Preparation Of Polyelectrolyte And Hierarchical-structured Photothermal Materials And Investigation Of Anti-icing Application

Icing can bring convenience and joy to people but it can also cause serious consequences.Studying related phenomena and developing anti-icing materials are of great value in practical application.The process of ice growth on the interface mainly involves ice nucleation,via keeping supercooled water off the surface,inhibiting ice nucleation,growth and propagation,reducing ice adhesion,suppressing icing by heat generation or directly deicing,this paper achieves the purpose of anti-icing through the following ideas.(1)The patterned polyelectrolyte is prepared,and the nature of the interfacial water in the system is tuned by changing the type of counterion in the polyelectrolyte to effectively control the ice heterogeneous nucleation temperature and ice propagation behavior.The condensation water on the patterned polyelectrolyte brush surface can freeze quickly while the condensation water on other parts of the substrate surface remains in an unfrozen state,and ice only grows on the surface of the polyelectrolyte.By limiting the ice growth area and ensuring that most substrate surfaces are free of condensed water,an ice-free surface of up to 96%of the area can eventually be obtained.(2)Inspired by antifreeze proteins,a polyelectrolyte hydrogel with polydimethylsiloxane(PDMS)side chains was designed.The ice heterogeneous nucleation temperature is tuned by the type of counterions distributed on the interface;the ice propagation behavior of hydrated surface is affected by the proportion and diffusion of free water at the interface;unfrozen interface water can be used as a water lubricating layer to reduce the ice adhesion on the surface.The synergistic effect of hydrophobicity and ion specificity tunes the structure and proportion of the interface water,and simultaneously prevents ice formation on the surface through ice nucleation,ice propagation and ice adhesion.(3)Herein,a dual-templated method is used to prepare a hierarchical structure composite material of porous PDMS and reduced graphene oxide(rGO),the light absorptivity is enhanced by the dual-scale structure.Under one sun illumination(qi=1.0 kW m-2),the surface temperature of the material can rise to 77.6? at room temperature,and the freezing time can be delayed for up to 2 h at-40 ?.The ice adhesion strength on the surface can be reduced to 0.2 kPa.In the simulated real environment,the deicing rate reached 1.05 Kg m-2 h-1,and three different types of ice e.g.frost,fog and rain(thickness of ice coating less than 2 mm)can be melted within 300 s,various types of ice problems can be solved in diverse environments.