Study On Hydrophobic And Hydrophilic Property Of Modified Cellulose Aerogel

The microcrystalline cellulose was dissolved by NaOH/urea system and regenerated cellulose solution was obtained. The cellulose aerogels were prepared by sol-gel method. Cellulose aerogels were hydrophobic modified with octadecyl trichlorosilane（OTS）.The study showed a clear relationship between OTS consumption and contact angle.The SiO₂/TiO₂/cellulose composite aerogels were prepared by soaking method,and study its hydrophilic properties.cellulose/Fe2O3 composite aerogels and cellulose/SiO₂ composite aerogels were prepared for discussing their performance.Two kind of composite aerogels were hydrophobic modified with octadecyl trichlorosilane（OTS） to gain aerogels materials of better hydrophobic.For regeneration cellulose aerogels, the results showed that the sample was a type of cellulose Ⅱ with porous network-like structure by making use of SEM、XRD and FTIR. The density of aerogels is small,range for 0.0322～0.0478 g/cm3. regeneration cellulose aerogels have the larger specific and the smaller diameter.As to the hydrophilic modified cellulose aerogels, the SEM analyses indicate that it presen ted a net structure which is similar to the unmodified. The main difference between the two is t hat the hole in the structure of the hydrophobic modified is smaller than that of the unmodified cellulose aerogels. According to the FTIR result, the hydrophobic modified cellulose aerogels e xhibited characteristic peaks of Cellulose Ⅱ and Octadecyltrichlorosilane, which well agrees wi th the SEM results. Contact angle measurement indicates that higher deposition of Octadecyltri chlorosilane makes better hydrophobic property of cellulose aerogels, and all the samples prese nt good hydrophobic properties.As to the hydrophobic modified cellulose aerogels, the SEM analyses indicate that it prese nted a net structure which is similar to the unmodified. The deposition of SiO₂ and TiO₂ incre ases the hydrophilic property of aerogels and has no effect on the microstructure.According to t he FTIR result, the hydrophobic modified cellulose aerogels exhibited characteristic peaks of C ellulose Ⅱ、SiO₂ and TiO₂.For cellulose/ferric oxide composite aerogel, the analysis results showed that ferric oxides were doped in cellulose aerogel with porous network-like structure through the use of SEM、 FTIR、Energy Spectrum and XRD. The add of ferric oxide did not affect the microstructure of cellulose aerogels. Composite aerogels were hydrophobic modified with octadecyl trichlorosilane（OTS）. The porous network-like structure of hydrophobic composite aerogels remains unchanged. However, regeneration cellulose fiber was wrapped by octadecyl trichlorosilane（OTS） hydrophobic membrane,so that the pores between the fibers become samller. The results of contact angel test showed that the modified cellulose/ferric oxide composite aerogel was hydrophobic state.Hydrophobic cellulose/ferric oxide composite aerogels have broad application prospects in the field of water-oil adsorption.For cellulose/SiO₂ composite aerogel, the analysis results showed that silicon element is in composite aerogel with porous network-like structure through the use of SEM、FTIR、 Energy Spectrum and XRD.Polymeric silica dioxide lie on the surface of cellulose molecules with a continuous thin layer of silica gels. The add of SiO₂ did not affect the microstructure of cellulose aerogels. Composite aerogels were hydrophobic modified with octadecyl trichlorosilane（OTS）. The porous network-like structure of hydrophobic composite aerogels remains unchanged. However, the pores between the fibers become samller comparison with cellulose aerogels. The results of contact angel test showed that contact angels of modified regenerated cellulose/SiO₂ aerogels were more than 90°,and hydrophobic state was reached。 As the growth of SiO₂ consumption,contact angle increased gradually.Hydrophobic modification of cellulose/SiO₂ composite aerogels provide data to support the expansion of application.