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FIZIKA A 18 (2009) 3 , 121-132
 
ELECTRO-ACTIVITY IN GUM MANGOSTEEN AND ITS COMPLEXES
S. S. PRADHAN and A. SARKAR
Department. of Physics, B. K. Girls' College, 5/3 M. G. Road,
Howrah 711101,
India, E-mail: alokesarkar@vsnl.net
Received 4 April 2009; Revised manuscript received 22 September 2009
Accepted 7 October 2009 Online 29 October 2009
Biomaterial has occupied a leading position in material science for its
various scientific and technological applications. The present work was carried
out with a natural gum extracted from raw fruit of mangosteen - an east Indian
tree Gercinia mangostana. Solid specimen of the gum was developed
following a sol-gel like process. AC and DC electrical analysis on the dried
solid specimen of the gum was carried out. It exhibits high electrical
conduction,
s ~ 2×10-
6 S/cm at room temperature, of which ionic and electronic
contributions are 70% and 30%, respectively. The experimental investigations
show that origin of high electrical conductivity is due to the presence of a
substantial amount of organic acid unit in its polysaccharide background. In
fact the observed
s is about 3 times that observed in gum Arabica - a
plant gum. Optical absorption of this new biomaterial was also studied using
UV-VIS spectro-photometry. The result shows its high absorption coefficient in
UV and blue part of the spectrum. The electrical characterization of the
material was also made. It has been observed that the electronic conduction can
be enhanced to 70% of the total electrical conductivity by forming complex with
iodine or an appropriate organic/inorganic acid, e.g. acetic acid. This
high-potential material is being studied for the development in device
application.
PACS numbers: 82.35.Pq, 82.35.Cd, 83.80.Mc, 87.68.+z, 82.35.Rs
UDC 537.311
Keywords: biopolymer, electro-active, ion-conductive, optical
absorption, mixed conduction
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