Preparation method and application of bionic nano melanin photothermal sunlight protective agent

The invention belongs to the technical field of fine chemicals, and relates to a preparation method and application of a bionic nano melanin photothermal sunlight protective agent. The preparation method comprises the following steps: (1) preparing PDA-coated PEG nanoparticles: dissolving 0.06 to 0.1 g of polydopamine particles in 50ml of tris (hydroxymethyl) aminomethane hydrochloride with the pH value of 8.1 to 8.2, adding 0.08 to 0.12 g of mercapto polyethylene glycol, and then magnetically stirring in an ice bath in a dark place for 24 hours to obtain the PDA-coated PEG nanoparticles; (2) preparing PF-127 hydrogel: taking 20-30g of Pluronic F-127 particles, adding the Pluronic F-127 particles into 70-80ml of phosphate buffered normal saline at 4 DEG C, and magnetically stirring for 24 hours in an open manner at 4 DEG C, so as to obtain the PF-127 hydrogel; and 3) mixing and stirring: mixing 85 g of the PF-127 hydrogel at 4 DEG C with 15 g of the PEG (at) PDA nanoparticles, and magnetically stirring for 24