Abstract

Abstract Equilibrium composition and pressure profiles are determined for spherical drops within a binary, Landau-Ginzburg fluid that has undergone phase separation. There is a smallest possible drop size, below which a drop would redissolve to form a homogeneous system. This minimum drop size has a radius of Ri = √k/-gn(ã) where κ is the gradient energy parameter and g(ã) is the Gibbs free energy of mixing evaluated at the system average concentration. The minimum drop size at equilibrium is approximately equal to the minimum size for growth by spinodal decomposition as predicted from linearized Cahn-Hilliard theory. It represents a practical limit on the ultimate fineness of polymer-in-polymer microdisper-sions. The minimum drop radius will be on the order of 0.02 microns for typical, high molecular weight polymers. The surface tension is calculated for systems of finite extent in both radial and spherical coordinates. It vanishes when the size of the system is less than the minimum size needed for bifurcation into two phases. The pressure distribution within spherical drops is calculated using a differential form of the Young-Laplace equation. The classical result, ΔP = 2σ/R overpredicts the internal pressure for small drop sizes although this is partially due to the ambiguity in specifying the radius of small drops.

Full Text
Paper version not known

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.