摘要
目的研究3种不同原材料(桉木漂白硫酸盐浆、长绒棉和短绒棉)制备纤维素纳米晶体(Cellulose Nanocrystals,CNC)薄膜的适合工艺条件及其性能变化规律,为CNC结构色防伪薄膜的研究提供参考。方法3种不同原材料在各自合适的水解条件下,通过硫酸水解制备CNC悬浮液,测定其粒径及Zeta电位、CNC颗粒的微观形貌。采用蒸发干燥自组装法形成CNC薄膜,测定薄膜的化学结构及晶型、微观结构、力学性能、偏光性能和最大反射波长。结果3种不同原材料制备的CNC悬浮液稳定性均较好,均保留了纤维素特有的官能团和天然Iβ晶型。随着酸水解时间的增加,CNC粒径均逐渐减小,长径比均为15左右;桉木漂白硫酸盐浆制备的CNC的结晶度低于短绒棉、长绒棉所制的CNC,其制备的CNC薄膜的柔韧性和抗拉强度优于短绒棉、长绒棉所制的薄膜。3种原材料所制CNC薄膜截面均具有胆甾相液晶层状结构,在偏光显微镜下薄膜均具有双折射效应;酸水解时间的增加使得CNC薄膜的螺距逐渐减小,最大反射波长也逐渐减小,薄膜的颜色均发生蓝移;与短绒棉、长绒棉制备的CNC薄膜相比,桉木漂白硫酸盐浆制备的CNC薄膜双折射特性较弱。结论原材料类型和水解时间对制备的CNC的粒径、结晶度、双折射等特性均产生影响。随着水解时间的增加,CNC薄膜螺距逐渐减小,可在一定范围内调控纤维素纳米晶薄膜的反射波长,从而达到了调节纤维素纳米晶薄膜结构色的目的。纤维素纳米晶材料后期有望应用于防伪包装领域。
The work aims to explore the suitable process conditions and properties change rule of cellulose nanocrystals(CNC)films prepared from 3 different raw materials(eucalyptus bleached kraft pulp,long-staple cotton and short-staple cotton),so as to provide reference for the study of CNC structural color anti-counterfeiting films.CNC suspensions were prepared by sulfuric acid hydrolysis of 3 different raw materials under appropriate hydrolysis condi-tions,and the particle size,Zeta potential and microscopic morphology of CNC particles were measured.CNC films were formed by evaporation drying self-assembly method.The chemical structure,crystal type,microstructure,me-chanical properties,polarizing properties and maximum reflection wavelength of the films were measured.The CNC suspensions prepared from 3 different raw materials had good stability and retained the unique functional groups of cellulose and natural Iβcrystal form.With the increase of acid hydrolysis time,the particle size of CNC gradually de-creased,and the length-diameter ratio was about 15.The crystallinity of CNC prepared from eucalyptus bleached kraft pulp was lower than that of CNC prepared from short-staple cotton and long-staple cotton,and the flexibility and ten-sile strength of the prepared CNC film were better than those of CNC film made from short-staple cotton and long-staple cotton.The cross sections of CNC films prepared from the 3 raw materials all had cholesteric liquid crystal layered structure and birefringence effect under polarized light microscope.With the increase of acid hydrolysis time,the pitch of CNC films gradually decreased,the maximum reflection wavelength also gradually reduced,and the color of the films all had blue-shifted.Compared with the CNC films prepared from short-staple cotton and long-staple cot-ton,the birefringence of the CNC films prepared from eucalyptus bleached kraft pulp was weaker.The type of raw materials and hydrolysis time both have an effect on the particle size,crystallinity and birefringence of the prepa
作者
闫然
谢开彬
刘蒙蒙
高萌
张正健
邵梦娟
YAN Ran;XIE Kai-bin;LIU Meng-meng;GAO Meng;ZHANG Zheng-jian;SHAO Meng-juan(School of Light Industry Science and Engineering,Tianjin University of Science and Technology,Tianjin 300457,China;China Key Laboratory of Light Industry Food Packaging Mate-rials and Technology,Tianjin University of Science and Technology,Tianjin 300457,China)
出处
《包装工程》
CAS
北大核心
2022年第15期186-194,共9页
Packaging Engineering
基金
天津市科技计划(20YDTPJC00830)
天津科技大学2021年度大学生创新创业训练计划(202110057276)。
关键词
纤维素纳米晶
结构色
薄膜
防伪
cellulose nanocrystals
structural color
film
anti-counterfeiting
