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Mechanical properties of DNA films
Author(s) -
Gevorkian S. G.,
Khudaverdian E. E.
Publication year - 1990
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.360300306
Subject(s) - chemistry , dna , denaturation (fissile materials) , modulus , dehydration , crystallography , analytical chemistry (journal) , thermodynamics , chromatography , nuclear chemistry , composite material , materials science , biochemistry , physics
The Young's dynamical modulus (E) and the DNA film logarithmic decrement ( v ) at frequencies from 50 Hz to 20 kHz are measured. These values are investigated as functions of the degree of hydration and temperature. Isotherms of DNA film hydration at 25°C are measured. The process of film hydration changing with temperature is studied. It is shown that the Young's modulus for wet DNA films ( E = 0.02–0.025 GN m −2 ) strongly increases with decreasing hydration and makes E = 0.5–0.7 GN m −2 . Dependence of E on hydration is of a complex character. Young's modulus of denatured DNA films is larger than that of native ones. All peculiarities of changing of E and v of native DNA films (observed at variation of hydration) vanish in the case of denatured ones. The native and denatured DNA films isotherms are different and depend on the technique of denaturation. The Young's modulus of DNA films containing > 1 g H 2 O/g dry DNA is found to decrease with increasing temperature, undergoing a number of step‐like changes accompanied by changes in the film hydration. At low water content (< 0.3 g H 2 O/g dry DNA), changing of E with increasing temperature takes place smoothly. The denaturation temperature is a function of the water content.