Preparation And Performance Of Functional Materials From Biomass-based Nanoparticles

Due to their abundance,high strength,stiffness,renewable and biodegradability,nano-scale biomass nanoparticles(nanocellulose and starch nanocrystals)are widely used in the preparation of functional materials.Derived from their enhancement,the presence of the nano-scale biomass nanoparticles in the polymeric materials can achieve the purpose of improving the mechanical,thermal,barrier properties.Focusing on the goal of high value utilization of biomass resources,we are devoted to carrying out physical and chemical modification of biomass nanoparticles and promoting its application in environment-friendly materials and high-valued materials.Inspired from the concept of organic-inorganic hybrid,we proposed the utilization of modified cellulose nanocrystals(Si-CNC)and red mud(RM,from the industrial waste)to fabricate the composite aerogels as the potential construction materials with the multifunction of adsorption,thermal insulation,acoustic resistance and inflaming retarding.At the equal loading level of Si-CNC and RM(1:1,w/w)components,the obtained aerogel was chemically crosslinked by the diisocyanate to enhance its structural stability and mechanical property,exhibiting the improved compression modulus of 3.7 MPa together with the high porosity(98.8%)and specific surface area(73.23 m~2/g).The composite aerogel Si-CNC/RM-1/c possessed the significant functional performances on the magnetic conductivity,rapid oil adsorption of 30 times weight as itself,20.8%reduction of thermal conductivity,24.5%increase of sound-absorption coefficient,and high-efficiency self-extinguishing behavior within 2 s.Utilizing the high crystallinity and stiffness of cellulose nanocrystals and the semi-flexible chain structure of cellulose nanofibrils,cationic cellulose nanocrystals(CCNC)and cationic cellulose nanofibrils(CCNF)with surface positive charges were prepared by cationic modification.Through the combination of cationic nanocellulose and anionic sodium alginate to form aerogel and chemically and ionically double crosslinked with hexamethylene diisocyanate,the mechanical properties of the composite aerogel are greatly enhanced based on the synergistic effect from the enhancement of CCNC and CCNF.A multifunctional composite nanopaper was developed based on soy protein isolates(SPI)from the synergistic reinforcement of sheet-like graphene(RGO)and platelet-like starch nanocrystals(SNC),providing conductive function as well as enhanced mechanical and barrier properties.As a highly-crystalline and rigid nanoparticle derived from natural polymer,the introduction of SNC improved the dispersion of graphene nanoparticles at the relative ratio of 15/1(SNC/RGO,w/w),and therefore promoted the electrical conductivity of the composite nanopapers under various humidity atmospheres.The proposed strategy of dual-enhanced fillers(with molecular interaction)in the composites can provide remarkable improvement of the properties,with simultaneous strengthening and toughening,water vapor and oxygen permeability reduction,water absorption reduction and solvent resistance.