Misao Horigome

Characterization of Surface Microstructures on Bio-based Polymer Film Fabricated with Nano-imprint Lithography by Synchrotron Radiation Small Angle X-ray Scattering

Nano-imprint lithography (NIL) is a simple, low cost and high-resolution patterning method. However the precise evaluation method of nano-imprinted structure has not been established. Synchrotron radiation small angle X-ray scattering (SR-SAXS) measurement is a nondestructive and high resolution characterization method. In this study, we attempt to fabricate nanostructures on the poly(lactic acid) (PLA) film by NIL and evaluated with microscopic and scattering techniques. The mold with line/space pattern was used for NIL. Scanning electron microscope observation confirmed the formation of surface nano-structure in large areas. Also, nano-imprinted PLA film was evaluated using SR-SAXS measurement. The scattering patterns obtained from nano-imprinted PLA films were clearly observed up to higher order scattering spots. These results suggested that highly regular structure was fabricated on the surface of PLA films.

Viscoelastic Property of Aqueous Solution of Associating Polymer in a High Frequency Range.

High frequency viscoelasticity of an aqueous solution of associating polymer was directly measured. Viscoelasticity of the solution was determined at frequencies 10-1-102 rad s-1 with a conventional dynamic measurement method and at frequencies 10-2-104 rad s-1 with pulse strain method and surface loading method. The viscoelastic behavior of the solution was close to that of the Maxwell model in a range of polymer concentration 2-5wt%. Relaxation time τ and modulus G were determined by fitting data to the Maxwell model. The value of G increased with polymer concentration, while τ was independent of polymer concentration. These results were in good agreement with the prediction of Tanakas theory.