Nanoparticle Illustration (IMAGE) University of Pennsylvania Caption The nanoparticles' ligands bumpers keep them from sticking together while remaining at the oil-water interface. Credit University of Pennsylvania Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.