The charge carrier mobility of p-type and ambipolar polymer field-effect transistors (FETs) has been improved substantially. Nonetheless, high-mobility n-type polymers are rare, and few can be operated under ambient conditions. This situation is mainly caused by the scarcity of strong electron-deficient building blocks. Herein, we present two novel electron-deficient building blocks, FBDOPV-1 and FBDOPV-2, with low LUMO levels down to -4.38 eV. On the basis of both building blocks, we develop two poly(p-phenylene vinylene) derivatives (PPVs), FBDPPV-1 and FBDPPV-2, for high-performance n-type polymer FETs. The introduction of the fluorine atoms effectively lowers the LUMO levels of both polymers, leading to LUMO levels as low as -4.30 eV. Fluorination endows both polymers with not only lower LUMO levels, but also more ordered thin-film packing, smaller π-π stacking distance, stronger interchain interaction and locked conformation of polymer backbones. All these factors provide FBDPPV-1 with high electron mobilities up to 1.70 cm(2) V(-1) s(-1) and good stability under ambient conditions. Furthermore, when polymers have different fluorination positions, their backbone conformations in solid state differ, eventually leading to different device performance.

Planar backbone, locked conformation, and low lowest unoccupied molecular orbital level provide polymer F4 BDOPV-2T with ultrahigh electron mobilities of up to 14.9 cm(2) V(-1) s(-1) and good air stability. It is found that the nonlinear transfer curves can be tuned to near-ideal ones by changing fabrication conditions, indicating that film morphology largely contributes to the nonlinear transfer curves in high-mobility conjugated polymers.

Minimalist multifunctional platforms for delivering diagnostic and therapeutic agents effectively and safely into tumor sites are highly desired in nanomedicine. Herein, we describe the fabrication of a supramolecular nanoplatform via the amphiphilic amino acid (9-fluorenylmethyloxycarbonyl-l-leucine, Fmoc-l-L)-modulated self-assembly of a magnetic resonance imaging (MRI) contrast agent (ionic manganese, Mn) and photosensitive drug (chlorin e6, Ce6). Coordination drives the coassembly of Fmoc-l-L and Mn to generate a nanoscale supramolecular network to adaptively encapsulate Ce6. The obtained biometal-organic nanoparticles exhibit a high drug loading capability, inherent good biocompatibility, robust stability, and smart disassembly in response to glutathione (GSH). The cooperative assembly of the multiple components is synchronously dynamic in nature and enables enhanced photodynamic therapy (PDT) to damage tumor cells and tissue by efficiently delivering the photosensitizer and improving the reductive tumor microenvironment via the competitive coordination of GSH with Mn. The antitumor effect can also be monitored and evaluated in vivo by MRI through the long-term intracellular biochelation of Mn. Therefore, this work presents a one-pot and robust method for the self-assembly of a multifunctional theranostic nanoplatform capable of MRI-guided PDT starting from minimalist biological building blocks.

Luminescent metal nanoclusters (NCs) are emerging as a new class of functional materials that have rich physicochemical properties and wide potential applications. In recent years, it has been found that some metal NCs undergo aggregation‐induced emission (AIE) and an interesting fluorescence‐to‐phosphorescence (F‐P) switching in solutions. However, insights of both the AIE and the F‐P switching remain largely unknown. Now, gelation of water soluble, atomically precise Ag9 NCs is achieved by the addition of antisolvent. Self‐assembly of Ag9 NCs into entangled fibers was confirmed, during which AIE was observed together with an F‐P switching occurring within a narrow time scale. Structural evaluation indicates the fibers are highly ordered. The self‐assembly of Ag9 NCs and their photoluminescent property are thermally reversible, making the metal–organic gels good candidates for luminescent ratiometric thermometers.

The ability of dispersing carbon nanotubes (CNTs) in aqueous solutions by a starlike amphiphilic block copolymer with PPO-PEO segments (AP432) was investigated in detail. For comparison, two commercially available linear amphiphilic block copolymers, Pluronics L64 and F127, were also selected. It was found that AP432 and F127 can get good CNT dispersions, while L64 was proved to be unable to disperse CNTs. AP432 with five branches could disperse CNTs efficiently at much lower concentrations compared with the linear F127, although it has a smaller molecular weight and shorter terminal EO groups. This indicated clearly that, once branched, copolymers would get a much better ability to disperse CNTs. Increasing concentration of AP432 or F127 would disperse more CNTs, but at high copolymer concentrations the aggregation of dispersed CNTs was observed, which may be related to the free micelles formed by AP432 or F127 around CNTs. Other influencing factors such as the mass ratio of CNTs to copolymers and sonication time and strength were also discussed. From the molecular dynamics simulation results, it can be found that copolymers with five branches can gain better steric repulsions between adjacent CNTs, which is consistent with the experimental results.