Reactivity of Mineral-Water Interfaces: A Game-changer for Adsorption.

Reactivity of Mineral-Water Interfaces: A Game-changer for
Adsorption
Abstract text: From shells to rocks, dissolution is intrinsic to all minerals.
Yet the colloidal interactions with solutes are often described without any
account for mineral dissolution. We discovered remarkable nonmonotonic
trends for the growth or dissolution of (Mg) carbonate
surfaces interacting with organic acids as a function of ion composition,
temperature and flow rate. Combining Quartz Crystal Microbalance
measurements with confocal Raman microscopy and potentiometric
titrations, we show the non-monotonous mass developments originate
NWO CHAINS 2021 <chains@nwochains.nl>
Mon 08/11/2021 11:35
To:Rao, Ashit (UT-TNW) <a.r.rao@utwente.nl>;
Email - a.r.rao@utwente.nl https://xs.utwente.nl/owa/#path=/mail/search
1 of 2 1/11/2022, 2:19 PM
from 3 coupled chemical equilibria: (i) carbonate dissolution via the
binding of Ca2+ ions to organic molecules, and the precipitation of
organo-calcium compounds as (ii) a surface phase on the mineral and (iii)
particles in bulk fluid. Our findings show that the ion concentrations and
associated precipitation tendency (saturation index) of organo-calcium
salts differ substantially between the bulk fluid and the vicinity of the
mineral surface. With even subtle perturbations to the fluid-mineral
interface affecting how minerals interact with organic solutes, observed
transitions from mineral dissolution to the surface and bulk precipitation
of organo-calcium salts have profound implications across disciplines
such as biomineralization, ocean acidification and reservoir chemistry.
Keywords: adsorption, Minerals, Organic acids, QCM-D, Calcium
carbonate