The cholesteric liquid crystals of the blend of ethyl cellulose (EC) and hydroxypropyl cellulose (HPC) with different percentages were prepared and characterized by using UV-vis spectrometer, XRD spectrometer and polarized microscope. With the increasing of the percentage of HPC in the blend, when the weight concentrations of the blend liquid crystals are the same, the pitch and the maximum wavelength of selective reflection of the blend liquid crystals are increased. It is confirmed that the increasing of the pitch and the maximum wavelength of selective reflection is related to the increasing of the distance of the cholesteric liquid crystal adjacent layers by the results of XRD experiments. It can be used as a method to regulate and control the optical properties and pitch of cellulose cholesteric liquid crystals.

Key words: cellulose liquid crystal, cellulose, cholesteric phase