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Annales UMCS, Chemistry (v.64, #-1)

The 65^th Birthday of Professor Roman Leboda by Vladimir Gun'ko; Vladimir Turov; J. Skubiszewska-Zięba; (pp. vii-ix).

Synthesis and structure of ethylene bridged polysilsesquioxanes functionalized with different groups by M. Barczak; A. Dąbrowski; (pp. 1-10).

Amino-, thiol-, urea-, and acethoxy- functionalized polysilsesquioxane xerogels have been obtained by co-condensation of 1,2-bis(triethoxysilyl)ethane with trifunctional silanes. The structural and chemical characterization of the xerogels was done by means of IR, ¹³C NMR, ²⁹Si NMR spectroscopy, AFM, elemental analysis and nitrogen adsorption measurements. The resulting xerogels have a porous structure (SBET in the range 500-800 m²/g) and a high content of functional groups (2.3-2.7 mmol/g). Majority of these groups are accessible on the surface generating specific adsorption sites. The nature of the functional group introduced by co-condensation substantially influences the porous structure - the resulting samples can be microporous or mesoporous depending on the type of the group used.

The study of the properties of the hydroxyapatite/electrolyte interface by W. Janusz; E. Skwarek; (pp. 11-20).

A physicochemical property of hydroxyapatite (HAP) [Ca₁₀(OH)₂(PO₄)₆] surface was studied and parameters of electrical double layer of the hydroxyapatite/NaCl solution system were described. The study sample of hydroxyapatite was synthesized. The structure of the hydroxyapatite was confirmed using X-ray diffraction (XRD), its particle size by PCS (photon correlation spectroscopy) AFM and SCM microscope and its surface properties by means of adsorption-desorption of nitrogen (ASAP), Raman spectra,. Then the point of zero charge and the isoelectirc point were measured.

Titania deposits on nanosilicas by V. M. Gun'ko; V. M. Bogatyrev; R. Leboda; J. Skubiszewska-Zięba; L. V. Petrus; Y. M. Nychiporuk; O. I. Oranska; O. A. Dudarko; V. D. Osovskii; Y. G. Ptushinskii; (pp. 21-48).

Titania (content C_TiO2 = 2.7-20.0 wt%) was synthesized on different fumed silica substrates (A-50, A-100, A-380) using Ti[OCH(CH₃)₂]₄ as a precursor interacting with silica/adsorbed water in 2-propanol or CCl₄ medium, dried and then heated at 1073 K for 1 h. Initial and pretreated nanosilicas and titania/silicas were studied using XRD, adsorption, FTIR, TEM, AFM, and TPD-MS methods. The morphology of grafted titania (anatase/rutile/amorphous phase composition, particle size distribution, aggregation, textural porosity) depends on the types of a nanosilica matrix and a solvent, suspension treatments and reaction conditions.

Argon adsorption studies of porous structure of nongraphitized carbon blacks by L. Gardner; M. Jaroniec; (pp. 49-63).

Structural properties of a series of commercial nongraphitized carbon blacks were studied by means of argon adsorption at 87 K and 77 K. The specific surface area of the samples was calculated using the standard BET method. The micropore volume and external surface area were both calculated by the α_s-plot method. Pore volume and adsorption energy distributions were calculated numerically by using the regularization method. The above mentioned quantities obtained from argon adsorption isotherms were compared with those evaluated from nitrogen adsorption at 77 K.

Preparation of nanostructured carbons for solid phase extraction by A. M. Puziy; O. I. Poddubnaya; B. Gawdzik; M. Sobiesiak; C. A. Reinish; M. M. Tsyba; T. P. Segeda; M. I. Danylenko; (pp. 64-74).

Nanostructured carbons have been obtained by the template method using silica gel and zeolite as structure directing agents. Carbons were characterised by nitrogen adsorption, acid-base titration, XRD and TEM, thermogravimetric analysis and IR spectroscopy. All carbons show developed and uniform porous structure with the mean size range mesopore 3.4 and 4.8 nm for silica gel derived carbons and in the micropore range 1.1 nm for zeolite derived carbon. The BET surface area of silica gel derived carbons is in the range 1230-1280 m²/g while zeolite derived carbon possesses very high BET surface area 3000 m²/g. Acid-base titration shows that carbons obtained by the template method contain a significant number of surface groups. Silica gel derived carbons possess mainly carboxylic and phenolic groups with small contribution of lactone/enol groups which totals 1.1-1.5 mmol/g. Extremely high number of surface groups (mainly phenolic) demonstrates carbon derived from zeolite - 11.3 mmol/g. The presence of phenolic groups was confirmed by IR spectroscopy. To study adsorption-desorption properties of nanostructured carbons towards phenol and chlorophenols a solid phase extraction method was used. High recoveries of chlorophenols were obtained (75-93%) at the breakthrough volumes 1200-1400 mL. The recoveries are much higher these that obtained with commercially available carbon ACC (Supelco).

