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Two kinds of Pluronics (PEO-PPO-PEO triblock copolymers) were used in these studies. They have mixed with anionic surfactant (sodium oleate). The adsorption isotherms of surfactant and copolymer-surfactant mixture onto dolomite have been determined.The adsorbed amount of the Pluronics increases with increasing concentration and reaches plateau. An increase of adsorbed amounts of anionic surfactant...
From year to year natural surfactants are gaining ever growing awareness because of their valuable properties (in the absence of negative impact on the environment, as with the use of synthetic surface active agents). In the group of surfactants of natural origin there are surface active agents produced by microorganisms (biosurfactants) or compounds having a natural part (hydrophilic head and/or...
Wettability of solids is a key phenomenon in many processes. One should mentioned those which accompany us in our everyday life i.e. washing or cementing as well as those applied in industry e.g. flotation of minerals. Value of the contact angles are affected by many factors. One of them is temperature. In this paper monocrystaline quartz was used in the investigations which were carried out in the...
On the basis of the surface tension ( LV g ) data of the aqueous solutions of p-(1,1,3,3-tetramethylbutyl)phenoxypoly(ethylene glycol) (Triton X-100 or TX-100) and cetyltrimethylammonium bromide (CTAB) mixture with ethanol published in our previous paper, the process of ethanol adsorption was investigated. For that reason, the values of Gibbs surface excess concentration of ethanol at the solution-air...
In the biomedical field, water contact angle is a useful gauge to follow how a biomaterial surface would interact with the surrounding water-like physiological environment. Ti6Al4V alloy is widely used in orthopedic applications. Nevertheless, the values of its water contact angle reported in the literature show a large dispersion, from 40° up 80°. However, in addition to the expected dependence of...
Wettability of poly(tetrafluoroethylene) (PTFE) by aqueous solutions of binary mixtures composed of sodium bis(2-ethylhexyl) sulfosuccinate (AOT) with polyoxyethylene (23) lauryl ether (Brij 35) was considered on the basis of the measured values of contact angle and surface tension. It was shown that the value of the critical surface tension of PTFE surface wetting at the studied system (23.5 mN/m),...
Activity coefficients at infinite dilution of the aqueous solutions of nonionic hydrocarbon surfactants, p-(1,1,3,3-tetramethylbutyl) phenoxypoly(ethylene glycols), Triton X-100 (TX100) and Triton X-165 (TX165), fluorocarbon surfactants, Zonyl FSN-100 (FSN100) and Zonyl FSO-100 (FSO100) and their ternary mixtures were determined from the Gracia-Fadrique et al. method for non-volatile compounds. The...
Beer is the world's oldest and most widely consumed alcoholic beverage. The transformation of bitter acids to iso-α and iso-ß-acids is recognized as the key step of beer production. The paper shows and discusses the transformation kinetics of α- and ß-acids into their iso-form. Following the performed experiments, the largest amounts of the bitter acids isomers are formed in the brewing process carried...
The adsorption and release of Naproxen as a model drug was studied. The MCM-41 silica was chosen as a model adsorbent. The synthesis of mesoporous silica was performed by template method using cetyltrimethylammonium bromide CTAB as a pore directing agent. Synthesized MCM-41 material of high quality was used as a carrier for Naproxen. The loading procedure was performed at normal conditions and under...
Determination of cadmium, lead, chromium and nickel in soil samples by slurry sampling graphite furnace atomic absorption spectrometry (GFAAS) was presented. Optimization of determination conditions, stability test for slurries and metal partitioning between solid and liquid phase was investigated. The method was successfully tested by the analysis of certified reference materials.
Solid-phase extraction (SPE) is simple and inexpensive sample preparation procedure which can be applied for the isolation/fractionation of essential oil compounds from wide variety of samples, such as foodstuffs, biological and environmental. Due to the complex nature of the examined matrices and frequently low concentration level of target components, analytical procedures require the use of initial...
Ion-imprinted polymers (IIPs) are created based on enzyme phenomenon, where these polymers exhibit selective recognition of metal ions in the presence of matrix ions. For that reason IIPs find many applications in sensors, solid phase extraction and membrane separation of metal ions. This review focuses on the synthesis, characterization and application of IIPs.
Synthesis of SBA-15 mesoporous organosilicas functionalized by phenylamino and gluconamide groups is reported. The organosilicas have been synthesized by co-condensation of proper monomers in the presence of Pluronic P123, and characterized by nitrogen sorption, X-ray diffractometry, elemental analysis, and FTIR spectroscopy to get detailed information about their porous structure, ordering and presence...
An unmodified boron-doped diamond electrode was used for the voltammetric determination of ascorbic acid (AA). The measurements were carried out in an acetate buffer solution of pH = 4.6 by differential pulse voltammetry (DPV). Under the optimized experimental conditions, AA gaves linear response in a broad concentration range from 5 · 10–7 to 2· 10–3 mol/dm3. The detection limit was 1.63 · 10–7 mol/dm3...
This study discusses the influence of water content in measuring system on the estimation of antioxidant activity of essential oils. The presented data show that the antioxidant activity of thyme, clove, summer savory and basil essential oils strongly depends on water concentration what has important impact on the estimation of correct and reliable antioxidant activity of examined essential oils.
A series of substituted (E)-N-benzylidene-5-bromopyridin-2-amine compounds have been synthesized from 5-bromo-2-aminopyridine with different substituted benzaldehydes. The structure of the adducts was confirmed by their physical constants, UV, IR and NMR spectral data. The observed UV absorption maximum λmaxC=N(nm), IR frequencies νC=N(cm-1), The 1H and 13C NMR δ(ppm) chemical shifts values have been...
A series of N-(substituted phenyl) formamides were synthesised by sulphated titania (TiO2-SO4 2-) catalyzed formylation of substituted anilines and formic acid in acetonitrile medium at room temperature. The synthesised formamide derivatives are characterized by their spectral data. The infrared νNH, CO (cm-1) stretches, chemical shifts(δ, ppm) of NH, COH and ipso carbons(Ar-C-NH) were assigned and...
A problem associated with the surface potential jump at the air-water interface has been studied for many years. However, to date, there is no consensus both as to its value and sign. This is due to the impossibility of direct measurement of the surface potential, which caused that many scientists have attempted to estimate the value and sign of this potential, indirectly by measuring other physical...
Some novel substituted hydrazone derivatives of amino guanidine have been synthesized with different substituted benzaldehydes by condensation method. The synthesized hydrazones were characterized by their physical constants, UV, IR and NMR spectra. The spectral data have been correlated with Hammett substituent constants and Swain–Lupton parameters. From the result of statistical analysis, the effects...
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