ASSEMBLY OF LATEX-PARTICLES BY USING EMULSION DROPLETS AS TEMPLATES .2. BALL-LIKE AND COMPOSITE AGGREGATES

We report data on using the emulsion-based method for the assembly of ball-like aggregates of a positively charged (amidine) latex. The late x particles are strongly hydrophobized with the use of sodium dodecyl sulfate, which induces their adsorption into the bulk of the emulsion droplets. The droplets are then sterically protected against coalescen ce, and the particles gathered inside them are fixed. After the emulsi on droplets are dissolved, a suspension of ball-like latex aggregates is obtained. The aggregates do not appear to be ordered, but their ove rall shape is precisely spherical. The process of fabricating ball-lik e aggregates was then combined with the assembly scheme for hollow sup raparticles (presented in the first paper of this series). As a result , we have been able to obtain composite particles, whose cores are bal l-like aggregates of amidine latex, surrounded by a shell of negativel y charged sulfate latex. The core-shell structure was visualized by fl uorescent microscopy. We also report data on the fabrication of compos ite particles by amidine heterocoagulation over hollow spherical shell s from the sulfate latex. The described methods seem applicable to the assembly of ball-like and composite aggregates from colloid species o ther than latex beads.