The Formation Mechanism And Performance Research Of Bamboo Cellulose Aerogels

Cellulose is one of biodegradable and renewable biomass resources.The cellulose content of bamboo ranges from 40 to 60%,which has extensive application because of its fast growth,short renovation,and easy propagation.It is also beneficial to environmental protection and sustainable management and has great development potential.In this paper,moso bamboo is considered as raw material.Great aspect ratio bamboo cellulose nanofibers(BCNFs)were obtained from moso bamboo via a combination of chemical pretreatments and subsequently ultrasonic treatments.The BCNF suspensions were subjected to solvent exchange,and composited with polyvinyl alcohol(PVA),freeze-dried to obtain BCNF/PVA bio-nanocomposite organic aerogels.Scanning electron microscope(SEM),Fourier transform infrared spectroscopy(FTIR),X-Ray diffraction(XRD),transmission electron microscopy(TEM),TG-DTG-DSC,compression test,contact angle experiment,BET specific surface area were employed to characterize bamboo cellulose treated with different processing stages and BCNF/PVA bio-nanocomposite organic aerogels.The mainly research work in this thesis are as following,1?The morphological structure,diameter distribution,crystallinity,functional group were studied systematically and the change of thermal stability of cellulose at various stages in the preparation process.As a consequence,the lignin,pectin and most hemicellulose of bamboo were removed after treatments.The color was turn from yellow to white,purified cellulose was obtained.The Selecta Sonopuls was employed to generate mechanical force via cavitation effect to achieve the purpose of open fiber,produce high aspect ratio BCNF and the average diameter is15.02 nm.2?The BCNF suspension liquid was subjected to water-ethanol-tert-butyl alcohol exchange,a certain quality of PVA was added,dissolving and freezing,freeze-dried to obtain BCNF/PVA bio-nanocomposite organic aerogels.The resulting BCNF/PVA aerogel,treated with methyltrichlorosilane via a simple thermal chemical vapor deposition process,was rendered both hydrophobic and oleophilic and the water contact angle is 136°.3?The condensed BCNF suspension liquid was freeze-dried to manufacture BCNF foam.Different quality of BCNF foam was added to the PVA solution,BCNF/PVA composite aerogel indifferent density can be gained by freeze drying,and to get the optimal amount of BCNF addition by a series of characterization and the optimal addition amount is 15%.