Papers by Stanisław Koter
An entry from the Cambridge Structural Database, the world's repository for small molecule cr... more An entry from the Cambridge Structural Database, the world's repository for small molecule crystal structures. The entry contains experimental data from a crystal diffraction study. The deposited dataset for this entry is freely available from the CCDC and typically includes 3D coordinates, cell parameters, space group, experimental conditions and quality measures.
ACS Applied Materials & Interfaces, 2021
Wetting of metal surfaces plays an important role in fuel cells, corrosion science, and heat-tran... more Wetting of metal surfaces plays an important role in fuel cells, corrosion science, and heat-transfer devices. It has been recently stipulated that Cu surface is hydrophobic. In order to address this issue we use high purity (1 1 1) Cu prepared without oxygen, and resistant to oxidation. Using the modern Fringe Projection Phase-Shifting method of surface roughness determination, together with a new cell allowing the vacuum and thermal desorption of samples, we define the relation between the copper surface roughness and water contact angle (WCA). Next by a simple extrapolation, we determine the WCA for the perfectly smooth copper surface (WCA = 34°). Additionally, the kinetics of airborne hydrocarbons adsorption on copper was measured. It is shown for the first time that the presence of surface hydrocarbons strongly affects not only WCA, but also water droplet evaporation and the temperature of water droplet freezing. The different behavior and features of the surfaces were observed once the atmosphere of the experiment was changed from argon to air. The evaporation results are well described by the theoretical framework proposed by Semenov, and the freezing process by the dynamic growth angle model.
International Journal of Greenhouse Gas Control, 2021
Gas separation is an important separation process to many industries, and membrane separation usi... more Gas separation is an important separation process to many industries, and membrane separation using hollow fibre membranes (HFMs) has become one of the emerging technologies. In this article, the gas separation concepts, gas transport mechanism, and the fabrication and gas separation performance of HFMs including asymmetric HFMs, thin film composite hollow fibre membranes (TFC-HFMs), and mixed matrix hollow fibre membranes (MM-HFMs), are reviewed and discussed. Dope composition and spinning parameters directly influence the structure of HFMs and subsequently the gas separation performance of HFMs. The gas separation performance of TFC-HFMs can be improved by the design of the coating solution, surface modification, and the addition of both a gutter layer and a protective layer. Mixed matrix membranes (MMMs) have been intensively investigated in flat sheet membranes and the inspiring gas separation results have been obtained. Therefore, the incorporation of nanoparticles into hollow fibre membranes is a desirable solution to increase the gas permeability and selectivity simultaneously. The functionalization of nanoparticles and fabrication methods of MM-HFMs are also presented.
International Journal of Molecular Sciences, 2020
Reverse electrodialysis (RED) is an electro-membrane process for the conversion of mixing energy ... more Reverse electrodialysis (RED) is an electro-membrane process for the conversion of mixing energy into electricity. One important problem researchers’ face when modeling the RED process is the choice of the proper membrane transport equations. In this study, using experimental data that describe the membrane Nafion 120 in contact with NaCl aqueous solutions, the linear transport equation of irreversible thermodynamics was applied to calculate the power density of the RED system. Various simplifying assumptions about transport equation (i.e., four-, three-, and two-coefficients approaches) are proposed and discussed. We found that the two-coefficients approach, using the membrane conductivity and the apparent transport number of ions, describes the power density with good accuracy. In addition, the influence of the membrane thickness and the concentration polarization on the power density is also demonstrated.
Microporous and Mesoporous Materials, 2019
Although porphyrin containing metal organic frameworks (PCMOFs) have found applications in differ... more Although porphyrin containing metal organic frameworks (PCMOFs) have found applications in different important fields, for example catalysis, phototherapy, adsorption etc. the mechanism of water adsorption on these materials remains unknown. In this study we analyze adsorption-desorption data on three PCMOFs. It is shown that hysteresis on adsorption-desorption isotherms is caused probably by the structural deformations. The application of SAFT-VR model to describe the experimental data is in agreement with the in-situ DRIFT insight of the process showing that the affinity between water and studied MOFS decreases as follows: CaTCPP > MgTCPP > ZnTCPP > TCPP. Application of the in-situ DRIFT method leads to important information about the nature of water material interactions showing for example the creation of aqua complexes and hydrogen bonds.
