Colloid-chemical Properties Research Articles

MODIFICATION OF WATER POLYMER COMPOSITIONS FOR ELECTRODEPOSITION BY METALLOPORPHYRINS

It is known that coatings produced by electrodeposition, cured at high temperatures (180ºC and above).The aim of this study is reducing the energy intensity of production of polymer coatings, improving physical, mechanical properties of the polymer coatings and expansion of colors of paints for the electrodeposition. As the object of study was chosen lacquer KCh-0125, the main component of which is maleated polybutadiene. A micelle of film-forming neutralized tertiary amine is a colloidal particle size of 40 to 70 nm. One of the most effective and lowcost ways to the above problems is the introduction of the water-based oligomeric compositions hydrophobic modifiers. As modifiers were selected naturally occurring metalloporphyrins - cobalt (II) complex of pheophytin a (СоPh) and copper (II) complex of methylpheophorbide a (CuMPP). The method of introduction of the СоPh and the CuMPP of the water-based compositions for electrodeposition was developed. Colloid-chemical properties of the resulting compositions were studied. It was presented the most probable structure of the scheme colloidal particles modified by metalloporphyrins. It was conducted viscometric, spectral studies; the method of dynamic light scattering was used to determine the zeta potential and the size of colloidal particles. It was demonstrated high catalytic activity of metal complexes of porphyrins examined in structuring processes electrodeposited coatings when cured. Introduction of metalloporphyrins in the coating helps to reduce the curing temperature to 160°C. This makes it possible to reduce or duration, or a temperature curing coatings. The introduction of CuMPP make possible to obtain transparent coatings emerald green. Modified electrodeposited coatings also have good water and salt resistance.

Colloid-chemical properties and physiological activity of water-soluble humic preparations

Conditions were found for solid-phase mechanochemical activation of coals, allowing a significant increase in the yield of water-soluble humic preparations enriched in humic acids and mineral elements. The humic preparations are characterized by a decrease in the molecular mass and by changes in the ionic composition and surface activity. The physiological activity of the humic preparations was determined.

Electrodeposition of Ni–ZrO2 Nanocomposites from Methanesulfonate Electrolytes

We study the colloid-chemical properties of methanesulfonate electrolytes used for the electrodeposition of Ni-ZrO2 nanocomposites. We observed higher aggregate stability of the dispersed phase as compared with sulfate electrolytes. This results in smaller sizes of the agglomerates of zirconium dioxide in the solution. It is shown that the mass content of the inert phase in the coating obtained from the methanesulfonate electrolyte is elevated and that the microhardness of these deposits is higher than the microhardness of the coatings electrodeposited from sulfate electrolytes.

FUNCTIONAL ORGANOSILICON SUBSTANCES AS STABILIZERS OF POLYMERIC SUSPENSIONS

The review presents schemes for obtaining homologous series of the linear α,ω-carbofunctional oligodimethylsiloxanes with the silicone chain length from 6 to 60 siloxane units containing carboxydecyl, aminopropyl and glycidoxypropyl groups at the chain ends allowing to obtain organosilicon surfactants with reproducible structure and properties. Data on the surfactant colloidchemical properties and kinetic regularities of styrene polymerization in their presence are provided. Systematic research of heterophase styrene polymerization kinetic regularities in the presence of water-insoluble α,ω-carbofunctional oligodimethylsiloxane allowed to formulate the fundamental differences of polymerization kinetic regularities from those observed in the presence of water-soluble surfactants. The mechanism of interfacial adsorption layers formation with water-insoluble α,ω-carbofunctional oligodimethylsiloxanes on the surface of monomer drops and polymer-monomeric particles was considered. This mechanism consists in the forced surfactant replacement by the formed polymer (because of their incompatibility) to the interfacial adsorption layer and in the formation of the surfactant supermolecular structures. The latter in total with the polymer provide its high durability.

Preparation and Colloid Chemical Properties of New Surfactant Derivatives of Chitosan

This paper presents the investigation of interaction of chitosan with carboxylate surfactants – cetyl oligo ethylene succinate and 1-stearoyl-2-hydroxypropyl-3-succinate. It is shown that depending on the type of surfactant and the ratio of components, viscous solutions or colloidal dispersions form on interaction with chitosan. For solutions of chitosan – surfactant derivatives a significant non-additive decrease in surface tension is characteristic, making them useful for obtaining stable emulsions of oil in water.

