Preparation Of Super-Wetting Shape Memory Sponge And The Application In Oil/Water Separation

The discharge of oily wastewater in life and industrial production and the leakage during oil extraction not only harm the ecological environment,but also threaten the life safety of humans and other organisms through the food chain.At present,scientists have a relatively systematic understanding of oil-water separation,and have also given many satisfactory designs and ideas from the aspects of material substrate and surface chemical modification.In general,most of the focus of intelligent oil-water separation materials is how to achieve intelligent control of surface wettability,but pore size is also an important factor affecting oil-water/emulsion separation,and there are few reports on intelligent control of pore size.In this paper,super-hydrophobic shape memory polyurethane sponge?SMP-TPI/PU sponge?and super-hydrophilic shape memory polyurethane sponge?SMPTPI/PDA/PEI PU sponge?were prepared on the basis of polyurethane?PU?sponge,and the modified sponge applied to the separation of common incompatible oil-water mixtures and emulsions.The specific research contents are as follows:First,we successfully prepared a super-hydrophobic SMP-TPI/PU sponge,using a simple impregnation method with a three-dimensional porous PU sponge as the substrate,and a shape memory polymer TPI?trans 1,4-polyisoprene?as a modifier.This paper proposes a method of combining PU sponge with shape memory polymer TPI,and successfully realized the idea of fixing PU sponge deformation.The study found that the TPI-PU sponge has a pore structure before flattening,and its surface wettability is superhydrophobic,which can realize the adsorption of heavy oil and floating oil in water,and the adsorption performance does not decrease within 5 cycles,and could absorb 80 times than their own weight of oils.After flattening,the pore size of SMP-TPI/PU sponge becomes smaller,which is suitable for demulsification of various water-in-oil emulsions.Secondly,we successfully prepared super-hydrophilic SMP-TPI/PDA/PEI PU sponge with SMP-TPI/PU sponge as the substrate and PDA/PEI as the hydrophilic modifier to achieve the change of TPI-PU sponge surface wettability.The change in surface wettability has expanded the application of shape memory sponges.The hydrophilicity of the surface remains stable at 70?,ensuring that its wettability does not change when heated at 70?,and thus does not affect the study of oil-in-water emulsion separation.However,it is unstable in the environment of strong acid or strong alkali,indicating that the super-hydrophilic SMP-TPI/PDA/PEI PU sponge cannot be used for separation under extreme conditions.In order to explore the demulsification of superhydrophilic SMP-TPI/PDA/PEI PU sponge to oil-in-water emulsion,we used cetyltrimethylammonium bromide?CTAB?,sodium lauryl sulfate?SDS?,Tween 20 are emulsifier,toluene,n-hexane,n-heptane are organic solvents which to obtain nine oil-in-water emulsions.The results show that the super-hydrophilic SMP-TPI/PDA/PEI PU sponge is suitable for the demulsification of each of the above emulsions,its flow rate exceeds 1500 L^-1m^-2h^-1,and the separation efficiency is close to 95%.