K.A. Tatarenko, P.A. Tatarenko, S.A. Chernyak, A.V. Lazarev
«Coil—Globule» Transition During the Microencapsulation of TiO2 Nanoparticles in the Jet of Supercritical CO2
The process of microencapsulation of titanium dioxide nanoparticles in polyethylene
glycol PEG 8000 at pulse expanding of the jets of polymer solution in supercritical
carbon dioxide in vacuum and in a background gas (helium) is experimentally studied.
In both cases, at given initial temperature and cosolvent (ethanol) concentration the
distance from the nozzle exit to the point of «coil—globule» transition on the jet axis
is determined using the electron microscopy data. The dependence of the transition
point position on the initial temperature and the concentration of ethanol in the
reactor is obtained.
Key words: supercritical carbon dioxide, microencapsulation, pulsed supersonic jet, TiO2 nanoparticles