离子减薄仪应用于植物纤维超微结构的观察

利用离子减薄仪制备薄膜样品的方法,能较好地满足透射电镜(TEM)对天然纤维细胞壁超微结构的观察.与传统的复型制样方法相比,这种薄膜样品制备方法能够观察到真实的纤维试样,而且制样过程中无毒,制样时间短,得到的信息较多,费用低.光叶楮木质部纤维细胞壁超微结构研究发现,初生壁(P层)和次生壁的S1层很薄,在较低打浆能耗下就被剥离掉,S2层较厚,S3层极薄以致透明,并与纤维细胞腔紧密相连.P层上微细纤维成网状排列,次生壁S1层上的微细纤维与纤维轴的夹角很小,几乎平行.次生壁S2层上的微细纤维与纤维轴的夹角较小,并存在三种排列方式.次生壁S3层上微细纤维成网状排列,与一般造纸用木材和草类原料相似.光叶楮木质部纤维细胞壁的超微结构的特征,是光叶楮杆芯硫酸盐浆比三倍体毛白杨硫酸盐浆易于打浆,浆料的结合强度较好的原因之一.

Application of Ion Beam Thinner in Observation of Cell Wall Ultrastructure of Fibres

By adoption of a new method of film preparation with Ion Beam Thinner, comparatively satisfying observations of ultrastructure with Transmission Electron Microscope could be obtained, with observable advantages such as poison-free, time-saving and information-enriching compared with the traditional method of ectypal preparation. Investigations of cell wall ultrastructure of Guangyechu xylem fibres show that,there were some differences between Guangyechu and the common materials applied for pulping. Although cell wall was composed of P, S 1, S 2 and S 3 layers, the primary wall with network-structured microfibrils and secondary wall S 1 with axis-paralleled microfibrils had relatively small thickness. Specifically, as far as the secondary wall S 3 is concerned, microfibrils which contained a randomly organized network, were quite thin so that they took on transparency and closed clung to the cell-antrum. Additionally, the angles of microfibrils to the fibre axis were smaller on S 2 layer for this kind of wood material, which include three kinds. Additionally, analysis of ultrastructure could be used to explain why good beating properties and bonding strength could be obtained.