School of Materials Science and Chemical Engineering, Ningbo Key Laboratory of Specialty Polymers, Ningbo University, Ningbo, 315211, China.
Department of Chemistry, University of Connecticut, Storrs, CT, 06269, USA.
Adv Mater. 2018 Mar;30(11). doi: 10.1002/adma.201706526. Epub 2018 Jan 15.
New fluorochromic materials that reversibly change their emission properties in response to their environment are of interest for the development of sensors and light-emitting materials. A new design of Eu-containing polymer hydrogels showing fast self-healing and tunable fluorochromic properties in response to five different stimuli, including pH, temperature, metal ions, sonication, and force, is reported. The polymer hydrogels are fabricated using Eu-iminodiacetate (IDA) coordination in a hydrophilic poly(N,N-dimethylacrylamide) matrix. Dynamic metal-ligand coordination allows reversible formation and disruption of hydrogel networks under various stimuli which makes hydrogels self-healable and injectable. Such hydrogels show interesting switchable ON/OFF luminescence along with the sol-gel transition through the reversible formation and dissociation of Eu-IDA complexes upon various stimuli. It is demonstrated that Eu-containing hydrogels display fast and reversible mechanochromic response as well in hydrogels having interpenetrating polymer network. Those multistimuli responsive fluorochromic hydrogels illustrate a new pathway to make smart optical materials, particularly for biological sensors where multistimuli response is required.
新的荧光变色材料在响应其环境时可逆地改变其发射特性，这对于开发传感器和发光材料很有意义。本文报道了一种新设计的含 Eu 的聚合物水凝胶，它具有快速自修复和可调荧光特性，可响应五种不同的刺激，包括 pH 值、温度、金属离子、超声和力。聚合物水凝胶是通过 Eu-iminodiacetate（IDA）在亲水聚（N，N-二甲基丙烯酰胺）基质中的配位作用制备的。动态金属配体配位允许在各种刺激下可逆地形成和破坏水凝胶网络，从而使水凝胶具有自修复和可注射性。通过在各种刺激下 Eu-IDA 配合物的可逆形成和解离，这种水凝胶表现出有趣的可切换的 ON/OFF 发光以及溶胶-凝胶转变。研究表明，含有 Eu 的水凝胶在具有互穿聚合物网络的水凝胶中也表现出快速和可逆的机械变色响应。这些多刺激响应荧光变色水凝胶为智能光学材料的制备提供了一种新途径，特别是对于需要多刺激响应的生物传感器。
