Reliable and fast evaluation of dispersibility of nanoclays in various solvents and rational solvent selection utilizing NMR relaxation and Hansen Solubility Parameter

Identifying suitable solvent system for nanomaterials like nanoclay is crucial for enhancing product quality and manufacturing efficiency. The effectiveness of a solvent in dispersing these nanoparticles is fundamentally governed by interactions at the molecular level. However, quantifying these interactions presents significant challenges, as current methods for assessing dispersion stability often involve time-consuming and resource-intensive procedures. This study presents a novel approach for evaluating the wettability and dispersibility of nanoclays in various solvents using Nuclear Magnetic Resonance (NMR) relaxation and Hansen Solubility Parameters (HSP). Four different nanoclays - natural montmorillonite (Cloisite Na+), organomodified montmorillonite (Cloisite 20 A), synthetic hectorite (Laponite RD), and kaolinite (Kaolin NZ) were investigated in a wide range of solvents. The synergistic use of NMR relaxation and HSP provided a rapid and accurate method for analyzing nanoclay-solvent interactions, even for rapidly settling dispersions. This technique offers a standardized approach to compare diverse systems and optimize dispersion properties based on NMR relaxation number and HSP values. The study demonstrates the effectiveness of this method in quantifying solvent-surface interactions and ranking interaction strengths , facilitating the selection of optimal solvents, solvent mixtures and sustainable or environment friendly options for nanoclay dispersions in various applications such as coatings, paints, inks, adhesives, cosmetics, and pharmaceuticals. • Explored a novel approach using NMR relaxation and HSP for evaluating nanoclay dispersibility. • Rapid and accurate method for analyzing nanoclay-solvent interactions. • Quantified solvent-surface interactions and ranked interaction strengths. • Facilitated optimal solvent and solvent-mixture selection for nanoclay dispersions in various applications. • Applicable to diverse nanoclay types, including montmorillonite, hectorite, and kaolinite .