Zirconia nanocolloids having a nanospace of poly(cyclodextrin): preparation and application to liquid crystal devices

Poly(gamma-cyclodextrin) (PgammaCyD)-protected ZrO2 nanocolloids were prepared by using a microwave reactor equipped with ultrasonic nozzle mixing at 240 degrees C for 30 min in a tetraethylene glycol solution of zirconium (IV) ethoxide in the presence of poly(gamma-cyclodextrin). Particles in PgammaCyD-protected ZrO2 nanocolloids have an average diameter of 7.2 nm and mainly distribute within the range of about 3 to 10 nm. The nanocolloids were dispersed in 4'-pentylbiphenyl-4-carbonitrile (5CB) and practical liquid crystal to construct novel twisted nematic liquid crystal devices (TN-LCDs). The response time of this TN-LCDs in the presence of PgammaCyD-protected ZrO2 nanocolloids was faster than that in the absence. The threshold voltage of TN-LCDs by doping PgammaCyD-protected ZrO2 nanocolloids decreased. The decrease of threshold voltage can reduce power consumption, which may meet the demands of future power-saving LCDs.