Ultraviolet light-driven molecular crystal-polymer composite film material and preparation method thereof

Abstract

The invention discloses an ultraviolet light-driven molecular crystal-polymer composite film material and a preparation method thereof. The composite thin film material includes: a polymer thin film, and nanocrystals of organic dye molecules distributed in the thin film. Structured organic dye molecules. Preferably, the organic dye molecular nanocrystals form an array structure in a closely arranged manner. The preparation method of the composite material includes: uniformly mixing the organic dye molecular nanocrystals and the polymer in a solvent, spreading them on the substrate, allowing the organic dye molecular nanocrystals to self-assemble, and volatilizing the solvent, so as to obtain the composite material. film material. The composite film material of the invention has the characteristics of large size, large deformation, good flexibility, fast light response speed, simple preparation, low cost, stable physical and chemical properties, deformation direction not affected by light direction, and the like.

Description

technical field [0001] The invention relates to a material for realizing the direct conversion of light energy to mechanical energy, in particular to an ultraviolet light-driven molecular crystal-polymer composite thin film material and a preparation method thereof. Background technique [0002] At present, materials that can convert ultraviolet energy into mechanical energy, or produce deformation responses to ultraviolet energy, mainly include organic dye molecular crystals and azobenzene-containing polymer liquid crystals. The principle is to take advantage of the high energy characteristics of ultraviolet photons, which can trigger reversible chemical reactions of certain photoactive groups. [0003] Azobenzene-containing polymer liquid crystals, whose mesogens are long rod-shaped molecules containing azo groups, are arranged in a nematic phase at room temperature. Under the irradiation of ultraviolet light, part of the liquid crystal molecules on the surface of the fil...

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Problems solved by technology

[0005] Among the two types of materials, the azobenzene polymer liquid crystal film has the advantages of flexibility, increased responsiveness, high energy conversion rate, and polarization selectivity, but it is difficult to design and synthesize, and the deformation speed is slow and the deformation accuracy is low. , The physical and chemical properties of the surface change with the light; molecular crystals have the characteristics of fast deformation and high precision, but their deformation is small, and there is a contradiction between deformation and size (if you want a large deformation, the crystal size must be small), fragile, Poor fatigue resistance, the UV light source used below 260nm is expensive, low power, and decays quickly in the air

In addition, these two materials also have the following disadvantages: the bending direction is affected by the direction of the light source, which will cause inconvenience in design under certain application requirements; the photoactive groups are exposed on the surface of the material, which is easy to deteriorate and fail

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