jp401751z_si_002.mpg (478 kB)
Effect of Surfactant on the Drying Patterns of Graphite Nanofluid Droplets
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posted on 2013-05-16, 00:00 authored by Alexandru Crivoi, Fei DuanWe
investigate the effect of surfactant on the formation of nanoparticle
aggregates that resulted from evaporation of sessile nanofluid droplets
theoretically and experimentally. A Monte Carlo model is developed
to explain the transition from the coffee-ring pattern to the uniform
deposition in drying the pinned sessile nanofluid droplets. The model
applies the diffusion limited cluster–cluster aggregation approach
coupled with the biased random walk of nanoparticles. The experiments
show that the addition of surfactant in nanofluids helps the formation
of a coffee ring instead of the uniform domain coverage. The simulations
suggest an explanation of this transition by controlling the sticking
probability parameter between the particles. The simulated results
statistically agree with the experimental observation of the finally
dried graphite nanoparticle structures from the pinned nanofluid droplets.