Paper Number
IR10 

Session
Interfacial Rheology

Title
Interfacial layer formation of clay particles with surfactants

Presentation Date and Time
October 24, 2019 (Thursday) 8:40

Track / Room
Track 7 / Room 306C

Authors (Click on name to view author profile)

1. Hong, Joung Sook (Seoul National University, Institute of Chemical Processes)
2. Fischer, Peter (ETH Zurich, IFNH)

Author and Affiliation Lines (in printed abstract book)
Joung Sook Hong¹ and Peter Fischer^2
1Institute of Chemical Processes, Seoul National University, SEOUL, Select From List 08826, Republic of Korea; ²IFNH, ETH Zurich, Zurich 8092, Switzerland

Speaker / Presenter 
Hong, Joung Sook

Text of Abstract
The combined addition of clay and surfactant stabilizes or destabilize the emulsion depending on interfacial interaction of clay and surfactant. In order to investigate the interaction of clay and surfactant at the interface, the interfacial layer formation of clay particles at the oil-water interface was studied through interfacial rheometry under the regulated flow of surfactant-aqueous solution. Also, it was compared with the observation of the interfacial localization of clay in a model emulsion (single droplet) with surfactant. The interfacial diffusion of surfactant mostly destroyed the formation of particulate interface by stronger interfacial adsorption of surfactant than clay. However, if there is a strong interaction between clay and surfactant, interfacial modulus of the oil-water interface with particles and surfactant was increased rapidly and also it abruptly decreased with a further addition of surfactant. It means that clays remain at the interface and rather generate a strong complex interface with a small amount of surfactant. As surfactant diffuses to the interface more, it enhances desorption of particles. The interfacial layer formation of clays with surfactant was significantly determined depending on the competition between the stronger interfacial adsorption of surfactant and the interaction between clay and surfactant, as well as the content. For the limited condition of surfactant, surfactant enhanced localization of clay and increased interfacial modulus due to complex structure formation between clay and surfactant. This work was supported by a grant from the National Research Foundation of Korea (NRF) funded by the Korean government(MSIP) (No.2016R1E1A1A01942362)