Osmotic pressure and viscoelastic shear moduli of concentrated emulsions

@article{citeulike:1706973, abstract = {We present an experimental study of the frequency ω dependence and volume fraction φ dependence of the complex shear modulus G * (ω;φ) of monodisperse emulsions which have been concentrated by an osmotic pressure Π. At a given φ; the elastic storage modulus G ′ (ω)=Re[ G * (ω)] exhibits a low-frequency plateau G p ′ ; dominating the dissipative loss modulus G ′′ (ω)=Im[ G * (ω)] which exhibits a minimum. Above a critical packing fraction φ c ; we find that both Π(φ) and G p ′ (φ) increase quasilinearly; scaling as (φ-φ c ) μ ; where φ c ≈φ c rcp ; the volume fraction of a random close packing of spheres; and μ is an exponent close to unity. To explain this result; we develop a model of disordered droplets which interact through an effective repulsive anharmonic potential; based on results obtained for a compressed droplet. A simulation based on this model yields a calculated static shear modulus G and osmotic pressure Π that are in excellent agreement with the experimental values of G p ′ and Π.}, author = {Mason, T. G. and Lacasse, Martin-D and Grest, Gary S. and Levine, Dov and Bibette, J. and Weitz, D. A. }, citeulike-article-id = {1706973}, doi = {http://dx.doi.org/10.1103/PhysRevE.56.3150}, journal = {Physical Review E}, keywords = {emulsion, experiment, force, mason, modulus, shear, weitz}, number = {3}, pages = {3150+}, posted-at = {2008-08-17 19:51:01}, priority = {2}, publisher = {American Physical Society}, title = {Osmotic pressure and viscoelastic shear moduli of concentrated emulsions}, url = {http://dx.doi.org/10.1103/PhysRevE.56.3150}, volume = {56}, year = {1997} }

TY - JOUR ID - citeulike:1706973 L3 - citeulike-article-id:1706973 N2 - We present an experimental study of the frequency ω dependence and volume fraction φ dependence of the complex shear modulus G * (ω;φ) of monodisperse emulsions which have been concentrated by an osmotic pressure Π. At a given φ; the elastic storage modulus G ′ (ω)=Re[ G * (ω)] exhibits a low-frequency plateau G p ′ ; dominating the dissipative loss modulus G ′′ (ω)=Im[ G * (ω)] which exhibits a minimum. Above a critical packing fraction φ c ; we find that both Π(φ) and G p ′ (φ) increase quasilinearly; scaling as (φ-φ c ) μ ; where φ c ≈φ c rcp ; the volume fraction of a random close packing of spheres; and μ is an exponent close to unity. To explain this result; we develop a model of disordered droplets which interact through an effective repulsive anharmonic potential; based on results obtained for a compressed droplet. A simulation based on this model yields a calculated static shear modulus G and osmotic pressure Π that are in excellent agreement with the experimental values of G p ′ and Π. IS - 3 JF - Physical Review E TI - Osmotic pressure and viscoelastic shear moduli of concentrated emulsions PB - American Physical Society VL - 56 SP - 3150 KW - emulsion KW - experiment KW - force KW - mason KW - modulus KW - shear KW - weitz AU - Mason, TG AU - Lacasse, Martin-D AU - Grest, Gary AU - Levine, Dov AU - Bibette, J AU - Weitz, DA PY - 1997/// UR - http://dx.doi.org/10.1103/PhysRevE.56.3150 ER -