College of Materials and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100, China; School of Materials Engineering, Yancheng Institute of Technology, Yancheng 224051, Jiangsu, China.
College of Materials and Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100, China; Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100, China.
Int J Biol Macromol. 2019 May 15;129:1081-1089. doi: 10.1016/j.ijbiomac.2018.07.055. Epub 2018 Aug 31.
Cellulose nanocrystals (CNCs) were successfully fabricated from waste pueraria root residue after starch extraction via the phosphoric acid hydrolysis method by a series of chemical treatment processes including ultrasonic washing, pectin elimination, bleaching, alkali boiling, and phosphoric acid hydrolysis. The high aspect ratio of CNCs with a crystallinity index of 60 ± 4.10% was observed by X-ray diffraction (XRD) and transmission electronic microscopy (TEM). The TEM results showed that CNCs were rod-like particles with 100-330 nm in length and 2 to 6 nm in width. The average aspect ratio of the CNCs was 40 ± 10. The XRD results also indicated that the crystalline structure of CNC was cellulose I, compared to that of MCC with the crystallinity index declining from 60 ± 4.10% to 48 ± 0.37%. The FTIR spectra showed the resulting samples were the cellulose species. Interestingly, stable colloidal suspensions were determined by the zeta potential measurement. The thermal properties of CNCs were investigated by thermogravimetric analysis, revealing that CNCs exhibited lower thermal stability compared to those of MCC and the raw pueraria root residue. This study provides a cost effective method and mild process conditions for preparing CNCs from waste pueraria root residue.
纤维素纳米晶体（CNCs）是通过一系列化学处理过程，包括超声清洗、果胶去除、漂白、碱煮和磷酸水解，从淀粉提取后的废葛根残渣中成功制备的。通过 X 射线衍射（XRD）和透射电子显微镜（TEM）观察到 CNCs 具有高纵横比和结晶度指数为 60±4.10%。TEM 结果表明，CNCs 是棒状颗粒，长度为 100-330nm，宽度为 2-6nm。CNCs 的平均纵横比为 40±10。XRD 结果还表明，CNC 的晶体结构为纤维素 I，与 MCC 的结晶度指数从 60±4.10%下降到 48±0.37%相比。FTIR 光谱表明得到的样品是纤维素类物质。有趣的是，通过zeta 电位测量确定了稳定的胶体悬浮液。通过热重分析研究了 CNCs 的热性能，结果表明 CNCs 的热稳定性低于 MCC 和葛根残渣。这项研究为从废葛根残渣中制备 CNCs 提供了一种经济有效的方法和温和的工艺条件。
