Study On Graphene Derivatives/wood Cellulose Composite:Preparation And Performance

Graphene is a versatile material in various fields,of which the extensive application and scalable production are facilitated by the explosive researches on ite derivatives.Not only can be readily modified to form functional materials itself,the graphene derivatives can also combine other ingredients to result in novel composites.Especially the graphene derivatives/cellulose composite,which shows the excellent performance of the graphene derivatives,along with fully utilizing the naturally most abundant polymer-cellulose.In one word,“sustainable development” in science is achieved here to meet the demand for materials with astonishing properties.In this study,main derivatives of graphene,graphene oxide?GO?and reduced graphene oxide?RGO?,are researched as objects with nano cellulose.However,fabrication process,chemical structures,and corresponding mechanisms,etc are all addressed with details.Conclusions are listed as follows:GO was reduced by green chemical-glucose to give RGO,of which the adsorption on different types of dyes was further studied with the possible mechanisms.As shown in FTIR and Raman,the oxygenated groups in RGO was significantely decreased and proved the reduction of GO.However,to lower concentration of methylene blue,bromocresol green,and methy orange,the average adsorption capacity of RGO could be 47.5mg/g without obvious selectivity,but great recyclability.Moreover,the adsorption of MB onto RGO was found well explained by both the Langmuir isotherm model?R2=0.9826?and the pseudo-second-order equation?R2=0.9933?.Meanwhile,the maximum adsorption capacity was obtained as 95.05mg/g,with the adsorption velocity might be chemically monitored by the electrons within RGO and MB molecules.In addition,the adsorption was verified by the thermodynamics study to involve a spontaneous and favorable physisorption process?R2=0.9911?.Nano TiO₂ and GO were combined by a solvothermal process to give the nanocomposite,using both ethanol and water as the mixed solvent.The photocatalytic activity of the resultant on MB and the related mechanisms were all discussed.According the results of XRD,Raman,and FTIR,GO was surely reduced,as well as the chemical bonding between GO and Nano TiO₂.However,the photocatalysis experiment gave a view that the nanocomposite was endowed with as high R% as 93% on MB;though through 4 recycles,R% exceeded 80% could still be acquired.Furthermore,the obtained R% could get close to 64% if without light source radiation,together with the adsorption capacity of 32mg/g.In comparison to Nano TiO₂,the SSA of nanocomposite increased 38% to 56.08 m2/g;while it also possessed the highest light efficiency and hydrophilicity.The feasibility for tailored and integrated production of CNC with CNF from BEP fibers through prehydrolysis using a recyclable dicarboxylic acid were demonstrated here.Prehydrolysis experiments were conducted in ranges of maleic acid concentrations of 15-75wt%,temperatures of 60-120 °C,and reaction time of 5-240 min.Maleic acid esterified cellulose to result in caboxylated CNC and CNF.Furthermore,acid prehydorlysis that solubilized xylan and depolymerized cellulose substantially reduced energy input for producing CNF through subsequent mechanical fibrillation.A combined hydrolysis factor?CHF?as an acid prehydrolysis severity was developed to control xylan dissolution as well as cellulose depolymerization to map the entire reaction space.It was found that CHF can be used to control the morphological and chemical properties of the resultant CNC and CNF,independent of the individual reaction conditions.This is important for process scale-up design for tailoring the properties of CNC and CNF for specific applications.The low temperatures and short reaction times along with low energy input in mechanical fibrillation and recyclability of maleic acid make the presented process promising for low cost and sustainable commercial production of CNC and CNF.Based on above,a facile one-pot method was reported to give GCC,followed the L-ascorbic acid reduction is performed to obtain CP.The as-reduced CP inherited abundant negatively-charged groups from GCC,thus brought it excellent aqueous dispersity,which is of great significance in the application.The ATR-FTIR,and Raman spectra proved that different ingredients of CP are well boned to each other.The morphology investigated by AFM explained how cellulose nanofibrils depositing on the graphene oxide substrate.Both were found to synergistically contribute to the improved performances of CP.The resistance test and TGA results indicated that CP was endowed with higher electrical conductivity as 116.3±1.5S/m and Tonset around 319.10 °C,respectively,considering the raw material and precursor.Besides,for the ultimate strain CP,competitive 0.45% was also obtained,with specific tensile strength in 20 N·m/g,suggesting good ductile behavior?On the other hand,post-ultrafiltration of GCC could result in a paper-based precursor,which was then in-situ L-ascorbic acid reduction to obtain ICP.After the same characterizations were performed,it was interesting that ICP was found endow with a two-face conductivity difference.This is the first report regarding a substrate of lower conductivity?297.0±15.8S/m from sheet resistance of 68.4±3.7?/sq?,which was formed in one piece with a top material had higher conductivity?375.6±3.7S/m from sheet resistance of 54.1±3.2?/sq?via a one-pot process.Except this,ICP just thermally and mechanically behaved like CP.