In this thesis, we investigated the adsorption of both organic and inorganic molecules at (aqueous) liquid-solid interfaces in the context of low salinity water flooding in enhanced oil recovery with various surface sensitive techniques and microfluidics. With ellipsometry, we are the first to quantitatively detect ion adsorption at silica-water interfaces. The combination with microfluidics and ellipsometry, enables us to conduct screening studies efficiently. As we develop a concentration gradient generator which creates a dilution series offering parallelization. With Quartz Crystal Microbalance (QCM), hexanoate adsorption at silica, alumina and gibbsite (each of them bearing a certain similarity to clays as found on rock surface)-water interfaces was explored with or without divalent cations. (Mass) adsorption curves suggest different adsorption mechanisms on these oxide surfaces as pH, cations and anions play different roles on different solid surfaces. The stability of the adsorbed organic film on the solid surface was also investigated with stearic acid monolayers (on exposure to water) after depositing them onto silica surfaces through the Langmuir-Blodgett (LB) technique. Results suggest the important effects of divalent ions (Ca2+), as they can form the cation bridge. In summary, we have developed techniques which can be used to study small molecule adsorption at solid-liquid interfaces fast and efficiently. Moreover, the important role of divalent cations such as Ca2+ has been demonstrated.
|Award date||20 Apr 2016|
|Place of Publication||Enschede|
|Publication status||Published - 20 Apr 2016|