Study on Preparation of Lignin-Containing Nanocellulose from Bamboo Parenchyma

Bamboo vascular bundle fiber and parenchyma(BP)are separated by high-temperature treatment with saturated steam.Bamboo vascular bundle fiber is widely used in the market,but how to develop and utilize parenchyma tissue is a difficult problem.The sulfated cellulose nanofibers(ANFs)were obtained by sulfating BP with a deep eutectic solvent(DES),which provided a theoretical basis for the value-added utilization of BP.Using DES as the reaction medium and reagent,the BP was grafted with a sulfonic acid group to form a gel substance in water,ANFs and nanocellulose gel were obtained by ultrasonic cell crusher.The highest yield of ANFS was 75%.The width of the ANFs was about 3 nm,and a small number of nanofiber aggregates existed at the same time.A high aspect ratio of ANFs,due to their high viscosity,has potential applications as enhancers at low concen-trations.Lewis acid(ZnCl 2)added based on binary(DES)greatly improved the thermal stability of the ANFs and maintained the crystal form of cellulose I.

Carbon isotopic study of individual n-alkanes in certain modern organisms

Simulation experiment was carried out on all kinds of modern organisms significant to oil-gas generation and the C-isotopic values of n-alkanes in different organisms. The distribution characteristics of individual n-alkane isotopes are studied. The experimental results supply important clues in biological provenance of n-alkanes in sedimentary organisms.

Spectroscopic/Microscopic Elucid

The Arundo donax is a typical fast-growing species from the family Gramineae,which is widely cultivated in China.With a huge yield of A.donax in China,this plant offers great potential for biofuels production.The different types of organization of cell and the tissue in the A.donax could influence the efficiency of enzymatic hydrolysis.In this study,A.donax was subjected to 0.5%(w/w)sulfuric acid(H2SO4)for pretreatment at 140℃for 10 min,20 min,40 min,and 60 min,respectively.The changes in microstructure,chemical composition,topochemical properties were comprehensively analyzed.Using a series of spectroscopic and microscopic techniques including Fourier transform infrared spectroscopy(FT-IR),X-Ray diffraction(XRD),polarized light microscopy(PLM),and confocal Raman microscopy(CRM)to obtain the correlative structural and chemical information.Analysis results of chemical composition,FT-IR spectra and XRD indicated that with increasing reaction time,more hemicellulose and lignin would be removed.Correspondingly,there was an obvious increase of the cellulose relative crystallinity via extending reaction time.Results of the PLM observations showed that the birefringence gradually dimmed due to the diminishing of the cellulose component.Furthermore,the CRM mapping images showed the lignin component in compound middle lamellar(CML)was difficult to remove relatively as compared with that in secondary walls.These results indicated that the combination of spectroscopic and microscopic elucidation could give an insightful understanding of chemical changes in cellular level during pretreatment.