TY  - JOUR
AU  - Begam, Nafisa
AU  - Chandran, Sivasurender
AU  - Sprung, M.
AU  - Basu, Jaydeep
TI  - Anomalous Viscosity Reduction and Hydrodynamic Interactions of Polymeric Nanocolloids in Polymers
JO  - Macromolecules
VL  - 48
IS  - 18
SN  - 1520-5835
CY  - Washington, DC
PB  - Soc.
M1  - PUBDB-2015-06298
SP  - 6646 - 6651
PY  - 2015
N1  - (c) American Chemical Society
AB  - One of the central dogmas of fluid physics is the no-slip boundary condition, whose validity has come under scrutiny, especially in the fields of micro and nanofluidics. Although various studies show the violation of the no-slip condition its effect on flow of colloidal particles in viscous media has been rarely explored. Here we report unusually large reduction of effective viscosity experienced by polymeric nano colloids moving through a highly viscous and confined polymer, well above its glass transition temperature. The extent of reduction in effective interface viscosity increases with decreasing temperature and polymer film thickness. Concomitant with the reduction in effective viscosity we also observe apparent divergence of the wave vector dependent hydrodynamic interaction function of these colloids with an anomalous power law exponent of  2 at the lowest temperatures and film thickness studied. Such strong hydrodynamic interactions are not expected for polymeric colloidal motion in polymer melts. We suggest hydrodynamics, especially slip present at the colloid–polymer interface which determines the observed reduction in interface viscosity and presence of strong hydrodynamic interactions.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000361935600032
DO  - DOI:10.1021/acs.macromol.5b00759
UR  - https://bib-pubdb1.desy.de/record/292691
ER  -