Figure 6
Optimized egg-box and asymmetric egg-box-like structures within hybrid hydrogel via the B3LYP method and the corresponding schematic drawing of calcium coordination of the different structures.
(a,b) Egg-box structure of alginate-Ca2+ formed by two alginate chains composed of two G units and one Ca2+ (GG-Ca-GG). (c–f) Asymmetric egg-box-like structure of alginate-Ca2+-CS formed by one alginate chain composed of two G units, one CSA or CSC chain and one Ca2+ (GG-Ca-CSA, GG-Ca-CSC) (red color represents oxygen atom; blue color represents nitrogen atom; white represents hydrogen atom; grey color represents carbon atom; yellow represents sulfur atom; green represents calcium atom). Data showed that the traditional egg-box and asymmetric egg-box-like structures were present in ALG-CS and were triggered by calcium ions.
