Jiang Tongxin, Zhang Yingying, Jiang Jinqiang, Liu Zhong-Wen, Liu Zhao-Tie, Li Guo
Key Laboratory of Syngas Conversion of Shaanxi Province, Key Laboratory of Applied Surface and Colloid Chemistry, Ministry of Education, School of Chemistry and Chemical Engineering, Shaanxi Normal University, Xi'an, Shaanxi, 710062, China.
Small. 2024 Jul;20(30):e2308352. doi: 10.1002/smll.202308352. Epub 2024 Mar 3.
Magnetic hydrogel actuators are developed by incorporating magnetic fillers into the hydrogel matrix. Regulating the distribution of these fillers is key to the exhibited functionalities but is still challenging. Here a facile way to spatially synthesize ferrosoferric oxide (FeO) microparticles in situ in a thermal-responsive hydrogel is reported. This method involves the photo-reduction of Fe ions coordinated with carboxylate groups in polymer chains, and the hydrolytic reaction of the reduced Fe ions with residual Fe ions. By controlling the irradiation time and position, the concentration of FeO microparticles can be spatially controlled, and the resulting FeO pattern enables the hydrogel to exhibit complex locomotion driven by magnet, temperature, and NIR light. This method is convenient and extendable to other hydrogel systems to realize more complicated magneto-responsive functionalities.
磁性水凝胶致动器是通过将磁性填料掺入水凝胶基质中而开发的。调节这些填料的分布是实现所展示功能的关键，但仍然具有挑战性。本文报道了一种在热响应水凝胶中原位空间合成四氧化三铁（Fe₃O₄）微粒的简便方法。该方法涉及聚合物链中与羧酸根基团配位的铁离子的光还原，以及还原后的铁离子与残余铁离子的水解反应。通过控制照射时间和位置，可以在空间上控制Fe₃O₄微粒的浓度，所得的Fe₃O₄图案使水凝胶能够展现出由磁、温度和近红外光驱动的复杂运动。该方法简便易行，并且可扩展到其他水凝胶体系，以实现更复杂的磁响应功能。
