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Cellulose is a beneficial material that has low cost, light weight, high compatibility, and biodegradability.
Recently electro-active paper (EAPap) composed with cellulose was discovered as a smart material for application to
variety industrial fields such as smart wall-paper, actuator, and magic carpet. It also exhibited actuator property through
ion migration and piezoelectric effect. Since cellulose acetate (CA) film has optically transparent property, we focused
on optical field application, such as electronic paper, prismsheet, and polarized film. Since CA can be easily dissolved in
variety of organic solvent, various weight % (from 1 to 25 wt. %) of CA solution in acetone was prepared.
Polydimethylsilane (PDMS) master pattern was fabricated on the silicone wafer. CA solution was poured to the master
mold and dried using spin-coating or tape casting method. Various shape and height patterns, such as circle, honeycomb,
and rectangular patterns were fabricated using 12 wt. % CA solution. The resulting pattern showed uniform size in the
large area without defect. These patterns can be utilized as a substrate and cell pattern for the electronic paper. To
investigate saponification (SA) effect to convert CA to regenerated cellulose, CA film was immersed into the sodium
methoxide solution in methanol for various times. The fabricated CA films were stretched and immersed into the sodium
methoxide solution in methanol to desubstitute the acetate group. These regenerated cellulose films have larger
mechanical strength than CA films. Although the UV-visible transmittance was decreased as increasing SA time, the
transmittance of the further SA process and stretched film backed up near untreated CA film. Although the cross-sectional
image of the saponified and unstretched CA film did not have specific directional structure, the cross-sectional
FESEM image of the saponified and stretched CA film had one directional fiber structure. The fiber was aligned to the
stretched direction. Most of the compositions were one directional ordered nanofibers having diameter of approximately
30nm.
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