This study presents an efficient extraction of nanocellulose crystals (CNCs) and nanofibers (CNFs) through ultrasound-assisted TEMPO oxidation method using deep-processed heavy metal-containing calabash as raw material. The extraction method, integrating TEMPO-mediated oxidation and ultrasound techniques, enhanced the yield of CNCs and CNFs. The results demonstrate that CNCs yielded 63 %, with a carboxyl content of 1.27 mmol/g, while CNFs yielded 31 %, with a carboxyl content of 1.21 mmol/g. CNCs and CNFs exhibited excellent mechanical properties, with CNCs having an average length of 214.4 nm, average diameter of 2.72 nm, and a length-to-diameter ratio of 78.8. CNFs had an average length of 437.8 nm, average diameter of 5.7 nm, and a length-to-diameter ratio of 76.8. X-ray diffraction (XRD) results showed crystallinity of 87.1 % for CNCs and 81.2 % for CNFs. The thermal stability of the fibers was confirmed up to 230℃. The film prepared by combining 10 % PVA with 90 % CNC exhibited a tensile strength of 32.11 MPa, Young's modulus of 2027.1 MPa, and could generate a maximum voltage of 0.83 V. This study provides an effective pathway for the value-added utilization of deep-processed calabash and highlights the broad application prospects of the composite film in the field of flexible sensors.

中文翻译：

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水葫芦的增值：利用超声辅助 TEMPO 氧化高效提取纳米原纤化晶体及其在柔性压电薄膜中的应用


本研究提出了一种以深加工含重金属的葫芦为原料，通过超声辅助 TEMPO 氧化法高效提取纳米纤维素晶体 （CNC） 和纳米纤维 （CNF）。该提取方法结合了 TEMPO 介导的氧化和超声技术，提高了 CNC 和 CNF 的产量。结果表明，CNC 产量为 63%，羧基含量为 1.27 mmol/g，而 CNFs 产量为 31%，羧基含量为 1.21 mmol/g。CNC 和 CNFs 表现出优异的机械性能，CNC 的平均长度为 214.4 nm，平均直径为 2.72 nm，长径比为 78.8。CNFs 的平均长度为 437.8 nm，平均直径为 5.7 nm，长径比为 76.8。X 射线衍射 （XRD） 结果显示 CNC 的结晶度为 87.1%，CNF 的结晶度为 81.2%。纤维的热稳定性在 230°C 以下得到证实。通过将 10% PVA 与 90% CNC 混合制备的薄膜具有 32.11 MPa 的拉伸强度，杨氏模量为 2027.1 MPa，并且可以产生 0.83 V 的最大电压。本研究为深加工葫芦的增值利用提供了一条有效的途径，凸显了复合膜在柔性传感器领域的广阔应用前景。