Investigation of the Properties of Protein Hydrolyzates Obtained from Leather Wastes

Leather and fur industry is a source for generation of considerable amount of the collagen-containing wastes as degree of the raw materials use is equal 60 % at most. The enterprises direct these wastes composed by flesh, cutoff pieces, split leather, cloth rags to disposal sites. The authors proposed the technology for processing the flesh from yak pelt and split leather from reindeer paws aimed at obtaining protein hydrolyzate for its subsequent use as an intensifier and biosurfactant in the processes of soaking and degreasing of leather and fur materials. The authors investigated physical-chemical and colloid-chemical properties as well as chemical and amino acid composition of protein hydrolyzates. It was shown that surface characteristics of protein hydrolyzates obtained from the yak pelt flesh and split leather from reindeer paws are comparable to the properties of synthetic surfactants used in liquid processes of leather and fur production. The authors established that amino acid composition of protein hydrolyzates include tyrosine, phenylalanine, leucine and isoleucine, valine, proline and oxyproline, serine, alanine, glycine. Histidine and methionine were found in protein hydrolyzate obtained from split leather from reindeer paws, and lysine and threonine—in protein hydrolyzate from yak pelt flesh.

Synthesis and Colloidal-Chemical Properties of Surfactants Based on Alkyl Amines and Propylene Oxide

AbstractOctyl amine, nonyl amine, dodecyl amine, hexadecyl amine and octadecyl amine are propoxylated with propylene oxide at mole ratios 1 : 1 and 1 : 2. The structure of the synthesized compounds has been identified by IR-and NMR-spectroscopy methods. Colloidal-chemical indices of these compounds have also been determined and their surface-active parameters have been measured, including the critical micelle concentration (CMC), the effectiveness of surface tension reduction (πCMC), the surface excess concentration (Γmax), area per molecule at the interface (Amin), the changes of Gibbs free energies of adsorption (ΔGad) and micellization (ΔGmic). Petroleum-collecting and petroleum-dispersing capacities of the synthesized compounds on the surface of water of varying mineralization degree have been studied.

Aspects of storage and corrosion characteristics of biodiesel

Process and corrosion engineers have critically addressed compatibility of biodiesel components in petroleum refinery infrastructure because of different processing, storage and dispatching histories of shipments. Concerns were related to aging and corrosion and to accumulation of a bottom layer in the dedicated storage tank. Corrosion tests were executed in a microcosm test environment modified to the recommended practice of ASTM G4-01 procedure. Colloid chemical properties and technology of biodiesel refining operations can plausibly explain different material responses at different temperatures. The sampled bottom layer consisted mainly of glycerides, resembling characteristics of extract byproducts that are separated in trans-esterification in biodiesel synthesis. This bottom layer exerts both beneficial and detrimental effects. The positive side is that it extracts polar components and by this improves quality. The negative side is that it reduces resistance of the oil against aging. There was no risk of detrimental effects in terms of corrosion of storage tank materials. Overall progress of corrosion is controlled by the slightly alkaline bottom layer via neutralizing the oxidation products and exerting protection to metallic surfaces. Microbial degradation can only pose risks if normal and prudent conditions are not observed. Upon extended incubation microorganisms that are present in the bottom layer below the level detection limit, can develop countable colonies, if nutrients are available and conditions are favorable. It can be concluded that there is no risk of significant corrosion in storage and downstream infrastructure if the stored biodiesel meets standard quality specifications and storage conditions are normal.

The Role of Oiling Agents in Modern processes of Producing Chemical Fibres and Filled Polymer Materials

A list of the main physical and colloid-chemical properties of industrial surfactants used as components of oiling agents for processes in the production of high-strength synthetic fibres is proposed.

Determination of quality of wastewater containing surfactants

The article presents the results of public service enterprises wastewater biotesting, which contain surfactants and model solutions in comparison with the colloidal-chemical properties. It is established that the maximum allowable concentration of surface active agents coincides with the concentration of saturation of the adsorption layers, which is determined by the isotherm of surface tension. This allows you to replace the tedious and less accurate biotesting measurement to the surface tension of surface active agents solutions to normalize indicators of wastewater.

Composites Based on Polyfluoroalkylacrylate Nanodispersions for Chemical Fiber Surface Modification

A method for preparing composites for chemical fiber surface modification that was based on nanodispersions of polyfluoroalkylacrylate and an industrial coarsely dispersed system was examined. The colloidal chemical properties of composites prepared by mixing the two dispersions in different polymer mass ratios were studied. The optimum conditions for modifying fibers with composites of latexes LFM-N and SKD-1S were found using mathematical experiment planning and process optimization.

