新型表面张力测定装置在物理化学实验教学中的应用

The application of new surface tension measurement device in physical chemistry experimental teaching

目的采用新型实验装置改善最大泡压法测定液体表面张力的实验结果。方法采用新型DMPY-3C表面张力测定装置,测定了25℃和35℃不同浓度乙醇水溶液的表面张力,以及在20℃时不同浓度的油酸钠水溶液的表面张力。结果结合实验结果和origin软件处理可计算25℃下乙醇分子的截面积为3.88×10^(-19)m^(2),35℃下乙醇分子的截面积为5.11×10^(-19)m^(2),20℃下油酸钠的临界胶束浓度(CMC值)为3.12×10^(-3)mol/L。结论采用新型DMPY-3C表面张力测定装置可方便测定溶液浓度对表面张力的影响,可大大减小实验偏差。该实验教学装置有助于药学类专业学生巩固并加深理解溶液表面张力测定的意义并熟知其在药学相关领域的应用。

Objective To improve the experimental results of surface tension of liquid obtained from maximum bubble pressure method by using new measurement device.Methods This research employed a new DMPY-3c surface tension measuring device to investigate the surface tension of water mixed with varying content of ethanol under the condition of 25℃and 35℃,respectively;as well as the surface tension of water mixed with varying content of sodium oleate aqueous solution at 20℃.Results Combined with the experimental results and origin software processing,the cross-sectional area of ethanol molecules can be calculated as 3.88×10^(-19)m^(2)at 25℃and 5.11×10^(-19)m^(2)at 35℃.The critical micelle concentration(CMC)of sodium oleate at 20℃was 3.12×10^(-3)mol/L.Conclusions The effect of solution concentration on surface tension could be easily measured by the new DMPY-3C surface tension measuring device.The experimental results greatly reduce the experimental bias.This work would help the students majored in pharmacy to consolidate and deepen the understanding of the significance of solution surface tension detection as well as its application in pharmaceutical related fields.