Construction Of Cellulose Based Super Wetting Material System And The Mechanism Of Oil And Water Separation

The oil spill events and various types of oil compounds seriously pollute soil resources and water resources,adhering to learning from the nature,people use bionics technology.to produce the super hydrophobic and super hydrophilic-underwater superoleophobic materials by using the principle of surface chemistry,But these materials have some problems:some materials are expensive and easy to be corroded,some have no large-scale use of recycled materials,such as poor performance;some modified methods are complicated,easy to cause secondary pollution;some material recycling performance are poor,not large-scale use,these defects limit the practical application of oil-water separation material.In this paper,we used cheap raw materials of cellulose as substrate materials,modified by a series of chemical on their surface,and prepared of superhydrophobic and superoleophilic oil-water materials,the main works as followed:?1?We used the cotton fabric of Xinjiang as the matrix material,built SiO₂ as roughness,with 3-?trimethoxysilyl?propyl methacrylate?TMSPMA?and 1-dodecanethiol?NDM?as monomers.The"thiol-alkenes"click reaction was a hydrophobic modifier to prepare the super hydrophobic cotton fabric.The cross contact angle detection showed the contact angle of water was 161±2 degrees.Through the study of oil and water separation we found that under normal pressure,the flux of the super hydrophobic cotton fabric was above 120 L/?h m²?,the separation efficiency was above 99%by separation floating oil,the super hydrophobic cotton fabric passed 20 cycles,the separation efficiency was still above 98.5%,and the optical display of the W/O emulsified oil was showned before and after the separation.Micromirror photo and DLS particle size analysis showed that the diameter of the emulsified oil before separation was about 1?m,and the particle size of the filtrate was reduced to about10 nm after separation,and the separation efficiency of the emulsified oil was above 98%,indicating that the super hydrophobic cotton fabric had a remarkable separation effect on the emulsified oil.?2?We used the cotton fabric of Xinjiang as the matrix material,the polyethylene glycol?PVA?was introduced on the surface of the cotton fabric.The super hydrophilic/underwater super oil cotton fabric modified by-C-O-C-bond was prepared by the acetal reaction and glutaraldehyde?GA?.The contact angle of the material was 159±1 degrees under the water.When addition of PVA was 4%,the separation efficiency could reach more than 99%.At the same time,the separation efficiency of the material was still more than 98%at pH=2,4,6,8,9,11,13,the separation efficiency of the materials was still more than 98%.The experiment was also compared to the super hydrophilic/underwater super oil cotton and super hydrophobic cotton fabric.The separation of high viscosity oil showed that the flux of super hydrophilic/underwater super oil cotton for all kinds of high viscosity oil was more than 120L/?h m²?,and the separation efficiency was above 98%.Through the analysis of optical microscope photographs and DLS particle size analysis of the separation of O/W emulsified oil before and after separation,it was known that the size of the emulsified oil before separation was about 1.5 um and the filtrate particle size after separation.lower than 20 nm,the separation efficiency of emulsified oil was above 99%.?3?We used the cotton fabric of Xinjiang as the matrix material,the SiO₂ as the micro-nano particles to construct the roughness.The cotton fabric was modified by the"click chemistry"method,and the Janus cotton fabric was prepared.The mechanism of the Janus cotton in the oil and water separation was studied.The contact angle of the cotton fabric that water surface was about 158±2 degree;the contact angle of the surface water to the oil was about 155±2 degrees.The separation efficiency of the water surface and the water surface of the Janus cotton fabric reached more than 98%.After 5 cycles,the separation efficiency of the Janus cotton fabric remained above 98%.?4?We analyzed and studied.the reasons for the difficulty in separating the emulsified oil and the low separation flux the specific separation material for different emulsified oils was designed by using the principle of electrostatic adsorption and separation.Using Xinjiang real cotton as raw material,cellulose/glass powder composite aerogels containing negative charge were prepared by the sol-gel method and freeze drying method.A positive charged cellulose/cyclodextrin microsphere polyelectrolyte brush composite aerogel,and the contact angles of the two composite aerogels on the oil were 158.7±2 and 155.5±2 degrees respectively.By investigating the density,porosity,separation flux,separation efficiency and DLS particle size analysis of the composite aerogels,it was indicated that when the amount of glass powder was 3%,the particle size of the cationic emulsified oil decreased from 1?m to80 nm,and the separation efficiency was more than 98%.When the adding amount of the polyelectrolyte brush was 5%,the separation particle size of the anionic emulsified oil decreased from 1?m to 50 nm.