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Abstract Graphene's wetting transparency offers promising avenues for creating multifunctional devices by allowing real‐time wettability control on liquid substrates via the flow of different liquids beneath graphene. Despite its potential, direct measurement of floating graphene's wettability remains a challenge, hindering the exploration of these applications. The current study develops an experimental methodology to assess the wetting transparency of single‐layer graphene (SLG) on liquid substrates. By employing contact angle measurements and Neumann's Triangle model, the challenge of evaluating the wettability of floating free‐suspended single‐layer graphene is addressed. The research reveals that for successful contact angle measurements, the testing and substrate liquids must be immiscible. Using diiodomethane as the testing liquid and ammonium persulfate solution as liquid substrate, the study demonstrates the near‐complete wetting transparency of graphene. Furthermore, it successfully showcases the feasibility of real‐time wettability control using graphene on liquid substrates. This work not only advances the understanding of graphene's interaction with liquid interfaces but also suggests a new avenue for the development of multifunctional materials and devices by exploiting the unique wetting transparency of graphene. 

The Diels–Alder (DA) reaction, a classic cycloaddition reaction involving a diene and a dienophile to form a cyclohexene, is among the most versatile organic reactions. Theories have predicted thermodynamically unfavorable DA reactions on pristine graphene owing to its low chemical reactivity. We hypothesized that metals like Ni could enhance the reactivity of graphene towards DA reactions through charge transfer. The results indeed showed that metal substrates enhanced the reactivity of graphene in the DA reactions with a diene, 2,3-dimethoxy butadiene (DMBD), and a dienophile, maleic anhydride (MAH), with the activity enhancement in the order of Ni > Cu, and both are more reactive than graphene supported on silicon wafer. The rate constants were estimated to be two times higher for graphene supported on Ni than on silicon wafer. The computational results support the experimentally obtained rate trend of Ni > Cu, both predicted to be greater than unsupported graphene, which is explained by the enhanced graphene–substrate interaction reflected in charge transfer effects with the strongly interacting Ni. This study opens up a new avenue for enhancing the chemical reactivity of pristine graphene through substrate selection. 

In this work, density functional theory (DFT) and diffusion Monte Carlo (DMC) methods are used to calculate the binding energy of a H atom chemisorbed on the graphene surface. The DMC value of the binding energy is about 16% smaller in magnitude than the Perdew–Burke–Ernzerhof (PBE) result. The inclusion of exact exchange through the use of the Heyd–Scuseria–Ernzerhof functional brings the DFT value of the binding energy closer in line with the DMC result. It is also found that there are significant differences in the charge distributions determined using PBE and DMC approaches. 

Abstract A one-electron model Hamiltonian is used to characterize the non-valence correlation-bound (NVCB) anions of hexagonal polycyclic aromatic hydrocarbons (PAHs) C 6 n 2 H 6 n ( n = 3–7). The model incorporates atomic electrostatic moments up to the quadrupole, coupled inducible charges and dipoles, and atom-centered repulsive Gaussians to describe the interaction between the excess electron and PAH. These model components are parameterized on and validated against all-electron calculations. Good agreement is found between the static dipole polarizabilities obtained from the model and those from PBE0 density functional theory and second-order Møller–Plesset perturbation theory calculations. In the model, charge flow dominates the in-plane polarizability of PAHs larger than C 54 H 18 , yielding an approximately quadratic scaling of the mean polarizabilty with the number of carbon atoms. Inclusion of electrostatic interactions decreases the electron binding energies for the largest PAHs considered by about 20% and shift charge distribution from above and below the plane of the ring system toward the periphery. Analysis of the electrostatic and polarization interactions provides insight into qualitative trends in the electron binding energy and the charge distribution of the lowest energy NVCB anion. 

This paper reports the fabrication and mechanical properties of macroscale graphene fibers (diameters of 10 to 100 μm with lengths upwards of 2 cm) prepared from a single sheet of single-layer graphene grown via chemical vapor deposition (CVD). The breaking strength of these graphene fibers increased with consecutive tensile test measurements on a single fiber, where fiber fragments produced from a prior test exhibited larger breaking strengths. Additionally, we observed an overall reduction of surface folds and wrinkles, and an increase in their alignment parallel to the tensile direction. We propose that a foundation of this property is the plastic deformations within the fiber that accumulate through sequential tensile testing. Through this cyclic method, our best fiber produced a strength of 2.67 GPa with a 1 mm gauge length.