A blueprint for the synthesis and characterization of thiolated graphene

Graphene derivatization to either engineer its physical and chemical properties or overcome the problem of the facile synthesis of nanographenes is a subject of significant attention in the nanomaterials research community. In this paper, we propose a facile and scalable method for the synthesis of thiolated graphene via a two step liquid phase treatment of graphene oxide GO . Employing the core level methods, the introduction of up to 5.1 at. of thiols is indicated with the simultaneous rise of the C O ratio to 16.8. The crumpling of the graphene layer upon thiolation without its perforation is pointed out by microscopic and Raman studies. The conductance of thiolated graphene is revealed to be driven by the Mott hopping mechanism with the sheet resistance values of 2.15 k amp; 937; sq and dependable on the environment. The preliminary results on the chemiresistive effect of these films upon exposure to ethanol vapors in the mix with dry and humid air are shown. Finally, the work function value and valence band structure of thiolated graphene are analyzed. Taken together, the developed method and findings of the morphology and physics of the thiolated graphene guide the further application of this derivative in energy storage, sensing devices, and smart material

Synthesis and structures of 2,3,6-triaryl-1-acyl-4-acyloxypiperideines

1-Acyl-4-acyloxy-2,3,6-triaryl-δ3- and δ4-piperideines were obtained by acylation of 2,3,6-triarylpiperidone and its 1-acetyl derivative with carboxylic anhydrides and chlorides. The molecular and crystal structures of 3-phenyl-2,6-bis(o-acetoxyphenyl)-1-acetyl-4-acetoxypiperidin-3-ene were established by x-ray diffraction analysis. © 1991 Plenum Publishing Corporation

Carbocyclic and nitrogen-containing fused CH-acids with an annelated indenyl fragment. Thermogravimetric and X-ray structural analysis of 6 H-indeno[1,2-b]quinoline

Based on thermogravimetric characteristics first obtained for the model 6 H-indeno [1,2- b]quinoline, the scheme of thermal conversions of this compound in the temperature range 20–700 °C has been proposed, and the limit of its thermal stability (∼300 °C) has been determined. This temperature is recommended as the optimum for synthesizing fused benzoaza(diaza)fluorenes. Based on the results of X-ray structural analysis, the molecules of the studied indenoquinoline form centrosymmetric pairs, which are arranged in (110) layers. The molecules are orientationally disordered. The observed self-association of these molecules is similar to the π-π association of fused heterocyclic systems with π-excessive and π****- deficient fragments. It has been suggested that interferon-inducing and antitumor compounds with an annelated indenyl fragment have a common mechanism of action according to the intercalation model of stacking structures. © 1995, Plenum Publishing Corporation. All rights reserved

Guiding Graphene Derivatization for the On Chip Multisensor Arrays From the Synthesis to the Theoretical Background

Engineering the physics and chemistry of 2D materials is a key to unlock the potential of the advanced e nose technologies limited by the current semiconductor technologies. Herein, the adjustment of the graphene s morphology, physics, and gas sensing properties upon its carboxylation via the developed photochemical method is demonstrated. Formation of matrices of nanoscale holes yet with the retention of the lamellar structure of the graphene layer is signified upon the introduction of up to 9.5 at of carboxyl groups. The impact of the applied carboxylation on the conduction mechanism and electronic structure is demonstrated. The appearance of a set of the localized states in the valence band is revealed, originating from the molecular orbitals of carboxyls as is signified by the proposed approach for the identification of electronic states in graphene chemical derivatives. Given holey structure, predominance of highly affine carboxyls, and lateral inhomogeneity, the enhanced detection and discrimination of various alcohols, acetone, and ammonia vapors at room temperature is demonstrated. The opposite chemiresistive response toward ammonia in the humid air is also experimentally revealed and justified by the performed density functional theory modeling on the effect of ammonia, water, and their mix on electronic structure, and resistivity of the carboxylated graphen

Toward On Chip Multisensor Arrays for Selective Methanol and Ethanol Detection at Room Temperature Capitalizing the Graphene Carbonylation

The artificial olfaction units or e noses capable of room temperature operation are highly demanded to meet the requests of society in numerous vital applications and developing Internet of Things. Derivatized 2D crystals are considered as sensing elements of choice in this regard, unlocking the potential of the advanced e nose technologies limited by the current semiconductor technologies. Herein, we consider fabrication and gas sensing properties of On chip multisensor arrays based on a hole matrixed carbonylated C ny graphene film with a gradually changed thickness and concentration of ketone groups of up to 12.5 at. . The enhanced chemiresistive response of C ny graphene toward methanol and ethanol, of hundred ppm concentration when mixing with air to match permissible exposure OSHA limits, at room temperature operation is signified. Following thorough characterization via core level techniques and density functional theory, the predominant role of the C ny graphene perforated structure and abundance of ketone groups in advancing the chemiresistive effect is established. Advancing practice applications, selective discrimination of the studied alcohols is approached by linear discriminant analysis employing a multisensor array s vector signal, and the fabricated chip s long term performance is show