Preliminary Research on Strueture and Properties of Nano-cellulose

The structure of bacterial cellulose （BC） produced by Acetobacter xylinum NUST4 （A.xylinum NUST4） under static （SBC） and shake culture condition （ABC） was studied by means of transmission electron microscopic （TEM）, X-ray diffraction （XRD） and Fourier transform-infrared spectrum （FT-IR）. It was revealed that BC is I crystal cellulose and the proportion of cellulose I, exceeds 80% and BC diameter is 10-80 nm. Mechanical properties and water absorption capacity were also determined. These properties could result from crystalline and nanometer structure of BC.

Improving the physical properties of nano-cellulose through chemical grafting for potential use in enhancing oil recovery

The performance of nano-cellulose fluid as a"green"flooding agent in enhancing oil recovery was evaluated in our previous study.Expanding upon our prior findings,in this study the physical properties of nano-cellulose were further improved through chemical grafting with 2-acrylamido-2-methylpropane sulfonic acid monomer(AMPS)and alkyl chain.Scanning electron microscopy(SEM)observation indicated that the morphology of the nano-cellulose maintained fibrillar and was not altered after the chemical modification.The thermal stability of the AMPS and alkyl chain grafted nano-cellulose was investigated through thermogravimetric analysis(TGA).A similar thermal response behavior was observed for the three evaluated samples.Compared to the non-grafted nano-cellulose,the grafted nano-cellulose remained homogenous in an electrolyte solution against storage time,suggesting a superior sanity-tolerance.Rheological analysis also proved the advanced viscoelastic properties of the nano-cellulose dispersion.

Laboratory investigation of emulsified asphalt binder modified with wood-derived nano-cellulose and nano paper-cellulose

Emulsified asphalt is the primary material for preventive maintenance and cold-mix paving,but its low cohesive strength and poor mechanical properties limit its wide application,even with polymer modification.In this study,Styrene-Butadiene Rubber(SBR)emulsified asphalt was modified with nano-cellulose materials,namely nano paper-cellulose(NPC)and wood-derived nano-cellulose(WDC),to improve its properties.A novel preparation method of nano-cellulose solution was developed,including blending,ultrasonic stirring,and centrifugal treatment.Four types of nano-cellulose solution(0.5%NPC,0.5%,1.0%,and 1.5%WDC by weight of water)were selected.The microscopy analysis indicated that 0.5%WDC emulsion had a smaller particle size than 1.5%WDC emulsion.The rheology test indicated that WDC modified residue improved rutting resistance with the increased solution dosage due to the cross-linking effect,but its creep-and-recovery performance was worse than that of SBR emulsion residue.The NPC modified binder had a higher rutting factor than WDC modified binder at the same dosage after short-term aging.In addition,1.0%WDC could be regarded as the optimal dosage in terms of fatigue and low-temperature performance.Furthermore,Fourier Transform Infrared Spectroscopy(FTIR)results showed that 0.5%NPC modified residue performed better in long-term aging resistance compared with 0.5%WDC modified asphalt.