DESALINATION AND WATER TREATMENT, 2018
The tested models of membrane transport were based on the steric, dielectric (Born and image forc... more The tested models of membrane transport were based on the steric, dielectric (Born and image force effects), and Donnan exclusions. Generally, the models with the concentration-dependent electrolyte permeability described the retention data satisfactorily, irrespectively of the origin of that dependence (dielectric or Donnan effect). Regarding the steric-dielectric exclusion, the same goodness of fit was obtained for many pairs of pore radius and dielectric constant. However, it was not possible to explain the differences in the electrolyte permeabilities, because of the inconsistency of the dielectric constant of a pore solution and/or an effective membrane thickness. Much too high values of that thickness obtained for the pure Donnan exclusion indicated that this type of exclusion was of marginal importance.
DESALINATION AND WATER TREATMENT, 2017
Filtration properties of membranes obtained by deposition of a few layer graphene oxide onto a po... more Filtration properties of membranes obtained by deposition of a few layer graphene oxide onto a polyamide support, with and without borate treatment, were examined. Filtrations of water, dilute solutions of electrolytes (Na 2 SO 4 , NaCl, MgSO 4 , MgCl 2), and dyes (bromophenol blue, eriochrome black T) were performed. It was found that the observed electrolyte retention series (Na 2 SO 4 > NaCl > MgSO 4 > MgCl 2) was in accordance with the Donnan exclusion theory. The membrane treated with borate and of higher graphene oxide load showed higher retention of sulfates than the untreated one. Despite of lower molecular weight, eriochrome black T was practically completely rejected by both types of membranes, contrary to bromophenol blue, irrespectively of its form (undissociated-retention 68%, dissociated-85%).
Polish Journal of Chemistry, 2009
Autooxidation of leuco-Methylene Blue to the dye, Methylene Blue, was studied in the 1.9-7.8 pH r... more Autooxidation of leuco-Methylene Blue to the dye, Methylene Blue, was studied in the 1.9-7.8 pH range under a large molar excess of dioxygen dissolved in the reaction solution using electronic spectroscopy. The synproportionation of the substrate and the reaction product, yielding Methylene Blue radical, plays a key role in the overall redox process. Numerical simulation of the complicated kinetic curves shows that presence of this radical opens an effective reaction path for the autooxidation process and results in coupling of the reaction steps. Reactive oxygen species (HO • 2 /O •― 2/ and H 2 O 2 ) formed in the examined system are not effective oxidants and do not affect the autooxidation kinetics under applied conditions.
Zeszyty Naukowe Inzynieria Środowiska Politechnika Śląska, 2002
ACS applied materials & interfaces, Jan 27, 2014
Hydrophobic titania ceramic membranes (300 kD) were prepared by grafting of C6F13C2H4Si(OC2H5)3 a... more Hydrophobic titania ceramic membranes (300 kD) were prepared by grafting of C6F13C2H4Si(OC2H5)3 and C12F25C2H4Si(OC2H5)3 molecules and thus applied in membrane distillation (MD) process of NaCl solutions. Grafting efficiency and hydrophobicity were evaluated by contact angle measurement, atomic force microscopy, scanning electron microscopy, nitrogen adsorption/desorption, and liquid entry pressure measurement of water. Desalination of NaCl solutions was performed using the modified hydrophobic membranes in air gap MD (AGMD) and direct contact MD (DCMD) processes in various operating conditions. High values of NaCl retention coefficient (>99%) were reached. The permeate fluxes were in the range 231-3692 g·h(-1)·m(-2), depending on applied experimental conditions. AGMD mode appeared to be more efficient showing higher fluxes and selectivity in desalination. Overall mass transfer coefficients (K) for membranes tested in AGMD were constant over the investigated temperature range. Ho...
Reaction Kinetics, Mechanisms and Catalysis, 2012
The kinetics of the oxidation of imipramine and opipramol using peroxydisulfate salts in the pres... more The kinetics of the oxidation of imipramine and opipramol using peroxydisulfate salts in the presence of a large excess of dibenzoazepine derivative (TCA) in acidic sulfate media was studied using UV-vis spectroscopy. The reaction between imipramine and S 2 O 8 2proceeds via the formation of two intermediates: a free organic radical and a dimeric dication. Further reaction of the intermediate dimeric dication leads to a positively charged radical dimer as one final product. Simultaneously, two other substituent cleavage degradation processes occur, leading to two dimeric derivatives. The first product, the positively charged radical dimer, and the next main product, a radical dimer without one alkyl substituent, were identified by EPR measurements. The measured kinetic trace is not first order and revealed a sigmoid shape with a characteristic induction time. The rate constants were determined by numerical analysis based on ordinary differential equations (ODEs). The reaction between opipramol and S 2 O 8 2proceeds by a two consecutive reaction scheme. The kinetics of the first degradation step were studied independently of the slower degradation reactions. Linear dependences, with zero intercept, of the pseudo-first-order rate constants (k obs) on [TCA] were determined for the first degradation process of opipramol.
