6533b862fe1ef96bd12c6468
RESEARCH PRODUCT
Isotropic-nematic interface and wetting in suspensions of colloidal platelets.
D. Van Der BeekHendrik ReichRichard L. C. VinkMarjolein DijkstraP.p.a.m. Van Der SchootMatthias SchmidtMatthias SchmidtHenk N. W. LekkerkerkerR. Van RoijTanja Schillingsubject
Materials scienceCondensed matter physicsbusiness.industryCapillary actionIsotropyHomeotropic alignmentGeneral Physics and AstronomyPhysics::Fluid DynamicsCondensed Matter::Soft Condensed MatterSurface tensionOpticsLiquid crystalPhase (matter)MeniscusWettingbusinessdescription
We study interfacial phenomena in a colloidal dispersion of sterically stabilized gibbsite platelets, exhibiting coexisting isotropic and nematic phases separated by a sharp horizontal interface. The nematic phase wets a vertical glass wall and polarized light micrographs reveal homeotropic surface anchoring both at the free isotropic-nematic interface and at the wall. On the basis of complete wetting of the wall by the nematic phase, as found in our density functional calculations and computer simulations, we analyze the balance between Frank elasticity and surface anchoring near the contact line. Because of weak surface anchoring, the director field in the capillary rise region is uniform. From the measured rise (6 microm) of the meniscus at the wall we determine the isotropic-nematic surface tension to be 3 nN/m, in quantitative agreement with our theoretical and simulation results.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2006-01-01 | Physical review letters |