Study On Fabrication And Multifunctional Applications For Superhydrophobic Photothermal Materials

Superhydrophobic photothermal materials have shown excellent research value and application prospects in the fields of anti-icing of buildings,cleaning of industrial wastewater,drag reduction of ships,anti-fog of vehicles,high-temperature sterilization,and solar steam power generation,which are of great significance for alleviating energy and environmental problems.However,the complex preparation and single function of superhydrophobic photothermal materials do not conform to the development trend of efficient green manufacturing,nor can they meet the needs of multifunctional devices in the rapid development of science and technology currently.For different multifunctional application scenarios,it is necessary to design and optimize the fabrication method of superhydrophobic photothermal materials.Therefore,this dissertation is based on the realization of the superhydrophobic surface and photothermal properties of the material,using the simple and efficient spray coating and dip coating as the main fabrication methods,combined with chemical modification and surface engineering design to obtain superhydrophobic photothermal materials,and verified the performance of materials in multifunctional and intelligent applications.The main content of this dissertation includes the following aspects:（1）To solve the problem of complex preparation of superhydrophobic photothermal materials,MXene-based superhydrophobic photothermal coatings were prepared by a simple method of spraying and fluorination modification.By designing MXene@Au plasmonic photothermal particles,the light absorption and photothermal conversion performance of the coating are effectively improved.When irradiated by an 808 nm laser with a power of 500 m W·cm^-2,the equilibrium temperature of the coating can reach121°C.By grafting fluorinated Si O₂ nanoparticles,the surface energy of the coating is greatly reduced and the rough structure on the surface is regulated,resulting in a stable superhydrophobic surface with a contact angle of 153°and a rolling angle of 4.5°.For corrosive solutions with p H ranging from 1 to 13,the coatings exhibited excellent superhydrophobicity.In the environment of low temperature and high humidity（-20°C,relative humidity 68%）,the coating achieved an ultra-long anti-icing time of 1053 s and a photothermal deicing efficiency of 73.1%.MXene-based superhydrophobic photothermal coatings obtained by surface fluorination have successfully realized multifunctional applications such as anti-corrosion,anti-frosting,anti-icing,photothermal defrosting and deicing.（2）For the environmental hazards of superhydrophobic photothermal materials prepared by fluorination,rough TiN@Polydimethylsiloxane（PDMS）micro-nano structures were formed on the sponge skeleton through the coupled self-assembly of TiN nanoparticles and PDMS,combined with an environmentally friendly and non-fluorinated surface engineering design,successfully realized TiN-based superhydrophobic photothermal sponge.The contact angle of the sponge surface is 160.5°and the rolling angle is 5.8°.The plasmon resonance enhancement effect of TiN nanoparticles makes the light absorption of the superhydrophobic photothermal sponge reach 97%,and enhances the photothermal conversion of the material.When illuminated by a sunlight-simulating light source with a power density of 100 m W·cm^-2,the surface temperature of the sponge can reach 116°C within 40 s.TiN-based superhydrophobic photothermal sponges have achieved multifunctional applications such as anti-corrosion,self-cleaning,and water-oil separation,and the fluorination-free fabrication method has greatly promoted the development of superhydrophobic photothermal materials towards an environmentally friendly trend.（3）To improve fluorination-free TiN-based superhydrophobic photothermal materials from static application scenarios to munfuncitional dynamic application scenarios,optically-driven TiN-based superhydrophobic photothermal paper and its multifunctional applications were studied.Using a simple and easy-to-operate spraying method,low-surface-energy TiN@PDMS rough hierarchical structures were attached to the filter paper to achieve superhydrophobic photothermal papers with refined surface engineering.The superhydrophobic surface reduces the resistance of the photothermal paper for optically-driven movement on the water surface.The efficient photothermal conversion performance of TiN-based superhydrophobic paper enables it to rapidly heat up and transfer heat to the liquid surface below the sample,forming a temperature gradient on the liquid surface,thereby effectively promoting the rapid generation of the Marangoni effect and surface tension gradient on the liquid surface.With the help of the Marangoni effect,the optically-driven TiN-based superhydrophobic photothermal paper has achieved a fast moving velocity(10.1 mm·s^-1)and fast response（0.8 s）.In addition,TiN-based superhydrophobic photothermal paper can perform optically-driven operations such as linear advancement,clockwise rotation,and counterclockwise rotation,and realize dynamic multifunctional applications such as transportation,moving to avoid obstacles,and cleaning oil stains on water surface.（4）For the problem that light-driven TiN-based superhydrophobic photothermal paper can only perform translational movement in multifunctional application scenarios,multi-angle deformable TiN-based superhydrophobic photothermal films and their multifunctional applications were studied.TiN-based superhydrophobic photothermal films with stable superhydrophobic surface and photothermal conversion properties were prepared by spray-coating TiN@PDMS on a low-density polyethylene substrate,and reversible photoresponsive deformation of the films between flat and bending states was successfully achieved.When irradiated by a low-power laser(150 m W·cm^-2),the temperature of the film increased by 71.5°C and the deformation angle reached 187°within 4 s.The photoresponse deformation of the superhydrophobic photothermal film was analyzed based on the thermal mismatch theory of the double-layer structure film,and the modulating effect of the photothermal conversion on the deformation angle was confirmed.For 500 cycles of photoresponsive deformation,the films exhibit stable superhydrophobic and photothermal conversion properties.Under the intelligent manipulation of light sources,deformable TiN-based superhydrophobic photothermal films have been successfully applied to amphibious robots capable of crawling on land and moving on water,as well as multifunctional application scenarios such as droplet manipulation and deformable robotic arms.