Jamroz M.H.,Industrial Chemistry Research Institute
Spectrochimica Acta - Part A: Molecular and Biomolecular Spectroscopy | Year: 2013
The principle of operations of the VEDA program written by the author for Potential Energy Distribution (PED) analysis of theoretical vibrational spectra is described. Nowadays, the PED analysis is indispensible tool in serious analysis of the vibrational spectra. To perform the PED analysis it is necessary to define 3N- 6 linearly independent local mode coordinates. Already for 20-atomic molecules it is a difficult task. The VEDA program reads the input data automatically from the Gaussian program output files. Then, VEDA automatically proposes an introductory set of local mode coordinates. Next, the more adequate coordinates are proposed by the program and optimized to obtain maximal elements of each column (internal coordinate) of the PED matrix (the EPM parameter). The possibility for an automatic optimization of PED contributions is a unique feature of the VEDA program absent in any other programs performing PED analysis. © 2013 Elsevier B.V. All rights reserved.
Zielecka M.,Industrial Chemistry Research Institute
Polimery/Polymers | Year: 2011
Silica nanoparticles (NP's) with immobilized NP's of copper or silver were synthesized by means of sol-gel process. The optimization of silica NP's synthesis was carried out under different conditions of temperature and stirring rate. Our results confirmed that the stirring rate plays an important role in growth, polydispersity and stability of nanoparticles. The properties of nanosilica containing immobilized nanosilver or nanocopper were examined by scanning electron microscopy (SEM), atomic absorption spectroscopy (AAS), photon correlation spectroscopy (PCS) and zeta potential analysis.
Brzozowski R.,Industrial Chemistry Research Institute
Journal of Catalysis | Year: 2011
In the article mentioned in the title, the authors challenged the hypothesis on shape-selective formation of 2,6-diisopropylnaphthalene (2,6-DIPN) in isopropylation of naphthalene over H-MOR catalysts. They claimed it was a myth, and there was no need to explain the high 2,6-DIPN selectivity with shape selectivity because it was in the range predicted by kinetics and thermodynamics. They also suggested that improper analysis of DIPN products could be a reason of the high 2,6-DIPN selectivity observed in the literature. However, in the current article I proved that some experimental results cannot be explained by kinetics, thermodynamics and analytical errors; therefore, shape-selective diisopropylation of naphthalene over H-mordenite is still the reality. © 2011 Elsevier Inc. All rights reserved.
Rudnik E.,Agricultural University of Athens |
Rudnik E.,Industrial Chemistry Research Institute |
Briassoulis D.,Agricultural University of Athens
Industrial Crops and Products | Year: 2011
Long-term degradation/disintegration behaviour, indicative of the biodegradation in soil behaviour of poly(lactic acid) films and fibres, was studied in natural Mediterranean soil environment during an eleven-month trial in the experimental field. In parallel, simulated soil burial experiments were carried out under controlled laboratory conditions. The degradation/disintegration behaviour of PLA was analysed using visual inspection, mechanical testing, DSC and FTIR analysis. The influence of the thickness and the type of the materials (film vs. fibre) on disintegration was investigated under the given mild conditions. For comparison purposes, degradation/disintegration of PLA film was also studied under low temperature composting conditions (house composting). During long-term exposure under natural soil environment dominated by complex and uncontrolled biotic-abiotic conditions and Mediterranean climatic conditions and under house composting conditions, PLA film samples of different thicknesses were partially, to a rather low degree, degraded mechanically or slightly disintegrated. The results showed that degradation behaviour of bio-based polymers like poly(lactic acid) in a real soil environment is a complex phenomenon, following different patterns regarding morphological changes. © 2010 Elsevier B.V.
Soszko M.,Industrial Chemistry Research Institute |
Lukaszewski M.,Industrial Chemistry Research Institute |
Mianowska Z.,Industrial Chemistry Research Institute |
Czerwinski A.,Industrial Chemistry Research Institute
Journal of Power Sources | Year: 2011
Methanol adsorption and electrooxidation have been studied on Pt-Rh-Pd alloys using cyclic voltammetry and chronoamperometry. Pt-Rh-Pd electrodes were prepared by a potentiostatic electrodeposition on a gold wire from chloride solutions. Alloy bulk composition was determined by SEM/EDAX measurements. Alloy surface composition was estimated adapting Rand and Woods's method for homogenous binary noble metal alloys utilizing the potential of surface oxide reduction peak. Electrode real surface area was calculated from the charge due to surface oxide formation/reduction. Methanol was oxidized both in stripping voltammetric experiments and continuously under potentiostatic conditions from 1 M CH 3OH/0.5 M H 2SO 4 solution. The values of electron per site, surface coverage and oxidation potential were used for the characterization of methanol adsorption products. The comparison of these results with analogous data for CO 2 and CO adsorption has revealed high similarity between CO 2 and methanol adsorption products, both consisting of mainly linearly and bridge-bonded CO species, however, with a higher contribution from bridge-bonded CO in the case of methanol. Current densities obtained during continuous methanol oxidation were the highest for Pt-Rh-Pd alloys with initial bulk composition 30.6% Pt, 23.7% Rh, 45.7% Pd, being of the same order as for pure Pt electrode. © 2011 Elsevier B.V.
