THE CRITICAL ONSET OF RADIATION INDUCED CONDUCTION IN HYDRATED BIOPOLYMERS AT ELEVATED WATER CONTENTS AND SUBZERO TEMPERATURES

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THE CRITICAL ONSET OF RADIATION INDUCED CONDUCTION IN HYDRATED BIOPOLYMERS AT

ELEVATED WATER CONTENTS AND SUBZERO TEMPERATURES

D. van Lith, J. Eden, J. Warman, M. de Haas, A. Hummel

To cite this version:

D. van Lith, J. Eden, J. Warman, M. de Haas, A. Hummel. THE CRITICAL ONSET OF RA-

DIATION INDUCED CONDUCTION IN HYDRATED BIOPOLYMERS AT ELEVATED WATER

CONTENTS AND SUBZERO TEMPERATURES. Journal de Physique Colloques, 1987, 48 (C1),

pp.C1-645-C1-645. �10.1051/jphyscol:1987190�. �jpa-00226456�

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JOURNAL DE PHYSIQUE

C o l l o q u e C1, s u p p l g m e n t a u

n o

3, Tome 48, m a r s 1987

THE CRITICAL ONSET OF RADIATION INDUCED CONDUCTION IN HYDRATED BIOPOLYMERS AT ELEVATED WATER CONTENTS AND SUBZERO TEMPERATURES

D. v a n LITH, J. EDEN, J . M . WARMAN, M.P. d e HAAS a n d A. HUMMEL I n t e r u n i v e r s i t y R e a c t o r I n s t i t u t e , Mekelweg 1 5 ,

NL-2600 GA D e l f t , The N e t h e r l a n d s

Abstract : The nanosecond time-resolved microwave conductivity ( M C )

pulse

radiolysis technique has been applied to the study of e l e c t r o n i c ccslduction

i n

hydrated biopolymers a t temperatures ranging from -20 t o -180°C. The polymers investigated were t h e nuclei acid DNA, the proteins collagen

and

g e l a t i n and t h e polysaccharide kapa-carageenan. I n no case

was

a ccnductivity t r a n s i e n t found f o r t h e dry conpounds. A c e r t a i n weight f r a c t i o n of water

was

required before a r a d i a t i o n induced t r a n s i e n t conductivity

was

observable. The " c r i t i c a l " water fractions for t h e b e oonpounds were 0.45, 0.30, 0.32 and 0.28 respectively. These water contents a r e thought to correspmd to those required f o r f o r m t i o n of the f i r s t , s t r o r q l y bound hydration layer of the biopolymer. Further addition r e s u l t s i n a m r e ice-like hydration layer which displays a highly m b i l e electronic charge c a r r i e r similar to t h a t found i n bulk ice. The

ice

doped HF and MI@ have marked e f f e c t s on t h e c d u c t i v i t y transients.

Article published online by EDP Sciences and available at http://dx.doi.org/10.1051/jphyscol:1987190