Thermophoretic force and velocity of nanoparticles in the free molecule regime 

 -  Physical Review E - Statistical, Nonlinear, and Soft Matter Physics, 70(2), p.021205-1-021205-11, 2004 .
<br/><br/> The kinetic theory analysis of drag on particles in a low-density gas to thermophoresis of nanoparticles in the free molecular regime was presented. The influence of nonrigid body collision due to van der Walls or other forces between the particle and gas molecules was analyzed. It was found that Waldmann's formula could be considered as a limiting case of the current result under the assumption of rigid body collisions. It was also found that the zigzag behavior of the velocity ratio was caused by the switching of the dominant scattering mechanisms which ultimately affect the drag force. 
<br/><br/><label>Subjects--Topical Terms: </label><br/>CONTINUUM MECHANICS<br/>ELEMENTARY PARTICLES<br/>KINETIC THEORY OF GASES<br/>MATHEMATICAL MODELS<br/>PARTICLE SIZE ANALYSIS<br/>POTENTIAL ENERGY<br/>REYNOLDS NUMBER<br/>THERMAL DIFFUSION<br/>THERMOPHORESIS<br/>VAN DER WAALS FORCES