SCATTERING STUDIES OF POLY(UREA-URETHANE) MICROCAPSULES IN SUSPENSION

Poly(urea-urethane) microcapsules containing tris(2-chloroethyl) phosp hate as the core material were characterized by means of laser light s cattering and synchrotron small angle X-ray scattering. The z-average hydrodynamic radius R(h) of the microcapsule was determined to be 165 +/- 7 nm from dynamic light scattering (DLS). The z-average radius of gyration R(g) = 130 +/- 4 nm from static light scattering and 120 +/- 8 nm from ultrasmall angle X-ray scattering, which coincide with the c alculated value of 129 nm by using a solid sphere assumption and the v alue of R(h) from DLS. These results were compared with previously pub lished data for microcapsules with the same membrane but different cor e materials. (C) 1996 Academic Press, Inc.