Estimation of Copolymer/Water Interfacial Tensions Using Pendant Drop Tensiometry
Year: 2018
Journal: Langmuir, Volume 34, JUN 12, page 6835–6843
Authors: Jasinski, Florent; Alkhater, Amjad; Thickett, Stuart C.; Brinkhuis, Richard H.; Zetterlund, Per B.
Copolymer/water interfacial tensions of statistical copolymers of styrene/n-butyl acrylate were estimated by pendant drop tensiometry using an "inverse" configuration according to which a drop of water was formed in toluene/copolymer solutions. The study first involved the precise measurement of copolymer solutions density using pycnometry. Subsequently, interfacial tensions of copolymer solutions against water were plotted as a function of copolymer concentration in toluene. Several methods were explored to fit the experimental data and obtain estimates of copolymer/water interfacial tensions at 100% copolymer concentration in toluene by extrapolation. The Belton Evans extrapolation resulted in the best fit with the experimental data. When plotted as a function of the styrene composition of the copolymer, the interfacial tensions estimates followed an additivity relationship. This enabled estimation of the copolymer/water interfacial tensions directly from their respective homopolymer/water interfacial tensions values. These results are particularly useful for the prediction of composite particle morphology involving copolymerization of multiple monomers.
