Electrophilic-nucleophilic properties as a factor in the formation of antifriction and hydrophobic properties of surface-modified metals with ammonium and organosilicon compounds

Abstract

Stabilisation of the functional properties of dispersed and compact metals, as well as the regulation of their reactivity, improvement of water-repellent, antifriction and anti-corrosion properties by creating the protective films on the surface is an urgent problem in relation to obtaining new materials. Previously, research conducted at REC “Nanotechnology” of the St. Petersburg Mining University proved that chemisorption of ethylhydridesiloxane vapours together with surfactants based on quaternary ammonium compounds has a beneficial effect on the water-repellent properties of metals. In order to obtain the physicochemical mechanism of the hydrophobisation of the surface of modified dispersed metals for the firsttime, the study of the electrophilic-nucleophilic properties of the active substances of the surface modifiers of metals was carried out using the methods of quantum-chemical modelling using HyperChem software package. The dipole moment, energy of the highest occupied and the lowest unoccupied molecular orbitals, electrophilic-nucleophilic properties were determined. The series of enhancement of ucleophilic/electrophilic properties and dipole moment for modifiers were obtained. The donor-acceptor properties, the differences in the characteristics of the molecules of alkamon, triamon, and hydrophobic silicone organic liquid were quantitatively and qualitatively established. The regularities of the formation of hydrophobic and antifriction properties in the composition of industrial oil I-20-surface-modified metal with various electrophilic-nucleophilic properties of the applied substances

Electrophilic and Nucleophilic Modifiers as a Factor of Formation of Lipophilic Properties of Surface-Modified Materials

“…The named method is a promising way for regulating various surface properties of dispersed metals such as copper, aluminum, nickel, etc. Surface modification of copper powders was carried out in vapor of QAC-based surfactants alkamon (GOST 10106-75) and (or) triamon (TU 6-14-1059-83), as well as in vapor of hydrophobic silicon-organic liquid HSL-94 (HSL) based on ethylhydridesiloxane at room temperature according to the procedure described in [1][2][3][4]. The specific interest is driven by the possibility of synergistic enhancement of water-repellent properties by adsorption of QAC and ethylhydridesiloxane molecules on the surface [1].…”

“…1). In opposite cases, the cation of the alkamon (A) contains a significantly greater hydrocarbon radical C17 [2]. The composition of the alkamon (A) corresponds to a chemical formula:…”

“…One of the promising approaches of obtaining the materials is the method of layering different sized molecules on metals (Patent RU 2425910) which is developed at St. Petersburg Mining University and implemented at a number of enterprises of the mineral resource complex of Russia and the Republic of Belarus. A part of the research conducted at REC "Nanotechnology" of Mining University proved that chemisorption of ethylhydridesiloxane vapors together with cationic surfactants based on quaternary ammonium compounds has a beneficial effect on the water-repellent properties of metals, such as, for example, aluminum and copper [1][2][3][4][5][6].…”

“…When studying the hydrophobic properties of the surface of modified samples based on copper powder, interesting effects were revealed after application of organic modifiers (ammonium compounds and ethylhydridesiloxane) on the surface in various combinations [1,2]. It was found that samples Cu/T/A, Cu/A/HSL, Cu/(A+T) mutually treated with ethylhydridesiloxane (HSL) and alkamon (A), triamon (T) based on quaternary ammonium compounds are characterized by a significant increase in water-repellent properties [1,2]. At the same time, treatment with only one modifier does not significantly enhance the hydrophobicity of the sample surface.…”

Studies on Extraction of Copper From Sulfuric Acid Solution After Thermochemical Enrichment of Rough Concentrate

“…Liquid extraction and electrolysis most often apply to process such solutions [23][24][25]. Liquid extraction of copper is the most widely used in the metallurgical industry [26][27][28][29]. The hydrometallurgical method of copper cathode production uses extraction to remove impurities from the pregnant leaching solution.…”