Effects of water salinity, electric stress and temperature on the hydrophobicity of nylon

The loss of hydrophobicity of nylon caused by water salinity, electric stress and temperature is investigated. The hydrophobicity is determined by measuring the contact angle using a droplet of distilled water at room temperature. To investigate the loss of hydrophobicity, nylon specimens are immersed in saline water solutions. The salinity is varied from 5 to 100,000 μS/cm. The aging temperatures are 0, 23.5 (room temperature), 50 and 75°C. The time of immersion is up to 336 hours. Electric field is applied in air at room temperature. From this study it is found that the contact angle of water on nylon decreases with increasing salinity of water. The contact angle decreases rapidly with increasing temperature of the saline water. The contact angle decreases with increasing time of subjecting the specimen to a fixed value of high dc electric stress in air at 23.5°C