论文部分内容阅读
孔隙结构是影响竹木材料流体输送的重要因素,是竹木材料物理或化学加工的最根本问题。本文以毛竹和樟子松木材为试验材料,采用压汞法对材料的孔隙率、孔体积、孔径分布等参数进行定量测试,分析材料的孔隙结构特征。采用扫描电镜对材料的组织结构(毛竹:导管、筛管、薄壁细胞和纹孔等部位;樟子松:管胞、射线薄壁细胞、纹孔等部位)进行直观观察,建立竹木材料孔隙孔径分布与组织构造的对应关系,总结竹木材料内部孔隙结构差异,分析其对材料流体渗透性能的影响。测试结果表明,毛竹内部孔体积低于樟子松(孔隙率(毛竹:47.58%,樟子松:67.16%)、汞压入量(毛竹:0.633 m L/g,樟子松:1.596 m L/g))。毛竹中大部分孔隙集中在孔径较小区域(32.4nm左右),而樟子松木材中孔隙孔径主要集中在226.7nm及7082.3nm左右处。结合扫描电镜观察结果可知,毛竹中孔径835.0nm处主要对应纹孔部位孔隙,而45.4μm左右处对应于导管、薄壁细胞等组织细胞腔的孔隙。孔径为32.4nm处孔隙可能位于细胞壁中。在樟子松木材中,226.7nm及749.9nm左右孔隙主要对应于纹孔塞缘部位孔隙,而7.1μm及22.7μm左右则对应于纹孔口及管胞腔部位孔隙。此外,毛竹与樟子松木材孔隙结构差异是其流体渗透速度及渗透均匀度差异产生的原因。
Pore structure is an important factor that affects the transport of bamboo material fluid and is the most fundamental problem of physical or chemical processing of bamboo material. In this paper, the bamboo and Pinus sylvestris var.Mongolica were used as the experimental materials, and the mercury porosimetry was used to quantitatively test the porosity, pore volume and pore size distribution. The pore structure characteristics of the materials were analyzed. Scanning electron microscopy (SEM) was used to observe the microstructure of the material (Phyllostachys pubescens: Catheter, sieve tube, parenchyma cells and pits and other parts; Pinus sylvestris: Tracheid, ray parenchyma cells, pits and other parts) Pore size distribution and the structure of the corresponding relationship between the bamboo material to summarize the differences in pore structure, analysis of the material fluid permeability. The results showed that the pore volume of bamboo was lower than that of Pinus sylvestris (porosity: 46.58% for Moso bamboo and 67.16% for Pinus sylvestris var. Mongolica), the influx of mercury (0.633 m L / g for bamboo, 1.596 m / g)). Most of the pores in the bamboo concentrate in the smaller aperture area (about 32.4nm), while the Pinus sylvestris wood pore pore size mainly in the 226.7nm and 7082.3nm around. According to the results of scanning electron microscopy, we can see that the pores of 835.0nm in the bamboo mainly correspond to the pores in the pits and 45.4μm correspond to the pores in the tissue cavities of the catheters and parenchyma cells. Pores with a pore size of 32.4 nm may be located in the cell wall. In Pinus sylvestris var. Mongolica, the pores at 226.7nm and 749.9nm mainly correspond to the pores in the margins of the margins of the pits, while the pores at 7.1μm and 22.7μm correspond to the pores in the pits and the tube cells. In addition, the difference in pore structure between the bamboo and Pinus sylvestris var. Mongolica is the reason for the difference in fluid penetration rate and penetration uniformity.