Diffusional Behavior ofn-Alkanes in Polypeptide Gel System with Highly Oriented Chains As Studied by Pulsed Field Gradient Spin Echo1H NMR Method

Abstract

The diffusion coefficients (D) of n-alkanes, n-pentane and n-decane, and 1,4-dioxane as solvent in poly(γ-benzyl l-glutamate) (PBLG) gel with highly oriented α-helical chains were measured by pulsed field gradient spin echo 1H NMR spectroscopy, of which the structure was determined by X-ray diffraction. From the experimental results, it was found that the diffusion coefficients of n-pentane and n-decane in the PBLG gel for the direction parallel and perpendicular to the magnetic field are D∥ = 8.4 × 10-6 cm2/s and D⊥ = 6.4 × 10-6 cm2/s, respectively, and D∥ = 6.1 × 10-6 cm2/s and D⊥ = 5.0 × 10-6 cm2/s, respectively, which correspond to the directions parallel and perpendicular to the α-helical main chain.