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 degrees C. Oxidized, reduced, omega-alkylcarboxylic acid, and omega-alkylamidoamine surface-modified adducts are prepared, and then characterized by techniques including C-13 cross-polarization (CP) magic-angle spinning (MAS) NMR. Clear improvement in removal of triglyceride was observed in the presence of nanodiamond, even at 15 degrees 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.