摘要
纤维素是地球上最丰富的可再生聚合物来源,由其制备的纤维素纳米纤维是一种具有生物相容性等优势的纳米材料。2,2,6,6-四甲基哌啶-1-氧自由基(TEMPO)介导的氧化体系(TEMPO/NaBr/NaClO)结合机械处理,可实现富羧纳米纤维(TOCNFs)的高效制备。然而,主氧化剂NaClO的质量摩尔浓度在传统试验中往往难以确定,并且以pH值达稳定状态作为终止添加的依据,会导致反应时间过长。以大麻纤维为试验对象,添加不同质量摩尔浓度的NaClO,分时间段提取样品,探究NaClO质量摩尔浓度和羧基的生成量随时间的变化情况。结果表明,在TEMPO氧化体系中,在10 mmol/g NaClO和120 min反应时间条件下,纤维素分子链上C6位羟基可有效转化为羧基(1.2 mmol/g),同时维持晶体区结构完整并形成适度表面电荷密度,实现纳米纤维稳定分散。该优化方法减少了单位产量化学品消耗量,缩短了反应时间,在保持纳米纤维素悬浮液相对较稳定的分散情况下,提高了制备富羧纳米纤维素生产的可持续性,符合绿色化学原则。
Cellulose is the most abundant renewable polymer source on Earth.Cellulose nanofibers prepared from it are a type of nanomaterial with advantages such as biocompatibility.The 2,2,6,6-tetramethylpiperidine-1-oxyl radical(TEMPO)-mediated oxidation system(TEMPO/NaBr/NaClO)combined with mechanical treatment can efficiently prepare carboxyl-rich nanofibers(TOCNFs).However,in traditional experiments,the mass molar concentration of the main oxidant NaClO is often difficult to determine,and terminating the addition on the basis of the pH reaching a steady state can lead to excessive reaction times.Taking hemp fibers as the research object,different mass molar concentrations of NaClO were added,and samples were extracted at different time intervals to investigate the changes in the mass molar concentration of NaClO and the amount of carboxyl groups generated over time.The results show that in the TEMPO oxidation system,under the conditions of 10 mmol/g NaClO and a reaction time of 120 min,the hydroxyl groups at the C6 position of the cellulose molecular chain can be effectively converted into carboxyl groups(1.2 mmol/g),while maintaining the integrity of the crystal zone structure and forming a moderate surface charge density,achieving stable dispersion of nanofibers.This optimized method reduces the consumption of chemicals per unit output,shortens the reaction time,and improves the sustainability of the production of carboxyl-rich nanocellulose while maintaining relatively stable dispersion of the nanocellulose suspension,in line with the principles of green chemistry.
作者
古宇
王燕鸽
仇公全
赵树元
秦智慧
刘柳
张瑞云
俞建勇
GU Yu;WANG Yange;QIU Gongquan;ZHAO Shuyuan;QIN Zhihui;LIU Liu;ZHANG Ruiyun;YU Jianyong(College of Textiles,Donghua University,Shanghai,China;Key Laboratory of Textile Science&Technology,Ministry of Education,Donghua University,Shanghai,China;Innovation Center for Textile Science and Technology,Donghua University,Shanghai,China)
出处
《东华大学学报(自然科学版)》
北大核心
2025年第3期18-27,共10页
Journal of Donghua University(Natural Science)
基金
中央高校基本科研业务费专项资金(2232024G-01)
纺织之光应用基础研究计划(J202305)
魏桥教研创新项目。