Synthetic carbon adsorbents - the method of their preparation and application in adsorption and chromatography by A. Gierak; (pp. 75-85).

This paper is devoted to the methods of preparation of the synthetic carbon adsorbents by carbonization of different polymer precursors and the research into the structural and surface properties of the obtained carbon adsorbents. The paper describes the research into the preparation of active carbons by carbonization of: polysufonated cation-exchanged resin, polyvinyl chloride and porous copolymer (4,4-diphenyl sulfone dimethacrylate). The carbonization of polymers was carried out in inactive atmosphere under the supervised conditions. The spherical shape of grains is a result of carbonization. The obtained carbon adsorbents were subjected to additional modification processes, i.e. hydrothermal activation in steam atmosphere, oxidation with nitric acid (6M HNO₃) and heated in hydrogen (H₂) atmosphere.

The adsorption from aqueous solutions of the chosen organic compounds on the modified synthetic active carbons, the adsorption of organic compounds in relation to water as well as structural characteristics of carbon adsorbents are discussed in this paper. The interaction of the organic substances and the synthetic active carbons in aqueous solutions depends on the structural properties of carbons (volume of micro- and meso-pores, distribution of pore sizes, specific surface area) and their chemical properties (i.e. concentration of functional oxygen groups, presence of mineral admixtures).

Synthesis of mesoporous ZrO₂-SiO₂ and WO₃/ZrO₂-SiO₂ solid acids by V. V. Brei; A. V. Melezhyk; S. V. Prudius; N. S. Bodul; P. A. Mutovkin; (pp. 86-95).

The method for preparation of mesoporous ZrO₂-SiO₂ and WO₃/ZrO₂-SiO₂ oxides with silicic acid sol is proposed. It was shown that these acidic oxides demonstrate high activity in the reaction of tetrahydrofuran oligomerization.

Physico-chemical methods for the chromatographic materials heterogeneity evaluation by M. Michel; M. Sprynskyy; B. Buszewski; (pp. 96-135).

The characterization methods used in the analysis of the chemical structure, microstructure and morphology, as well as the physical properties, of the chromatographic support are varied. This paper will focus on some techniques often used for the investigation of polymer/silica stationary phases. Many of these techniques are specific for characterization of particular properties of phases, and the properties of phases are also discussed correspondingly. To fully understand structure-property relationships, several characterization techniques are presented.

Advantages and risk related with carbon nanomaterials (CNMs) application for water remediation. Mini review by P. Oleszczuk; (pp. 136-146).

Water is one of the most valuable substances in the world and its availability in the form of potable and drinking water is of great importance for any society. Conventional water treatment methods have been reported to be ineffective in removing some kinds of organic pollutants including endocrine disrupting chemicals (EDCs), personal care products (PCP), pharmaceuticals, etc. Nanotechnology - especially application of the carbon based nanomaterials (CNMs) to water decontamination - is promising technology. The physico-chemical properties of CNMs (e.g. high surface area to volume ratio, high equilibrium rate) make them an excellent adsorbent which can be effectively used to remove pollutants from water. The present mini-review provides an overview of the research progress about organic chemical adsorption on CNMs in relation to water decontamination. The paper also discussed the possible risk related with desorption pharmaceuticals from CNMs.

Chromatographic characterisation of acceptor-donor properties of MCMs by H. Grajek; J. Paciura-Zadrożna; Z. Witkiewicz; (pp. 147-158).

The values of the specific retention volumes of non-polar and polar adsorbates chromatographed on the ordered mesoporous silica adsorbents (MCMs) were determined under their infinite dilution conditions. Two methods were employed for the calculation of the standard free energy of adsorption, ΔG_ads, of the chromatographed adsorbates on the basis of the specific retention volumes. The ΔG_ads values were employed for the estimation of the van der Waals contribution and specific contribution of the free surface energy for the MCMs and the parameters characterising their ability to act as acceptors, K_A, and donors, K_D, of electrons.

