tailieunhanh - Molecular simulation of nanoparticle diffusion at fluid interfaces

In  Molecular simulation of nanoparticle diffusion at fluid interfaces molecular dynamics simulations are used to exam- ine the transport properties of a nanoparticle in both bulk solvent and at a liquid–liquid interface. Specifically it aims to address the effect of interfacial adsorption on the diffusion of nanoparticles (at low concentration).  | Chemical Physics Letters 495 2010 55-59 Contents lists available at ScienceDirect Chemical Physics Letters journal homepage locate cplett Molecular simulation of nanoparticle diffusion at fluid interfaces . Cheung Department of Chemistry and Centre for Scientific Computing University of Warwick Coventry CV4 7AL UK ARTICLE INFO ABSTRACT Article history Received 7 April 2010 In final form 24 June 2010 Available online 30 June 2010 Using molecular dynamics simulations the transport properties of a model nanoparticle in solution are studied. In bulk solvent the translational diffusion coefficients are in good agreement with previous simulation and experimental work while the rotational diffusion is more rapid than in previous simulations. When the nanoparticle is adsorbed at a liquid-liquid interface it becomes strongly attached to the interface. This leads to highly anisotropic motion with in-plane diffusion being several orders of magnitude larger than out-of-plane diffusion. By contrast the rotational diffusion is only slightly changed when the particle is adsorbed at the interface. 2010 Elsevier . All rights reserved. 1. Introduction Motivated by the long-standing observation that solid particles may adhere to liquid interfaces 1 2 the behaviour of nanoparticles at fluid interfaces has over the past few years become an area of active interest 3 . Much of this interest has been driven by the potential use of liquid interfaces as a template for the formation of dense nanoparticle structures such as monolayers and membranes. The modification of interfacial properties by the adhesion of nanoparticles may also be used to stabilize the formation of large-scale structures. It has long been recognized that the dynamic and transport properties of nanoparticles in the bulk 4-8 and at interfaces may be significantly different to those of larger particles. The translational motion of particles at interfaces is important in understanding the interfacial .