Sr‐alginate and Ca‐alginate hydrogel fibers were fabricated via microfluidic spinning technology, and various analytical methods were adopted to characterize fibers and disclose the coordination model of Sr²⁺ binding with alginate molecule chain. For both fibers, the more crosslinking sites of Sr²⁺ with alginate molecule were illustrated in comparison with that of Ca²⁺. The more robust mechanical performance of Sr‐alginate fibers than Ca‐alginate counterpart was a strong indication of the more strong binding of Sr²⁺ with alginate molecular chain. FTIR and electric conductivity disclosed the chelation type of Sr²⁺ with alginate macromolecule being similar to that of Ca²⁺, which was core‐shell of the analogous “egg‐box” structure. Circular dichroism spectroscopy further certified the extra coordination sites for Sr²⁺ with alginate molecule than Ca²⁺. Research on the coordination model will be more beneficial to optimizing the physicochemical properties of alginate fibers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020, 137, 48571.

中文翻译：

---

锶离子取代藻酸盐基水凝胶纤维及其配位结合模型

通过微流体纺丝技术制备了Sr-藻酸盐和Ca-藻酸盐水凝胶纤维，并采用了各种分析方法来表征纤维，并揭示了Sr ²⁺与藻酸盐分子链结合的配位模型。对于两种纤维，与Ca ²⁺相比，Sr ²⁺与藻酸盐分子的交联点更多。Sr-海藻酸盐纤维比Ca-海藻酸盐具有更强的机械性能，这强烈表明Sr ²⁺与海藻酸盐分子链具有更强的结合力。FTIR和电导率揭示了Sr ²⁺与藻酸盐大分子的螯合类型与Ca ²⁺相似，它是类似的“蛋盒”结构的核心外壳。圆二色谱法进一步认证锶额外的配位²⁺用海藻酸钠分子比的Ca ²⁺。对配位模型的研究将对优化藻酸盐纤维的理化特性更为有益。分级为4 +©2019 Wiley Periodicals，Inc.J.Appl。Polym。科学 2020，137，48571。