Confined flows of a polymer microgel.

摘要: In this paper, we probe the influence of confinement on flows a polymer microgel, namely Carbopol. We compare its bulk rheological behavior, measured with rheometer and well described by Hershel-Bulkley law, to velocity profiles in rough microchannels, obtained particle tracking velocimetry technique. show strong disagreement between prediction for ones microchannels. Velocity confined conditions are successfully analyzed within framework non-local fluidity model introduced recently (J. Goyon et al. Nature, 454, 84 (2008)). This allows determine cooperativity length ξ, whose order magnitude compares structure size microgel. Moreover, measure flow curves using different gap also that set data exhibit effect properties. is again characterized typical same as scale ξ. thus evidence effects two complementary experiments which both give rearrangements flows.