title: Fundamental Study of Emulsions Stabilized by Soft and Rigid Particles.
abstract: Two distinct uniform hybrid particles, with similar hydrodynamic diameters and comparable zeta potentials, were prepared by copolymerizing N-isopropylacrylamide (NIPAM) and styrene. These particles differed in their styrene to NIPAM (S/N) mass ratios of 1 and 8 and are referred to as S/N 1 and S/N 8, respectively. Particle S/N 1 exhibited a typical behavior of soft particles; that is, the particles shrank in bulk aqueous solutions when the temperature was increased. As a result, S/N 1 particles were interfacially active. In contrast, particle S/N 8 appeared to be rigid in response to temperature changes. In this case, the particles showed a negligible interfacial activity. Interfacial shear rheology tests revealed the increased rigidity of the particle-stabilized film formed at the heptane-water interface by S/N 1 than S/N 8 particles. As a result, S/N 1 particles were shown to be better emulsion stabilizers and emulsify a larger amount of heptane, as compared with S/N 8 particles. The current investigation confirmed a better performance of emulsion stabilization by soft particles (S/N 1) than by rigid particles (S/N 8), reinforcing the importance of controlling softness or deformability of particles for the purpose of stabilizing emulsions.
authors.affiliation: †Department of Chemical and Materials Engineering, University of Alberta, 9107 - 116 Street, Edmonton, Alberta T6G 2V4, Canada.
authors.forename: Zifu
authors.initials: Z
authors.lastname: Li
authors.affiliation: †Department of Chemical and Materials Engineering, University of Alberta, 9107 - 116 Street, Edmonton, Alberta T6G 2V4, Canada.|‡School of Chemical and Process Engineering, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: David
authors.initials: D
authors.lastname: Harbottle
authors.affiliation: †Department of Chemical and Materials Engineering, University of Alberta, 9107 - 116 Street, Edmonton, Alberta T6G 2V4, Canada.
authors.forename: Erica
authors.initials: E
authors.lastname: Pensini
authors.affiliation: §Department of Chemistry, The Chinese University of Hong Kong, G59, Ma Lin Building, Science Centre South Block, Shatin, N. T., Hong Kong.
authors.forename: To
authors.initials: T
authors.lastname: Ngai
authors.affiliation: ∥Institute of Physical Chemistry, RWTH Aachen University, Landoltweg 2, D-52056 Aachen, Germany.
authors.forename: Walter
authors.initials: W
authors.lastname: Richtering
authors.affiliation: †Department of Chemical and Materials Engineering, University of Alberta, 9107 - 116 Street, Edmonton, Alberta T6G 2V4, Canada.|⊥Institute of Nuclear and New Energy Technology, Tsinghua University, Beijing 100084, China.
authors.forename: Zhenghe
authors.initials: Z
authors.lastname: Xu