Zetapals dynamic light scattering

The size, polydispersity, and zeta potential of the hydrogel nanoparticles were determined using a ZetaPALS dynamic light scattering (DLS) detector (Brookhaven Instruments, Holtsville, NY).^{33 (link)} The samples at a concentration of 1 mg mL⁻¹ in DI water were prepared, and sizes of these nanoparticles were determined at 24 and 37 °C, respectively. Furthermore, to observe morphology of the nanoparticles, Scanning Electron Microscope (SEM) was employed as described earlier.^{34 (link)} Briefly, a drop of the diluted particle dispersion was placed onto a glass slide cover adhered to a SEM specimen holder with the conductive tape, and then dried at ambient temperature. After sputter-coating with silver, SEM images were recorded by a Hitachi S-4800 II FE Scanning Electron Microscope.^{34 (link)}