Fig. 2

Characterization of hydrogels. (A) FTIR spectra of Alg, Algs-L, and Algs-H. Line indicates peaks characteristic to S = O stretching at 1250 cm^− 1 or 1260 cm^− 1. (B) TEM images of PBNPs. (C) The hydrodynamic particle distribution of PBNPs in aqueous media. (D) SEM images of hydrogels and element mappings of O, S, Fe, C, and N elements of PB@Algs-H hydrogels. Scale bar: 100 μm and 1 μm. (E) The energy-dispersive X-ray spectrum (EDS) of PB@Algs-H hydrogels. (F) Storage modulus (G’) of hydrogels. (G) Percent mass swelling of hydrogels after 24 h. (n = 3; mean ± s.d.; ns, not statistically significant; ***p < 0.001, ****p < 0.0001)