BET流动法测固体比表面积实验的改进

Improvement in Experiment to Measure Specific Surface Area of Solid by BET Flow Method

多层吸附(BET吸附)理论作为本科实验课的固体比表面积测定原理,通常应用于流动法测固体样品比表面的实验。实验中,吸附剂的支撑材料——玻璃纤维丝使用过程中不可避免地产生大量的细微玻璃纤维在空气中飘浮,对师生健康产生严重危害;新型多功能材料——聚四氟乙烯具有良好的安全性、稳定性,及易加工、可重复利用等性能已被应用于一些特殊场合。基于对师生安全的考虑,选用了聚四氟乙烯塑料丝替代玻璃纤维丝作为吸附剂的支撑材料。实验结果表明,使用聚四氟乙烯的BET吸附实验数据稳定可靠,而且安全环保,测试方法简便,教学效果显著提高。

BET adsorption theory provides the principle of solid specific surface area determination in undergraduate experimental courses,and is usually used in the specific surface area determination experiments of solid samples by flow adsorption instruments.The experiment is of great significance for students to understand the adsorption principle and improve their practical operation ability.However,the supporting material of the sample—glass fiber may inevitably produce lots of fibers and be spread widely in the air,causing serious harm to students’health.The new multifunctional plastic-polytetrafluoroethylene(PTFE)has good safety,stability,easy processing and reusability,and has been used in some special occasions.Based on safety considerations,we choose polytetrafluoroethylene plastic wire instead of glass fiber as the sample support material.The experimental results show that compared with the original experimental materials,the BET adsorption experimental data using PTFE is stable,reliable and environmentally friendly.The teaching effect is significantly improved with this simple method.