Preparation Of Functional Materials Based On Cellulose Aerogel

Aerogel is a kind of new material with porous network structure.It has the characteristics of high porosity,large specific surface area,low density and so on.Cellulose aerogel has many unique properties,such as good biorenewable,good biocompatibility and biodegradability.Since the molecular structure of cellulose contains a large number of active hydroxyl,proned to sulfonation,esterification,etherification,crosslinking and chemical reaction.Therefore,it has potential applications in many fields,such as catalysis,separation,drug delivery,tissue engineering etc.Cellulose aerogel was prepared by freeze drying method through cellulose microfibrils(CF).In order to increase the mechanical properties of CF aerogels,chemical crosslinking of CF with silane coupling agent of vinymethyltrimethoxysilane(VTMO)was carried out.The as-prepared aerogel was well characterized by scanning electron microscopy(SEM),transform infrared spectroscopy(FT-IR),and mechanical test.The results show that the density of SA is 12.3 mg/cm3,the porosity is 99.6%,and water contact angle can reach 160 °.The stress-strain curve shows that a high mechanical properties of 62 KPa and compressive strain can be restored to 52.9%,and the specific surface area can reach 11.33 cm2/g.And its thermal stability is improved by 23 ° compared with the initial decomposition temperature of pure CF.Cellulose/Polymer composite material was prepared by a new method based on cellulose aerogel.We use vinyl-trimethoxysilane to obtain the hydrophobic SA aerogel.Two different methods were used to prepare the Polymer/cellulose composites.The first,erogel was immersed into the three monomer soultion containing AIBN initiator(methyl methacrylate monomer MMA,styrene St,butylacrylate BA)after in situ polymerization with the aerogel to achieve the polystyrene/cellulose aerogel composite material.The pore size distribution of the composite material is uniform,and the polymer is distributed around the pore size.The thermal stability of the polymer is higher than that of pure polymer,and its decomposition temperature can reach at least 400 °.The second,aerogel directly into the PMMA solution with blending,and then hot pressing to prepare the PMMA/cellulose aerogel composite materials.The surface of the composite film prepared by the method is smooth,and the cross-sectional area can be seen in the aggregate distribution in the cellulose microfibrils,and the thermal stability of the composite material is greatly improved.The study showed that the mechanical strength of silylated cellulose microfibrils/ PMMA composites increased first and then decreased with the increase of the content of SA aerogels.When the content of SA aerogels was 8%,the tensile strength of the composites reached the maximum is 31.8 Mpa.Thiol-ene click reaction had been designed to synthesize hydrophilic cellulose aerogel by grafting 3-mercaptopropionic acid(MPA)and cysteamine hydrochloride(Cys)on the silylated cellulose microfibrils aerogel surface.The as-prepared aerogel was well characterized by scanning electron microscopy(SEM),infrared spectrometer(FT-IR),and compression tests analysis.Results show that SA-MPA and SA-Cys aerogel had a high adsorption efficiency to remove dye,and the aerogel could adsorb the dye repeatedly.And this SA-MPA had a great potential in removing oil from oil/water emulsion and oil/water mixtures with a high separation efficiency.