Mechanofluorochromic materials, which are dependent on changes in physical molecular packing modes, have attracted considerable interest over the past ten years. In this review, recent progress in the area of pure organic mechanofluorochromism is summarized, and majority of the reported organic mechanofluorochromic systems are discussed, along with their derived structure–property relationships. The existence of a structural relationship between aggregation-induced emission compounds and mechanofluorochromism is recognized based on our recent results, which considered aggregation-induced emission compounds as a well of mechanofluorochromic materials. The established structure–property relationship will guide researchers in identifying and synthesizing more mechanofluorochromic materials.
Mechanochromic luminescent metal complexes have recently attracted considerable interest as smart materials for use in the fields of luminescence switches, mechanosensors, mechanohistory indicators, security papers, optoelectronic devices, and data storage. In this review, recent advancements in metal complex mechanochromic luminescence are summarized. The majority of the reported mechanochromic luminescent metal complex systems are discussed, including Zn(II), Au(I), Pt(II), Ag(I), Cu(I), Al(III), and Ir(III) complexes. Aggregation-induced emission (AIE) complexes are described based on the existence of a structural relationship between AIE compounds and mechanochromism. It is expected that AIE complexes may become important alternative sources of mechanochromic luminescent complexes.
Novel fluorescent nanoparticle (FNP)-based bioprobes are expected to generate new medical diagnostic techniques in biomedical and biological areas for their superior brightness and photostability compared with conventional molecular probes including small organic dyes and fluorescent proteins. Potentially interesting nanoscale platforms for various biomedical applications are greatly attractive due to the potential to avoid exposure of human tissues to toxic drugs, enhancing delivery of hydrophobic therapeutics and fabricating multifunctional imaging, targeting and delivery system. In this review, recent progress in the area of novel aggregation induced emission (AIE)-based FNPs is summarized over the past few years (2007–2013), and the reported fabrication methodologies of these fluorescent systems including non-covalent and covalent strategies are mainly discussed, and the biomedical applications of AIE-based FNPs are also summarized.
Assembling epoxy, one of the most common and widely used thermosets, by welding with remote control is extremely difficult and has not been realized so far, as epoxy cannot melt or be dissolved. Here we present a very simple but highly efficient solution by exploring the photothermal effect of carbon nanotubes (CNTs) to manipulate the transesterification reaction in vitrimers. The carbon nanotube dispersed vitrimer epoxy presented here can be welded by light within seconds or minutes. Moreover, various CNT–vitrimer epoxy materials with different chemical compositions and physical properties can be joined together. Furthermore, transmission welding can be used to weld CNT–vitrimers with other kinds of epoxy or thermoplastic polymers, which is not applicable to welding by direct heating and impossible to realize using the currently available photoweldable covalently cross-linked polymer networks. Additionally, these networks can be efficiently healed by light without the involvement of any glue or sealing agents.