Mechanochemical synthesis of barium titanate and its photocatalytic properties by V. Sydorchuk; S. Khalameida; V. Zazhigalov; (pp. 159-168).

The nano-dispersed barium titanate was synthesised by mechanochemical treatment of barium titanyl oxalate and mixture of BaO and TiO₂. Prepared barium titanate demonstrates higher photoactivity in comparison to the same sample obtained by traditional solid state reaction. Shift of absorption edge in the visible region and respective narrowing of the band gap for the milled samples were observed.

Properties of materials as determined by inverse gas chromatography by A. Voelkel; K. Adamska; (pp. 169-183).

The application of inverse gas chromatography (IGC) in the determination of the physicochemical properties of various materials is presented and discussed. The special attention is focused on the determination of solubility parameters.

Clusterization of water at a surface of nanosilica A-380 by A. Yu. Petin; V. M. Gun'ko; A. V. Turov; V. V. Turov; R. Leboda; (pp. 184-196).

Thermodynamic and structural characteristics of water (0.07-1 g per 1 g of silica) bound to nanosilica A-380 (S_BET = 378 m²/g, primary particle diameter 7.2 nm) alone or on co-adsorption with chloroform alone or in the mixture with DMSO or acetonitrile were determined using ¹H NMR spectroscopy with layer-by-layer freezing-out of water at 200-273 K and NMR-cryoporometry.

Ceria-zirconia supported gold catalysts by J. M. Rynkowski; I. Dobrosz-Gómez; (pp. 197-217).

This paper presents the most important achievements and conclusions coming from the contributions concerning ceria-zirconia supported Au catalysts for low temperature water gas-shift reaction and low-temperature CO oxidation. The usefulness of CeO₂-ZrO₂ mixed oxides as supports for Au nanoparticles has been reviewed, mainly from the point of view of their contribution to those reactions. A special attention was paid to the active sites of CO oxidation and WGS reaction over Au/ceria-zirconia systems. Some aspects of the reactions mechanisms are also discussed. Ceriazirconia supported gold catalysts appear to be very promising systems, which have a potential to create a new quality in the catalysis of WGS reaction. Ceria-zirconia mixed oxides also seem to be very promising supports for Au nanoparticles in CO oxidation. They could find a practical application in ambient conditions, especially in air purification systems and a breathing apparatus. It is possible that gold could be usefully incorporated into automobile catalysts, considering that the price of other noble metals is rising rapidly. Their use in this application will, however, require demonstration of adequate stability at operating temperatures.

Specific control parameters in the technology of aerosol nanocatalysis by I. M. Glikina; M. A. Glikin; S. A. Kudryavtsev; (pp. 218-226).

This article shows the benefits of new technology for the implementation of gas-phase chemical reactions by aerosol nanocatalysis. The influence of new managing factors such as the concentration of catalyst, frequency, amplitude of motion of catalyst particles, dispersive material, etc. This enhances the process management and increases the rate of reaction per mass of catalyst in the 104-106 times. The selectivity of chemical transformations increases by 10-20%. Sometimes, new valuable products of the reaction are formed.

Application of novel complexing agent in sorption of heavy metal ions from wastewaters on ion exchangers of various types by D. Kołodyńska; Z. Hubicki; (pp. 227-245).

Ethylenediaminetetraacetic acid (EDTA) and nitrilotriacetic acid (NTA) are very effective chelating agents used in many branches of industry. However, they are characterized by low biodegradability (EDTA) and carcinogenic effect (NTA), additionally they are quite persistent in the environment. The search for a cost effective alternative to these two most frequently used chelating agents has long been an industry target. One of them is N, N-bis(carboxylmethyl)-L-glutamic acid whose tetrasodium salt known as Dissolvine GL-38. The aim of our work was to investigate Dissolvine GL-38 as a potential alternative for EDTA or NTA in effective removal of heavy metal ions from waters and wastewaters. In the presented paper there were used for the sorption of of heavy metal ions two commercially available ion exchangers: Lewatit MonoPlus MP 64 and Purolite S-920. A series of experiments was conducted to optimise the method for the Cu(II), Zn(II), Ni(II) and Cd(II) removal from industrial effluents. It was found that the sorption efficiency of the monodisperse polystyrene anion exchanger as well as the chelating ion exchanger varied depending on metal ions concentration, pH, phase contact time, agitation, temperature and properties of ion exchangers.

