Research On Underwater Superoleophobicity Of Patterned Double-network Hydrogel Films

Interface materials with special wettability have always been one of the hot research topic in recent years,especially the interface materials with underwater oleophobic,even superoleophobic properties.This kind of underwater oleophobic surface has potential applications in the fields such as anti-biofouling,oil-water separation,and oil droplet control.At present,the researchers have used a variety of materials to prepare different kinds of underwater oleophobic materials.However,the current underwater oleophobic materials often have the problems such as complicated preparation process,poor mechanical properties,and poor long-term stability of antifouling performance,which restricts the real applications of these materials.To solve these problems,this dissertation aims to develop a kind of underwater oleophobic materials based on patterned double-network hydrogel,with the expectation to improve oleophobic properties,mechanical strengthes,and antifouling performance.We used a two-step method to prepare the patterned double-network hydrogels doped with the nanoclay.First,polystyrene porous films with honeycomb structures as the sacrificial template were prepared by using the Breath Figure method,and the two-step gelatinization reaction was achived by filling the porous structure of polystyrene templates with the precursor mixture containing sodium alginate(or chitosan),nanoclay,and other reactant.Finally,patterned double-network composite hydrogels were obtained by the removal of the polystyrene template through dissolving.This approach should be able to improve the performance of the materials by combining patterning,double-network structure,and nanoclay doping.Sodium alginate and chitosan that form the first network are natural macromolecule with hydrophilic properties,and the crosslinking of acrylamide monomers with N,N'-methylenediacrylamide and nanoclay results in the second network.The contact angle test showes that the patterned structures derived from the honeycomb structures could improve the underwater oleophobic properties of the double-network hydrogels.The underwater contact angles of the hydrogels tested with various oil droplets reachee up to 155o or higher.The nanoclay doping has no significant effect on the underwater oleophobic properties of hydrogels.The compressive stress-strain curves show that the nanoclay doping can further improve the mechanical properties of double-network hydrogels.The test on the antifouling performance showes that both the nanoclay doping and patterning are beneficial to preventing the adhesion and aggregation of Chlorella Vulgaris on the surface of double-network hydrogels.In conclusion,the patterned double-network hydrogel materials doped with nanoclaies show good underwater oleophobic properties,mechanical strength,and anti-biofouling performance.These studies could provide new routes for the development of novel underwater oleophobic materials based on composite hydrogels and their applications in areas such as marine antifouling.