This invention relates to the field of
liquid crystal materials technology, and discloses a
humidity-responsive
cholesteric liquid crystal film based on the photodimerization regulation of
anthracene functional groups, its preparation method, and its application. The preparation method includes: blending a
liquid crystal polymerizable
monomer,
anthracene-containing polymerizable
monomer, a carboxyl-containing polymerizable
monomer, a carboxyl-containing non-polymerizable monomer, a
liquid crystal chiral agent, and a
photoinitiator to obtain a liquid
crystal mixture; filling the mixture into a
liquid crystal cell, then polymerizing it under
ultraviolet light; immersing the resulting self-supporting film in a
potassium hydroxide aqueous solution to convert the carboxyl groups into hygroscopic
potassium salts, thus obtaining the target liquid
crystal film. This invention, by irradiating the liquid
crystal film with
ultraviolet light, can induce orthogonal [4+4]
cycloaddition reactions of
anthracene groups in the
polymer network. By controlling the
ultraviolet exposure, preset information can be pre-encoded as a spatially heterogeneous crosslinking
density distribution within the film, achieving
dynamic display and concealment of colorful patterns across the entire spectrum under
ambient humidity.