In this study, parenchyma cellulose, which was extracted from maize stalk pith as an abundant source of agricultural residues, was applied for preparing cellulose nanoparticles (CNPs) via an ultrasound-assisted etherification and a subsequent sonication process. The ultrasonic-assisted treatment greatly improved the modification of the pith cellulose with glycidyltrimethylammonium chloride, leading to a partial increase in the dissolubility of the as-obtained product and thus disintegration of sheet-like cellulose into nanoparticles. While the formation of CNPs by ultrasonication was largely dependent on the cellulose consistency in the cationic-modified system. Under the condition of 25% cellulose consistency, the longer sono-treated duration yielded a more stable and dispersible suspension of CNP due to its higher zeta potential. Degree of substitution and FT-IR analyses indicated that quaternary ammonium salts were grafted onto hydroxyl groups of cellulose chain. SEM and TEM images exhibited the CNP to have spherical morphology with an average dimeter from 15 to 55 nm. XRD investigation revealed that CNPs consisted mainly of a crystalline cellulose Ι structure, and they had a lower crystallinity than the starting cellulose. Moreover, thermogravimetric results illustrated the thermal resistance of the CNPs was lower than the pith cellulose. The optimal CNP with highly cationic charges, good stability and acceptable thermostability might be considered as one of the alternatively renewable reinforcement additives for nanocomposite production.

中文翻译：

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通过超声介导的阳离子醚化从玉米秸秆髓中制备和表征纤维素纳米颗粒。

在这项研究中，从玉米秸秆髓中提取的薄壁组织纤维素作为农业残留物的丰富来源，通过超声辅助醚化和随后的超声处理，被用于制备纤维素纳米颗粒（CNP）。超声辅助处理极大地改善了缩水甘油基三甲基氯化铵对髓纤维素的改性，导致所得产物的溶解度部分增加，从而使片状纤维素分解为纳米颗粒。尽管通过超声形成CNP的过程很大程度上取决于阳离子改性体系中纤维素的稠度。在纤维素浓度为25％的条件下，较长的声波处理持续时间因其较高的Zeta电位而产生了更稳定和可分散的CNP悬浮液。取代度和FT-IR分析表明，季铵盐被接枝到纤维素链的羟基上。SEM和TEM图像显示CNP具有球形形态，平均直径为15至55nm。XRD研究表明，CNP主要由结晶纤维素I结构组成，并且它们的结晶度低于起始纤维素。此外，热重分析结果表明CNP的耐热性低于髓纤维素。具有高阳离子电荷，良好的稳定性和可接受的热稳定性的最佳CNP可以被认为是用于纳米复合材料生产的替代性可再生增强添加剂之一。SEM和TEM图像显示CNP具有球形形态，平均直径为15至55nm。XRD研究表明，CNP主要由结晶纤维素I结构组成，并且它们的结晶度低于起始纤维素。此外，热重分析结果表明CNP的耐热性低于髓纤维素。具有高阳离子电荷，良好的稳定性和可接受的热稳定性的最佳CNP可以被认为是用于纳米复合材料生产的替代性可再生增强添加剂之一。SEM和TEM图像显示CNP具有球形形态，平均直径为15至55nm。XRD研究表明，CNP主要由结晶纤维素I结构组成，并且它们的结晶度低于起始纤维素。此外，热重分析结果表明CNP的耐热性低于髓纤维素。具有高阳离子电荷，良好的稳定性和可接受的热稳定性的最佳CNP可以被认为是用于纳米复合材料生产的替代性可再生增强添加剂之一。热重分析结果表明，CNP的热阻低于髓纤维素。具有高阳离子电荷，良好的稳定性和可接受的热稳定性的最佳CNP可以被认为是用于纳米复合材料生产的替代性可再生增强添加剂之一。热重分析结果表明，CNP的热阻低于髓纤维素。具有高阳离子电荷，良好的稳定性和可接受的热稳定性的最佳CNP可以被认为是用于纳米复合材料生产的替代性可再生增强添加剂之一。