Contact Angle Measurements and Contact Angle Interpretation. 1. Contact Angle Measurements by Axisymmetric Drop Shape Analysis and a Goniometer Sessile Drop Technique
| Autor: | H. J. Jacobasch, A. W. Neumann, T. Gietzelt, Daniel Y. Kwok, Karina Grundke |
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| Rok vydání: | 1997 |
| Předmět: | |
| Zdroj: | Langmuir. 13:2880-2894 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | Low-rate dynamic contact angles and static advancing contact angles of 13 liquids were measured, respectively, by axisymmetric drop shape analysis (ADSA) and a conventional goniometer technique, on two copolymers, poly(propene-alt-N-(n-propyl)maleimide) and poly(propene-alt-N-(n-hexyl)maleimide); both have polar groups. In the case of the former technique for measuring contact angles (at very low velocity of the three-phase contact line), very complex contact angle responses were observed for some solid−liquid systems. In a specific case, slip and stick contact angle behavior occurs where the contact angle increases steadily by as much as 35° at constant three-phase contact radius and subsequently decreases sharply due to a sudden jump in the three-phase contact line. Thus, circumspection is necessary in the decision whether or not the experimental contact angles can be used to interpret surface energetics in conjunction with Young's equation and whether the solid−liquid systems violate the basic assumpti... |
| Databáze: | OpenAIRE |
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