Preparation Of Superhydrophobic Composites Of CNTs And Its Application In Light-driven

Materials for stimuli-responsive actuators have broad application prospects.According to external stimulus sources,they can be divided into electrical,thermal,magnetic,and photoactuators,etc.Among them,photo-responsive actuators can utilize abundant solar energy and can be remotely and precisely controlled,green environmental protection and other advantages,has been widely concerned by researchers.The development of high-performance and multi-functional photo-actuators has important practical application value.In this paper,surface-stable and durable multifunctional superhydrophobic composites were successfully prepared by combining carbon nanotubes（CNTs）photothermal materials with substrates,introducing magnetic nanoparticles and low-surfactants,and spraying or suction filtration.Based on the Marangoni effect,the water surface controllable photo-driven can be realized by controlling the irradiation position of near-infrared light.The thesis consists of the following three parts:1.First,the CNTs were acidified to obtain ACNTs,and then the ACNTs were hydrophobically treated to obtain fluorinated CNTs（F-ACNTs）.Through a simple two-step spraying process,a layer of F-ACNTs was first sprayed on the surface of the filter paper,and then a layer of Fe3O4/PDMS was sprayed.Finally,a superhydrophobic composite with a multilayer structure was successfully prepared.The composite coating exhibits excellent selfcleaning properties with static contact angles as high as 159° and rolling angles as low as 3°.The hydrophobic properties of the composite coating were basically maintained after physical abrasion and chemical erosion tests,reflecting good surface stability and durability.The composite coating has excellent photothermal conversion performance,and the final temperature can be raised to the equilibrium temperature of 130℃ under the irradiation of near-infrared light.The composite material can be used as an opto-magnetic brake,and the near-infrared light radiation and external magnetic field can drive the controllable movement of the composite material on the water surface,and can be used for non-contact oil removal.2.The Fe3O4 nanoparticles were grown in situ on the surface of CNTs,and then superhydrophobic modified with octadecylamine（ODA）,and the superhydrophobic composite coated paper was prepared by a simple one-step spraying method.Compared with the fluorination treatment,the superhydrophobicity was further improved after amination treatment.PDMS not only reduces the surface energy,but also acts as a layer of "glue" to strengthen the interfacial interaction between CNTs/Fe3O4 nanoparticles and with the filter paper.The composite coating has fast photoresponse ability,and the temperature can be raised to 100℃ after 10 s of infrared light irradiation.The superhydrophobic properties and excellent photothermal conversion capability enable the composites to realize controllable light actuation on the water surface.In addition,the superhydrophobic coating can also be used to remove crude oil with high viscosity.3.A flexible self-supporting superhydrophobic ANFs/CNTs composite membrane was successfully prepared by layer-by-layer vacuum filtration by dispersing CNTs in dimethyl sulfoxide（DMSO）solution dissolving aramid nanofibers（ANFs）.The ANFs/CNTs composite film has excellent heat resistance,and the maximum weight loss rate temperature is as high as 520℃.The superhydrophobicity and the intertwined network of ANFs and CNTs ensure the surface stability and durability of the composite membrane.In addition,the excellent photothermal response enables the temperature to rise to 100℃ within 3 s under near-infrared light irradiation.When used as a surface controllable optical driver,the response time is only 0.3 s,and the good heat resistance can ensure the stability and reliability of the optical driver.