Active Micelle Pumping Channel Triggers Nonequilibrium Surface Excess Aggregation

Langmuir. 2023 Aug 29;39(34):12260-12269. doi: 10.1021/acs.langmuir.3c01716. Epub 2023 Aug 15.

Abstract

Adsorbate transport during the electrochemical process mostly follows the electric-field direction or the high-to-low direction along the concentration gradient and thus often limits the reactant concentration at the adsorption site and requires specific mechanical or chemical bonds of adsorbates to trigger local excess aggregation for advanced framework structure assembly. Herein, we have discovered an active pumping channel during electrochemical adsorption of a manganese colloid, which follows a low-to-high direction inverse concentration gradient. It triggers surface excess micelle aggregation with even over 16-folds higher concentration than that in bulk owing to hydrogen-bonding difference of the micelle surface between in bulk and at the water surface. Micelles in the channel exhibit unique polymerization behaviors by directly polymerizing monomer micelles to form highly catalytic MnO2 of dendritic frameworks, which can serve as a scalable thin-layer aqueous-phase reactor. It increases the understanding of the interface-dependent dynamic nature of micelle or more adsorbates and inspires transformative synthesizing approaches for advanced oxide materials.