  The wavelength of a periodic spatial structure of Turing type is an intrinsic
property of the considered reaction-diffusion dynamics and we address the
question of its control at the microscopic scale for given dynamical
parameters. The direct simulation Monte Carlo method, initially introduced to
simulate particle dynamics in rarefied gases, is adapted to the simulation of
concentrated solutions. We perform simulations of a submicrometric Turing
pattern with appropriate boundary conditions and show that taking into account
the role of the solvent in the chemical mechanism allows us to control the
wavelength of the structure. Typically, doubling the concentration of the
solution leads to decreasing the wavelength by two. The results could be used
to design materials with controled submicrometric properties in chemical
engineering. They could also be considered as a possible interpretation of
proportion preservation of embryos in morphogenesis.
