University Institute of Chemical Engineering and Technology, Panjab University, Chandigarh, India.
Carbohydr Res. 2011 Jan 3;346(1):76-85. doi: 10.1016/j.carres.2010.10.020. Epub 2010 Oct 30.
Cellulose nanofibrils of diameter 10-50nm were obtained from wheat straw using alkali steam explosion coupled with high shear homogenization. High shear results in shearing of the fiber agglomerates resulting in uniformly dispersed nanofibrils. The chemical composition of fibers at different stages were analyzed according to the ASTM standards and showed increase in α-cellulose content and decrease in lignin and hemicellulose. Structural analysis of steam exploded fibers was carried out by Fourier Transform Infrared (FT-IR) spectroscopy and X-ray diffraction (XRD). Thermal stability was higher for cellulose nanofibrils as compared to wheat straw and chemically treated fibers. The fiber diameter distribution was obtained using image analysis software. Characterization of the fibers by AFM, TEM, and SEM showed that fiber diameter decreases with treatment and final nanofibril size was 10-15nm. FT-IR, XRD, and TGA studies confirmed the removal of hemicellulose and lignin during the chemical treatment process.
直径为 10-50nm 的纤维素纳米纤维是通过碱蒸汽爆破结合高剪切均化从麦草中获得的。高剪切导致纤维团聚体的剪切，从而实现均匀分散的纳米纤维。根据 ASTM 标准分析了不同阶段纤维的化学成分，结果表明α-纤维素含量增加，木质素和半纤维素含量减少。通过傅里叶变换红外（FT-IR）光谱和 X 射线衍射（XRD）对蒸汽爆破纤维的结构进行了分析。与麦草和化学处理纤维相比，纤维素纳米纤维的热稳定性更高。使用图像分析软件获得纤维的直径分布。通过 AFM、TEM 和 SEM 对纤维进行的表征表明，纤维直径随处理而减小，最终纳米纤维的尺寸为 10-15nm。FT-IR、XRD 和 TGA 研究证实了在化学处理过程中去除了半纤维素和木质素。
