Study On The Preparation Of Nylon Fabric With Special Wettability For Oil/water Separation

With the maturity of offshore crude oil extraction technology,the business volume of maritime transportation of crude oil is increasing gradually,accompanied by the occurrence of oil spills and the irreversible harm to the marine ecological environment.Therefore,special wettability materials that are derived from green raw materials,environmentally friendly and simple in use process have high-efficiency separation of oil/water mixtures have attracted more and more attention.Nylon mesh(PIM)is a polymer material with controllable porosity and good flexibility.Because of its good tensile strength,biocompatibility,and processability,it has become one of the most promising synthetic fibers.However,the poor hydrophilicity of PIM greatly limits the promotion and application of PIM as a special wettability material in oil/water separation.In this work,surface modification of PIM is used to prepare special wettability PIM materials,and the structure and performance of special wettability PIM materials are analyzed and studied.The specific work is as follows.First,in order to improve the surface energy and surface roughness of nylon fabrics,soluble starch and polydopamine(PDA)were used to modify the surface of PIM,the underwater superoleophobic PIM was named PDA/starch@PIM.PDA/starch@PIM’s underwater oil contact angle(OCA)can reach 153.8° to the chloroform,meanwhile,its wettability is resistant to harsh physical and chemical environments,indicating the stability of the hybrid coating.The separation efficiency of PDA/starch@PIM for oil/water mixtures is over 99.5%,it can separate corrosive oil/water mixtures efficiently and quickly.After 60 cycles of oil/water separation,PDA/starch@PIM still maintains a high separation efficiency,and its recycling performance is excellent.Secondly,the Ce/Cu metal organic framework(MOF)is used to modify the nylon fabric to successfully make it underwater superoleophobic/superhydrophilic.The obtained modified sample is called Ce/Cu-PIM.The underwater oil contact angle of Ce/Cu-PIM exceeds 153°.After 24 hours of soaking in corrosive solution,hot water and cold water,respectively,it still has underwater oleophobicity,the bimetal MOF coating has good stability.The separation efficiency of Ce/Cu-PIM for oil/water mixture is higher than 98.5%.Even after 50 oil/water separation cycles,the Ce/Cu-PIM efficiency is still about 98%,which indicates that the prepared PIM has good oil/water separation performance.In addition,Ce/Cu-PIM has a separation efficiency of >98% for oil/corrosive solution mixtures,which shows that it has a high and stable oil/water separation function in a corrosive environment.Finally,the nylon fabric was modified by beeswax/attapulgite clay to make it have special wettability.The modified underwater superoleophobic PIM was named UWS-PIM,the concentration of beeswax/attapulgite clay was adjusted to obtain underoil superhydrophobic PIM,and name it UOS-PIM.UWS-PIM’s underwater oil contact angle can reach 155°,the hybrid coating has good stability,and it still maintains underwater oleophobicity in harsh physical and chemical environments.UWS-PIM has excellent oil/water separation performance and can efficiently separate light oil/water mixtures by gravity,corrosive oil/water mixtures can also be separated smoothly.After 50 cycles of oil/water separation,UWS-PIM has an oil/water separation efficiency of 98%,showing good recyclability.UOS-PIM has a hydrophobic angle of 155° under oil,its wettability has a certain degree of stability.