Strong Viscosity Increase in Aqueous Solutions of Cationic C22-Tailed Surfactant Wormlike Micelles

The viscoelastic properties and structure parameters have been investigated for aqueous solutions of wormlike micelles of cationic surfactant erucyl bis(hydroxyethyl) methylammonium chloride with long C22 tail in the presence inorganic salt KCl. The salt content has been varied to estimate linear to branched transition conditions due to screening of the electrostatic interaction in the networks. The local cylindrical structure and low electrostatic repulsion was obtained by SANS data. The drastic power law dependencies of rheological properties on surfactant concentrations were obtained at intermediate salt content. Two power law regions of viscosity dependence were detected in semi-dilute solutions related to “unbreakable” and “living” micellar chains. The fast contour length growth with surfactant concentration demonstrated that is in good agreement with theoretical predictions.

Synthesis of Hematite Nano Material and Its Effect on Properties of Water Based Drilling Mud

The worldwide use of nanotechnology in most industries, such as in oil and gas industries, the world now has been directed towards introducing this modern technology in drilling fluids for the purpose of reaching and extracting hydrocarbons that exist at high depth where high temperatures and high pressure present using this technology to achieve the required mud properties with lowest cost. In this research, the particles of Nano hematite were prepared in laboratory using two methods, the first method by chemical reaction between iron nitrate (Fe (NO3)3• 9H2O) and ammonium hydroxide (NH4OH), after that, prepared Nano-materials were subjected to AFM, XRD testing in order to investigate the size and type of particles, the investigations showed that the formed particles were Fe2O3 (<100nm). The second method is similar to the first method except adding (CTAB) material in order to reduce the interfacial tension leading to 4.5nm Nano-material. Three samples of drilling mud were prepared, the first sample was prepared from water and bentonite only, the second sample was prepared from water, bentonite and nano (prepared from first method), the third samples was prepared from water, bentonite and nano (prepared from second method), rheological properties, filtration, density, lubricity, sagging and magnetism properties were measured by analyzing and comparing the results. The results were obtained showed that the small effect of nano material filtration, density, lubricity, and sagging properties, except the viscosity increase when the second sample of Nano hematite was added to the mud prepared from water and bentonite. Also, the magnetism increase when the second sample of nano hematite was added to the mud prepared from water and bentonite, due to the difference in the molecular arrangement caused by the presence of CTAB.

Strong Viscosity Increase in Aqueous Solutions of Cationic C22-Tailed Surfactant Wormlike Micelles

The viscoelastic properties and structure parameters have been investigated for aqueous solutions of wormlike micelles of cationic surfactant erucyl bis(hydroxyethyl) methylammonium chloride with long C22 tail in the presence inorganic salt KCl. The salt content has been varied to estimate linear to branched transition conditions due to screening of the electrostatic interaction in the networks. The local cylindrical structure and low electrostatic repulsion was obtained by SANS data. The drastic power law dependencies of rheological properties on surfactant concentrations were obtained at intermediate salt content. Two power law regions were detected in semi-dilute solutions related to &ldquo;unbreakable&rdquo; and &ldquo;living&rdquo; micellar chains. The fast contour length growth with surfactant concentration was demonstrated that is in good agreement with theoretical predictions.

Antimicrobial Activities of Propolis in Poloxamer Based Topical Gels

Propolis contains a group of compounds with various activities. However, their low solubility is a drawback for the development of pharmaceutical formulations. In this study, poloxamers as a solubilizer and gelling agent were evaluated to develop a topical antimicrobial formulation of propolis. The effects of poloxamer type and concentration on the propolis solubility, release rate, and antimicrobial activities were investigated. Staphylococcus aureus (S. aureus) and Candida albicans (C. albicans) were the representative bacteria and fungi, respectively. At 5%, poloxamer 407 (P407) and poloxamer 188 (P188) enhanced the propolis solubility by 2.86 and 2.06 folds, respectively; at 10%, they were 2.81 and 2.59 folds, respectively. The micelle size in the P188 formulation increased in the presence of propolis, whereas there was no change in the P407 formulation. Release rates of propolis decreased with the P188 concentration increase, which was attributed to viscosity increase. Both P188 and P407 formulations showed antimicrobial activity against S. aureus in a time-kill kinetics assay. However, only the P188 formulation reduced the cell’s numbers significantly against C. albicans, compared to the control. We speculate that P188 mixed micelles were more effective in releasing free active compounds to exhibit anti-microbial activity compared to the P407 micelles encapsulating the hydrophobic compounds in their cores. Propolis in P188 formulation is proposed as a potential topical antimicrobial agent based on its activity against both S. aureus and C. albicans.

