Characterization of Carbon Nanomaterials Dispersions: Can Metal Decoration of MWCNTs Improve Their Physicochemical Properties?

A suitable dispersion of carbon materials (e.g., carbon nanotubes (CNTs)) in an appropriate dispersant media, is a prerequisite for many technological applications (e.g., additive purposes, functionalization, mechanical reinforced materials for electrolytes and electrodes for energy storage applications, etc.). Deep eutectic solvents (DES) have been considered as a promising “green” alternative, providing a versatile replacement to volatile organic solvents due to their unique physical-chemical properties, being recognized as low-volatility fluids with great dispersant ability. The present work aims to contribute to appraise the effect of the presence of MWCNTs and Ag-functionalized MWCNTs on the physicochemical properties (viscosity, density, conductivity, surface tension and refractive index) of glyceline (choline chloride and glycerol, 1:2), a Type III DES. To benefit from possible synergetic effects, AgMWCNTs were prepared through pulse reverse electrodeposition of Ag nanoparticles into MWCNTs. Pristine MWCNTs were used as reference material and water as reference dispersant media for comparison purposes. The effect of temperature (20 to 60 °C) and concentration on the physicochemical properties of the carbon dispersions (0.2–1.0 mg cm−3) were assessed. In all assessed physicochemical properties, AgMWCNTs outperformed pristine MWCNTs dispersions. A paradoxical effect was found in the viscosity trend in glyceline media, in which a marked decrease in the viscosity was found for the MWCNTs and AgMWCNTs materials at lower temperatures. All physicochemical parameters were statistically analyzed using a two-way analysis of variance (ANOVA), at a 5% level of significance.

Effect of metal decoration on sulfur-based gas molecules adsorption on phosphorene

Based on first-principles calculation, the adsorption of sulfur-based gas molecules (H2S, SO2, SO3) on various metal-decorated phosphorenes is researched systematically. Eleven metals (Li, Na, K, Rb, Cs, Ca, Sr, Ba, Ni, La, Tl) which can avoid the formation of clusters on the phosphorene are considered. Noticeably, all metal decorations can enhance the adsorption strength of phosphorene to sulfur-based gas molecules except for H2S on Tl-decorated phosphorene. Meanwhile, the adsorption energy (Eads) shows the trend of Eads(H2S) < Eads(SO2) < Eads(SO3) for the same metal decoration case. In addition, some metal-decorated phosphorene systems exhibit intriguing magnetic and electrical variation after sulfur-based gas molecule adsorptions, indicating that these systems are promising to be candidates for the detection and removal of sulfur-based gas molecules.

Effect of metal decoration on sulfur-based gas molecules adsorption on phosphorene

Using the first-principles calculation based on density functional theory (DFT), we systematically studied the adsorption of sulfur-based gas molecules (H2S, SO2, SO3) on various metal-decorated phosphorenes. To avoid the formation of metal clusters on the surface of phosphorene, eleven metals (Li, Na, K, Rb, Cs, Ca, Sr, Ba, Ni, La, Tl) with bulk cohesive energy less than the binding energy on the phosphorene are considered. Except for H2S on Tl-decorated phosphorene, all metal decorations can improve the adsorption strength of phosphorene to sulfur-based gas molecules, and Eads(H2S) < Eads(SO2) < Eads(SO3) for the same metal decoration case. In addition, some metal-decorated phosphorene systems exhibit interesting magnetic and electrical changes after sulfur-based gas molecule adsorptions, indicating that these metal-decorated phosphorene systems are promising to be used for the detection and removal of sulfur-based gas molecules.

Effect of metal decoration on sulfur-based gas molecules adsorption on phosphorene

Using the first-principles calculation based on density functional theory (DFT), we systematically studied the adsorption of sulfur-based gas molecules (H2S, SO2, SO3) on various metal-decorated phosphorenes. To avoid the formation of metal clusters on the surface of phosphorene, eleven metals (Li, Na, K, Rb, Cs, Ca, Sr, Ba, Ni, La, Tl) with bulk cohesive energy less than the binding energy on the phosphorene are considered. Except for H2S on Tl-decorated phosphorene, all metal decorations can improve the adsorption strength of phosphorene to sulfur-based gas molecules, and Eads(H2S) < Eads(SO2) < Eads(SO3) for the same metal decoration case. In addition, some metal-decorated phosphorene systems exhibit interesting magnetic and electrical changes after sulfur-based gas molecule adsorptions, indicating that these metal-decorated phosphorene systems are promising to be used for the detection and removal of sulfur-based gas molecules.

Elucidating hydrogen storage properties of two-dimensional siligraphene (SiC8) monolayers upon selected metal decoration

DFT investigation of hydrogen (H2) adsorption on pristine and light metal decorated siligraphene SiC8 showed that Ca@SiC8 and Li@SiC8 have promising thermodynamic properties and H2 uptake, which surpasses the U.S. Department of Energy's 2025 goal.

Chemical and Microscopic Analyses of The Afghan Turkmen Ersari Tribe Headdress

In accordance with the research plan of the Material Culture Unit within the framework of the project entitled ‘Sinophone Borderlands – Interaction at the Edge’, a study of the chemical composition and surface features of metal parts of the Afghan Ersari Tribe headdress was performed. The headdress consists of a textile base and ornamental metal decoration called gupba and a metal diadem called sünsüle. The obtained results of the analyses, using a scanning electron microscopy (SEM) equipped with an energy dispersive spectrometer (EDS) and an X-ray fluorescence (XRF) spectrometry, uncovered the microscopic features and composition of the metal pieces of the gupba and sünsüle. The main goal of the work was to reveal the chemical compositions of the metal parts in order to determine which metals and procedures were used over the course of their production and to support the current assumptions based on visual appraisals of objects of this type. These results undoubtedly broaden our view of the Turkmen culture in Afghanistan and help us form a database of knowledge and facts about artefacts from the Sinophone borderlands.