| The ocean and freshwater cover 71%area of the earth.It not only gives birth to the life but also stores abundant resources.The development and utilization of resources have been transformed from land to ocean due to the shortage of land resources.The influences of oily sewage to the marine environment are becoming more and more obvious.Traditional oil-water separation materials cannot meet the requirements of modern economic development.Therefore,advanced and green materials are needed in urgent to meet the requirements of sustainable development in the process of development and utilization of marine resources.Meanwhile,higher performance materials are needed due to the harsh marine environment.In this paper,we fabricated two kinds of special wettable surfaces by the micro and nano morphology construction and chemical modification.We studied the relationship between the wettability and the micro and nano morphology construction and chemical modification.We further investigated the special wettability in the application of oil-water separation,drag resistance,anticorrosion and self-cleaning.A superhydrophobic and superoleophilic polyurethane?PU?sponge was synthesized via an environmentally friendly surface grafting of a polymer molecular brush for oil spill cleanup and recycle.Compared with the unmodified PU sponge,the prepared PU sponge exhibited superhydrophobicity with water contact angle of 152°,superoleophilicity with oil contact angle of 0°,high oil absorption rate and high oil absorption capacity of 23 times of its self weight.The prepared PU sponge had high oil retention of 93%which can avoid secondary pollution during the recycling of saturated sponge.A quick clean-up of marine spilled oil/organic solvents on or under the water surface and the separation/recycling of an oil–water mixture/emulsion can also be achieved.In addition,the prepared PU sponge owned high mechanical strength and good recyclability?more than 400 times?.To avoid the heavy,complicated,time-consuming,toxic work and damage of superhydrophobicity and mechanical strength of the three-dimensional porous adsorbing materials,a porous unmanned ship?PUS?was fabricated with properties of superhydrophobicity,superoleophilicity,and low drag by imitating the structure of nonwetting leg of water strider.The superhydrophobicity of the PUS is stable with water contact angle of 158°and sliding angle of 5°.The PUS can hold a force of?14times the weight of the PUS without piercing the water surface due to its superhydrophobicity.When the PUS contacts with oil,the oil is quickly pulled toward and penetrates into the PUS automatically due to its superoleophilicity.The superhydrophobicity and low water adhesion force of the PUS surface endow the PUS with high oil recovery capacity?above 94%?and drag-reducing property?31%at flowing velocity of 0.38m/s?.In addition,the PUS has good corrosion resistance and reusability.We fabricate superhydrophobic surface with ultra low water adhesive force on various metals for enhanced corrosion protection.The superhydrophobic surface is constructed by passivated ZnO and low surface energy polydimethylsiloxane?PDMS?.The superhydrophobicity of as-prepared surface is stable with water contact angle of154°and sliding angle of 7°.The results of surface adhesive force shown the as-prepared surface had an extremely low adhesive force of 0.0062 mN to water which could suppress the corrosion liquid condensation on the metal surface.The results of salt spray test and electrochemical measurement reveal that the ultra low water adhesive force of the superhydrophobic surface can effectively inhibit corrosion.We fabricate a cellulose sponge with stable superoleophobicity(?oil>150°)under water and superhydrophilic wettability(?water?0°)under oil without any further chemical modification for oil-water emulsion separation.The cellulose sponge shows superoleophobicity to various oils under water and possesses stable superoleophobicity in corrosive liquids like strong acid,alkali and salt solution.The sponge is made from the dissolution and regeneration of cellulose powder which is green,low cost,simple and easy to scale up.The natural hydrophilicity of the cellulose ensures its excellent under-water superoleophobicity and antifouling properties.The double layer construction of different pore sizes,which contains a top-layer with a pore size lower than 1?m and a sub-layer with a pore size larger than 3?m,ensures that the oil phase is resisted and the water phase easily and quickly permeates the sponge.Our cellulose sponge can separate oil-water mixtures,with>99.94%separation efficiency,solely using gravity and has excellent antifouling properties. |
PDF Full Text Request