ISO 15901-2:2006 用水银孔率法和气体吸附测定固体材料的孔径分布和气孔率 第2部分：用气体吸附分析中孔和大孔
标准编号：ISO 15901-2:2006
中文名称：用水银孔率法和气体吸附测定固体材料的孔径分布和气孔率 第2部分：用气体吸附分析中孔和大孔
英文名称：Pore size distribution and porosity of solid materials by mercury porosimetry and gas adsorption — Part 2: Analysis of mesopores and macropores by gas adsorption
发布日期：2006-12
标准范围
ISO 15901-2:20 06描述了通过气体吸附评估孔隙率和孔径分布的方法。这是一个比较测试，而不是绝对测试。该方法仅限于在受控的恒定温度下测定每单位质量样品吸附的气体量。ISO 15901-2:20 06没有规定特定吸附气体的使用，然而氮气是此类方法中最常用的吸附气体。同样，液氮的温度是最常用的分析温度。有时使用其他吸附气体，包括氩、二氧化碳和氪，以及其他分析温度，包括液态氩和固态二氧化碳的温度。在液氮温度下氮吸附的情况下，该方法的基础是测量在77K下吸附的氮的量作为其相对压力的函数。传统上，氮吸附最适合于宽度约为0.4 nm至50nm的孔。温度控制和压力测量的改进现在允许评估更大的孔宽度。ISO 15901-2:20 06描述了2nm至50nm之间的中孔尺寸分布和高达100nm的大孔分布的计算。ISO 15901-2:20 06中描述的方法适用于广泛的多孔材料，即使某些材料的孔结构有时通过预处理或冷却而改变。规定了两组程序来确定吸附的气体量:那些取决于从气相中除去的气体量的测量（即气体容量法），以及那些涉及吸附剂吸收气体的测量（即。e.通过重量法直接测定质量增加）。在实践中，可以使用静态或动态技术来确定吸附的气体量。为了从等温线导出孔径分布，有必要应用一个或多个数学模型，这需要简化某些基本假设。
ISO 15901-2:2006 describes a method for the evaluation of porosity and pore size distribution by gas adsorption. It is a comparative, rather than an absolute test. The method is limited to the determination of the quantity of a gas adsorbed per unit mass of sample at a controlled, constant temperature.ISO 15901-2:2006 does not specify the use of a particular adsorptive gas, however nitrogen is the adsorptive gas most commonly used in such methods. Similarly, the temperature of liquid nitrogen is the analysis temperature most commonly used. Use is sometimes made of other adsorptive gases, including argon, carbon dioxide and krypton, and other analysis temperatures, including those of liquid argon and solid carbon dioxide. In the case of nitrogen adsorption at liquid nitrogen temperature, the basis of this method is to measure the quantity of nitrogen adsorbed at 77 K as a function of its relative pressure.Traditionally, nitrogen adsorption is most appropriate for pores in the approximate range of widths 0,4 nm to 50 nm. Improvements in temperature control and pressure measurement now allow larger pore widths to be evaluated. ISO 15901-2:2006 describes the calculation of mesopore size distribution between 2 nm and 50 nm, and of macropore distribution up to 100 nm.The method described in ISO 15901-2:2006 is suitable for a wide range of porous materials, even though the pore structure of certain materials is sometimes modified by pretreatment or cooling.Two groups of procedures are specified to determine the amount of gas adsorbed:
- those which depend on the measurement of the amount of gas removed from the gas phase (i.e. gas volumetric methods), and
- those which involve the measurement of the uptake of the gas by the adsorbent (i.e. direct determination of increase in mass by gravimetric methods).
标准预览图
