Figure 8 shows the air/water interfacial tensions of PVA solutions, HmPVA solutions, PVA--EPC solution, and HmPVA--EPC conjugate solutions. The interfacial tension of PVA solution effectively decreased to 43 dyne/cm when the concentration increased to 0.005% and thereafter the interfacial tension decreased slowly with the concentration.
The air/water interfacial tensions of PVA solution, PVA--EPC solution, HmPVA solution, and HmPVA--EPC conjugate solution were measured on a surface tension meter (SEO, DST 60, South Korea).
UV ([lambda]= 254 nm, 6 W) was irradiated to EPC solution in DMSO and HmPVA--EPC conjugate solution in distilled water.