Optimization of the Retardance in Dextran-citrate Coated Ferrofluids Using PSO and SA.

Single or double coating citrate and dextran on the Fe3O4 ferrofluids (FFs) have been conducted for biomedical application such as hyperthermia and magnetic resonance imaging. The magnetic retardance of dextran-citrate (DC) coated FFs was measured and magnetic heating effect in alternating magnetic field was investigated previously. Conducting experiment by uniform design; enabling the formula to fit with experimental data of retardance through stepwise regression (SR) analysis. The developed regression model had highly predictable ability with a high correlation coefficient R of 0.99989 between measured and predicted retardances. In order to find the maximum retardance, intelligent search methods including particle swarm optimization (PSO) and simulated annealing (SA) were used. The optimized parametric combinations were determined as [0.0750, 75.7945, 0.3225, 0.6500] and [0.0750, 75.844, 0.323, 0.65], respectively, corresponding to Fe3O4 concentration, coating temperature, citrate mass, and dextran mass. The corresponding maximum retardances were found as 119.6576° and 119.6558°. Overall, PSO algorithm was more effective than SA to optimize the retardance of the DC coated FFs.