HIGHLY POROUS HYBRID COMPOSITE HYDROGELS BASED ON CELLULOSE AND 1,10-PHENANTHROCYANINE OF Zn(II): SYNTHESIS AND CHARACTERIZATION WITH WAXS, FTIR, 13C CP/MAS NMR AND SEM

Abstract

Hybrid composite hydrogels were synthesized by immobilization of 1,10-phenanthrocyanine zinc(II) complex in cellulose hydrogels. The hydrogels exhibited long-term stability, high water retaining capacity and porosity, which were determined using chemical methods. They were characterized with wide-angle X-ray scattering (WAXS), Fourier transform infrared spectroscopy (FTIR), high-resolution solid-state 13C CP/MAS NMR spectroscopy and scanning electron microscopy (SEM). According to FTIR analysis, the immobilization of the complex in the hydrogels led to its interaction with the cellulose inside the matrices of the hydrogels. Additional crystallization of the cellulose in the hydrogels occurred during the formation of the composite hydrogels, as revealed with WAXS. The surface and morphology of the cross-sections of the hydrogels, as well as the pore distribution and pore size, were defined with SEM. The SEM study also ascertained the impact of the molecular mass of the embedded complex on the efficiency of the immobilization.

Cellulose-Based Metallogels—Part 3: Multifunctional Materials

“…A higher concentration of trisodium citrate facilitated the rapid stabilization of smaller-sized Au nanoparticles, while a lower concentration led to larger Au nanoparticles due to aggregation. Silver nanoparticle sizes ranged from 20 to 260 nm (Figure 2e), showing a more uniform size distribution for gold nanoparticles compared to silver nanoparticles [46]. It was demonstrated that cellulose hydrogels that contained from 0.30 to 5.66 wt.% of Ag or Au nanoparticles revealed antimicrobial activity against Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria (Figure 2c) [24,46,47].…”

Cellulose-Based Metallogels—Part 2: Physico-Chemical Properties and Biological Stability

“…The proportion of hydrogel volume occupied by the pores (porosity) is calculated according to the following equation: P t = 1 − m 0 · P −1 · L −1 · ρ − 1 , where m 0 is the weight of the dried hydrogel, g, P is a square of the surface of the hydrogel, cm 2 , L is the thickness of the hydrogel, cm, and ρ is the density of cellulose ( ρ = 1.561 g∙cm −3 ) [ 71 ].…”

“…Introduction of a metal phase into the hydrogel decreases the average pore size; for instance, after the formation of the metallogel with Zn(II) organic complex, the porosity of the composite hydrogels fell to 95.8% and 94.8% compared with those of the flax and deciduous hydrogels listed in Table 1 , row 3 [ 71 ]. It was also mentioned in the same study that the surface of the hydrogels was loose, and the inner structure of the hydrogels was composed of randomly distributed pores that formed a cellular honeycomb-like structure.…”

“…It was also mentioned in the same study that the surface of the hydrogels was loose, and the inner structure of the hydrogels was composed of randomly distributed pores that formed a cellular honeycomb-like structure. As a result, the metallogels retained great amounts of water [ 71 ].…”

“…The additional crystallization occurred during the formation of the composite hydrogel with Zn(II) organic-complex [ 71 ]; however, the authors admit the possibility of the change in crystallinity not by the immobilization of 1,10-phencyanine Zn(II) but due to the eventual crystallization of the complex itself in the matrix of the hydrogel. Oppositely, the decrease of the initial cellulosic material’s crystallinity index after introducing Ag particles was reported in [ 61 ].…”