A new method for the preparation of TiO2/Ag bilayers via colloid self-assembly process using well-characterized titanium dioxide and silver suspensions was developed. The titanium dioxide nanoparticles, forming a supporting layer, were 46 nm in diameter, exhibiting an isoelectric point at pH 6.4. The silver nanoparticles, forming an external layer of the diameter of 50 nm were prepared via a chemical reduction method with the presence inorganic phosphate salts. The electrophoretic mobility measurements revealed that the zeta potential of silver nanoparticles was highly negative for a broad range of pH and ionic strengths. By explaining this information, the optimum condition for the silver nanoparticle immobilization on TiO2 supporting layers were selected. The coverage of the first layer was adjusted by ionic strength of the suspensions and by the deposition time. Afterward, the silver nanoparticle monolayers of controlled coverage were deposited under the diffusion-controlled transport. Their coverage was determined by a direct enumeration of deposited nanoparticles from AFM images and SEM micrographs. The experimental results showed that for extended deposition times, the coverage of silver nanoparticle layers significantly increases with ionic strength. Therefore, it was proven that the formation of bilayers is mainly controlled by electrostatic interactions and that it is feasible to produce uniform TiO2/Ag materials of desired coverage and structure.

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 vacuum. The release of drug was measured for differentially prepared samples. The results for MCM-41 are compared to those measured for silica gel for column chromatography Si-100 containing substantially larger pores. The results are discussed taking into account the penetration of pore system by loading solution as well as in terms of the proportion of dimensions of Naproxen molecule and pore dimensions of MCM-41.

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.

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 sample preparation stage. The paper shows the possibility of essential oil components fractionation from different plant materials using SPE method. The results presented in this paper shows that the proposed SPE procedure allows for easy and total fractionation of essential oil constituents (especially low-molecular oxygen compounds) from the sample matrix.

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 of substituents on the spectral data have been predicted. The antimicrobial activities of these synthesized hydrazone compounds have been screened by Bauer-Kirby method using human pathogenic bacteria and fungal species. The antimicrobial activities of all synthesized hydrazone compounds have shown significant activity.

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.

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 out at 80oC for more than 100 minutes. The presented data are in good agreements with the knowledge of experienced brewers who learned about the brewing process relying on sensory tests.

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 of introduced functional groups. The obtained materials were tested as sorbents of model pharmaceutical (diclofenac) to verify a potential application for removal of pharmaceutical: the observed static sorption capacities were ~50mg/g and ~130mg/g, for phenylamino- and gluconamidefunctionalized samples, respectively, while for pristine sample no adsorption was observed.

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.

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 correlated with Hammett substituent constants and F and R parameters using single and multi-linear regression analysis. From the results of statistical analysis, the effect of substituents on the spectral data has been studied. The antimicrobial activities of all synthesized imines have been studied using Bauer-Kirby method.

Measurements of the dynamic surface tension of the aqueous solutions of methanol, ethanol, propanol, CTAB and SDDS at their given concentrations were made. From the obtained results and the literature data it was concluded that the adsorption of short-chain alcohols at the water-air interface is somewhat similar to that of classical surfactants. For that reason the relationship between the Gibbs standard free energy of adsorption of short-chain alcohols and classical surfactants at that interface was established. The correlation between the chemical potential of mixing of alcohols and surfactants was also analysed. This analysis concerned the critical aggregation concentration (CAC) of alcohols and the critical micelle concentration (CMC) of surfactants. The chemical potential of surfactant mixing was calculated from the literature CMC data for the homologous series of alkyl sulfates, alkyl sulfonates, alkyl ammonium chlorides, alkyl trimethylammonium bromides, and alkyl pyridinium bromides. The influence of the hydrophobic chain length of alcohol and surfactant molecules on the Gibbs standard free energy of their adsorption at the water-air interface and their chemical potential of mixing were considered. It appeared that there is a linear dependence between these thermodynamic functions and the number of carbon atoms increased by 1 in the hydrocarbon chains of these compounds. This confirms clearly our conclusion that the behaviour of short-chain alcohols and classical surfactants at the water-air interface and in the bulk phase of aqueous solutions is similar. 

Multilayer clustering based adsorption model (uniBET) is aimed at adsorption phenomena modeling with having regard to surface geometrical and energetical heterogeneities. Facilitation of the uniBET model formulas leads to the LBET class models. A review on uniBET model and the analysis of the multilayer heterogeneous adsorption models for characterization of porous materials of carbonaceous origin are presented.

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 correlated with Hammett substituent constants using single and multi-regression analysis. From the results of statistical analyses, the effect of substituents on the spectral data have been studied.

Functional hybrid materials based on magnesium lignosulfonate and silica were obtained and characterized. Magnesium lignosulfonate is a common waste product of the wood pulp industry, while silica is a well-known inorganic material with exceptional physicochemical properties. In this study, silicas with a spherical particle shape were synthesized using a sol-gel method and alternatively in a nonpolar medium. Silica was found to improve the thermal and electrokinetic properties of the final products. The resulting lignosulfonate/silica hybrid materials were analyzed with the use of advanced techniques and measuring methods: scanning electron microscopy, a laser diffraction method enabling particle size measurements, Fourier transform infrared spectroscopy, elemental analysis, thermogravimetry, electrophoretic light scattering, zeta potential measurements, low-temperature nitrogen sorption, and colorimetric analysis. The results enabled the hybrid materials to be characterized from the point of view of potential applications in various branches of industry (for example as polymer fillers, electroactive blends and biosorbents). We additionally indicate new methods for the utilization of waste products, a category to which lignosulfonate certainly belongs.

