Formation of films on water droplets floating on a polymer solution surface

The behavior of water droplets deposited on a polymer solution/air interface has been studied. Encapsulation of water droplets with polymer films was observed for solutions based on chlorinated & aromatic solvents, and amorphous polymers. The possibility of producing thin polymer films(including composite ones) is demonstrated. Analysis of the specific surface energies of the interfaces involved in the process easily explains the observed encapsulation. The kinetics of the process is connected with evaporation of the moving solution layer. A mathematical model of the encapsulation process is proposed. The presented experimental data are important for understanding the water-assisted self-assembly with rapidly evaporated polymer solutions.