The Effect of Temperature on Water Surface Tension Through Cohesion and Adhesion Forces and the Role of Liquid Molecular Interactions

Abstract

Surface tension is a physical property of liquids that is important in daily phenomena, scientific analysis, and pharmaceutical formulation. This study aimed to evaluate the capillary rise and surface tension behavior of 96% ethanol, polyethylene glycol (PEG) 400, and glycerin, and to observe the effect of temperature on distilled water using the capillary rise method. The laboratory experiment was conducted at the Pharmaceutical Technology Laboratory, Department of Pharmacy, Faculty of Sports and Health, Universitas Negeri Gorontalo. Measurements included specific gravity and capillary rise of each liquid, while distilled water was heated to 40°C, 60°C, and 80°C before observation. The solvent test showed that PEG 400 produced the highest capillary rise (1.9 cm), followed by 96% ethanol (1.0 cm) and glycerin (0.9 cm). The temperature test showed capillary rise values of 1.3 cm, 0.3 cm, and 1.5 cm at 40°C, 60°C, and 80°C, respectively, indicating that the relationship was not fully linear under the practical conditions. These findings confirm that capillary phenomena are influenced by density, viscosity, cohesion, adhesion, and experimental control. The results provide practical information for understanding liquid behavior relevant to pharmaceutical dosage-form development.