Hexylamine, chloro-derivative of propylamine, and ammonium chloride were used for flotation of Permian carbonaceous copper bearing shale from the Legnica-Glogow Copper Basin region in SW Poland. It was confirmed that naturally hydrophobic shale, known as Kupferschiefer, can be made floatable by application of short chain amines as frothers. It was also established that the short chain amine chloro-derivatives as well as salmiac, the first member of the amine family, can be used as a frother for flotation of the investigated shale sample. It results from the paper that the investigated amine frothers work similarly if the comparison of the flotation results is made using their concentration expressed in relative form taking into account the critical coalescence concentration of the frother.

In the present studies the bacterial leaching process is used to extract uranium from the uranium mining wastes. The bioleaching process is environment friendly and gives the extraction yield of over 90%. The bioleaching solutions were obtained from the waste materials located at different places at Lover Silesia (Kowary, Grzmiąca, Kopaniec). Among various templates the hematite Fe2O3 nanoparticles are most useful. Interactions uranium ions with synthesized nanoparticles of hematite, magnesite, and iron were examined. 

The paper presents the studies of metal wettability using two methods: the sessile droplet and immersion ones. Based on the measured contact angles, there was calculated apparent surface free energy from the acidic–basic approach and the contact angle hysteresis. The advancing contact angles measured using the immersion method exhibit a little higher values than those measured by the sessile droplet method. The application of the immersion method leads to obtaining higher contact angle hysteresis. Both methods give different values of contact angles but they can be applied independently for estimation of metal surface wettability.

Lately there has been observed the increased presence of chlorates(VII) in the natural environment which can affect human health negatively. Therefore the removal of chlorate(VII) ions using the gel type resin functionalized with the tri-n-butyl ammonium (Dowex™PSR-2) from waters was studied. The main aim was to evaluate the effects of experimental conditions including contact time, initial solution concentration, pH and temperature on chlorate(VII) ions removal as well as the anion exchanger properties on chlorate(VII) ions sorption. It was found that only the pseudo second order model described the experimental data well and the intraparticle diffusion was not the rate-limiting step. According to the Freundlich model, the qe value was to be 69.26 mg/g at optimum conditions (pH 7.0 at 25 oC).

Recycling of actinides from spent nuclear fuel by their selective separation followed by transmutation in fast reactors will optimize the use of natural uranium resources and minimize the long-term hazard from high-level nuclear waste. This paper describes solvent extraction processes recently developed, aimed at the separation of americium from lanthanide fission products as well as from curium present in the waste. Depicted are novel poly-N-heterocyclic ligands used as selective extractants of actinide ions from nitric acid solutions or as actinide-selective hydrophilic stripping agents.

Technetium is one of the most important radionuclides in the spent nuclear fuel in context of reprocessing, storage and long term disposal. Spectroelectrochemical studies on the redox behavior of this element are presented and possible pathways of pertechnetate ions reduction are discussed. The stability of technetium (III/IV) species are discussed.

Alpha spectrometry is a highly sensitive and modern measurement technique which can be used to radiochemical and radiological studies of the natural environment. In the paper were presented the results on application of alpha spectrometry in the study for determination of natural (210Po, 210Pb, 234U, 238U) and artificial (238Pu, 239+240Pu and 241Pu) alpha and beta radionuclides in environment of Poland and Baltic Sea. Amongst the radionuclides, alpha particle emitters play the most important role as they are highly radiotoxic to organisms. The concentrations of alpha radionuclides in the environmental samples of Poland are characterized based on the environmental materials collected between 1998 and 2009. Biogeochemistry of polonium, uranium and plutonium in the southern Baltic Sea ecosystem combined with the use of radioactive disequilibrium 210Po/210Pb, 234U/238U and 238Pu/239+240Pu and 241Pu/239+240Pu allows you to identify the sources of these radionuclides in natural ecosystems. It also allows to determine their circulation in the environment (e. g. to assess the impact of the Chernobyl nuclear accident on the radioactive contamination of Poland). 

This paper presents the results of determination of artificial 137 Cs and natural 40K  activity concentrations and same heavy metals in soil samples from Tatra Mts. Results  show some differences in the vertical distribution and of examined radionuclides and metals. The change of  activity of 137Cs in the  soil samples depends mostly on the soil volume density and on the concentration of organic material. The state of "zero" 137Cs activity was developed in the form of maps.

Using the layer wicking method (TLW method) the electron-donor interactions of surface free energy of the organic liquids: benzene (C6H6), toluene C6H5CH3), and tetrahydrofuran ((CH2)4O) was determined. For this purpose the penetration rate measurements of these liquids in the porous layers of silica gel and alumina were performed. The obtained values of the electron-donor parameter of surface free energy of the studied organic liquids were compared with the literature data obtained by the direct measurement of the interface tensions of water/organic liquids.

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 onto the mineral surfaces (dolomite) has been observed at the presence of Pluronic copolymers. The adsorption effect of triblock copolymers has been investigated on the zeta potential of dolomite at the water suspension. The interaction of anionic surfactant with copolymers causes a decrease of zeta potential to small amount due to the deformation of double electrical layer. The adsorbed non-ionic Pluronic layer partially screens the surface charge of mineral particles, and thus, reduces the zeta potential. On the other hand, the adsorption of anionic surfactant and copolymer caused a decrease of negative value of zeta potential both investigated minerals. The stability of dolomite suspension depends on the both copolymer and sodium oleate concentrations.

Positronium (a hydrogen-like bound state of an electron and a positron) is a convenient probe to determine the sizes of subnanometric free volumes (voids) in condensed matter. A review of experimental methods used in positron spectroscopy and examples of their application to the free volume studies are presented.

