Study on Method of Recycling Liquid Crystal from Waste LCD Based on Supercritical CO<sub>2</sub> Fluid Technology

For recycling liquid crystal from waste LCD with high value, the method based on supercritical CO2fluid technology is proposed. The principle of extracting liquid crystal using supercritical CO2fluid is analyzed and the factors influencing liquid crystal recycling effect are discussed. The solubility of supercritical fluid is enhanced by adding polar entrainer in order to raise the recycling rate. The procedure for recycling liquid crystal with supercritical fluid technology is studied. Choosing TFT mode LCD as researching object, selecting different temperature and pressure and adopting isothermal and depressurization method, a series of recycling experiments are completed. The results show that the recycling rate of liquid crystal can reach 90% with the aid of supercritical carbon dioxide fluid technology and the purity and recycling efficiency of liquid crystal are high.