Nanosize Polymeric Foams and Microparticles Prepared In Situ From Janus-Type Microbubble Constitutions.

In this work, we generate Janus-type microbubbles that have distinct morphological patterns by utilizing microfluidics technology. A V-Junction Microfluidic (VJM) device was designed through a Solidworks program with three inlets and one microfluidic outlet attached at 30° to produce a closed system. 3% wt. PLA and 3% wt. PEG were chosen owing to the distinct physicochemical features of these polymers. Two hundred and seventy-five microliters/min PLA and 180 μL/min PEG were fed into the system with a nitrogen gas pressure of 12 kPa, where five different solvents produced Janus-type microbubbles. In addition, the effect of the change in inlet velocity of nitrogen gas on the composition of the solutions, volume fraction, and density changes was numerically examined. The results indicate that honeycomb structures and particle formation were observed at different scales, ranging from 854 ± 49 nm to 6.5 ± 0.5 μm. Numerical analysis showed that the speed associated with the 3 wt.% PLA and 3 wt.% PEG solutions had a direct effect on phase formation. Numerical results also showed that the difference in the inlet velocity of nitrogen gas in the apparatus can play a significant role in the composition of the solutions; this change may also affect the formation of microbubbles.