Exfoliation of Few‐Layer Graphene in Volatile Solvents Using Aromatic Perylene Diimide Derivatives as Surfactants

Abstract

Commercial, aromatic perylene diimide (PDI) dyes were used to exfoliate few‐layer graphene nanosheets in low‐boiling organic solvents such as chloroform and tetrahydrofuran. Importantly, in such solvents, graphene cannot be exfoliated in the absence of the aromatic perylene diimide (PDI) dyes. The PDIs are physisorbed onto the basal plane of the nanosheet surface, which stabilized them in solution; the aromatic core lies flat on graphene and the PDI side groups influenced the physisorption strength and molecular packing. Upon varying just a single atom in the chemical structure of the side groups, significantly different exfoliation efficiencies were observed. The graphene–PDI interaction was studied at the nanoscale by scanning tunneling microscopy and molecular dynamics, at the microscale by atomic force and electron microscopy, and at the macroscale by optical spectroscopy. Thanks to the high volatility of the chosen solvent, the nanosheets can be embedded in standard polymer composites through a simple solvent‐induced swelling procedure.

A robust, modular approach to produce graphene–MOx multilayer foams as electrodes for Li-ion batteries

“…Standard SSA measurements in gas could not be used due to the low SSA of the mesoscopic foams, thus we measured SSA by adsorption of a commercial organic dye, as described in ref. 35, 36 and in exp. details (see Fig.…”

“…The fraction of molecules adsorbed on graphite was calculated by monitoring the change in the maximum absorption peak (the molar attenuation coefficient of PDI-F is 79 489 L mol −1 cm at 527 nm) for each sample. 35 The specific surface area (SSA) of the GF related materials was estimated using the formula:…”

“…The value of X m was obtained from PDI-F adsorption isotherms at varying concentrations. 35 UV absorption data were recorded with a LAMBDA 650 UV/ Vis spectrophotometer. For spectrophotometric measurements, all the solutions, with and without graphite, were filtered using "CHROMAFIL® XTRA H-PTFE-45/25" filters with a mesh size of 25 μm.…”

Functionalization of 2D Materials with Photosensitive Molecules: From Light‐Responsive Hybrid Systems to Multifunctional Devices

“…On this view, π–π interactions might be exploited to physically tether onto the surface of 2D materials possessing an extended π‐conjugation, such as graphene, a broad range of photoresponsive molecules including spiropyran derivatives, metal complexes, perylene diimides, and coumarin derivatives, for several different applications spanning from (bio)sensing to optoelectronics. The perylene diimide derivatives have also been used as surfactants for the exfoliation of graphene nanosheets . In the last few years, the noncovalent functionalization has been exploited on 2D systems beyond graphene as well, and a prime example is represented by TMDs.…”

Interaction between perylene-derivated molecules observed by low temperature scanning tunneling microscopy

“…Optoelectronic characteristic of perylene derivative compounds are due to the π-conjugated system of its polyaromatic structure. On the other hand, it is possible to change the characteristics of these molecules using appropriate pe-35 ripheral groups, particularly if these groups are polar [20,21].…”