The lanthanide(III) complexes with 2,3-pyridinedicarboxylate ligand (PDC) were obtained as crystalline compounds from the water solutions. These compounds form the series of Ln2(PDC)3 · nH2O. All compounds are stable in air and insoluble in both water and common organic solvents. The hydrated complexes have been characterized by elemental analysis, thermal analysis (TG/DSC/DTA, and TG−FT-IR), FT-IR spectroscopy and X-ray analysis. 2,3-pyridinedicarboxylates of lanthanides(III) are stable in air below 313−323 K. Upon heating, hydrated complexes lose crystallization and lattice water in two steps. The values of dehydration enthalpy complexes are calculated from the DSC curves. The anhydrous compounds are stable at the temperature from 473 K to about 623 K and when heated they decompose to lanthanide oxides. Thermal and spectroscopic studies are essential for further studies and classification of compounds as MOF-like structures.

A series containing ten aryl 3-(substituted phenyl) bicyclo [2.2.1] heptene-2-yl-methanone derivatives including 3- (substituted phenyl) bicyclo [2.2.1]hepten-2-yl-(pyren-1-yl)- methanones have been synthesized by aqueous phase fly-ash catalyzed [4+2] Diels-Alder cyclo addition reaction of cyclopentadiene and aryl chalcones. The yields of the methanones are more than 60%. The synthesized methanones are characterized by their physical constants and spectral data. The insect antifeedant activities of synthesized methanones have been studied using Dethler’s leaf-discs bioassay method.

Some 4-aryl-5,6-dihydro-6-(substituted phenyl)-4H-1,3-oxazine- 2-amine derivatives including 4-(4-methyl-1-naphthyl)-5,6- dihydro-6-(substituted phenyl)-4H-1,3-oxazine-2-amines have been synthesised by hydroxyapatite catalyzed solvent-free cyclization of aryl chalcones and urea using microwave irradiation under solventfree condition. The yields of the oxazines were more than 85%. The synthesised oxazine amines have been characterized by their physical constants, analytical and spectroscopic data.

A series of Schiff’s bases (aryl E-imines) have been derived from the perchloric acid catalyzed condensation of aryl amines and substituted benzaldehydes. The yield of the Schiff’s bases are more than 80%. The synthesized Schiff’s bases are characterized by their physical constants, analytical and spectroscopical data. The antibacterial activities of these Schiff’s bases have been studied using Bauer-Kirby method.

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 the surface wettability on preliminary treatments, the values of the water contact angle on the pristine Ti6Al4V alloy suffers from an important variability and lack of reproducibility.The present research pays attention to this difficulty and proposes a simple experimental procedure to ensure adequate contact angle reproducibility. Controlled passivation growth in mild underwater conditions of freshly polished disks, followed by ultrasonic washing, avoiding the rubbing of the surface, gives average water contact angles of 80° with very low standard deviations also among samples from the same batch.

The kinetics of collision and bouncing of an air bubble on hydrophilic and hydrophobic solid surfaces immersed in distilled water is reported. We carried out the experiments and compared the bubble collision and bouncing courses on the stagnant and vibrating, with a controlled frequency and amplitude, solid/liquid interface. For stagnant interface differences in the outcome of the bubble collisions with hydrophilic and hydrophobic solid surfaces are resulting from different stability of the intervening liquid film formed between the colliding bubble and these surfaces. The liquid film was unstable at Teflon surface, where the three-phase contact (TPC) and the bubble attachment were observed, after dissipation of most of the kinetic energy associated with the bubble motion. For vibrated solid surface it was shown that kinetics of the bubble bouncing is independent on the hydrophilic/hydrophobic properties of the surface. Similarly like at water/glass hydrophilic interface, even at highly hydrophobic Teflon surface time of the bubble collisions and bouncing was prolonged almost indefinitely. This was due to the fact that the energy dissipated during the collision was re-supplied via interface vibrations with a properly adjusted acceleration. The analysis of the bubble deformation degree showed that this effect is related to a constant bubble deformation, which determined constant radius of the liquid film, large enough to prevent the draining liquid film from reaching the critical thickness of rupture at the moment of collision. The results obtained prove that mechanism of the bubble bouncing from various interfaces depends on interrelation between rates of two simultaneously going processes: (i) exchange between kinetic and surface energies of the system and (ii) drainage of the liquid film separating the interacting interfaces.

Wetting properties of synthetic surfactant Rokanol NL6, biosurfactant JBR 425 and their mixture have been investigated. On the basis of these investigations, the ability of used surfactants to remove the synthetic base oil (PAO6) from sandy soil and clay loam was evaluated. Surfactant solutions were applied for soil flushing in batch experiments. The results show that synthetic surfactant addition worsens physicochemical properties of pure biosurfactant but exhibits much higher oil removal efficiency than biosurfactant does.

About eleven substituted (E)-N׳-(1-(substituted phenyl) ethylidene) benzo- hydrazides have been synthesized. They are characterized by their analytical, ultraviolet, infrared and NMR spectral data. The antibacterial and fungal activities of these chalcones have been evaluated.

The volumes of reactions in solution are usually ignored in problem solving. Neglection of reaction volumes may lead to errors on the order of 1 % in the final result. Calculation of the volume of neutralization reaction based on the specific densities of solutions from chemical tables is demonstrated.

This review paper focused on the effect of typical phosphorlipid (or lecithin) and enzyme modification on electrokinetic parameters of oil/water emulsion. Physicochemical properties of the systems were investigated taking into account the effective diameter of the droplets as well as the zeta potentials using the dynamic light scattering technique. The effect of phospholipid and phospholipase modification on interfacial properties of o/w emulsion was examined as a function of temperature, pH and ionic strength (effect of Na+ or Ca2+ ions which occur in the physiological fluids). The particular role of Ca2+ ions in the dispersions with zwitterionic phospholipids (the main components of biological membrane) was confirmed.The phospholipids dipalmitoylphosphatidylcholine, DPPC or dioleoylphosphatidylcholine, DOPC having the same headgroup bound to the apolar tail composed of two saturated or unsaturated chains were used as stabilizing agents. The effective diameters do not always correlate with the zeta potentials. A possible reason for such behaviour might a mechanism different from the electrostatic stabilization. Phospholipids and their mixtures (e.g. lecithin) may undergo spontaneous aggregation in aqueous solution and selforganize into liposomes, which possess different sizes and surface affinities. These unique behaviours of phospholipid dispersion can be controlled using the investigated parameters. These findings are expected to increase in importance as phospholipid systems see more use in self-assembly applications.The other aim of the paper was the comparison of the enzyme phospholipase influence on lipid hydrolysis in the o/w emulsion environment. The work is the study which presents the twofold effect of ethanol dipoles on phosholipid hydrolysis. It is believed that the enzyme effect on the phospholipid aggregation behaviour at the oil-water interface will be helpful for understanding differentbiological phenomena.

