Professur Polymerchemie, Institut für Chemie, Technische Universität Chemnitz, Straße der Nationen 62, 09111, Chemnitz, Germany.
Department of Chemistry "G. Ciamician" and INSTM UdR of Bologna, University of Bologna, via Selmi 2, 40126, Bologna, Italy.
Adv Mater. 2018 Sep;30(39):e1802813. doi: 10.1002/adma.201802813. Epub 2018 Aug 22.
Mechanochromic polymeric systems are intensively investigated for real-time stress detection applications. However, an effective stress-sensing material must respond to low deformation with a detectable color change that should be quickly reversible upon force unloading. In this work, mechanochromic nanofibers made by electrospinning are used to produce mechanochromic nanofiber/poly(dimethylsiloxane) (PDMS) composites with isotropic and anisoptropic response. Due to chain alignment of spiropyran copolymer chains within the nanofibers, only very small strains are required to yield a mechanochromic response. Composites with aligned and isotropic nanofibers show anisotropic and isotropic mechanochromic behavior, respectively. Due to the special substitution pattern of spiropyran in the copolymer, the mechanochromic response of these nanofiber/PDMS composites shows fast reversibility upon force unloading. The outstanding benefit of using highly sensitive mechanochromic nanofibers as filler in composite materials allows the detection of directional stress and strain, and it is a step forward in the development of smart, mechanically responsive materials.
机械变色聚合物系统被广泛研究用于实时应力检测应用。然而，有效的应力感应材料必须对低变形做出响应，并具有可检测的颜色变化，而且在力卸载后应能迅速可逆。在这项工作中，通过静电纺丝制成的机械变色纳米纤维被用于制备具有各向同性和各向异性响应的机械变色纳米纤维/聚二甲基硅氧烷（PDMS）复合材料。由于螺吡喃共聚物链在纳米纤维内的链排列，只有非常小的应变就可以产生机械变色响应。具有取向和各向同性纳米纤维的复合材料分别表现出各向异性和各向同性的机械变色行为。由于螺吡喃在共聚物中的特殊取代模式，这些纳米纤维/PDMS 复合材料的机械变色响应在力卸载后具有快速的可逆性。使用高灵敏度机械变色纳米纤维作为复合材料填料的突出优势允许检测定向应力和应变，这是开发智能、机械响应材料的一个进步。
