초록 |
Anion-coordination chemistry have played important roles in biology and industrial processes, in addition to environmental issues. Thiourea has been studied for the tailored anion receptors via hydrogen bonding interactions, but seldom applied to anion-responsive actuators. In this study, we prepared thiourea-based soft gels using a facile one-step synthesis and tested for anion-specific or anion-selective responses in actuation (i.e., volume transition). The thiourea-based soft gels showed visually considerable color changes depending on the anions’ basicity (e.g., highly basic F- and CN-). But remarkably different size changes were observed for F- (contraction) and CN- (expansion). We investigated anion-specific effects, similar to Hofmeister effects in water, and found that the interesting volume changes were due to the interplay of anions’ basicity, solvation energy and accompanying osmosis. Finally, such properties were utilized as anion-responsive soft actuators. |