摘要
【目的】研究万寿菊秸秆的微观形貌、化学元素组成和官能团的变异规律,可以在微观尺度和分子水平上为科学合理利用农作物秸秆提供技术依据。【方法】采用场发射扫描电镜(FE-SEM)和电子能谱(EDS)表征万寿菊秸秆横切面的微观结构变异和化学元素组成变异情况;采用彩色图像计算机分析系统,对万寿菊秸秆的上段、中段、下段进行胞壁率测量;采用傅里叶一维红外光谱(FTIR)、二阶导数光谱(SDIR)和二维相关红外光谱(2DIR)表征万寿菊秸秆沿高度方向上的官能团变异规律。【结果】万寿菊秸秆的径向尺寸在上段变异较小(极差为7.3),而在中段和下段的变异较大(极差分别是10.0和10.7);万寿菊秸秆的上段组织结构"粗疏",但在中段和下段的管孔直径及分布密度差异不大,导管类型主要是单管孔或复管孔,万寿菊秸秆的碳氧比在高度方向由上至下为0.73、0.79、0.83,呈现递增趋势,氮元素原子百分比也有同样趋势;万寿菊秸秆的胞壁率沿径向由内向外,高度方向由上向下均呈现出递增趋势;万寿菊秸秆不同高度对应的FTIR谱图在2 816~2 972 cm-1、1 651、1 461 cm-1、849~800 cm-1处,SDIR谱图在1 700、1 280 cm-1处,以及2DIR谱图在3 240~3 409 cm-1、2 921、2 850、1 619 cm-1处均存在较明显变化,表明对应官能团的种类与吸收峰强度和秸秆高度位置的变化有一定的相关性。【结论】通过对万寿菊秸秆微观形貌和官能团分析,揭示了万寿菊秸秆的径向尺寸、内部组织结构、碳氧原子百分比、细胞的胞壁率与秸秆生长高度方向的对应关系;推测出秸秆主要化学成分所含官能团的种类和数量在秸秆生长高度方向上的变异规律。
[Objective]The variation of micromorphology,chemical composition and functional groups of marigold straw was studied to provide scientific and reasonable technical basis for the utilization of crop straw at the micro-scale and molecular level.[Method]Field emission scanning electron microscopy(FESEM)and energy dispersive spectrometer(EDS)were used to characterize the microstructural variation and chemical element composition difference of the cross section of marigold straw.The cell wall percentage of marigold straw was measured by color image computer analysis system.And the functional group distribution rule of marigold straw along the direction of height was characterized by Fourier transform infrared spectrometer(FTIR),second derivative infrared(SDIR)and two-dimensional correlation infrared(2 DIR).[Result]The results showed that:(1)the radial size of marigold straw had a small variation in the upper part(range 7.3),but a large variation in the middle and root(range 10.0 and 10.7,respectively).(2)The upper structure of marigold straw was"sparse",but the diameter and distribution of tube holes in the middle and lower segments were not significantly different.The type of catheter was mainly single-tube or complex tube.The carbon and oxygen ratio of marigold straw was 0.73,0.79 and 0.83 from tip to root,showing an increasing trend.The content of nitrogen atom percentage also had the same trend.(3)The cell wall ratio showed an increasing trend from the inside to outside and the height direction from the tip to root.(4)FTIR spectra corresponding to different heights were significant changes in 2816-2972 cm-1,1651,1461 cm-1 and 800-849 cm-1.1700,1280 cm-1 of the SDIR curve and 3240-3409 cm-1,2921,2850 cm-1,1619 cm-1 of the 2 DIR.The results indicated that the species and quantity of corresponding functional groups were correlated with the variation of straw height,it could infer changes of three kinds of basic units of straw.[Conclusion]Through the analysis of Micromorphology and functional groups of marigold straw,the corresponding relationship between radial size,internal structure,percentage of carbon and oxygen atoms,cell wall percentage and height direction of marigold straw were revealed.The variation of the types and quantities of functional groups contained in the main chemical constituents of straw in the direction of straw height was deduced.
作者
杨国超
王楠
黄新鑫
耿亚茹
刘婧
张求慧
Yang Guochao;Wang Nan;Huang Xinxin;Geng Yaru;Liu Jing;Zhang Qiuhui(Key Laboratory of Wooden Material Science and Application of Ministry of Education,School of Materials Science and Technology,Beijing Forestry University,Beijing 100083,China)
出处
《北京林业大学学报》
CAS
CSCD
北大核心
2020年第1期149-156,共8页
Journal of Beijing Forestry University
基金
国家自然科学基金项目(31670564).
关键词
万寿菊秸秆
微观形貌
化学组成
变异规律
marigold stalk
microscopic morphology
chemical composition
variation rule
作者简介
第一作者:杨国超,博士生。主要研究方向:生物质材料研究。Email:1006649108@qq.com,地址:100083北京市海淀区清华东路35号北京林业大学材料科学与技术学院。;责任作者: 张求慧,博士,教授。主要研究方向:木质材料研究。Email:qhzh66@163.com,地址:100083北京市海淀区清华东路35号北京林业大学材料科学与技术学院。