Preparation of matrix-free reference materials of volatile analytes based on the controlled decomposition of surface compounds: a new concept by K. Kupiec; P. Konieczka; J. Namieśnik; (pp. 246-258).

The use of reference materials in analytical laboratories is on the increase. Undoubtedly, the reason for this is the need for traceable and therefore comparable results of measurements. The use of reference materials is necessary in all analytical laboratories and especially in those which examine environmental samples characterised by:

- low or very low concentration levels of analytes,

- complex matrices

- temporal and spatial variability of samples, and

- the possibility of interference.

The development of analytical techniques for measuring components of gaseous media (outdoor air, indoor air, workplace air) has been going on for many years. This trend is closely associated with the need to obtain results of high quality, which necessitates the use of matrix-free (standard gaseous mixtures) as well as matrix reference materials. The use of reference materials with matrix compositions and analyte concentrations close to those of real samples yields more reliable measurement results.

This article presents a new approach to the problem of generating standard gaseous mixtures: the analyte is generated during the thermal decomposition of compounds immobilised on (i.e. chemically bonded to) the surface of an appropriate support material.

Soft-templating synthesis of nanoporous carbons with incorporated alumina nanoparticles by J. Choma; A. Żubrowska; J. Górka; M. Jaroniec; (pp. 259-272).

Soft-templated microporous-mesoporous carbons with embedded alumina nanoparticles were synthesized using resorcinol and formaldehyde as carbon precursors, different inorganic acids as a catalyst and poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) block copolymer as a soft template. The carbons studied have very good adsorption properties such as high specific surface area, uniform pore size distribution and a large total pore volume. The choice of catalyst seems to play an important role for the incorporation of aluminum species to the carbon framework, which after thermal treatment form aluminum oxide nanoparticles. This simple approach seems to be very promising for the design of carbon-based materials for a broad range of applications.

SPE and GC methods of preconcentration and determination of phenol, o-chlorophenol, and benzene by means of chemically modified silica by I. Rykowska; W. Wasiak; (pp. 273-281).

In the paper preparation, characteristics and potential applications of two new sorbents with chemically bonded transition metal complexes have been presented. The sorbents have been synthesized by attaching copper (II) chlorides to the silica surface through ketoimine groups. The suggested application area of the proposed sorbents is related with solid-phase extraction (SPE) of aromatic compounds of different structure, e.g., phenol, 2-chlorophenol, and benzene from water matrix. The experiments proved high efficiency of the sorbents, the ranging recovery rates from 88% to 96% and the LOD values from 0.2 for phenol, and 1.0 for o-chlorophenol.

Basic characteristics of the sorbents synthesized were determined by the use of elemental analysis and UV-VIS spectroscopy.

Zipf's law in concentration distributions by M. Kosmulski; (pp. 282-290).

Concentrations of impurities in fluids often follow Zipf's law, that is, relatively few impurities occur at high concentrations and numerous impurities occur at low concentrations. The concentrations of compounds in air and of elements in ocean water are examples of such distributions. This principle can be used to predict the number of components in a mixture, which occur above certain concentration level, also beyond the range of analytical methods. In most practical applications the existence of minor components can be ignored, but the level of concentration, at which certain component can be ignored depends on the specific problem.

Comparision of methods used for estimation of lipophilicity of biologically active phenylthioamides by M. Kostecka; (pp. 291-299).

Effectiveness of compound actions on living organisms depends on optimal lipophilicity. For studied 2,4-dihydroxyphenylthioamides of microbiocidal properties there were determined the values of lipophilicity parameters: log k_w, using high performance liquid chromatography and log P - the theoretical distribution coefficient in the n-octanol/water system. The search for a theoretical method was made which could replace chromatographic methods in preliminary choice of compounds of presumably high fungicidal activity.

The obtained results point to the Crippens and Ghose method and the values log P determined in this way correlate well with log kw and allow to choose a lipophilicity range in which the biological activity is the largest.

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Annales UMCS, Chemistry (v.64, #-1)