Mazurek A.,Polish National Medicines Institute |
Dobrowolski J.C.,Polish National Medicines Institute |
Dobrowolski J.C.,Industrial Chemistry Research Institute
Organic and Biomolecular Chemistry | Year: 2013
New descriptors of the double bonded substituent effect, sEDA() and pEDA(), were constructed based on quantum chemical calculations and NBO methodology. They show to what extent the σ and π electrons are donated to or withdrawn from the substituted system by a double bonded substituent. The new descriptors differ from descriptors of the classical substituent effect for which the pz orbital of the ipso carbon atom is engaged in the π-electron system of the two neighboring atoms in the ring. For double bonded substituents, the pz orbital participates in double bond formation with only one external atom. Moreover, the external double bond forces localization of the double bond system of the ring, significantly changing the core molecule. We demonstrated good agreement between our descriptors and the Weinhold and Landis' "natural σ and π-electronegativities": so far only descriptors allowing for evaluation of the substitution effect by a double bonded atom. The equivalency between descriptors constructed for 5- and 6-membered model structures as well as linear dependence/independence of the constructed parameters was discussed. Some interrelations between sEDA() and pEDA() and the other descriptors of (hetero)cyclic systems such as aromaticity and electron density in the ring and bond critical points were also examined. © The Royal Society of Chemistry 2013.
Brzozowski R.,Industrial Chemistry Research Institute |
Buijs W.,Technical University of Delft
Journal of Catalysis | Year: 2012
To finally dispel any doubts on the shape-selective formation of 2,6-diisopropylnaphthalene (2,6-DIPN) over H-MOR zeolites, naphthalene alkylation was carried out over high-silica H-MOR catalysts with propylene or isopropanol as an alkylating agent and with or without cyclohexane as a solvent. Isomeric composition of DIPN's, determined by one-dimensional GC analysis, was additionally confirmed with advanced two-dimensional GC × GC. Our results proved beyond any doubt shape-selective formation of 2,6-DIPN over these H-MOR catalysts from naphthalene and propylene and without cyclohexane as a solvent. The DIPN mixture contained 60-64% 2,6-DIPN, and the ratio of 2,6-DIPN/2,7-DIPN was in the range 2.5-2.8. We also showed that shape-selective formation of 2,6-DIPN over H-MOR catalyst was depressed by using isopropanol instead of propylene and in the presence of cyclohexane. © 2012 Elsevier Ltd. All rights reserved.
Sadlej J.,University of Warsaw |
Sadlej J.,Polish National Medicines Institute |
Dobrowolski J.C.,Polish National Medicines Institute |
Dobrowolski J.C.,Industrial Chemistry Research Institute |
Rode J.E.,Industrial Chemistry Research Institute
Chemical Society Reviews | Year: 2010
Most of the research in contemporary physical chemistry is devoted to the development of methods that extend our understanding, interpretation, and capacity to predict structural properties and dynamic behavior of molecules. The optical and magnetic spectroscopies, as well as diffraction techniques, are the principal methods for studying properties of molecules, biomolecules, and biopolymers of which the vast majority are chiral. On the other hand, information on molecular configuration can be obtained mainly from optical spectroscopies because other well-established spectroscopic techniques used for structural investigations, such as crystallographic, ESR, and NMR methods, do not allow for registration of signals from an individual conformer owing to intrinsic slow response to structural changes. This is the reason why the optical spectroscopy methods, based on natural chiroptical phenomena, have become so important and their renaissance in the last decade is noticed. Vibrational circular dichroism (VCD) spectroscopy is one such chiroptical technique that sheds new light on many important phenomena studied intensively. We provide an overview of recent theoretical predictions and innovative VCD observations of chirality transfer (called by other authors "induced chirality") from a chiral molecule to an achiral one as a result of hydrogen bond interactions between them. In this tutorial review we search for answers as to whether we can obtain further information about intermolecular interactions using the VCD technique. In our opinion this technique has opened new horizons for both understanding and monitoring intermolecular interactions and it could be used as a relatively new and powerful physicochemical method. © 2010 The Royal Society of Chemistry.
Lukaszewski M.,University of Warsaw |
Czerwinski A.,University of Warsaw |
Czerwinski A.,Industrial Chemistry Research Institute
Thin Solid Films | Year: 2010
The procedures of Pd-noble metal alloy (Pd-Au, Pd-Pt, Pd-Rh, Pd-Pt-Rh) preparation by electrochemical deposition from chloride solutions are described. The influence of deposition conditions on alloy composition is presented. The deposits were characterized electrochemically in acidic solutions (H2SO4 aq) by cyclic voltammetry. The surface morphology of the alloys was examined by scanning electron microscopy and scanning tunneling microscopy. The alloy surface composition was investigated in situ by the electrochemical method and ex situ by Auger electron spectroscopy, while the bulk composition was determined by energy dispersive analysis of X-rays and atomic absorption spectroscopy. The electrochemical methods of the real surface area determination were compared and discussed. © 2009 Elsevier B.V. All rights reserved.
Adamiak J.,Industrial Chemistry Research Institute
Journal of Molecular Catalysis A: Chemical | Year: 2015
Nitroanisoles have wide applications in pharmaceuticals, perfumery and production of corresponding amines used extensively in dye industry. The presence of activated methoxy group in the aromatic ring, causes the nitration of anisole to be complex and difficult to control. The catalysts obtained by mixing phosphoric acid with ammonium molybdate, and impregnating the solution on silica gel, are composed of PO43- ions built in the structure of surface Mo∞O3∞ lattice (heteropolyanion structure-like species). Using various amounts of the molybdenum species, it is possible to manipulate the catalyst acidity and simultaneously its activity. At room temperature, for 30 min with using fuming nitric it is possible to obtain ca. 90% anisole conversion with 62% selectivity to 4-nitroanisole. When 65% HNO3 is used, the conversion decreases to 76%, however the selectivity to 4-nitroanisole increases to 74%. Another advantage of the obtained catalysts is the possibility of their effective reuse in the subsequent reactions. © 2015 Elsevier B.V. All rights reserved.