Peptide–graphene conjugates have the cytocompatibility, electrical, and mechanical properties of graphene with the cell instructive properties of the peptide.

No abstract

While nanocarbons doped with more than one heteroatom continue attracting growing interest owing to a wide range of applications, precise control of their nanostructure and porosity remains a major challenge. Herein, we report a new route to synthesize N/S co-doped nanocarbons with precise porosity control through introduction of sulfur into the synthesis copolymer-templated nitrogen-enriched carbons (CTNC). Sulfur served as both a heteroatom source and morphology stabilizing agent. The produced N/S co-doped nanocarbons showed interconnected pores with relatively high specific surface area (∼480 m2/g) and high heteroatom content (N, 8.2 atom %; S, 8.8 atom %). To demonstrate the dual benefits of sulfur stabilization (incorporation of heteroatoms and improved morphology control), such prepared nanocarbons were fabricated into supercapacitors with geometric capacitance (50 μF/cm2), well above the value observed for single N-doped carbon (33 μF/cm2). Importantly, linear relationship of mesopore size with block length of copolymer precursor was observed for N/S co-doped nanocarbons, allowing optimization of the mesopore size for supercapacitor applications. This new technique not only expands CTNC method from N-doping to N/S co-doping systems with excellent porosity control but also opens up new possibilities widely applicable to other PAN-based soft-templating systems.

Teaching chemistry without access to a traditional laboratory space is an ongoing challenge that has become especially relevant because of the SARS-CoV-2 pandemic. While several remote learning options exist for covering general chemistry concepts (including kitchen-based experiments, online modules, and virtual reality), few options provide opportunities for hands-on learning about the chemistry of synthetic polymer materials. Here, we offer remote learning modules that use household adhesives as a platform for teaching polymer chemistry outside of the laboratory. These modules are designed for students who have taken at least one semester of organic chemistry and have varied hands-on time commitments, ranging from 2 to 10 total hours each. Concepts covered include polymer synthesis, intermolecular interactions, thermomechanical properties, structure–function relationships, and molecular design. The experiments described in these modules also give students a chance to practice research-relevant skills such as searching for primary literature sources, fabricating test samples, explaining unexpected experimental results, and revising experimental procedures to improve methodologies. Ultimately, these modules provide educators with an additional tool for teaching experimental chemistry outside of the laboratory.

High molecular weight, synthetic block copolypeptides that self-assemble are in high demand for biomedical applications. The current standard method for synthesis of block copolypeptides is the controlled ring-opening polymerization (ROP) of α-amino acid N-carboxyanhydride (NCA) monomers, where block architectures can be created by sequential NCA monomer addition. Recently, researchers have focused on developing reaction conditions and initiation systems that make NCA ROP more convenient, particularly for interdisciplinary labs without designated polypeptide facilities. In an effort to further simplify and increase the convenience of polypeptide synthesis, we developed a one-shot copolymerization strategy that allows access to block copolypeptides by capitalizing on the inherently faster reactivity of NCA monomers, compared to NTA (N-thiocarboxyanhydride) monomers. For the first time, we combine an NCA and NTA monomer in one reaction to kinetically promote block copolypeptide formation, providing a convenient alternative to sequential monomer addition. The controlled nature of this copolymerization technique is supported by a molecular weight that is modulated by the concentration of the initiator and low dispersities. We used this one-shot copolymerization to synthesize p­(lysine)-b-p­(leucine), a known peptide amphiphile (PA). Our one-shot PAs are antimicrobial and can spontaneously form ordered, micron-scale assemblies. Covalent conjugation of one-shot PAs to a graphenic backbone results in a functional graphenic material (FGM) with a self-assembled morphology, paving the way for creation of sophisticated FGM scaffolds with polypeptide-templated, hierarchical order. Overall, we demonstrate that this novel, one-shot copolymerization strategy produces functional copolypeptides with macroscopic sequence control.