In certain aspects, where the polyelectrolyte polymers in both phases are PAA and PAAm-co-AA for electrohydrodynamic co-jetting experiments, a pH modifying agent, such as NaOH, can be used to alter the conductivity of the jetting solution, and the resultant particle architectures range from anisotropic (e.g., Janus) particles to core-shell particles (as shown in FIGS. 3A-3D).