红壤中纳米颗粒的分布及其表征.docVIP

 红壤中纳米颗粒的分布及其表征# ** 5 10 15 摘要：红壤中富含粘粒，存在大量纳米尺度矿物,这些纳米尺度矿物在决定土壤的理化性质 和环境过程中起到重要作用。本文使用激光粒度仪,高分辨电子显微镜(HRTEM)结合 X 射线 能谱(EDX)对红壤中纳米物质的颗粒分布，形貌，及存在形态进行表征。结果表明：红壤中 的粘粒大多以纳米颗粒形态存在，主要类型为硅氧化物，铁氧化物和铝氧化物。红壤中的纳 米颗粒易于团聚为片状，丝状或长条的带状，致使激光粒度测定结果呈现典型的偏态双峰分 布。对红壤中纳米颗粒的高分辨电子衍射结果表明，红壤中存在结晶度很好的纳米颗粒，晶 格间距在 0.226 nm 左右，结合 X 射线能谱判断，这些结晶度较好的纳米颗粒以赤铁矿为主。 关键词：红壤；纳米颗粒；表征 中图分类号：S152.4 Distribution and Characteristic of Nanoparticles in Red Soil WANG siyuan, LU shenggao (College of Resource and Environment,Zhejiang University, HangZhou 310058) Abstract: Red soils are rich in clay and large numbers of nano scale minerals are present in these clay rich soils. These nano scale minerals play an important role in determining soil physical and 20 25 30 35 40 chemical properties and environmental processes. In this study different techniques such as High resolution transmission electron microscopy (HRTEM) and the X-ray spectroscopy (EDX) were used to determine the particle size distribution, morphology and there existing form while Zetasizer was used to measure the mean diameter and its distribution. The results shows that the red clay contains high number of nanoparticles with silicon oxide, iron oxide and aluminum oxide as there main minerals. Nanoparticles in Red soil are easy to reunion for sheet, filamentous or strip band. The result of the laser particle size shows the typical skewness bimodal distribution while the results of high resolution electron diffraction and X-ray spectrum shows that the nanoparticles existing in the red soil have good crystallization with lattice spacing of about 0.226 nm. Based on these results we can conclude that the highly crystallized nanoparticles in red soil are hematite. Keywords: Red soil; Nanoparticles; Representation 0 绪言 在土壤科学中， Navrotsky(2003)将岩石风化称为纳米尺度侵蚀，土壤可以称作是有机、 无机、生物不同大小粒子形成的混合纳米材料[1]。营养物质、污染物、重金属等的运输都发 ，3] 环和生物有效性等起到控制作用；它强烈影响着土壤发生、土壤理化性质和土壤环境质量演 变等环境动态过程。土壤中存在多种金属（氢）氧化物、铝硅酸盐矿物和无定型纳米物质， 其中最多的就是纳米氧化铁矿物，它存在于各种各样的地球化学过程中，以纳米微晶或胶体 状态分布在水体和土壤矿物中