Viscosity Analysis of Battery Electrode Slurry

We report the effects of component ratios and mixing time on electrode slurry viscosity. Three component quantities were varied: active material (graphite), conductive material (carbon black), and polymer binder (carboxymethyl cellulose, CMC). The slurries demonstrated shear-thinning behavior, and suspension properties stabilized after a relatively short mixing duration. However, micrographs of the slurries suggested their internal structures did not stabilize after the same mixing time. Increasing the content of polymer binder CMC caused the greatest viscosity increase compared to that of carbon black and graphite.

Low-Temperature Rheology and Thermoanalytical Investigation of Lubricating Oils: Comparison of Phase Transition, Viscosity, and Pour Point

According to the ASTM D97, the pour point is the temperature below which petroleum products cease to flow. To evaluate the relevance of pour point measurements for synthetic lubricating oils, we investigated the crystallization, melting temperature and low-temperature flow behavior of one mineral and five synthetic lubricating oils. The classification of three groups emerged from this process. The formation of paraffin crystals in mineral oils (I) below the crystallization temperature causes shear-thinning behavior and a yield point. The crystallization temperature determined in the thermal analysis and rheology correlates well with the pour point. Synthetic lubricating oils, which solidify glass-like (II), exhibit a steady viscosity increase with falling temperature. The temperature at which viscosity reaches 1000 Pas corresponds well to the pour point. Synthetic oils, especially esters, with complex crystallization behavior (III), exhibit supercooling depending on the shear rate and cooling conditions. For these lubricating oils, the pour point provides no information for low-temperature applicability.

Synergy between Phenoxy and CSR Tougheners on the Fracture Toughness of Highly Cross-Linked Epoxy-Based Composites

A remarkable synergistic increase in fracture toughness by 130% is demonstrated for a CFRP high performance epoxy composite when adding an equal weight combination of phenoxy thermoplastic and core-shell rubber (CSR) toughening agents, as compared to a single toughener at a comparable total concentration of around 10 wt%. The dual-toughened matrix exhibits an unusual morphological arrangement of the two toughener agents. The interlaminar shear strength of the composites is also synergistically improved by about 75% as compared to the reference while the compression modulus reduction and viscosity increase are significantly smaller than for the single phenoxy toughened system. A partial filtering of the CSR particles by the dense CF fabric during pre-pregging leads to a less than optimum CSR dispersion in the composites, showing that the synergy can be further optimized, possibly to the same level as the unreinforced systems.

SYNTHESIS AND PROPERTIES OF 2-HYDROXY-5[1(3)-METHYLCYCLOALKYL]-BENZYLAMINOETHYLNONYLIMIDAZOLINES

The paper deals with the results of cycloalkylation of phenol with 1-methylcyclopentene, 1(3)-methylcyclohexene in the presence of KU-23 catalyst and influence of various parameters on the yield of the target product. The reaction temperature was varied from 80 to 140 °C, the reaction time - from 2 to 8 h, molar ratio of phenol to cyclene – from 1:2 to 2:1 mol/mol, the catalyst amount – from 5 to 15%. Maximum yield of para-[1(3)-methylcycloalkyl] phenols is obtained under the following conditions: temperature – 110-120 °C, duration – 5-6 h, molar ratio of phenol to 1(3)-methylcycloalkene – 1:1 mol/mol and the catalyst amount is 10% based on taken phenol. Simultaneously, the yield of the target products – para-[1(3)-methylcycloalkyl] phenols is 68.6-73.5% per taken phenol, the selectivity is 91.8-94.3% on the target product. As a result of the chromatographic studies of the products of phenol cycloalkylation with 1(3)-methylcycloalkenes in the presence of KU-23 catalyst it becames clear that the alkylate mainly contains paracycloalkyl-substituted phenols (89.6-94.1%). After rectification of the alkylate at low pressure (10 mm Hg), the target products were obtained with a purity of 97.6-98.2% and their physico-chemical properties were determined. The resulting para-[1(3)-methylcycloalkyl] phenols were aminomethylated by formaldehyde and aminoethylnonylimidazoline at the ratio of 1:2:2. As a result, Mannich bases were obtained with yield of 68.3-76.7% from theory. The synthesized methylcycloalkylbenzylaminoethylnonylimidazolines were tested as antioxidants of M-8 engine oil. The oxidation resistance of the oil has been investigated without the addition and with the addition of ИХП-21 antioxidants, known benzylphenylamines and the compounds of the invention. Addition of the obtained compounds to the base oil leads to enhancement of its antioxidant properties, at application of which viscosity increase is 14.07-15.28%, and precipitate - 0.45-0.57%.

