Large-scale kinetic roughening behavior of coffee-ring fronts Articles uri icon

publication date

  • October 2022

start page

  • 044801-1

end page

  • 044801-16

issue

  • 4

volume

  • 106

abstract

  • We have studied the kinetic roughening behavior of the fronts of coffee-ring aggregates via extensive numerical simulations of the off-lattice model considered for this context [Dias et al., Soft Matter 14, 1903 (2018)].
    This model describes ballistic aggregation of patchy colloids and depends on a parameter rAB which controls
    the affinity of the two patches, A and B. Suitable boundary conditions allow us to elucidate a discontinuous
    pinning-depinning transition at rAB = 0, with the front displaying intrinsic anomalous scaling, but with unusual
    exponent values α 1.2, αloc 0.5, β 1, and z 1.2. For 0 < rAB 1, comparison with simulations of
    standard off-lattice ballistic deposition indicates the occurrence of a morphological instability induced by the
    patch structure. As a result, we find that the asymptotic morphological behavior is dominated by macroscopic
    shapes. The intermediate time regime exhibits one-dimensional KPZ exponents for rAB > 0.01 and the system
    suffers a strong crossover dominated by the rAB = 0 behavior for rAB 0.01. A detailed analysis of correlation
    functions shows that the aggregate fronts are always in the moving phase for 0 < rAB 1 and that their kinetic
    roughening behavior is intrinsically anomalous for rAB 0.01.

subjects

  • Physics

keywords

  • kardar-parisi-zhang equation; numerical approximation & analysis; lattice models in statistical physics; critical exponents; nonequilibrium statistical mechanics; phase transitions; transport phenomena