Preparation Of Nanofibrillated Cellulose Gel Ang Research Of Oil/water Separation Performance

In the context of the global consensus on renewable resources,the rational development of wood resources has attracted the attention of many researchers.Nanocellulose can be separated from biomass materials,and aerogels with excellent properties can be developed by its high aspect ratio,good biocompatibility and high strength.By transmission electron microscopy(tem),scanning electron microscope,X-ray diffraction and other equipment in the process of preparation of nano cellulose aerogels micro structure of each composition,crystal structure characterization and analysis,through the determination of nano cellulose aerogels maximum bearing capacity,durability test and contact Angle measurement of different solvents and the micro/nano particles in solution containing different types of filtration separation of nano cellulose oil-water separation mechanism and interception performance of micro/nano particles.The main results of this study are as follows:(1)Using poplar wood powder as the raw material for the preparation of nanocellulose,the nanocellulose obtained by chemical pretreatment combined with the fibrillation process of ionic ultrasound has the advantages of high aspect ratio,strong reactivity and easy assembly.A series of nanocellulose aerogels were obtained by freeze-drying nanocellulose solutions with different concentrations after 12 hours of pre-freezing.The process plan of nanocellulose aerogels with the best oil-water separation effect was explored by changing the dosage and concentration of nanocellulose.(2)Using transmission electron microscopy,scanning electron microscope,X-ray diffractometer,contact Angle tester on the micro structure of nano cellulose aerogels and characterizing the structure and wettability analysis,it is found that nano cellulose aerogels with ultra high porosity,and it has special wettability,after being distilled water wetting,because water oleophobic performance and good ability of underwater hydrophobic oil can use its own gravity driven oil and water filtration separation of oil-water mixture is achieved,fast separation,the separation efficiency can reach 100%.(3)The oil-water separation performance of nanocellulose aerogel under severe conditions was studied.Through configuration of hydrochloric acid,potassium hydroxide solution,sodium chloride solution and oil mixture,the research of nano cellulose aerogels separation velocity and separation efficiency,experiments show that different PH does not affect the separation speed of nano cellulose aerogels,also does not affect the durability,the separation speed drop is similar with distilled water,drop ratio,separation efficiency always keep 100%.Dichloromethane,dichloroethane and carbon tetrachloride have very little difference in the contact Angle values under six different environments.The wetting condition of nanocellulose aerogel under water is almost unchanged,and it has been in a state that it cannot be wetted.The hydrophobic property of nanocellulose aerogel under water has universality and stability.The study on the continuous oil-water separation performance of nanocellulose aerogel shows that it can separate 1975 ml oil-water mixture in one time,and the separation effect is 19515g/g,which can be used for continuous separation of oil and micro-nano particles.(4)The filtration and separation performance of nano-cellulose aerogel on six kinds of water suspensions containing micro-nano particles,including nano-iron trioxide,nano-barium titanate,nano-titanium dioxide,nano-silicon carbide,silver nanowire and nano-iron oxide,was studied.Nanocellulose aerogel has a high separation efficiency and separation speed for micro-nanoparticles.With the increase of the size of nanoparticles(silver nanowire>iron tetroxide>iron oxide>barium titanate),the separation speed increases in turn,and the micro-nanoparticles will not block the pores of the aerogel and can be reused.