“…Then, the solution was cooled up to room temperature. After this phase, the micronized PEI was added to NH 4 PAA solution, and then homogenized with a magnetic stirrer for 30 minutes (Texier et al, 1993;Gardner, 1998;Nohara et al, 2007). The NH4PAA/PEI mass ratio was 0.05 and the concentration of PEI in the suspension was 10% mass (Gardner, 1998).…”