Articles by Khashayar Saleh in JoVE
Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions Sven Drücker1, Isabell Krautstrunk2, Maria Paulick2, Khashayar Saleh1, Martin Morgeneyer1, Arno Kwade2 1Industrial Process Engineering, University of Technology of Compiègne, 2Institute for Particle Technology, Technische Universität Braunschweig The coefficient of restitution is a parameter that describes the loss of kinetic energy during collision. Here, a free-fall setup under vacuum conditions is developed to be able to determine the coefficient of restitution parameter for particles in micrometer range with high impact velocities.
Other articles by Khashayar Saleh on PubMed
Contact Angle Assessment of Hydrophobic Silica Nanoparticles Related to the Mechanisms of Dry Water Formation Langmuir : the ACS Journal of Surfaces and Colloids. Feb, 2010 | Pubmed ID: 20141200 Dry water is a very convenient way of encapsulating a high amount of aqueous solutions in a powder form made of hydrophobic silica nanoparticles. It was demonstrated in previous studies that both solid and liquid interfacial properties influence the quality of the final product resulting occasionally in mousse formation. To explain this behavior, contact angles of silica nanoparticles have been measured for water and water/ethanol solution by means of liquid intrusion experiments. It was found that the quality of the final product correlates with the contact angle, i.e., contact angle close to 105 degrees leads to mousse formation whereas a slightly higher value of approximately 118 degrees allows dry water formation. The proposed explanation was based on the energy of immersion and adhesion defined as the energy needed for a spherical particle to respectively penetrate into the liquid or attach at the liquid/air interface. Significantly lower energy of immersion calculated for lower contact angle might account for particle penetration into the liquid phase during processing, leading to continuous network aggregation, air entrapment, and finally mousse formation.