IRIDESCENT SOLID NANOCRYSTALLINE CELLULOSE FILMS INCORPORATING PATTERNS AND METHOD FOR THEIR PRODUCTION

摘要

A new method to producesolid nanocrystalline cellulose (NCC)films containing patterns by differentialheating of aqueous suspensions of NCChas been discovered. When acid-formNCC suspensions are dried by heating totemperatures above 50 °C, darkening ofthe NCC can occur, while neutral formsof NCC can produce iridescent chiralnematic films by heating to temperatures upto 105 °C. Placing materials of differentthermal conductivity beneath the containercontaining an evaporating NCC suspensionresults in watermark-like patternsof different iridescent colour imprintedwithin the film structure. Other colloidalrod-like particles can be employed inplace of nanocrystalline cellulose (NCC),for example chitin or chitosan.