Preparation And Research On Flexible Transparent Mxene-Based Film With Photothermal Energy Conversion Performance

Transparent heating film has a wide range of application value in aerospace,transportation,medical and health and other fields.Due to high cost,high rigidity and other disadvantages,the traditional metal oxide-based transparent heating film has been unable to meet the current market requirements for the integration and flexibility of the transparent heating film.With the continuous development of green chemistry,new nanomaterials with light-to-heat conversion properties have brought new application prospects for transparent heating films.Transition metal oxide or nitride(MXene),a new type of two-dimensional material with excellent photoelectric properties and high efficiency of photothermal conversion performance,has been widely studied as a photothermal conversion material and has broad application prospects.However,due to the shortcomings that MXene is easily oxidized and greatly affected by the environment,research in the field of photothermal conversion has been stagnant.Therefore,the development of a low-cost,multi-application scenario,high light-to-heat conversion efficiency MXene-based flexible transparent heating film has important practical significance.In this paper,a flexible transparent heating film with high light-to-heat conversion efficiency is prepared by simple modification and the use of surface coating methods based on two-dimensional MXene nanomaterials.The main contents include:(1)The surface of MXene was modified with polypyrrole(PPy)to synthesize MXene@PPy with high light-to-heat conversion efficiency,and then sprayed uniformly on the surface of flexible and transparent polycarbonate(PC)film with the help of spraying equipment,thereby preparing flexible and transparent light-to-heat conversion PC/MXene@PPy(MP-PC)film.Due to the synergistic light-to-heat effects of MXene and the attached PPy nanoparticles,the obtained MP-PC film can achieve better photothermal conversion performance(100 m W/cm²,47.5 ^oC)at a lower spraying density of MXene@PPy and thus show an effective transmittance(51.61%@550 nm).Besides,arising from the excellent surface electrical resistance(413(?)/sq),the MP-PC film also exhibits an effective Joule heating capacity with a high heating temperature of 108°C at 24 V input voltage.As one of the promising applications,the MP-PC film exhibits the effectiveness and feasibility as a light-triggered thermal therapy film for human skin in cold environments.(2)Aiming at the high heat loss of the photothermal film,the polydimethylsiloxane(PDMS)mixed with high photothermal conversion efficiency of Fe₃O₄ was successfully prepared into PC/MXene/PDMS@Fe₃O₄ multilayer film with the spin coating process.By adjusting the content of Fe₃O₄,a light-to-heat conversion film with high transmittance was obtained.The results show that under the protection of the PDMS@Fe₃O₄ coating,the photothermal conversion temperature of the PC/MXene/PDMS@Fe₃O₄ film under a sunlight intensity reaches 72.6 ^oC,and the transmittance at the wavelength of 550 nm is increased to 54.2%.Electric heating experiments show that the equilibrium temperature of the PC/MXene/PDMS@Fe₃O₄film reaches 62 ^oC under a voltage of 12 V.Through a simple greenhouse model test,the obtained film shows excellent performance(32.2 ^oC).The application of film in the field of greenhouses has broad prospects.