物理吸附仪在环境材料中的应用_环境科学.doc

摘要

　　　在环境中广泛应用的多孔材料的表面是不光滑的，有的内部还有许多肉眼难以观察的微孔，这些结构与多孔材料的某些性质有密切的关系，因此，测定多孔材料的比表面积、孔容、孔径分布具有重要的意义。

　　　测定比表面积应用最广泛的是BET氮气吸附法，孔径孔容测试则多应用BJH公式。其原理是当固体表面暴露在外界气体中时，其接触气体的界面会吸附所接触的气体分子，并且这种吸附是可逆的。人们利用固体的这种特性发明了气体吸附法来测定多孔材料的比表面积和孔径分布情况。因为常温下固体吸附气体的量极其微小难以检测，因此多通过降低外界温度增加其气体吸附量（一般是-192℃，液氮温度），同时氮气因为其价廉易得，不具有任何腐蚀性，不会对固体结构产生任何影响所以常被用作吸附质。因此这种方法也常被称为氮气吸附法。 

　　　本文介绍了两种常用吸附环境材料——活性碳材料和硅化物（二氧化硅）的性质、吸附原理以及应用用途等，ASAP2020物理吸附仪在环境材料中应用的发展史，ASAP2020的原理和计算方法等作了介绍，具体操作和数据展示，最后对实验数据及结果进行分析和总结讨论。

关键词：多孔材料  吸附  物理吸附仪

Abstract

　　　Widely used in the environment of the surface porous materials is not smooth, some internal and many macroscopic difficult to observe the microporous, these structure and porous materials some properties have close relations, and therefore, the determination of porous materials provides specific surface area, pore size distribution, and has an important meaning.

　　　　Determination of specific surface area are the most widely BET nitrogen adsorption, aperture is much provides BJH formula used to test. Its principle is when the solid surface exposed to the gas where the contact gas interface traps contacts of gas molecule, and this adsorption is reversible. People use solid this characteristic invented the gas absorption method to determine the porous materials than specific surface area, pore size distribution. Because under normal temperature solid adsorption volume of air extremely small, so more difficult to test by lowering the temperature outside increase its gas adsorption (19.2 ℃, general is - liquid nitrogen temperature) and nitrogen because its cheap, don't have any corrosive of solid structure, won't produce any effect so often used as adsorption quality. So this method also often called nitrogen adsorption method.

　　　　This article introduces two common environmental materials - active carbon adsorption materials and silicides (silica) properties and adsorption principle and application USES, ASAP2020 physical adsorption instrument applied in environmental materials, the history of the principle and ASAP2020 calculation method is introduced, such as concrete operation and data display, finally to experimental data analysis and summary results and discussion.

Keywords: Porous materials  adsorption  Physical adsorption instrument