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 values of activity coefficients were calculated taking into account the surface tension data of the studied systems at 293K and compared to those determined on the basis of the values of the contact angle of solutions on the polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) surfaces and the solid-liquid interface tension.

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 range 5−50°C with the step every 5°C. As follows the value of the contact angle of both water and diiodomethane changes with the increasing temperature. The change of its value for water is much larger than in case of another liquids of apolar character. Using Chibowski approach the apparent surface free energy was calculated in two ways with and without correction about temperature change of the surface tension. The calculation show difference between both results. Taking into consideration another value of the surface tension should not be neglected even if measurements is taken at a temperature close to 20°C which is the standard in one in such measurements.

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), does not depend on the concentration and composition of the binary mixtures of studied surfactants in water, and it was higer than the surface tension of PTFE (20.2 mN/m). The best wettability of polytetrafluoroethylene (PTFE) by studied aqueous solutions of binary surfactants mixtures occurs at the mixtures concentration corresponding to the critical micelle concentration of their solutions.

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 interface and Gibbs standard free energy of its adsorption at that interface were calculated and compared with those determined for the aqueous solutions of ethanol. The surface excess concentration of ethanol at the solution-air interface was calculated with two different methods. The standard free energy of alcohol adsorption was determined from both the Gu and Zhu and Langmuir equations.

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 hydrophobic tail) [1]. This review includes the short characteristic of surfactants with sugar-head group in their structure called sugar-based surfactants. The structure, properties and some applications of these surfactants are described in this paper.

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 parameters or using simulation methods. In this review, the most important results concerning this issue were collected and briefly described.

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. The proposed procedure was applied for simple and fast voltammetric determination of ascorbic acid in human urine samples and commercially available dietary supplements.

Thin layer chromatography (TLC) has been used for screening analysis of extracts from Rhodiola rosea roots. TLC is a fast, simple and inexpensive screening technique, often used in qualitative analysis of plant substances. The results of TLC analysis confirmed presence of sugars, terpenes, terpenoids, saponines and propylpropanoids in Rhodiola roots. The extracts of Rhodiola rosea revealed strong antioxidant activity.

The overutilization of fossil fuels will inevitably cause the global environmental problems and dwindling of available resources. For that reason, identifying renewable sustainable alternatives has attracted an increasing attention. Lignocellulosic biomass has been considered to be one of the most logical feedstock to replace traditional fossil resources as one of the most accessible renewable forms of carbon. One of the primary components of lignocellulosic biomass, next to hemicellulose and cellulose is lignin. It is a by-product in paper and pulp industry. Lignin is mainly used as fuel directly, without further utilization which is suggested to be a waste of natural resources. With this purpose, the valorization of lignin into value-added products needs particular attention of researchers. This review article focuses on chosen possible applications of lignin in chemical industry.

Nowadays, it is not possible to produce food packaging without the use of polygraphic varnishes. Their main task is to protect packaging from the effects of external factors, as well as to give the effect of clarity with greater exposure of the colors used. However, such varnishes contain in their composition low-molecular-weight photoinitiators that can easily migrate to a protected product. The aim of this work was to determine the migration of 4-PBZ from various types of substrates used in the printing industry, i.e. paper, aluminum foil and polyethylene foil. In addition, extensive studies on the impact of the storage conditions of a fresh reprint on the change in the migration of the photoinitiator to food were carried out.

Skin injuries are a health problem and can lead to serious, significant deterioration in the quality of life and, consequently, even illness and disability. Therefore, after wounding, immediate regeneration of the tissue is necessary to avoid further complications and pathogenesis. Consequently, many wound healing strategies have been developed, leading to the progress in constructing of multifunctional tissue substitutes for the skin, biomembranes, scaffolds and intelligent dressings. The field of science focusing on the creation of the above-mentioned products is tissue engineering (TE). Its main goal is to find a system that is able to replace or be a model that perfectly mimics the form and function of the skin. Research carried out on such constructs is mainly based on the analysis of mechanical properties (porosity, elasticity), as well as the assessment of the impact of individual components on processes related to the formation of new tissue as cell proliferation and differentiation, proliferation, angiogenesis - through in vivo studies (using animal models: mice, New Zealand rabbits) and in vitro (most often using mouse fibroblasts - L929). Skin constructions may have potential applications as wound dressings or skin substitutes in cases of severe skin damage.

Surface free energy measurements of solids are a very important issue in various fields of science. Many functional, chemical and physical properties of a given material depend on its surface free energy. The basic method of the surface free energy determination are the contact angle measurements. There are several empirical methods useful to calculate the surface free energy of solids. They are based on the measurements of the contact angle of liquids with the defined surface tension. The aim of this paper is to examine the significance of the receding contact angle measurements in the determination of surface free energy of solids.