The influence of detonation synthesis conditions on surface properties of detonation nanodiamonds

The paper addresses the influence of an armor protection composition of an explosive compound on the colloid-chemical properties of the detonation nanodiamonds. Adding an oxidation inhibitor to the armor protection composition and to the explosive bulk itself is experimentally shown to be a promising method of producing aggregates of nanodiamond particles with preset surface characteristics.

Polymer colloid complexes of chitosan with sodium dodecyl sulfate in water-alcohol media

The formation of polymer colloid complexes based on chitosan and sodium dodecyl sulfate in aqueous ethanol media was studied. The infl uence of the composition of water-ethanol mixtures on the parameters of surfactant binding with chitosan, on the stability of the complexes, on the phase state of the system, and on the colloid-chemical properties of the complexes was analyzed. Addition of small (up to 34 vol %) amounts of ethanol to water enhances the intensity of binding of sodium dodecyl sulfate with the polyelectrolyte and promotes formation of insoluble associates.

Effect of oxidative treatment on the colloid-chemical properties of lignosulfonates

The effect of oxidative treatment on colloid-chemical properties of lignosulfonates was studied. Oxidation of lignosulfonates (403–423 K, \(P_{O_2 } \) = 0.2–0.8 MPa, 0.5–1 h) is accompanied by a decrease in the content of hydroxy groups and by an increase in the content of carbonyl groups in oxidation products. Under severe oxidation conditions (423–433 K, \(P_{O_2 } \) = 0.8 MPa, 3 h), lignosulfonates undergo chemical degradation with the formation of lower carboxy derivatives. The oxidized lignosulfonates exhibit lower performance, compared to the initial samples, in wetting and dispersion of sphalerite and elemental sulfur.

Properties and use of aqueous dispersions of an epoxy oligomer, prepared in the presence of various emulsifiers

The colloid-chemical properties of aqueous dispersions of ED-20 epoxy-4,4′-isopropylidenediphenol resin, prepared by the method of phase inversion in the presence of various emulsifiers, were studied, and possible applications of these dispersions were outlined.

The change in activated sludge surface properties after heavy metals leaching

The change in colloid-chemical properties of natural sludge sol formed as a result of biological treatment of domestic wastewater in the process of heavy metals leaching induced by metabolizing heterotrophic (acidogenic and alkaligenic) chemotrophic biocoenosis was investigated. It was found that bioleaching of heavy metals involving heterotrophs results in hydrophobization of sludge colloids and reduces its negative charge. Heavy metals leaching also results in destabilization of sludge sol, maximum in biological processes. Exopolysaccharides significantly stabilizing sludge sol have a little effect on its stability after heavy metals have been leached.

Association and colloid-chemical properties of humic acids in aqueous solutions

Colloid-chemical properties of humic acids in aqueous solutions have been studied as functions of their concentration, medium pH, and counterion nature. It has been established that, at pH 4, the state of humic acids depends on the solution concentration. At low concentrations, they exist as individual molecules; as the concentration is increased, they associate to form supramolecular structures at 5 mg/dm3 and micelles at 8 g/dm3. An increase in the counterion charge has been shown to decrease the critical concentration of supramolecular structuring. Supramolecular structures have increased adsorbability on clay minerals and promote the manifestation of solubilizing properties of humic acids in solutions even at a concentration of 5 mg/dm3, which is three orders of magnitude lower than the critical micelle concentration (8 g/dm3).

Demulsification of water-oil emulsions by polymeric compositions

Study contain date about investigation of colloid-chemical and deemulsifier properties of polymeric compositions on the basis of Polyacrilonitrile derivatives. It is established, that compositions are more effective at ratio of concentration in the intervals 0,25-0,5 and 4-6, that scientifically justificated by results of investigation of their colloid-chemical properties.

Colloid-chemical properties of biological dispersions

The results of the study of colloid-chemical properties of microorganism cells were. The behavior of yeast cells Torulopsis kefir var kumis, Sacharomyces cerevisiae and spherosome at the interface oil / water is determined by the properties at boundaring phases: the dielectric constant, the nature and size of the molecules of the organic medium. The fact of the immutability of charge electrokinetic potential of yeast cells when the pH from 2 to 8 and the presence of electronic devices for spherosome and seaweed at pH 5.0-5.2. The high sorption capacity of the cells to metal ions.

Colloid-chemical properties of water solutions of biosurfaсtants

The microorganisms Pseudomonas sp. and Bacillus sp. are effective producers of surface-active substances obtained at growth both on hydrophilic (glucose), and hydrophobic (sunflower oil) substrates. It is shown at growth on glucose Bacillus sp. form the endo-bio surface-active substances connected with a cellular wall of bacteria.