nafion® is <br /> <br /> <br /> <br /> <br /> <br /> <br /> a commercial membrane currently used for this application, but unfortunately, it is very <br /> <br /> <br /> <br /> <br /> <br /> <br /> expensive. Therefore, attempts have to be done to find alternatives to substitute Nafion®. Nata <br /> <br /> <br /> <br /> <br /> <br /> <br /> de coco, a bacterial cellulose, is considered as a potential material for this purpose. In this work <br /> <br /> <br /> <br /> <br /> <br /> <br /> nata de coco was produced from coconut water by Acetobacter xylinum in various harvest time <br /> <br /> <br /> <br /> <br /> <br /> <br /> (3, 6, and 9 days). In order to increase its proton conductivity, chemical modification of nata de <br /> <br /> <br /> <br /> <br /> <br /> <br /> coco was carried out by sulfonation. Nata de coco membranes were then immersed in a 1% (v/v) <br /> <br /> <br /> <br /> <br /> <br /> <br /> solution of chlorosulfonic acid in N,N-dimethylformamide (DMF) for 4 hours at 4oC followed <br /> <br /> <br /> <br /> <br /> <br /> <br /> by microwave-assisted sulfonation for 40 seconds using various powers (240, 400, and 560 W). <br /> <br /> <br /> <br /> <br /> <br /> <br /> Several characterizations have been done including sulfonate functional group analysis by FTIR, <br /> <br /> <br /> <br /> <br /> <br /> <br /> determination of ion exchange capacity (IEC), proton conductivity, swelling index, contact angle, <br /> <br /> <br /> <br /> <br /> <br /> <br /> methanol permeability, membrane morphology by Scanning Electron Microscope (SEM) and <br /> <br /> <br /> <br /> <br /> <br /> <br /> quantitative analysis of sulfonic groups by Electron Dispersive X-Ray Spectroscopy (EDS). The <br /> <br /> <br /> <br /> <br /> <br /> <br /> experimental results show that the optimal membrane was obtained by 6-days synthesis and <br /> <br /> <br /> <br /> <br /> <br /> <br /> modified by microwave-assisted sulfonation using 400 W. This membrane has an IEC value of <br /> <br /> <br /> <br /> <br /> <br /> <br /> 2,056 mEq/g, a proton conductivity of 2,16 x 10-2 S/cm at 80oC, swelling index of 100%, and a <br /> <br /> <br /> <br /> <br /> <br /> <br /> methanol permeability of 2,36 x 10-4 cm2/s.