The form of the active drug administered to patients is important as far as effectiveness of the disease therapy is concerned. From this point of view modifications of medicinal substances are searched for that the obtained compounds have the best physicochemical and pharmacodynamic properties. Pharmaceutical companies allocate significant funds for this type of research. The key property that needs to be improved is the solubility of biologically active substances. This is related to the fact that over 40% of drugs available on the pharmaceutical market are characterized by low solubility in water.Thus, the paper describes the most important strategies used in the poorly soluble drug delivery systems, e.g. physical and chemical modifications, formulation based, modification of partition coefficient and lipid systems. The authors discussed various techniques used to enhance solubility of poorly water soluble drugs with their advantages and limitations.

Rare earth metals are a group of elements widely used in high technology products. They are included in the group of critical mineral resources for the EU economy. Rare earth elements are found in computers and mobile phones, as well as in low-emission energy technologies. They are also applied in chemical processes as catalysts in the oil refining. Some of them occur even in considerable quantities in the earth's crust but not very often in the concentrations justifying the profitability of their extraction. Additionally, the constantly growing demand and the current market situation cause that alternative resources of rare earth elements recovery are sought after. Therefore, the recovery and separation methods as well as recovery from the secondary sources are becoming more and more important. The following paper presents the possibilities of recovery and separation of rare earth elements from primary and secondary sources.

This paper addresses the problem of the intensive development of the pharmaceutical industry and its consequences for the natural environment. The characteristics of the most commonly consumed pharmaceutical preparations and the ways of these substances penetrating into water ecosystems are presented. Attention was paid to the need to monitor environmental contamination and to search for new methods that would enable routine quality control of natural water samples. The application of modern, miniature screen-printed sensors for the determination of trace concentrations of selected active substances of pharmaceutical preparations are presented.

Brief information connected with industrial synthesis of EDTA is given. Moreover, selected examples of industrial applications for metal recovery with the use of EDTA-type chelating compounds is given. The prospect of using biodegradable chelates has been emphasized.

Currently significant amounts of wastes, which pose a real threat to the natural environment and human health, are produced worldwide. One way to get rid of waste materials is to dispose them in landfills but some of them no longer perform their function due to overfilling. For this reason, scientists pay more and more attention to the search for  their possible disposal and/or recycling, as it is impossible to prevent its generation completely. Recently, many researchers have taken up the topic of the use of agri-food wastes due to their low cost and widespread availability as a starting material for the production of activated carbons. As a result, it was found out that organic wastes are very successful precursors of organic matter and the obtained activated carbons are characterized by a very well developed porous structure. The paper presents a literature review regarding the possibility of using various waste materials under different impregnation and preparation conditions to obtain activated carbons with a developed surface area and good adsorption properties.

Catalysts preparation, investigation its basic properties, activity and selectivity measurements in carbon dioxide methanation reaction was proposed as laboratory course for international students doing a period of study at Maria Curie-Sklodowska University within the frame of the Erasmus mobility programme.

The development of technology is associated with a strong need for changes in the design and manufacture of new types of materials. Monolithic materials such as ceramics or metals have become insufficient for the needs of the modern market. The combination of several types of materials in one system turned out to be the right solution. Composite materials as multi-phase materials show improved properties compared with individual structural elements and can give the opportunity to design systems with enhanced specific characteristics.The presented work provides a review of actual literature dedicated to composite materials. In this work, the basic terminology, the division of composite systems, the most commonly used methods for composites preparation as well as physicochemical characteristics and potential applications of these types of matter were presented.

For the last two decades the CMK-3-type carbon was the subject of study by researchers from all over the world for wide range of applications: adsorptive, catalytic, magnetic and electric. Changing of modification strategies resulted in obtaining carbonaceous materials with interesting properties. In this review the synthesis, properties and applications of the CMK-3-type nanocarbon are described.

Chiral organophosphorus compounds are one of the main groups of ligands used in asymmetric homogenous catalysis. Ongoing progress in transition metal-catalyzed reactions requires that efficient methods for the synthesis of chiral phosphines and their derivatives are available. This review is focused on desymmetrization of heteroleptic tertiary phosphine derivatives via stereoselective lithiation using organolithium/sparteine complexes as chiral bases combined with oxidative homocoupling or trapping the P-chiral intermediates with electrophiles. The method has been used to obtain both known and new chiral ligands with application in stereoselective reactions catalyzed by transition metal complexes.

Glycerol is a main by-product of transesterification reaction of plants oils to its methyl esters which are used as a substitute or as an additive to diesel fuel. Still growing so-called biodiesel production leads to large amounts of glycerol fraction flooding the market. One of the possible ways of its utilization is steam reforming reaction which main product is synthesis gas containing high concentration of hydrogen for which is still growing demand. In this work four metallic (Ni, Pt, Ru and Re) catalysts supported on ceria-zirconia mixed oxides have been investigated in glycerol steam reforming reaction.

Alginates are salts of alginic acid, natural polymers and polysaccharides. They are usually obtained from marine algae. Their solutions often take the form of a gel. The first references to alginates appeared in 1881, so over the years these compounds have been thoroughly studied. Alginates have a lot of valuable properties, which is why they are used in many industries, from stabilizers in the food industry through additives for wound dressings to substances used in bone and muscle regeneration in medicine.

This paper presents earlier published results, as well some new ones, of the flotation tests carried out with the help of a Hallimond tube for several different apolar and polar minerals. This is to depict the relationship between mineral surface free energy and its flotability. Although the thermodynamic condition for the efficient flotation of a mineral is well known, this paper prompts the not-acquainted readers to get familiar with the fundamental thermodynamic relationships involved in the wetting processes and to learn about usefulness of the simple flotation experiments for this purpose. This relationship between the flotation recovery of a mineral and the work of water spreading on the mineral surface is clearly illustrated. The work of spreading is the difference between the work of adhesion and the work of water cohesion. This work has to be negative to carry out an efficient flotation of a mineral sample. Thus, the purpose of this paper is to show that the simple Hallimond tube is a very useful tool for studying solid (mineral) surface hydrophobic/hydrophilic character under the kinetic conditions.

