Water Purification Vials (IMAGE) Michigan Technological University Caption After shaking, the oil and water in the vial separate, trapping unwanted nanomaterials in the bottom of the oil layer. Credit Michigan Tech, Sarah Bird 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.