Surface Treatment and Its Influence on Contact Angles of Water Drops Residing on Polymers and Metals

Studies have been made to identify concise polishing, pressing and surface cleaning procedures for producing standard surfaces for contact angle determinations using copper and polytetrafluoroethylene (PTFE). A review of previous workers’ methods and their efficacies is also reported. © 1985, Taylor & Francis Group, LLC. All rights reserved

The influence of environment on the drop size - contact angle relationship

Advancing contact angles are reported for the water-PTFE, water-copper, water-stainless steel, water-PMMA and n-decane-PTFE systems for a range of liquid drop sizes. The angles were determined at 25 °C in an air or nitrogen-saturated atmosphere and compared with those measured at the boiling point in an environment only of its vapor. For water-PTFE and water-PMMA systems, a decrease in contact angle with decreasing drop size was observed in an air-saturated environment at 25 ° confirming the data of Good and Koo. An increase in contact angle however occurred with decreasing drop size at the boiling point in the pure vapor atmosphere confirming the results of Boyes and Ponter. The introduction of nitrogen decreased the contact angle although the trend remained the same

Contact angle variation on polymer surfaces

It is demonstrated that extraneous electric charge can produce a large variation in contact angle for water drops on polytetrafluoroethylene surfaces. © 1984