Fabrication, Characterization, and Biocompatibility of Polymer Cored Reduced Graphene Oxide Nanofibers

Graphene nanofibers have shown a promising potential across a wide spectrum of areas, including biology, energy, and the environment. However, fabrication of graphene nanofibers remains a challenging issue due to the broad size distribution and extremely poor solubility of graphene. Herein, we report a facile yet efficient approach for fabricating a novel class of polymer core-reduced graphene oxide shell nanofiber mat (RGO–CSNFM) by direct heat-driven self-assembly of graphene oxide sheets onto the surface of electrospun polymeric nanofibers without any requirement of surface treatment. Thus-prepared RGO–CSNFM demonstrated excellent mechanical, electrical, and biocompatible properties. RGO–CSNFM also promoted a higher cell anchorage and proliferation of human bone marrow mesenchymal stem cells (hMSCs) compared to the free-standing RGO film without the nanoscale fibrous structure. Further, cell viability of hMSCs was comparable to that on the tissue culture plates (TCPs) with a distinctive healthy morphology, indicating that the nanoscale fibrous architecture plays a critically constructive role in supporting cellular activities. In addition, the RGO–CSNFM exhibited excellent electrical conductivity, making them an ideal candidate for conductive cell culture, biosensing, and tissue engineering applications. These findings could provide a new benchmark for preparing well-defined graphene-based nanomaterial configurations and interfaces for biomedical applications

Additional file 1: of Polyaniline-Coated Activated Carbon Aerogel/Sulfur Composite for High-performance Lithium-Sulfur Battery

Supporting information. Figure S1. TEM images of (a) ACA-500-S and the corresponding elemental mapping for (b) carbon, (c) sulfur, (d) oxygen. Figure S2. STEM images of (a) ACA-500-S@PANi and the corresponding elemental mapping for (b) carbon, (c) nitrogen, (d) sulfur, and (d) oxygen. Figure S3. The total XPS spectra of (a) ACA-500-S, (b) C 1s, and (c) S 2p spectra of ACA-500-S. The peaks at 164.0 and 165.2 eV in (c) indicate that the uniformly encapsulated sulfur exists in the form of elemental sulfur. Figure S4. (a) The total XPS spectra and (b) N 1s spectrum of ACA-500-S@PANi. Figure S5. Discharge-charge curves at various rates for (a) ACA-500-S@PANi and (b) ACA-500-S cathodes. Figure S6. Discharge-charge curves recorded at different cycles for (a) ACA-500-S@PANi and (b) ACA-500-S cathodes at 1C. Figure S7. TGA curves of (a) ACA-500-S-70% (black), ACA-500-S@PANi-61% (blue), and ACA-500-S@PANi-55% (red) and (b) ACA-500-S-54% (violet) and ACA-500-S@PANi-45% (olive). Figure S8. (a) Rate performances of ACA-500-S-54% and ACA-500-S@PANi-55% cathodes. Discharge-charge curves at various rates for (b) ACA-500-S@PANi-55% and (c) ACA-500-S-54% cathodes. (d) Cycle performances of ACA-500-S@PANi-45% and ACA-500-S@PANi-61% cathodes at 1C. Table S1. Textual characteristic of ACA-500, ACA-500-S, and ACA-500-S@PANi. Table S2. Summary of cycle stability performances of representative conductive PANi coating for carbon/S cathodes at 1 C rate. (DOCX 980 kb

Preparation of Polymeric Nanoscale Networks from Cylindrical Molecular Bottlebrushes

The design and control of polymeric nanoscale network structures at the molecular level remains a challenging issue. Here we construct a novel type of polymeric nanoscale networks with a unique microporous nanofiber unit employing the intra/interbrush carbonyl cross-linking of polystyrene side chains for well-defined cylindrical polystyrene molecular bottlebrushes. The size of the side chains plays a vital role in the tuning of nanostructure of networks at the molecular level. We also show that the as-prepared polymeric nanoscale networks exhibit high specific adsorption capacity per unit surface area because of the synergistic effect of their unique hierarchical porous structures. Our strategy represents a new avenue for the network unit topology and provides a new application for molecular bottlebrushes in nanotechnology

Water-Dispersible, Responsive, and Carbonizable Hairy Microporous Polymeric Nanospheres

Multifunctionalization of microporous polymers is highly desirable but remains a significant challenge, considering that the current microporous polymers are generally hydrophobic and nonresponsive to different environmental stimuli and difficult to be carbonized without damage of their well-defined nanomorphology. Herein, we demonstrate a facile and versatile method to fabricate water-dispersible, pH/temperature responsive and readily carbonizable hairy microporous polymeric nanospheres based on combination of the hyper-cross-linking chemistry with the surface-initiated atom transfer radical polymerization (SI-ATRP). The hyper-cross-linking creates a highly microporous core, whereas the SI-ATRP provides diverse functionalities by surface grafting of hairy functional blocks. The as-prepared materials present multifunctional properties, including sensitive response to pH/temperature, high adsorption capacity toward adsorbates from aqueous solution, and valuable transformation into well-defined microporous carbon nanospheres because of hybrid of carbonizable core and thermo-decomposable protection shell. We hope this strategy could promote the development of both functional microporous polymers and advanced hairy nanoparticles for multipurpose applications