𝔖 Bobbio Scriptorium
✦   LIBER   ✦

Cholesteric order in gels and films of regenerated cellulose

✍ Scribed by Anna M. Ritcey; Derek G. Gray

Publisher
Wiley (John Wiley & Sons)
Year
1988
Tongue
English
Weight
890 KB
Volume
27
Category
Article
ISSN
0006-3525

No coin nor oath required. For personal study only.

✦ Synopsis

Synopsis

Congo red bound to regenerated cellulose in highly swollen gel films formed by slow precipitation from LiCl/N,N-dimethylacetamide solution exhibits induced optical activity. The induced CD band of the dye vanishes when these films are dried under uniaxial stress, indicating that the effect is structural in origin and not simply due to association of dye with chiral centers on the cellulose chain. Cellulose was also regenerated from cellulose acetate films, cast both from isotropic and cholesteric solution, by deacetylation in aqueous ammonia. Congo red bound to cellulose regenerated from cholesteric cellulose acetate exhibits an induced CD band similar to that obtained for films precipitated from LiCl/DMAC solution. The CD spectrum of Congo red in cellulose films regenerated from isotropic cellulose acetate is featureless. These observations indicate that cellulose adopts cholesteric order on slow precipitation from solution.

πŸ“œ SIMILAR VOLUMES

Inter- and intramolecular order in regen
Inter- and intramolecular order in regenerated cellulose
✍ A. J. Pennings; W. Prins; R. D. Hale; B. G. RΓ₯rnby πŸ“‚ Article πŸ“… 1961 πŸ› John Wiley and Sons 🌐 English βš– 773 KB

## Abstract Cellulose was regenerated from technical viscose as bulk gels and thin films (never dried) and then conditioned by repeated swelling with sodium hydroxide solutions and steam treatments. These extraction and conditioning treatments of the gels increased the crystallinity and decreased t

Thermal depolarization currents of regen
Thermal depolarization currents of regenerated cellulose films
✍ Gary A. Baum πŸ“‚ Article πŸ“… 1973 πŸ› John Wiley and Sons 🌐 English βš– 541 KB

The thermal depolarization current technique is applied to plasticized and unplasticized regenerated cellulose films. In unplasticized cellulose, two depolarization current bands are observed. The band with a current maximum occurring near 298'K (T,,,), and with an activation energy, U, of 0.57 eV,

Gas transport phenomena in hydroxypropyl
Gas transport phenomena in hydroxypropyl cellulose solid film retaining cholesteric liquid crystalline order
✍ Shinichi Suto; Tetsuya Kobayashi πŸ“‚ Article πŸ“… 1998 πŸ› John Wiley and Sons 🌐 English βš– 248 KB πŸ‘ 2 views

Two kinds of hydroxypropyl cellulose (HPC) films were prepared: one retained cholesteric liquid crystalline order (HPC-A), and another was amorphous (HPC-B). Gas transport phenomena in the HPC-A films were determined at 20Β°C, which is below the T g of HPC, compared with those in the HPC-B films, by

Supramolecular Structure and Properties
Supramolecular Structure and Properties of High Strength Regenerated Cellulose Films
✍ Shilin Liu; Lina Zhang; Yunxia Sun; Yi Lin; Xianzheng Zhang; Yoshiharu Nishiyama πŸ“‚ Article πŸ“… 2009 πŸ› John Wiley and Sons 🌐 English βš– 579 KB

## Abstract Water‐swollen cellulose films prepared from LiOH/urea solution were uniaxially drawn to investigate the effect of orientation on their supramolecular structure and properties. Their structures and properties were investigated with X‐ray diffraction, atomic force microscopy and tensile t