title: Thermophoretic force on micro- and nanoparticles in dilute binary gas mixtures.
abstract: We theoretically investigate the thermophoretic force on spherical particles in binary monatomic gas mixtures in the free molecular regime. Based on gas kinetic theory and by considering the gas-particle interactions, we derive the analytical formulas of the thermophoretic force for two limiting gas-particle collision models; namely, specular and diffuse scattering scenarios. The formulas are consistent with those in simple gases and apply to both micro- and nanoparticles; for the latter the intermolecular interactions are important. As an example, the thermophoretic force on Ag nanoparticles in He-Ar mixtures is illustrated.
authors.affiliation: Department of Mechanical Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong.
authors.forename: Jun
authors.initials: J
authors.lastname: Wang
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Li