Fig. 1 . Characterization of PB, HMPB and OHH NPs . (A-C)TEM images of PB, HMPB and OHH NPs. (D) Hydrodynamic sizes distribution of PB, HMPB and OHH NPs determined by dynamic light scattering (E) Zeta potentials of PB, HMPB and OHH NPs. (F) UV–Vis spectra of NPs. (G,H) FT-IR spectra of NPs. (I) XPS survey scan of NPs.