STRUCTURAL AND MECHANICAL PROPERTIES OF THE DEVELOPED FRUIT AND BERRY SEMI-FINISHED PRODUCT

One of progress directions of the modern food industry is the development and introduction of innovative technologies and assortment of functional food products, allowing to decrease risks of disease progression and favoring the population health. Such products include multicomponent fruit and berry pastes and dried powder fractions. They are natural vitamin carriers, may be used as a supplement or a base for creating a wide spectrum of food products with healthy properties. A production way for fruit and berry semi-finished product using non-traditional raw materials has been created. For creating paste or dried faction, raw materials with a high content of pectins for better structuring and with correspondent healing-prophylactic properties were selected. Apple was taken as a base of the paste with adding non-traditional raw materials – ziziphus and black aronia. The way differs by the process of dehydration by concentrating up to 44…46 % of dry substances in a rotor evaporator, then, if necessary, additional drying in a thermoradiative one-drum rolling dryer up to 5..8 % of dry substances. Structural-mechanical parameters of experimental samples of the paste after concentrating up to 45 % content of dry substances have been determined. An effective viscosity increase for all three experimental samples as 33…59 % comparing with apple paste has been established. It is explained by higher content of pectin substances in ziziphus. The most effective viscosity index is 584 Pa∙s belongs to a sample with the components content: apple – 50 %, ziziphus – 45 %, black aronia – 5 %. The developed semi-product may be used as a vitamin supplement, filler or thickener at producing functional food products in confectionary, milk, bakery industry and also for preparing dishes and drinks at restaurant economies and under home conditions

Brewers’ spent grain as substrate for dextran biosynthesis by Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16

Background Lactic acid bacteria can synthesize dextran and oligosaccharides with different functionality, depending on the strain and fermentation conditions. As natural structure-forming agent, dextran has proven useful as food additive, improving the properties of several raw materials with poor technological quality, such as cereal by-products, fiber-and protein-rich matrices, enabling their use in food applications. In this study, we assessed dextran biosynthesis in situ during fermentation of brewers´ spent grain (BSG), the main by-product of beer brewing industry, with Leuconostoc pseudomesenteroides DSM20193 and Weissella confusa A16. The starters performance and the primary metabolites formed during 24 h of fermentation with and without 4% sucrose (w/w) were followed. Results The starters showed similar growth and acidification kinetics, but different sugar utilization, especially in presence of sucrose. Viscosity increase in fermented BSG containing sucrose occurred first after 10 h, and it kept increasing until 24 h concomitantly with dextran formation. Dextran content after 24 h was approximately 1% on the total weight of the BSG. Oligosaccharides with different degree of polymerization were formed together with dextran from 10 to 24 h. Three dextransucrase genes were identified in L. pseudomesenteroides DSM20193, one of which was significantly upregulated and remained active throughout the fermentation time. One dextransucrase gene was identified in W. confusa A16 also showing a typical induction profile, with highest upregulation at 10 h. Conclusions Selected lactic acid bacteria starters produced significant amount of dextran in brewers’ spent grain while forming oligosaccharides with different degree of polymerization. Putative dextransucrase genes identified in the starters showed a typical induction profile. Formation of dextran and oligosaccharides in BSG during lactic acid bacteria fermentation can be tailored to achieve specific technological properties of this raw material, contributing to its reintegration into the food chain.