Polymer electrolytes from gellan gum for electrochromic devices and solar cells

• Grant number: 10/20878-2
• Support Opportunities: Research Grants - Visiting Researcher Grant - International
• Start date: May 01, 2011
• End date: August 31, 2011
• Field of knowledge: Engineering - Materials and Metallurgical Engineering - Nonmetallic Materials
• Principal Investigator: Agnieszka Joanna Pawlicka Maule
• Grantee: Agnieszka Joanna Pawlicka Maule
• Visiting researcher: Siti Rohana Binti Majid
• Visiting researcher institution: University of Malaya (UM), Malaysia
• Host Institution: Instituto de Química de São Carlos (IQSC). Universidade de São Paulo (USP). São Carlos , SP, Brazil

Abstract

This project proposes the preparation and characterization of polymer electrolytes using gellan gum. The project consists in the preparation of transparent gellan gum-based membranes for technological applications, such as electrochromic devices and solar cells. These membranes should have good adhesion to glass surfaces and good ionic conduction properties. To achieve the objectives of this proposal, the membranes will be obtained by gellan gum plasticization processes using plasticizers, such as glycerol, ethylene glycol, ethylene carbonate, propylene carbonate and others, and adding lithium salts, as LiClO4 , LiBF4, LiCF3SO3, LiI/I2 or acetic acid to promote the proton conduction. The ion conductive membranes will be characterized using thermal analysis (DSC, DTA, TG), structural analysis (X-ray) and optical measurements (IR, UV-Vis). The visualization of the sample surface will be performed by scanning electron microscopy coupled with chemical analysis (EDX). Finally the most important measurements of ionic conduction will be taken by complex impedance, including dielectric constant, dielectric loss and electric module analysis. The samples with best ionic conductive values, transparency and thermal stability will be applied to electrochromic devices and solar cells and characterized by transmittance measurements, contrast ratio, number of cycles of coloration/bleaching, memory tests and electrochemical performance in the case of solar cells. (AU)