A supramolecular carbohydrate-functionalized two-dimensional (2D) surface was designed and synthesized by decorating thermally reduced graphene sheets with multivalent sugar ligands. The formation of host-guest inclusions on the carbon surface provides a versatile strategy, not only to increase the intrinsic water solubility of graphene-based materials, but more importantly to let the desired biofunctional binding groups bind to the surface. Combining the vital recognition role of carbohydrates and the unique 2D large flexible surface area of the graphene sheets, the addition of multivalent sugar ligands makes the resulting carbon material an excellent platform for selectively wrapping and agglutinating Escherichia coli (E. coli). By taking advantage of the responsive property of supramolecular interactions, the captured bacteria can then be partially released by adding a competitive guest. Compared to previously reported scaffolds, the unique thermal IR-absorption properties of graphene derivatives provide a facile method to kill the captured bacteria by IR-laser irradiation of the captured graphene-sugar-E. coli complex.

Herein we report on the solvent-free free radical grafting of styrene homo-and copolymers onto functionalized graphene nanosheets without requiring initiator addition. The key intermediate is an organophilic stearylaminemodified graphite oxide (Stearyl-GO), containing both olefinic unsaturation and stable graphene radicals. According to the online tracking of the C-centered graphene radicals by timeresolved EPR spectroscopy, the graphene radical concentration markedly increases during the early stage of polymerization and is depleted as the viscosity builds up with progressing styrene conversion. "Grafting-to" by addition of polystyrene radicals to graphene and "grafting-from" by graphene-initiated free radical polymerization afford high graft yields, as determined by ultracentrifugal separation of polystyrene-grafted functionalized graphene (PS-g-FG) from the styrene homopolymer byproduct. The addition of TEMPO enables control of the further grafting yields by a controlled radical "grafting-from" polymerization. In sharp contrast to graphene/polystyrene solution blends (PS/Stearyl-GO), morphological and rheological investigations reveal that the in situ formation of PS-g-FG accounts for much more uniform graphene dispersion in polystyrene melts and also in various organic solvents. This is paralleled by enhanced elasticity of the graphene particle network and markedly improved electrical conductivity of the resulting graphene/polystyrene nanocomposites. Owing to the effective polymer radical addition to FG, both Stearyl-GO and PS-g-FG significantly improve the thermal stability of polystyrene, as measured by thermogravimetric analysis of thermal decomposition during prolonged heating at 250 °C. This versatile in situ self-initiated polymerization process enables grafting of styrene copolymers with butyl acrylate and acrylonitrile.

Efficient inhibition of cell-pathogen interaction to prevent subsequent infection is an urgent but yet unsolved problem. In this study, the synthesis and functionalization of novel multivalent 2D carbon nanosystems as well as their antiviral efficacy in vitro are shown. For this reason, a new multivalent 2D flexible carbon architecture is developed in this study, functionalized with sulfated dendritic polyglycerol, to enable virus interaction. A simple "graft from" approach enhances the solubility of thermally reduced graphene oxide and provides a suitable 2D surface for multivalent ligand presentation. Polysulfation is used to mimic the heparan sulfate-containing surface of cells and to compete with this natural binding site of viruses. In correlation with the degree of sulfation and the grafted polymer density, the interaction efficiency of these systems can be varied. In here, orthopoxvirus strains are used as model viruses as they use heparan sulfate for cell entry as other viruses, e.g., herpes simplex virus, dengue virus, or cytomegalovirus. The characterization results of the newly designed graphene derivatives demonstrate excellent binding as well as efficient inhibition of orthopoxvirus infection. Overall, these new multivalent 2D polymer nanosystems are promising candidates to develop potent inhibitors for viruses, which possess a heparan sulfate-dependent cell entry mechanism.

Gaining spatially resolved control over the mechanical properties of materials in a remote, programmable, and fast-responding way is a great challenge toward the design of adaptive structural and functional materials. Reversible, temperature-sensitive systems, such as polymers equipped with supramolecular units, are a good model system to gain detailed information and target large-scale property changes by exploiting reversible crosslinking scenarios. Here, it is demonstrated that coassembled elastomers based on polyglycidols functionalized with complementary cyanuric acid and diaminotriazine hydrogen bonding couples can be remotely modulated in their mechanical properties by spatially confined laser irradiation after hybridization with small amounts of thermally reduced graphene oxide (TRGO). The TRGO provides an excellent photothermal effect, leads to light-adaptive steady-state temperatures, and allows local breakage/de-crosslinking of the hydrogen bonds. This enables fast self-healing and spatiotemporal modulation of mechanical properties, as demonstrated by digital image correlation. This study opens pathways toward light-fueled and light-adaptive graphene-based nanocomposites employing molecularly controlled thermal switches.

Novel families of polystyrene carbon nanocomposites and graphene brushes were prepared by means of free radical styrene grafting using sulfur-functionalized graphene (S-FG) as macro-chain-transfer agent. Two strategies were examined for growing polystyrene chains onto graphite oxide (GO), stearylamine-modified GO (Stearyl-GO), and thermally reduced GO (TRGO): (i) chain transfer with novel thiolfunctionalized graphenes and (ii) RAFT-mediated polymerization using dithiourethane-, dithioester-and dithiocarbonate-functionalized graphenes. Novel thiol-functionalized graphenes were obtained from FG either by esterification with 3-mercaptopropionic acid or by reaction with propylene sulfide. The styrene graft polymerization was initiated either with AIBN at 65 °C or by thermal styrene self-initiation at 130 °C. The graphene content, varying between 0 and 5.2 wt %, was determined by means of thermogravimetric analysis (TGA). Upon hydrolytic cleavage of the dithiocarbonate linker, the stability of the S-FG dispersion in polystyrene was lost, and the nonbonded S-FG was separated quantitatively from polystyrene by solvent extraction. During melt processing the graphene brushes self-assembled to produce nanoribbons and skeleton-like carbon superstructures, as determined by means of transmission electron microscopy (TEM). Both grafting effectiveness and superstructure formation were monitored by means of melt rheology.