Nonconventional poly(maleic anhydride-alt-vinyl pyrrolidone) copolymers exhibit distinct AIE characteristics, as well as molecular weight-dependent and excitation-dependent fluorescence. They can emit blue to red colours under different excitation wavelengths.
Many nonconventional luminescent polymers are found to exhibit intrinsic photoluminescence and “aggregation‐induced emission” (AIE) behavior. Strong physical interactions among polymer chains and/or a rigid molecular conformation of polymer chains are thought to be beneficial to boost stronger emissions. The purpose of this work is to prove that increasing chain flexibility is, at least in some cases, beneficial to enhance the photoluminescence of nonconventional luminescent polymers. Poly(itaconic anhydride) (PITA) and poly[(1‐octene)‐co‐(itaconic anhydride)] (POITA) synthesized in this work are highly emissive in concentrated solutions and in solid state, exhibiting typical AIE characteristics, and very interestingly, the copolymer POITA exhibits stronger and red‐shifted emissions than the homopolymer PITA in both solutions and in the solid state. These results are explained by the increase of chain flexibility, which makes the nonconventional chromophores adopt proper conformations for strong intra‐ and/or interchain n‐π* and/or π–π* interactions. This study sheds some light on designing nonconventional luminescent materials with high emission efficiency and long wavelength emission.
Green processes to exfoliate graphene would be advantageous but is challenged by issues such as stability and dispersibility. Here, stable silk fibroin nanofibers (SFNs) with high crystallinity (β-sheet content) and high net negative charge were endowed with hydrophobic features yet excellent water dispersibility. These nanofibers were used to exfoliate graphite into graphene in aqueous solutions. A high concentration (1.92 mg mL −1 ) and yield (approaching 20%) were achieved for the exfoliated graphene dispersions using low initial graphite concentrations via sonication treatment. This approach was superior to most protein-assisted exfoliation processes reported to date, and the graphene obtained in the process exhibited fewer defects, good conductivity, and cell compatibility. The graphene prepared by this new process provided an option for SF-graphene composite materials and devices where defect-free graphene with improved performance through the introduction of SFNs into the preparation strategies will bring a desired revolution in graphene materials.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.