【摘要】 采用拉脱法和激光衍射法分别对蒸馏水、自来水、供水水库水、水源地水等的表面张力进行了实验研究。结果表明,拉脱法和激光衍射法测试结果与理论分析基本一致,表面张力随温度的增大而减小,随水中可溶杂质物含量的增加而增大,水样品表面张力的大小依次为:水源地水>水库水>自来水>蒸馏水。水中可溶杂质物与水分子相互作用,强化了水分子团簇缔合结构,使得水表层内分子间的平均距离减小,处于表层上的水分子平均间距大于表层内水分子的平均间距,从而导致表层分子间作用力增强,表现为水的表面张力增大。激光衍射法是动态法测试表面张力,测试结果受汽相影响较大。因此拉脱法的结果相对于激光衍射法更接近于水表面张力的理论值。更多还原

【Abstract】 In order to develop a safe and efficient physical method for water quality inspection,the surface tension of distilled water,tap water,supplied water in reservoir,source water,etc. were researched by pull-off method and laser diffraction method. The experimental test results are broadly consistent with theoretical analysis. The surface tension of water decreases with temperature raising,and raises with the increasing of the soluble impurities’ concentration. The surface tension of the water specimens rank in descending order as: source water,reservoir water,tap water,and distilled water. The interaction between soluble impurities and water molecules strengthens the associated structure of water molecule clusters,which decreases the average distance of water molecules beneath surface layer. While,the intermolecular distance of the water’s outermost layer is larger than that under the surface layer. So the intermolecular force of the water ’s outermost layer is enhanced,it shows as the increase of surface tension. Laser diffraction is a dynamic method to measure the surface tension,and the results are easily influenced by the state of vapor phase. Thus,the results from pull-off method are closer to the theoretical values,compared to the laser diffraction method.更多还原