Photophoresis of spherical particles with interfacial thermal resistance in micro-nano fluids

Based on Mie scattering theory and steady thermal conduction function, we establish the theoretical analysis of particlesʼ photophoresis in micro-nano fluids by taking into account the interfacial resistance between particles and the fluid. It is found that the heat source function can determine not only the magnitude but also the direction of the photophoretic velocity, while the interfacial resistance can only play a role in the magnitude of the velocity. Numerical results show that there is positive (negative) photophoresis for particles with large (small) size parameter α, high (low)-absorption κp, and low (high)-refraction np. In addition, lower thermal conductivity and smaller interfacial resistance of the particle may result in faster photophoretic motion.