Estimation of copolymer/water interfacial tensions using pendant drop tensiometry
Jasinski, F and Alkhater, A and Thickett, SC and Brinkhuis, RH and Zetterlund, PB, Estimation of copolymer/water interfacial tensions using pendant drop tensiometry, Langmuir, 34, (23) pp. 6835-3843. ISSN 0743-7463 (2018) [Refereed Article]
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.
interfacial tension, pendant drop tensiometry, copolymers, surface free-energies, macromolecular systems, polymer, morphology, density, water, polyethylene, adsorption, particles, micelles