Description and application of an interfacial viscometer

• Published in: Journal of applied polymer science 1974-06, Vol.18 (6), p.1693-1709
• Main Author: Karam, H. J.
• Format: Article
• Language: English
• ISSN: 0021-8995; 1097-4628
• DOI: 10.1002/app.1974.070180610

This paper describes an interfacial viscometer. Rheological data of polymeric surfactants were obtained with the use of the instrument for liquid–liquid and liquid–gas interfaces. The surfactants studied were methylcellulose, poly(vinyl alcohol), polymer of diethylene glycol n‐butyl ether acrylate, and sulfonated poly(vinyltoluene). Investigations were conducted over a wide range of temperatures and concentrations of the surfactants in the liquid phase. The instrument was used to obtain surface area coverage data for the surfactants studied. The experimental data were compared with theoretical calculations. The data indicated that the absorbed film at the interface was an irregular film, i.e., not an ordered packing of the molecules at the interface. Significance of interfacial viscosity on droplet break‐up in a simple shear field was investigated. Droplet breakup studies substantiate the hypothesis that an absorbed polymeric film at an interface forms a complex viscous film.