Solidified liquid crystals of cellulose with optically variable

Details Solidified liquid crystals of cellulose with optically variable Solidified liquid crystals of cellulose with optically variable

1994-02-14

1997-05-13

Ahmad, Nasser

Stock material or miscellaneous articles

Liquid crystal optical display having layer of specified...

With charge transferring layer of specified composition

4283222, 428326, 349164, 349105, C08L 100, C09K 1900

Patent

active

056290551

ABSTRACT:
Solid films with novel optical properties are produced from colloidal suspensions of cellulose crystallites; the colloidal suspensions are prepared by acid hydrolysis of crystalline cellulose under carefully controlled conditions; the solid materials possess a helicoidal arrangement of the constituent crystallites; by appropriate selection of conditions for preparation and treatment of the colloidal suspensions, solid films are produced that reflect circularly polarized visible light; the wavelength of the reflected light can be controlled to give colours across the visible spectrum from red to violet, and if necessary to infrared and ultraviolet wavelengths. The reflected iridescent colours arise from optical interference effects, and change with the viewing angle; this makes the materials ideally suited for optical authenticating devices, since no printing or photocopying technique can reproduce this effect; furthermore, they are easily distinguishable from other optical interference devices since they have additional optical properties.

REFERENCES:
patent: 4614619 (1986-09-01), Shannon
patent: 4637896 (1987-01-01), Shannon
patent: 4840673 (1989-06-01), Cuculo
patent: 5215757 (1993-06-01), El-Nokaly
Dobrowolski, J.A.; Ho, F.C. and Waldorf, A., Applied Optics, vol. 28, No. 14, (1989).
DeVries, H., Acta Crystallogr., 4, 219 (1951).
Fergason, J.L., Molecular Crystals, 1, 293 (1966).
Jacobs, D.C., "Liquid Crystals for Laser Applications", in Optical Materials Properties, CRC Handbook of Laser Science and Technology, vol. IV ed. Weber, M.J., pp. 409-465 (1986).
Hikmet, R.A.M. and Zwerver, B.H., Liquid Crystals, 13, No. 4, 561 (1993). Note to the Editor "Helicoidal self-ordering of cellulose microfibrils in Aqueous Suspension", Revel et al, 170 Int. J. Biol. Macromol., 1992, vol. 14, Jun.
Chiral Nematic Suspensions of Cellulose Crystallites; Phase Separation and Magnetic Field Orientation, Revol et al.
Julie Giasson et al "Electron Microscopic Evidence for Cholesteric Structure in Films of Cellulose and Cellulose Acetate, Biopolymers", vol. 27, 1999-2004 (1988).
Charlet et al, "Solid Cholesteric Filsm Cast from Aqueous (Hydroxypropyl) cellulose", American Chemical Society, Macromolecules 1987, 20, 33-38.
Liquid Crystalline Structure in Aqueous hydroxpropyl Cellulose Solutions, Werbowyj et al, Mol.Cryst.Liq.Cryst.,Col.34 (Letters) pp-97-103.
"Optical Rotatory Power of Liquid Crystals", Chandrasekhar et al, Acta. Cryst. (1968)A24,445.
"Twisted Architectures in Cell-Free Assembled Collagen Gels:Study of Collagen Substrates Used for Cultures", Bouligand et al Biol.Cell. 54, 143-162(1985).
"In vitro Chiral Nematic Ordering of Chitin Crystallites", Revol et al IJBM1593.MCP.
Color Gamut of Liquid Crystal Polysiloxanes, D. Makow, Mol.Cryst.Liqu.Cryst., 1985, vol. 123, pp. 347-353.
Scarabaeid Beetle Exocutical as an Optical Analogue of Cholesteric Liquid Crystals, Neville et al Biol.Rev. (1969), 44 pp. 531-562.
Chiroptical Filters from Aqueous (Hydroxypropyl) cellulose Liquid Crystals, Charlet et al, Journal of Applied Polymer Science, vol.37,2517-2527 (1989).
"The Cholesteric Phase in Polypeptide Solutions and Biological Structures" Robinson, Mol.Crys., 1966,vol. 1, pp. 467-494
Chem.Ab. 112:79036d,vol.112,1990,p.79.
Chem.Ab. 105:154823u,vol.105,1986,p.95.
Chem.Ab. 111:218368h,vol.111,1989,p.250.
Chem.Ab. 106:111459h,vol.106,1987,p.74.
Chem.Ab. 101:181722j,vol.101,1984,p.671.
Chem.Ab. 106:165853a,vol.106,1987,p.628.
Chem.Ab. 112:120237k,vol.112,1990,p.61.
Chem.Ab. 114:92031j,vol. 114,1991,p.705.
Chem.Ab. 113:68894b,vol.113,1990,p.656.
U.S. Nat. Tech. Inform. Serv., AD Rep., No. 74986, 10 pp. From: Gov. Rep. Announce (U.S.) 1972, 12(17), 54, "Solid State Morphology of Some Polypeptide Films", Friedman et al.

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