Influence of repeating sequence on structural and thermal stability of crystalline domain of bombyx mori silk fibroin


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Aksakal B. , Akdere Ü. , Günay S. D. , Çağın T., Taşseven Ç.

MATERIALS RESEARCH EXPRESS, vol.6, no.12, pp.125356-125364, 2020 (Journal Indexed in SCI Expanded)

  • Publication Type: Article / Article
  • Volume: 6 Issue: 12
  • Publication Date: 2020
  • Title of Journal : MATERIALS RESEARCH EXPRESS
  • Page Numbers: pp.125356-125364

Abstract

Thermophysical properties of polar-antiparallel β-sheet crystalline domains of B.mori silk fibroin has

been investigated via molecular dynamics (MD) simulations between 300 Kand 700 K. In general, the

type of interactions determines the character of the thermal expansion in corresponding directions

except that the crystalline domains with serine residue contracts along the chain direction resulting

with a negative thermal expansion (NTE) coefficient of ay » -10- K-

4 1at 300 K. The heat capacity at

constant pressure CP increases sublinearly up to about 650 Kwith an almost continuous decrease in

the rate of change of entropy . dS

dT P ( ) Energetic behavior of the β-sheet crystalline units is determined

by the main chain below 400 Kthen thermally activated motion of side chain (HG1) of serine residue

becomes effective up to the degradation point. These are particularly important in designing thermally

controlled composite materials.