Preparation And Performance Study Of Polydopamine Hydrophobic Lipophilic Ramie Fiber Materials

Oil is an important energy substance.Marine exploration and freight transportation are an important way to obtain oil.However,during the mining and transportation process,unexpected marine oil spills will occur due to the influence of unstable factors such as man-made and environment.After the accident,corresponding emergency technologies and follow-up measures are required to deal with the cleanup of oil spills on the sea surface,and the cleanup process of oil spills needs to combine multiple measures.Among them,oil-absorbing materials have been continuously researched and developed as an essential emergency material.In this paper,the ramie fiber material was used as the substrate,and the low surface energy substances n-dodecyl mercaptan and octadecylamine were subjected to hydrophobic modification treatment using the bioactivity and adhesion of polydopamine.The modification method has the advantages of excellent economy,environmental protection,and simple preparation.By use of single factor and orthogonal experiments,the optimal experiment conditions for preparing n-dodecanethiol-modified hydrophobic ramie fiber were temperature 30?,time 12h,buffer p H is 9.5,and dopamine concentration 4mg/m L,respectively.And The contact angle for water is 144°,when the optimal conditions for preparing octadecylamine-modified hydrophobic ramie fiber were temperature 50?,time 14h,buffer p H 9.5,and octadecylamine concentration 12mmol/m L.the contact angle of the material for water is 143°.Using the analysis of SEM?EDS?FTIR?and TGA,the surface morphology and functional group changes of the material before and after modification were characterized and analyzed.The results showed that the surface of the material became rough and wrinkled,hydrophobic coating was clearly attached,and hydrophobic long chains-CH₃ and-CH₂ appeared.Based on the Cassie-Baxter wetting model,the contact angle data measured before and after the modification treatment was analyzed using the least square method.The analysis results showed that after the modification treatment,the material changes from wetted state to non-wettable state for water,showing hydrophobic properties.There was no significant change in oil infiltration before and after modification.By fitting the one-dimensional linear regression equation of surface tension and contact angle data,it was found that the modified material had wetting performance to liquids in a specific surface tension range,and also be applied to the adsorption treatment of organic solvents.Through dynamic environmental simulation adsorption and environmental adaptability analysis,experimental results showed that the oil-water system p H changes will affect the hydrophobic properties of n-dodecyl mercaptan modified materials.Octadecylamine modified materials show more stable performance than that of n-dodecanethiol modified materials.