Inelastic neutron scattering studies of natural silkworm proteins

ABSTRACTUnderstanding the interaction of water with biological materials is of fundamental importance. One of main driving forces behind the renewed activity of biomimetic materials involves the dramatic physical properties that many of them exhibit. Two main factors that are critical for understanding silks: the nanoscale semi-crystalline folding structure, and the degree of hydration of the disordered fraction. We describe our investigation of the preparation, characterization and inelastic neutron scattering (INS) studies of the microscopic dynamics of natural Bombyx mori silk fibroin proteins derived from silkworm cocoons. An in situ quartz microbalance is used for monitoring/controlling the hydration and solvent levels of the proteins electrospun onto neutron sample holders. By employing these novel methods our INS investigation facilitated a snapshot of the microscopic silk protein dynamics heretofore not investigated or reported. Preliminary INS measurements illustrate the effect of water and methanol interaction on the dynamics of the fibroin β-pleated sheet component. Evidence of what appears to be a water component (intersheet) distinct from bulk water is clearly apparent in the INS spectrum when the dynamical response from the dry silk is subtracted away.</jats:p

COMMENSURATE-INCOMMENSURATE TRANSITION OF MONOLAYER KRYPTON ON GRAPHITE BY HELIUM-ATOM SCATTERING

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