Thermosensitive P(AAc‐co‐NIPAm) Hydrogels Display Enhanced Toughness and Self‐Healing via Ion–Ligand Interactions
Thermosensitive P(AAc‐co‐NIPAm) Hydrogels Display Enhanced Toughness and Self‐Healing via Ion–Ligand Interactions
复制标题
热敏 P(AAc-co-NIPAm) 水凝胶具有增强的韧性和自愈能力，可通过离子与配体相互作用进行修复
DOI：
10.1002/marc.202200320
复制
发表时间：
2022
影响因子：
4.6
通讯作者：
Franck J Vernerey
中科院分区：
文献类型：
--
作者：
Lin Xu;Yu Fu;Robert J. Wagner;Xiang Zou;Qingrui He;Tao Li;Wenlong Pan;Jianning Ding;Franck J Vernerey
含有热敏聚合物的水凝胶，如聚（N-异丙基丙烯酰胺）（P（NIPAm）），可以在加热过程中收缩，并在从软机器人到热敏生物传感器等领域显示出巨大的前景。然而，这些凝胶通常表现出低刚度、拉伸强度和机械韧性，限制了它们的适用性。通过P（NIPAm）与聚丙烯酸（P（AAc））的共聚反应，并在P（AAc）链上引入与沿着官能团配位的铁离子（Fe 3+），得到了一种具有增强的机械延伸性、强度和韧性的温敏性水凝胶。使用实验和本构模型，它被发现，增加的比例m（AAc）：m（NIPAm）的预聚物中的强度和韧性降低，但提高了延伸性。相比之下，增加Fe 3+浓度通常提高强度和韧性，而延伸率几乎没有降低。由于Fe 3+键的可逆配位，这些凝胶在循环加载期间显示出优异的机械强度恢复和自修复能力。虽然由潜在的P（NIPAm）引起的热敏性收缩随着Fe 3+浓度的增加而略微降低，但温度转变范围变宽并向人体温度（30 ° C至40 °C）向上移动，可能使这些凝胶适合作为体内生物传感器。最后，这些凝胶显示出优异的吸附性能与各种材料，使他们可能的候选人在粘合剂应用。
Hydrogels containing thermosensitive polymers such as poly(N-isopropylacrylamide) (P(NIPAm)) may contract during heating and show great promise in fields ranging from soft robotics to thermosensitive biosensors. However, these gels often exhibit low stiffness, tensile strength, and mechanical toughness, limiting their applicability. Through copolymerization of P(NIPAm) with poly(Acrylic acid) (P(AAc)) and introduction of ferric ions (Fe3+) that coordinate with functional groups along the P(AAc) chains, here a thermoresponsive hydrogel with enhanced mechanical extensibility, strength, and toughness is introduced. Using both experimentation and constitutive modeling, it is found that increasing the ratio of m(AAc):m(NIPAm) in the prepolymer decreases strength and toughness but improves extensibility. In contrast, increasing Fe3+ concentration generally improves strength and toughness with little decrease in extensibility. Due to reversible coordination of the Fe3+ bonds, these gels display excellent recovery of mechanical strength during cyclic loading and self-healing ability. While thermosensitive contraction imbued by the underlying P(NIPAm) decreases slightly with increased Fe3+ concentration, the temperature transition range is widened and shifted upward toward that of human body temperature (between 30 and 40 °C), perhaps rendering these gels suitable as in vivo biosensors. Finally, these gels display excellent adsorptive properties with a variety of materials, rendering them possible candidates in adhesive applications.