Study About Flexible Surfaces With Condensate Microdrop Selfpropelling Functionality Based On Carbon Nanotube Films

Condensation widely exists in nature and industrial production.The retention of condensate on the surface of traditional materials will cause problems such as surface corrosion,icing and frosting,and reduced heat transfer efficiency,which seriously affects industrial production efficiency and equipment stability.Inspired by condensed self-transport functional biological surfaces,a novel superhydrophobic surface with condensed droplet selfdisplacement(CMDSP)function can effectively solve these problems.But these biomimetic surfaces are constructed on rigid substrates,and there are still few reports on the self-drive of condensed droplets from functional surfaces.Herein,we use carbon nanotube film(CNTF)as a flexible substrate,biomimetic nanostructures were prepared on this flexible substrate by electrodeposition method,and the functions of self-drive-off and anti-icing of condensed droplets were obtained;in-depth research on flexibility,surface nanostructure and surface chemistry The synergistic regulation and influence of condensed droplets on the self-expulsion behavior of condensed droplets,the combination of theory and experiments revealed the structure-property structure-property relationship,and realized the icing delay on the surface of flexible nanostructures.Electrothermal anti-icing performance.The relevant results obtained from the above studies will help promote the development of flexible functional surfaces and the exploration of new applications of carbon nanomaterials.The main contents of the research in this paper are as follows:(1)First,numerical simulations were used to predict that the tip of the triangular cone is easier to condense,and optimal nanostructure for condensation was obtained as needle cones shape based on these simulation results,and conclusion was used to guide the shape of nanostructures prepared in subsequent experiments;and theoretical simulations also predicted that CNTF has ultra-fast water evaporation characteristics under light conditions compared with copper materials,and this conclusion was used to design and obtain the photothermal anti-icing function in subsequent experiments.(2)Next,a novel CNTF-based flexible superhydrophobic surface was prepared using electrodeposition and chemical bath to construct ZnO nanoneedle cone structures on the CNTF surface,which achieved the selfrepelling function of condensation droplets with a surface contact angle of ～154 °.The CMDSP function was stable after one thousand bends of the flexible substrate.The nucleation density of condensation microdroplets on the surface of ZnO nanoneedle cones obtained at a growth time of 30 min was the largest,the repulsion diameter was smaller,and the self-ejection frequency was faster by changing the growth time of the chemical bath to modulate the nanoneedle height and thickness.It was found that the conformational relationship of the needle tip structure on the regulation of CMDSP function was obtained,and a flexible surface with optimal CMDSP function was obtained.(3)Further,the anti-icing performance of the functional surface with optimal CMDSP is explored.This functional film has significantly better antiicing performance than pristine CNTF at low temperature,whether in a flat state or not,and the delay time of icing on the surface at-5 °C can reach about50 min.Micro-scopic observation of the icing process on the surface of the films showed that the films with nanostructures delayed the icing time by merging the condensed microdroplets and then detaching from the surface.This indicates that the tightly arranged nanostructures can reduce the pegging of condensate on the surface and thus delay the icing.(4)Finally,the exploration of photothermal anti-icing and electrothermal anti-icing properties of functional surface of optimal CMDSP was continued.The functional films have excellent light absorption and high energy transfer efficiency(76.71%).The flexible CMDSP film has strong photothermal antiicing/de-icing performance.The icing delay time was able to exceed 4 h under4406 Lux illumination,even at a low temperature of-5 °C.This excellent property was attributed to the microdrop self-repelling function on its surface and the ultra-fast evaporation mechanism of the substrate carbon nanotube film.