Istanbul Technical University, Department of Chemistry, 34469 Maslak, Istanbul, Turkey.
J Mater Chem B. 2019 Mar 14;7(10):1581-1596. doi: 10.1039/c8tb02767f. Epub 2018 Nov 29.
Synthetic hydrogels are generally amorphous in nature without any order at the molecular level. This is in contrast to biological gels containing ordered aggregates contributing significantly to their mechanical performance. Semicrystalline hydrogels, first developed in 1994, are moderately water-swollen hydrogels containing crystalline domains. Recent work shows that physically cross-linked semicrystalline hydrogels belong to one of the groups of mechanically strong and highly stretchable hydrogels exhibiting melt-processability, self-healing and shape-memory functions. They can undergo an abrupt and reversible change from a solid-like to a liquid-like state at the melting temperature, opening up several applications such as shape-memory hydrogels, injectable gels, chemical motors, and smart inks for 3D or 4D printing. In this review article, recent advances in the field of semicrystalline physical hydrogels prepared from hydrophilic and hydrophobic vinyl monomers via a free-radical mechanism are summarized. Synthesis-molecular structure-property relations of semicrystalline hydrogels, current challenges and future directions are also discussed.
合成水凝胶通常在分子水平上没有任何有序性，是无定形的。这与含有有序聚集物的生物凝胶形成对比，后者对其机械性能有重要贡献。半结晶水凝胶于 1994 年首次开发，是适度溶胀的含有结晶区的水凝胶。最近的研究表明，物理交联的半结晶水凝胶属于机械强度高、拉伸性好的水凝胶的一组，具有熔融加工性、自修复和形状记忆功能。它们可以在熔点下经历从固态到液态的突然和可逆的转变，为形状记忆水凝胶、可注射凝胶、化学马达和用于 3D 或 4D 打印的智能墨水等应用开辟了道路。在这篇综述文章中，总结了通过自由基机制由亲水和疏水乙烯基单体制备的半结晶物理水凝胶领域的最新进展。还讨论了半结晶水凝胶的合成-分子结构-性能关系、当前的挑战和未来的方向。