Separation Science and Technology, 1989
The interaction between the current efficiency of electrodialytic separation with ion-exchange me... more The interaction between the current efficiency of electrodialytic separation with ion-exchange membranes and all the fluxes depressing selectivity, i.e., electric transport of coions, electroosmotic flow of water, diffusion, and osmosis, are described and experimentally examined. A simple method for the determination of current efficiency for any concentration difference across the membrane and current density is presented. A simple relationship between
Separation and Purification Technology, 2013
The model of metal ion permeation through a bulk liquid membrane (BLM), based on the Nernst-Planc... more The model of metal ion permeation through a bulk liquid membrane (BLM), based on the Nernst-Planck equation, was developed. It was satisfactorily tested using the experimental data on the cadmium permeation from Cd(NO 3) 2 solution through BLM (D2EHPA in kerosene) to 1 M H 2 SO 4 solution. According to the model simulations, the cadmium permeation was controlled by K eq on the feed side; the knowledge of the exact K eq value on the strip side under the condition c H 2 SO 4) c Cd was not required. None of the following: an assumed Cd-D2EHPA complex (CdP 2 (HP) 2 , CdP 2 HP), presence of undimerized D2EHPA in BLM, or ion pair formation Cd 2þ Á SO 2À 4 in the strip solution, influence the goodness of fit. Assuming the model based on the Fick's law with the constant cadmium mass transfer coefficient, a large dispersion of its optimal fitting values which depends on the model assumption was found. Thus, that coefficient can only be treated as a fitting parameter.
Journal of Physics: Condensed Matter, 2012
Tetrafluoromethane, CF 4 , is powerful greenhouse gas, and the possibility of storing it in micro... more Tetrafluoromethane, CF 4 , is powerful greenhouse gas, and the possibility of storing it in microporous carbon has been widely studied. In this paper we show, for the first time, that the results of molecular simulations can be very helpful in the study of CF 4 adsorption. Moreover, experimental data fit to the results collected from simulations. We explain the meaning of the empirical parameters of the supercritical Dubinin-Astakhov model proposed by Ozawa and finally the meaning of the parameter k of the empirical relation proposed by Amankwah and Schwarz.
Journal of Membrane Science, 2005
Letter to the Editor The Kedem-Katchalsky equations and the sieve mechanism of membrane transport... more Letter to the Editor The Kedem-Katchalsky equations and the sieve mechanism of membrane transport Some time ago, in this Journal [1], a mechanistic model of transport through a porous membrane based on the sieve mechanism was presented. The main finding is that the solute flow, J s , is given by the following equation (Eq.
Journal of Membrane Science, 2002
The transport of aqueous binary electrolyte solutions (NaCl, HCl) through the cation- and anion-e... more The transport of aqueous binary electrolyte solutions (NaCl, HCl) through the cation- and anion-exchange membranes (Nafion, Neosepta) has been described in terms of the capillary model based on the thermodynamics of irreversible processes. The equivalent radius of pores has been calculated from the electroosmotic number of water. The Lik coefficients have been calculated for each membrane/electrolyte system basing on the
Journal of Membrane Science, 2008
ABSTRACT
Journal of Membrane Science, 1993
In the framework of a series layer model of a membrane a test of the Onsager reciprocal relations... more In the framework of a series layer model of a membrane a test of the Onsager reciprocal relations (ORR) for a cation exchange membrane in aqueous and nonaqueous electrolyte solutions was performed. It was found that for zero-current transport processes the ORR and the linearity of the fluxes to forces relation are not fulfilled.
Journal of Membrane Science, 1999
The equilibrium and transport properties (conductivity, transport number, diffusion) of crosslink... more The equilibrium and transport properties (conductivity, transport number, diffusion) of crosslinked ionomer membranes based on sul®nated and sulfonated PSU in aqueous solutions of HCl, NaCl and KCl have been investigated and compared with a Na®on 117 membrane. It has been found that these membranes are more compact and their conducting paths are of smaller dimension than that of the Na®on 117. The in¯uence of length of crosslinking chain, changing from ±(CH 2) 4 ± to ±(CH 2) 12 ±, is particularly indicated by the diffusion coef®cients; the conductivity and transport numbers of counterions are in¯uenced only slightly. Practically no dependence of this effect on the transport number of H has been found.
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Papers by Stanisław Koter