Nanodiamond Promotes Surfactant-Mediated Triglyceride Removal from a Hydrophobic Surface at or below Room Temperature

We demonstrate that ca. 5 nm nanodiamond particles dramatically improve triglyceride lipid removal from a hydrophobic surface at room temperature using either anionic or nonionic surfactants. We prepare nanodiamond–surfactant colloids, measure their stability by dynamic light scattering and use quartz crystal microbalance–dissipation, a technique sensitive to surface mass, in order to compare their ability to remove surface–bound model triglyceride lipid with ionic and nonionic aqueous surfactants at 15–25 °C. Oxidized, reduced, ω-alkylcarboxylic acid, and ω-alkylamidoamine surface-modified adducts are prepared, and then characterized by techniques including 13C cross-polarization (CP) magic-angle spinning (MAS) NMR. Clear improvement in removal of triglyceride was observed in the presence of nanodiamond, even at 15 °C, both with nanodiamond–surfactant colloids, and by prior nanoparticle deposition on interfacial lipid, showing that nanodiamonds are playing a crucial role in the enhancement of the detergency process, providing unique leads in the development of new approaches to low-temperature cleaning.