## 3 Result and Discussion
### Characterization of Transferring from Pre-Solution  
It is the central issue of this study to consider why the DEG can work for obtaining aqueous solutions of BL-01, BL03, and BL-05 but MEK cannot. The evident difference between the DEG and MEK solutions was the speed of dispersing into the aqueous phase, based on the viscosity of the solutions; probably, the MEK solutions are too rapidly dispersed into the aqueous phase to fully neutralize the polymer by KOH at the molecular level, thus dispersing as aggregation, due to the shortage of hydrophilicity. On the other hand, DEG solutions of BL-01, BL-03, and BL-05 were slowly dispersed into aqueous solutions, eventually converting into aqueous polymer solutions, probably owing to enough time for neutralization of the polymers at the molecular level. To verify this consideration, we changed the polymer state in the aqueous phase by controlling the speed of dispersing the pre-solution of the polymers into the aqueous solution, which would be modulated by the viscosity of the pre-solutions.  
Then, the DEG pre-solutions of BL-01, 03, and 05 at varied concentrations were prepared, to change the viscosity, and were all clear and viscous solutions. As shown in Figure 6, we successfully obtained the DEG pre-solutions having a viscosity in the range from below 100 mPa-sec to above 1000 mPa-sec.  
Subsequently, the DEG solutions were settled on the bottom of the sample bottles, followed by pouring large amounts of KOH aqueous solution and irradiating the ultrasonic wave for 1 h, whereby the polymer concentration finally became 0.1 wt% aqueous solution and KOH molars were 1.2 times in excess of those of the carboxyl groups contained on the polymers. When using the pre-solutions of 10 wt% BL-01 and BL-03, transparencies of the finally obtained aqueous-solutions were low, whereas the pre-solutions with the higher polymer concentrations made transparent aqueous solutions of the polymers (Figures 7 and 8a). Furthermore, larger particle sizes were detected in the aqueous solutions prepared from the pre-solution with the lower concentration of the BL-01 and BL-03, i.e., with lower viscosity (Figure 8b). These results indicate that the viscosity of the pre-solution would be a crucial parameter to determine the polymer state in the aqueous solution, as we expected. On the other hand, all of the BL-05 solutions among those investigated were transparent (Figure 7c), showing that the particle size of BL-05 did not change at any concentration (Figure 8b). There might be a lower concentration range which BL-05 would not solve. This phenomenon is probably due to the slower diffusion of BL-05 from the DEG solution to the aqueous solution, expected by its larger molecular weight compared to the other two (BL-01, BL-03).  
Figure 5: Plot of pyrene II/I3 vs. concentration of polymers. A total of 0.1 mL of 1 mM pyrene in EtOH was added to 10 mL of 0.1 wt% polymer sample, and was irradiated by ultrasonic wave for 15 min.  
Figure 8: _Cont._  
Figure 6: Viscosity of pre-treated solution of BL-01, BL-03 and BL-05 using EMS viscometer.  
Figure 7: Photograph of BL-01, BL-03 and BL-05 alkaline solution: (**a**) from left to right, 10% BL-01 solution in DEG, 15% BL01 solution in DEG and 20% BL-01 solution in DEG; (**b**) from left to right, 10% BL-03 solution in DEG, 16.7% BL03 solution in DEG and 25% BL-03 solution in DEG; (**c**) from left to right, 10% BL-05 solution in DEG, 15% BL05 solution in DEG and 20% BL-05 solution in DEG.