I am working on complex coacervation between gelatin and sodium alginate as shell materials and ammonium phosphate as the core material to form microcapsules for flame retardant of cotton fabrics. I used 3% core and 1.5% shell at high speed of mixing using homogenizer, then I did centrifugal at high speeds (8000 rpm) to separate the microcapsules from the solution, but the amount of resulting microcapsules was little, their weight was just 0.8 g and the microencapsulation was only 1%. I tried to increase the concentration of core and wall materials with keeping (core /shell) ratio, but the medium became gelling so I diluted it with distilled water, but also the amount of resulting microcapsules was little.

There is a thing, I used just distilled water to dissolve both core and wall materials in the emulsion because both of them can dissolve in water, is it necessary to use an organic phase to dissolve the core material? Does that effect on the amount of resulting microcapsules?

And is there another way to separate the microcapsules from the solution else the centrifuge method?