Surfactants are various types of chemical compounds that are present in almost every aspect of our life. They are used in many branches of industry, especially in food, cosmetics, pharmaceuticals and even in confectionery. They are considered one of the best solutions for oil residues, soil bioremediation and dealing with PAHs contaminations. Their versatility comes from their amphiphilic build – one part of the compound has hydrophilic properties (head), the other has hydrophobic properties (tail). This fact causes surfactants affinity both to polar and nonpolar compounds. Some of the classical surfactants still can affect fauna and flora by accumulating in ground waters or simply by causing allergies. In that case, many companies decide to limit their surfactant usage and reach for substances present in nature which have very similar, if not better, properties. Biosurfactants are surface active agents produced mainly by microorganisms such as bacteria, fungi and yeasts. There are many papers related to different properties (CMC, aggregation number, surface excess concentration) of various types of surfactants. However, it is difficult to find papers describing the same properties for different surfactants. In this study, adsorption effectiveness and adsorption efficiency at the water-air interface of chosen surfactants: sodium dodecylsulfate (SDDS), cationic: cetyltrimetylammonium bromide (CTAB), nonionic: Triton X-100 (TX-100) and biosurfactants: surfactin (SF) and monorhamnolipid (RL)  has been compared. Both efficiency and effectivenes decide about the practical surfactants application.

Carbon nanomaterials have been very popular in the scientific community in recent years, because of their unusual physical and chemical properties. Their high electrocatalytic activity, very good electrical conductivity and mechanical resistance mean that scientists are constantly looking for new technological solutions to take advantage of the opportunities offered by nanomaterials in many areas of human activity. One of such area are potentiometric sensors. There are many publications in which scientists describe methods of construction, analytical parameters and practical applications of new sensors obtained using carbon nanomaterials, and often also describe methods of synthesis of new original nanomaterials. The purpose of this work was to characterize carbon-based nanomaterials and their application in the construction of ion-selective electrodes.

 The presence of heavy metals in aquatic systems can be harmful to living species. Heavy metals are not biodegradable, and their tendency to accumulate in living organisms often causes different, undesirable consequences. Therefore, removing these impurities from wastewater has become one of the key issue related to environmental protection [Babel and Kurniawan 2004].There are many methods developed to remove heavy metals from wastewater and adsorption is one of the most popular one. Despite of the diversity of these technologies there is still a need to develop methods that do not require a large financial input [Hegazi 2013, Renu et al. 2017].The most important features that determine materials used as adsorbent is their low cost, biocompatibility and environmental friendly nature and hydroxyapatite presents all of them. Moreover, hydroxyapatite particles are characterized by high specific surface area and simple method of synthesis. It is also reported that it can be obtained from agricultural waste based on calcium like eggshells [Akram et al. 2014].The aim of this paper is to show and compare different methods of hydroxyapatite synthesis using eggshells as a source of calcium and it sorption capacity due to different metal cations from aqueous solution.

The paper presents changes in wettability of the unmodified and modified polyethylene terephthalate (PET) surfaces. A low temperature air plasma was used to activate the polymer surface and to change its hydrophilic–hydrophobic properties. Then, using the Langmuir-Blodgett technique, the Langmuir monolayers of 1,2–dipalmitoyl–sn–glycero–3–phosphocholine (DPPC) and cyclosporine A (CsA) with different molar fractions, i.e. χ=0.25, 0.50, 0.75, were deposited onto the activated PET surface. A series of DPPC and CsA monolayers was also transferred onto the PET-supported chitosan layer, previously produced by the dip-coating method. The wetting properties of such modified PET surfaces were then investigated by the contact angle measurements using three test liquids with well known surface tension components. The obtained results show that wettability depends on the composition of the deposited DPPC/CsA layer with or without chitosan. Presence of chitosan makes the DPPC/CsA film surface more polar due to specific organization of molecules that expose their polar heads outside.

Oxide cobalt-manganese catalysts with different contents of cobalt and manganese, as well as pure cobalt and manganese catalysts have been tested in the process of methane flameless combustion (complete catalytic oxidation). The X-ray diffraction and X-ray photoelectron spectroscopy results showed that cobalt-manganese catalysts mainly composed of the spinel phase of Co3O4, Mn2CoO4 and/orMnCo2O4. The highest initial activity was presented bythe cobalt-manganese catalyst withahigh cobalt content.However, after 50-hours stability test the highest activity was presented by the cobalt-manganese catalyst with Co and Mn content close to the equimolar value.

The polymer containing desired functional group can be obtained by a direct-polymerization or post-polymerization modification. These functionalization methods offer different way of insertion of functionality into the polymeric materials. In the literature, scientist can meet with the descriptions of many techniques of functionalization process. This review article focuses on the pathway for post-polymerization modification of polymeric materials bearing pendant epoxide groups.

About nine 4-substituted 1-naphthacyl bromides and its esters have been synthesized by greener synthetic method using fly-ash catalyzed water mediated reaction.  These acyl bromides and esters have been characterized by their physical constants, Mass, IR and NMR spectral data.  These carbonyl frequencies(cm-1) of existed rotomers of these compounds have been assigned and correlated with Hammett substituent constants, F, R and Swain-Lupton’s parameters.  The insect antifeedant activities of the synthesized acyl bromide and esters have been evaluated using 4th instar larvae Achoea Janatha L.

Synthesis and characterization of SBA-15 were proposed as a laboratory course: linked series of exercises for graduate students. The standard preparation method was modified to fit a typical schedule of students’ classes, that is, 3-hours units every second week. The properties of materials obtained by different students’ groups were compared with the properties of materials obtained by means of a standard method.

