Nanomechanical insights into hydrophobic interactions of mineral surfaces in interfacial adsorption, aggregation and flotation processes

Abstract

Hydrophobic interactions play a critical role in many interfacial processes of mineral systems, such as water treatment, particle separation, and functional materials for self-cleaning or electrocatalysis. The quantification and modulation of hydrophobic interactions at the mineral/water interface can help unravel the mechanisms underlying the interfacial processes of mineral particles. Over the past several decades, surface forces apparatus (SFA) and atomic force microscope (AFM) have been employed to quantify the hydrophobic interactions. This work has reviewed the latest progress on nanomechanical understanding of hydrophobic interactions of mineral surfaces in interfacial processes. We first introduce the water structure at mineral/water interface and wettability of mineral surface, which are closely related to the hydrophobic interactions of mineral surfaces. Subsequently, the hydrophobic interactions in homo/hetero-agglomeration of mineral particles, bubble attachment on mineral surfaces, and adsorption of organics on mineral surfaces at the nanoscale are quantitatively discussed. Moreover, the recent advances in applying stimuli-responsive polymers in the modulation of hydrophobic interactions at mineral/water interfaces are presented, and the perspectives for future studies are also highlighted. This review provides insightful information on the understanding and modulation of hydrophobic interactions at the mineral/water interfaces, which hold great promise for developing effective strategies to mediate the interfacial processes of mineral particles in chemical, environmental and materials engineering.