Linked Life Data

16283762

Source:http://linkedlifedata.com/resource/pubmed/id/16283762

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2005-11-14
pubmed:abstractText
The structure of thin films cast from regenerated solutions of Bombyx mori cocoon silk in hexafluoroisopropyl alcohol (HFIP) was studied by synchrotron X-ray diffraction during heating. A solid-state conformational transition from an alpha-helical structure to the well-known beta-sheet silk II structure occurred at a temperature of approximately 140 degrees C. The transition appeared to be homogeneous, as both phases do not coexist within the resolution of the current study. Modulated differential scanning calorimetry (DSC) of the films showed an endothermic melting peak followed by an exothermic crystallization peak, both occurring near 140 degrees C. Oriented fibers were also produced that displayed this helical molecular conformation. Subsequent heating above the structural transition temperature produced oriented beta-sheet fibers very similar in structure to B. mori cocoon fibers. Heat treatment of silk films at temperatures well below their degradation temperature offers a controllable route to materials with well-defined structures and mechanical behavior.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1525-7797
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3328-33
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:articleTitle
Thermally induced alpha-helix to beta-sheet transition in regenerated silk fibers and films.
pubmed:affiliation
Materials and Manufacturing Directorate, Air Force Research Laboratory, Wright-Patterson AFB, Dayton, Ohio 45433, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't