Normal and anomalous Knudsen diffusion in 2D and 3D channel pores
نویسندگان
چکیده
channel pores where no very long jumps are possible. For pores with an elevation that varies like a random walk (red) and alternating pores (blue) the scaled mean square displacement /t is asymp-totically constant. 1. Introduction In general, diffusion of gas particles depends on the collisions between the gas molecules as well as on the collisions of the gas with the pore walls. Of particular interest for many real gases is the so-called Knudsen regime, where the interaction of the molecules with the pore walls plays the crucial role and the intramolecular collisions can be neglected. We implement pores with different roughness, by considering the first four iterations of a generalized fractal Koch curve. For these model pores we have performed detailed investigations of diffusion coefficients using a cube-based algorithm. We know, the diffusion properties can be mapped onto Levy walks [1] to predict the diffusion properties. In 2D linear channel pores we observe anomalous diffusion [2, 3], which can also be induced by using different reflection laws in smooth or rough 3D pores. Normal diffusion is found in convoluted 2D pores and in all 3D pores when applying diffuse reflection.
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Normal and anomalous diffusion of non-interacting particles in linear nanopores
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