In Model 2, the one degree terms A, B and C had extremely significant effects on the PDI (Y 2 ) of the AAP-NPs ( p < 0.01), and the F -values revealed that the contributions of the factors in this experiment were A > B > C.
023A − 0.034B − 2.273E − 0.003C − 0.018AB − 0.022AC + 0.016BC + 0.11A 2 − 0.069B 2 −0.049C 2 (2) As shown in Table 2 , the Model F-values of (Y 1 ) average size and (Y 2 ) PDI were 99.86 and 58.63, respectively, and both had p -values < 0.0001, indicating that both of the two models had reached the highly significant level and had statistical significance.