Potential theory of adsorption was used for description of adsorption isotherms of n-butane on microporous active carbon. It was shown that characteristic curve of adsorption can be treated as specific form of thermal equation of adsorption giving the possibility to calculate and predict both equilibrium and thermodynamic characteristics of adsorption in wide range of temperature and relative pressure. The results can be used for the design of adsorption systems and for predicting adsorption equilibrium behavior of binary and/or multicomponent gaseous mixtures on active carbon under wide range of conditions, without time consuming and expensive experimental determination.

Plastics are widely used in industry as well as in a daily lives. Large amounts of plastics debris are delivered into environment, especially into aqueous ecosystems and transformed into microplastics. The present work describes microplastics as the marine environment contaminants, their sources and also methods of their identification in the environment. Moreover, the ability of plastics to acculumation of organic and inorganic contaminants and possible harmful effect on the aquatic organisms is also discussed in presented work.

The purpose of this work was to determinate the amount of titanium in different environmental water samples spiked with crop biostimulant Tytanit. The measurements were conducted using adsorptive stripping voltammetry (AdSV). The titanium complex with chloranilic acid was accumulated on mercury film silver based electrode (Hg(Ag)FE) at the potential -0.3 V. The analysis of natural water samples enriched with Tytanit, collected in the eastern part ofPolandconfirms that this procedure is fast and essential for the determination of titanium in environmental water samples.

Some aryl hydrazide derivatives have been synthesized including 1-(3-chloro-4-nitrophenyl)-2-(3-substituted benzylidene) hydrazines by  FeCl3/Bentonite catalyzed solvent-free  condensation of  substituted phenyl hydrazine and aldehydes under microwave irradiation.  The yields of the hydrazides are more than 70%.  The synthesized hydrazides are characterized by the physical constants, micro analysis and spectroscopic data.  Effect of catalyst,  solvent effect  substituent effect and optimization of the catalyst was studied by the percentage of isolated yields.  From the catalyst optimization, the present study catalyst gave the better yield of products.  The antimicrobial activities of all synthesized of 1-(3-chloro-4-nitrophenyl)-2-(3-substituted benzylidene) hydrazines have been evaluated using Bauer-Kirby disc diffusion method.

This paper shows a novel, simple and rapid voltammetric procedure, which enables Cd and Pb determination at traces concentrations. All measurements were carried out by differential  pulse anodic stripping voltammetry (DPASV) with total time of analysis of 210 s. The obtained detection limits were 8.46 · 10-10 mol L-1 and 2.57 · 10-10 mol L-1  for Cd(II) and Pb(II), respectively. This procedure was successfully applied for the quantification of mentioned metal ions in water samples collected from the Vistula River.

Influence of the binary mixtures of fluorocarbon surfactants Zonyl FSO-100  (FSO100) and Zonyl FSN-100 (FSN100) on the surface tension of the water was studied. The effectiveness of adsorption process of the surfactant at the water-air interface was calculated from the obtained values of the surface tension of studied mixtures. Also the maximum surface area per molecule of surfactant in the interfacial area  and the free energy at the water-air interface  were determined. Moreover, the existence of synergetizm or antagonism effect, which reduces the surface tension of the water was examined. On the basis of the Rosen's model parameter the values of intermolecular interactions in the mixed monolayer adsorption were calculated.

The stability of colloidal systems is very important in numerous already existing and new formulations. In most cases if such systems are not characterized by an appropriate stability they can not find any useful applications. The opposite process to the stabilization is the flocculation. Generally, it is undesirable. However, in a few cases the flocculation is very useful, for example in  the wastewater treatment. That is why the methods used to determine stabilizing-flocculating properties of the colloidal systems are of significant importance.The paper describes types of stability and flocculation as well as the factors influencing those processes, e.g. the addition of polymers or surfactants. The methods presented in this paper are UV-VIS spectrophotometry,  turbidimetry, zeta potential and density measurements.

The development of new methods for the synthesis of organophosphorus compounds is still an important part of organic chemistry due to the high demand for these compounds in organic synthesis as well as in asymmetric catalysis. Most of the methods for the synthesis of these compounds include the reactivity of the phosphorus atom, which depending on the structure might exhibit both electrophilic and nucleophilic properties. Herein, I will present the results concerning synthesis of diphenylphosphinic acid esters.

The aim of this research was to optimise methods of magnetic particles of iron oxides implantation into superabsorbent polymer based on partially neutralized acrylic acid (SAc/AAc) crosslinked with ethylene glycol dimethacrylate (EGDMA). The structure of the obtained materials was confirmed by infrared spectroscopic analysis (FT-IR/ATR). The quality of implantation process was evaluated on the basis of microscopy images. Swelling properties of the obtained implanted materials were also determined.

The article illustrates the preparation of unsaturated polyester as well as the mechanical and thermal properties of his copolymers with crosslinking monomers (styrene and diethylene glycol dimethacrylate). The starting polyester was obtained from maleic anhydride, propylene glycol and isobutanol. The prepared series of unsaturated polyester resins were subjected to different studies concerning evaluation of their viscosity, mechanical and thermal properties and also dynamic mechanical behaviour (DMA).

