Chemical study of conjugated polymers for dosimetry of ionizing radiation

• Grant number: 08/06603-0
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Start date: November 01, 2008
• End date: October 31, 2010
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Physical-Chemistry
• Principal Investigator: Carlos Frederico de Oliveira Graeff
• Grantee: Erika Soares Bronze-Uhle
• Host Institution: Faculdade de Ciências (FC). Universidade Estadual Paulista (UNESP). Campus de Bauru. Bauru , SP, Brazil
• Associated research grant: 05/00157-0 - New materials and methods applied to (bio) medicine, AP.TEM

Abstract

The combined use of polymers as a possible material for detection of ionizing radiation started up around 20 years ago. Around 1990 film of poly (p-phenylenevinylene) PPV and derivatives were used as detectors of ionizing radiation. However changes in opto-electronic properties are only observed with the use of high doses (> 1kGy). This fact makes them of no use for dosimetry of ionizing radiation at low doses of interest in medicine. In a recent study by the research group of Prof. Carlos F. O. Graeff revealed that the solutions of semiconducting polymers are much more sensitive to ionizing radiation than the polymers in the form of powder or films. The proposed dosimeter uses a polymer solution that changes color when irradiated due to the reduction of its effective conjugation length. In this sense, this project aims to carry out a detailed study on the physical and chemical processes involved in the irradiation of polymer (MEH-PPV), in particular the analysis of fragments formed during the chemical reaction. Having identified the reaction mechanism, other polymers derived from PPV can be synthesized in the laboratory optimized for this effect. For such studies chemical and spectroscopic techniques will be used, such as 1H-NMR, 13C-NMR spectroscopy, mass spectrometry, GPC, infrared and ultraviolet.