Effect of barium chloride doping on PVA microstructure: positron annihilation study

Bhajantri, R. F. and Ravindrachary, V. and Harisha, A. and Ranganathaiah, C. and Kumaraswamy, G. N. (2007) Effect of barium chloride doping on PVA microstructure: positron annihilation study. Applied Physics A, 87 (4). pp. 797-805. ISSN 1432-0630

Text (Full Text) Effect of barium chloride doping on PVA.pdf - Published Version Restricted to Registered users only Download (571kB) | Request a copy

Abstract

Microstructural studies on BaCl2 doped polyvinyl alcohol (PVA) polymer films were carried out using density, PAL and dielectric measurements at room temperature. The positron annihilation studies on these samples shows considerable effect on the PVA microstructure due to doping and is understood by invoking the chemical reaction between Ba2+ ions of BaCl2 with OH groups of PVA via intra/inter molecular hydrogen bonding, which forms the complex. This complex formation modifies the free volume content in the amorphous fraction, and results in an enhancement of the polymer crystallinity. At higher dopant concentrations, the number of such complexes increases, and ends up with the formation of dopant aggregates or agglomerates leading to certain phase separation into a polymer-rich phase and a dopant-rich phase. These phase separations are thought to be due to the existence of two or more crystalline phases within the polymer matrix. The XRD study also supports this enhancement of PVA crystallinity due to doping. The electrical studies on the doped PVA reflects that the complex formation due to doping affects the microstructure and hence the dielectric properties including the dc and ac conductivities of the polymer. All of these observed results were analyzed and understood based on the microstructural modification of PVA as a function of dopant concentrations.

Item Type:	Article
Subjects:	D Physical Science > Physics
Divisions:	Department of > Physics
Depositing User:	C Swapna Library Assistant
Date Deposited:	16 Sep 2019 06:16
Last Modified:	16 Sep 2019 06:16
URI:	http://eprints.uni-mysore.ac.in/id/eprint/8155

Actions (login required)

View Item