Chlorogenic acids (CQAs), the esters of caffeic acid and quinic acid, are biologically important phenolic compounds present in many plant species. Nowadays much is known from their pro-health properties, including anti-cancer activity. Yet, the supposition that they may be helpful in fighting obesity and modify glucose-6-phosphatase involved in glucose metabolism have led to a revival of research on CQAs properties and their natural occurrence. Much attention is also paid to the proper analysis of CQAs content in plants and plant products due to the fact that the main CQAs representative in nature i.e. 5-O-caffeoylquinic acid (5-CQA) is commonly employed as a quality marker in the control of various natural products.The common procedures used so far for CQAs determination in plants involve conventional long lasting solvent extraction realized at higher temperatures prior to chromatographic analysis. The drawbacks associated to the conventional extraction techniques have led to the search for new alternative extraction processes that additionally could improve extracts quality. The latter is particularly important as regards CQAs applications, and the fact that these compounds easily transform/degrade to others. According to reports, the conventional heating of 5-CQA in the presence of water causes its isomerization and transformation. The reports prove that 5-CQA not only isomerizes to 3- and 4-O-caffeoylquinic acid, but also undergoes other transformations such as esterification and reactions with water. Hence, in the attempt to improve the process of chlorogenic acids extraction and to make it more effective and environmentally friendly, innovative so-called "enhanced" techniques of extraction have been recently developed and applied. To guarantee the proper analysis of compounds with very similar properties forming the chlorogenic acids family and their numerous transformation/degradation products, hyphenated techniques, in particular LC-MS, are currently being used.

Halloysite is commonly occuring in Poland a natural mineral which, due to its structure is very popular among researchers. First of all, the large number of sorption areas and their various selectivity makes the material capable of adsorbing the compounds of different nature at the same time. As a result, there is a lot of possible applications. In addition, ease of functionalization of the surface of the material increases its sorption capacity and makes its more attractive. 

An important factor determining the quality of optical fibers is their mechanical reliability. The control of the mechanical reliability allows define the lifetime of a fiber, which was under the stress during the work. Decisive influences on the mechanical and optical properties of the optical fibers have the protective coatings. Optical fiber technology requires that the coatings were applied on them on-line, directly after they have been drawn. So far, little attention has been paid to optimizing the conditions of coatings curing. In this work, the comparison of a thermoanalytical and spectroscopic analysis of coatings that were cured in an UV oven in which the power of the UV lamps was changed will be shown. As part of the research tasks, completed mechanical strength measurements were made with a silica fiber of 0.125 mm diameter.

The state of water in the fruit body of the Amanita muscaria mushroom and its composite with “wetting-drying”nanosilica A-300 was studied by low-temperature 1H NMR spectroscopy. It was found that even in the initial biomaterial, part of the water is in a weakly associated state. After drying, the portion of weakly bound water decreases, but in the medium of CDCl3, almost all water becomes weakly boned. This effect is accompanied by a threefold increase (from 3.4 to 10.3 J/g) of the total binding energy of water, which, is probably due to the transition of water from the system of spherical (cylindrical) clusters to a two-dimensional film, uniformly distributed over the surface of the biomaterial. It is suggested that due to the binding by the surface of the silica from the composite, the toxic substances present in the mushroom in the form of complexes with enzymes, will not be desorbed.

In this work, a role of the number of free silanol groups at a nanosilica surface (specific surface area SBET = 250 m2/g, initial amount of silanols αОН = 0.60-0.62 mmol/g) was analyzed in interaction with poly(vinyl pyrrolidone) (PVP) vs. the degree (QTMS) of silica hydrophobization by hexamethyldisilazane at 100 oC. The value of QTMS was 0.07, 0.42, 0.67, 0.81, 0.82, and 1.0. Adsorption of PVP onto a nanosilica surface was carried out from a water and water-ethanol (1:1) solutions of the polymer. It was shown that free silanol groups play a crucial role in the adsorption of poly(vinyl pyrrolidone). The value of the maximal adsorption (monolayer capacity) on completely hydrophobic nanosilica surface is approximately by 6.5 times lower than that for unmodified nanosilica

The structure of sodium sulfate in tip3p water solution with the concentration of 0.1191 mol/dm3 was studied by means of classical molecular dynamics. Both ions have clear hydration shells. The comparison between radial distribution functions and cumulative numbers of selected atoms around the reference one makes it possible to precisely describe the structure of investigated system. Applying such tools geometrical parameters of the hydrogen bond of the dimer SO42-/H2O have been obtained. 

The role of MgO as a factor improving the resistance to coking of the alumina supported nickel catalysts in the steam reforming of hydrocarbons is discussed.    A series of catalysts containing variable amounts of MgO, NiO and a constant amount of Al2O3 was prepared by the co-precipitation method. It was found that the specific activity of the catalysts exhibits a broad but not deep minimum for the MgO contents from 8.5 to 27.3 wt.%. At the same time these catalysts reveal a high resistance to coking either in the reaction with methane or with n-butane. The most promising composition, in terms of the activity and simultaneous resistance to the coke formation, was found to be 27.3 wt.% of MgO and 39.0 wt.% of NiO. The analysis of various factors controlling the activity and resistance to coking leads to the conclusion that MgO reduces the catalysts acidity what, in consequence, reduces the rate of coke formation during the reforming reactions. Furthermore, The resistance to coking correlates well with the mean size of nickel crystallites, the same is observed for the specific catalyst activity. 

Headspace gas chromatography (HS-GC) is a powerful technique for the analysis of volatile compounds. It has found broad applications for quantitative and qualitative analyses of various samples as well as for physicochemical measurements. This paper briefly reviews the basic physicochemical applications of HS-GC including vapour pressure measurements and studies of vapour-liquid equilibria in multicomponent systems. A special attention is paid to methodological aspects of these measurements. The advantages and limitations of HS-GC in this field as well as typical applications are also pointed out.

The aim of this research was the synthesis of polymers with the addition of S,S'-thiodi-4,1-phenylene bis(thiomethacrylate) (DMSPS) by bulk polymerization. Styrene (St), divinylbenzene (DVB) and ethylene glycol dimethacrylate (EGDMA) were used for the copolymerization as main monomers. The chemical structures of sulfur-containing polymers were confirmed by the spectroscopic analysis (ATR/FT-IR). In order to determine the impact of the sulfur derivative (DMSPS) addition on thermal properties of the obtained copolymers, differential scanning calorimetry (DSC) was performed. The hardness tests of the obtained copolymers were also applied using a Shore durometer.