木棉纤维的微细结构研究——胞壁层次结构与原纤尺度

通过对木棉纤维横截面超薄切片的透射电镜观察，获得了木棉纤维的胞壁层次结构、原纤尺度及排列。木棉纤维胞壁具有清晰可见的多层状结构，基本上可以分为外表皮层S、胞壁1层W1、胞壁2层W2、胞壁3层W3和内皮层IS共5个基本的层次，各层具有不同的厚度和原纤堆砌密度与排列方向。可见木棉纤维横截面最小结构单元宽度为3．2～5．0nm，与棉纤维基原纤尺寸相当。实验证明，碱液对木棉纤维的可及性存在显著的个体差异；对于同一纤维胞壁各层的溶胀也存在差异。其中W2是最易被溶胀的；内皮层的原纤容易被分离出来。而未经溶胀处理的木棉纤维电镜照片反差弱，层次结构不够细致。

Study on the Fine Structure of the Kapok Fiber——The Structure of Cell Walls and the Sizes of Fibrils

The layer structures of the cell walls and the sizes of fibrils about the cross section of kapok fibers were observed by Transmission Electronic Microscope(TEM), and the expansion features of the kapok fibers dealed with alkali have also been analyzed. The walls of kapok fibers consist of cuticle (S), primary wall (W_1), secondary wall (W_2) tertiary wall (W_3) and inner wall (IS). Every layer has different thickness, packing density and the different arrangements of the fibrils. The size of visible elementary structural units is 3.2 nm thick which is close to the scale of the elementary fibrils of cotton fiber. The swollen rate of the kapok fiber treated with alkali is individual differences and the different walls in the same cross section are also expanded to different extent. W_2 is the most easily swollen part and is most weak resistant to alkali. The fibrils in the inner wall are easily departed from the body.