Preparation,Structure And Properties Of Eye Thermal Management Materials Based On Photothermal And Radiative/Evaporative Cooling

With the increasing development of modern life,human eyes and skin are underthreat from diseases,lasers,dehydration,bacterial infections and high/low temperature imbalance.The development of materials for the management of ocular heating/cooling is of great significance for the adjunctive treatment of related ocular diseases and the effective protection of the eye.In this paper,multifunctional wearable contact lenses with photoheating ability and polymer composite film materials with passive（radiation/evaporation）cooling ability were designed and fabricated respectively based on the thermal management of eye heating/cooling.And its photothermal conversion performance,laser protection performance,radiative cooling performance,evaporative cooling performance in-depth research,the main contents are as follows:（1）Ti₃C₂T_x MXene nanosheets were prepared by etching Al atom layer in Ti₃Al C₂using HCl and Li F in-situ synthesis HF method.By simple spraying method,Ti₃C₂T_xMXene with different concentrations was sprayed on the surface of commercial contact lenses,and MXene modified multi-functional photoheating contact lenses（M-contact lenses）were prepared.The transmittance of the M₃₀-contact lens sprayed 30 times remains high,with a transmittance of 74%at 550 nm.Under the irradiation of infrared physiotherapy lamp,the surface saturation temperature of M-contact lens reached 65℃,and the inner surface temperature close to the simulated eyeball reached 39.5℃,showing excellent photoheating performance.M-contact lenses show good photothermal conversion performance in rabbit eyes in vitro/in vivo,and can effectively enhance the blood flow of rabbit anterior segment vessels and improve the degree of vasodilation after infrared light irradiation.In addition,M-contact lenses show good water retention and laser protection.The water vapor transmission rate of the water retention evaluation was 0.088 g cm^-2 d^-1,which was 6.3%lower than that of ordinary contact lenses.At the same time,M-contact lenses have good antibacterial activity against common Escherichia coli（E.coli）and Staphylococcus aureus（S.aureus）,which is easy to infect the eye.Furthermore,the MXene lamella demonstrated a reliable biosafety profile,confirming the biosafety of M-contact lenses during wearing.（2）Porous polydimethylsiloxane（PDMS）films were prepared by sodium chloride（Na Cl）template method.The average emissivity at atmospheric window（8～13μm）is as high as 94.35%（the average infrared emissivity of pure PDMS films is 92.19%）.In the solar radiation band（0.28～2μm）,the average reflectivity is 26.66%（5.93%for pure PDMS film）.The porous PDMS film can effectively reduce the surface temperature of skin:in the refrigeration of eye skin,the highest cooling temperature of PDMS-0.5 film is 1.75℃,and the highest cooling temperature of arm skin is 0.67℃.In outdoor environment,porous PDMS film also shows excellent cooling effect,and the cooling temperature increases with the increase of pore density.In a sunny environment,the cooling temperature of PDMS-2 film is as high as 7.57℃,7.34℃higher than that of PDMS film（0.23℃）.（3）Through the organic combination of porous PDMS film and polyvinyl alcohol（PVA）hydrogel,a double-layer polymer film（P-PDMS-x）with both radiative cooling and evaporative cooling was prepared.Compared with the single porous PDMS film,P-PDMS-x film can reduce the surface temperature of skin more effectively:in the refrigeration of eye skin,the highest cooling temperature of P-PDMS-0.5 film reached2.71℃,and the highest cooling temperature of arm skin reached 3.13℃.In outdoor environment,P-PDMS-x film also has excellent refrigeration effect:in sunny environment,the cooling temperature of P-PDMS-0.5 film is as high as 10.01℃,which is 2.56℃higher than that of PDMS-0.5 film（7.45℃）.