A composite film with reversible light control hydrophobicity and its preparation method

Abstract

The invention discloses a reversible light-controlled hydrophobic azobenzene fluorine-containing copolymer / nano-SiO 2 A composite film and a preparation method thereof, the preparation of the composite film comprises the following steps: (1) trifluoroethyl methacrylate and acrylic acid ester monomers containing azophenyl groups are used in a molar ratio of 10:1 to 1: 10 is added in the solvent a; azobisisobutyronitrile is used as an initiator to carry out free radical solution polymerization; the polymer generated by the reaction is repeatedly dissolved, precipitated, and then dried to prepare a binary random copolymer; (2 ) dissolving the binary random copolymer of step (1) in solvent b to obtain a copolymer solution; adding nanometer SiO in the copolymer solution 2 , so that nano-SiO 2 The content is 0.1-10wt%, ultrasonically treated, spin-coated on the substrate, and dried to form the composite film. The preparation method of the present invention is simple, and the reversible change range of the hydrophobicity of the prepared composite film is large, and the interface strength is high, which is especially suitable for the preparation of photoresponsive materials.

Description

technical field The invention relates to the technical field of preparation of stimuli-responsive materials, in particular to a reversible light-controllable hydrophobic composite film and a preparation method thereof, in particular to a reversible light-controllable hydrophobic azobenzene-based fluorine-containing copolymer / nano SiO 2 Composite membrane and method for its preparation. Background technique Stimuli-responsive materials are a class of materials that can produce "smart" responses to external stimuli. It can receive stimuli from external environments such as pH, light, temperature, redox agents, and voltage to change its molecular structure or state, thereby affecting its physical and chemical properties, and then exhibiting corresponding intelligent responsiveness. Stimuli-responsive polymers have broad application prospects in the fields of nanomaterial science, life science and clinical medicine. Compared with other stimuli-responsive materials, photoresp...

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Problems solved by technology

At present, the methods of preparing photoresponsive materials using polymers containing azobenzene mainly include electrostatic self-assembly, surface graft copolymerization and LB film technology, etc., but the wettability of the azobenzene film prepared by the above method changes before and after ultraviolet light irradiation The change of the contact angle is only about 10°, which seriously restricts the application of azobenzene film as a photoresponsive material; moreover, due to the low content of azo molecules on the surface, the isomerization process is affected by the polymer chain segment, resulting in The photoresponse speed of the prepared azobenzene film is slow

In addition, the above methods generally rely on rough substrates made of other materials to obtain superhydrophobicity. The preparation process is relatively complicated, and it is difficult to obtain a surface with uniform properties and high mechanical strength. After repeated irradiation, the film surface is prone to damage.

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