Perera M Mario, Chimala Prathyusha, Elhusain-Elnegres Abdul, Heaton Paul, Ayres Neil
Department of Chemistry, The University of Cincinnati, P.O. Box 210172, Cincinnati, Ohio 45221, United States.
ACS Macro Lett. 2020 Nov 17;9(11):1552-1557. doi: 10.1021/acsmacrolett.0c00718. Epub 2020 Oct 20.
Wavelength-dependent light-responsive seleno-sulfide dynamic covalent bonds were used to prepare organogels with reversible changes in stiffness. The disulfide cross-link organogels prepared from norbornene-terminated poly(ethylene glycol) (PEG-diNB) and poly(2-hydroxypropyl methacrylate--mercaptoethyl acrylate) (PEG-diNB-poly(HPMA--MEMA)) polymers underwent exchange reactions with 5,5'-diselenide-bis(2-aminobenzoic acid) upon irradiation with UV light. Following irradiation with visible light, the seleno-sulfide bonds were cleaved, reforming disulfide cross-links and the 5,5'-diselenide-bis(2-aminobenzoic acid). Reduction in ' with disulfide-diselenide exchange was consistent with that observed following a thiol-disulfide exchange reaction. Recovery of ' upon disulfide bond formation was 85-95% of the initial value in the as-prepared gel over five cycles of bond cleaving and reformation. This initial study shows the potential of the wavelength-controlled disulfide-diselenide chemistry to develop light-responsive reversible organogels. These organogels have the potential to be used in functional materials such as polymeric actuators or biomimetic soft robotics.
利用波长依赖性光响应硒硫化物动态共价键制备了具有可逆刚度变化的有机凝胶。由降冰片烯封端的聚乙二醇（PEG-diNB）和聚（甲基丙烯酸2-羟丙酯-丙烯酸巯基乙酯）（PEG-diNB-聚（HPMA-MEMA））聚合物制备的二硫键交联有机凝胶在紫外光照射下与5,5'-二硒双（2-氨基苯甲酸）发生交换反应。在可见光照射后，硒硫键断裂，重新形成二硫键交联和5,5'-二硒双（2-氨基苯甲酸）。二硫键-二硒键交换导致的“”降低与硫醇-二硫键交换反应后观察到的一致。在五个键断裂和重新形成循环中，二硫键形成时“”的恢复为制备的凝胶初始值的85-95%。这项初步研究表明了波长控制的二硫键-二硒键化学在开发光响应可逆有机凝胶方面的潜力。这些有机凝胶有潜力用于功能性材料，如聚合物致动器或仿生软机器人。
