The Synthesis Of Functional Materials Based On Nanocellulose And Their Applications

Cellulose,as the most widely distributed natural ploymer with largest storage capacity,is a kind of renewable precious resource which has been not fully utilized by human beings.Because of lots of advantages,such as high crystallinity and high mechanical strength,large specific surface area and excellent biodegradability and biocompatibility,nanocellulose has good application prospect in the field of drug delivery,paper making,catalysis,adsorption and energy materials.In this work,cellulose nanocrystals?CNCs?were prepared from the microcrystalline cellulose?MCC?by hydrochloric acid hydrolysis under hydrothermal condition.CNCs presented a rod-like structure,200-300 nm in length and 10-50 nm in width by transmission electron microscopy?TEM?.Disperse dye microcapsules were simply prepared by interfacial polymerization of Hexamethylene diisocyanate?HDI?and ethylenediamine in the system of Pickering emulsion stabilized by CNCs.The disperse dye microcapsules showed the irregular and elliptical microspheres with the diameter of 30 ?m by scanning electron microscopy?SEM?and particle size test.It demonstrated that HDI had reacted completely with ethylenediamine by FTIR analysis.The initial decomposition temperature of disperse dye microcapsules is about 200? by thermogravimetic analysis?TGA?and absolutely can meet the requirements of high temperature and high pressure dyeing.The disperse dye microcapsules were subsequently applied on the high temperature and high pressure dyeing of polyester fabrics and excellent dyeing performance was achieved.The dyeing performance tests showed that,both the crocking and washing fastness of polyester fabrics dyed by the disperse dye microcapsules were equal with or slightly higher than that of polyester fabrics dyed by commercial disperse dye.Most importantly,the absorbance values of dyeing waste water from microcapsules were much lower than that fromthe commercial disperse dye.Super water absorbent cellulose nanofibril?CNF?aerogels with chemical crosslinking and high mechanical strength were prepared by utilizing carboxyl modified CNF as raw material.CNF presented a linear structure,10-30 nm in width and several microns even more than a dozen microns in length by TEM.CNF aerogels showed a porous network structure consisted of sheet-like cellulose and size of pores is between 10 and 50 ?m by SEM.The density and porosity of CNF aerogels can respectively reach as low as 7.6 mg.cm^-3 and more than 99%.CNF aerogels also have high surface area(9.35 m².g^-1)by BET test.The chemical crosslinking CNF aerogels have the excellent water absorption and recycling performance.Their water absorption values can reach as high as 107 g.g^-1 and would maintain above 95% of the initial water absorption value after 20 times.