Sylwia Golba | University of Silesia in Katowice (original) (raw)

Papers by Sylwia Golba

Journal of Ecological Engineering, Mar 1, 2024

It was established that the change in the structure of the amorphous metal alloy (AMA) as a resul... more It was established that the change in the structure of the amorphous metal alloy (AMA) as a result of heat treatment of the amorphous metal alloy Al 87 Gd 5 Ni 4 Fe 4 at T = 645±1 K significantly affects the decolorization of the dye Basic Blue 6/Mendola Blue (BB6/MB) at pH = 1.7±0.3. The MB solution with a concentration of 4.39 μM was decolorized by 99% within 27 hours, in the case of annealed AMAs for 30, 45, 60 min., which is 3.8 times more effective than in the case of as-cast AMAs. A change in the AMA structure due to annealing was established by X-ray analisys; kinetic analysis was performed based on experimental data and the kinetic parameters (kobs, t1/2, ksa, etc.) of the MB decolorization reaction were calculated. The surface of AMAs after reaction with aniline dye MB and the proposed scheme of decolorization of aniline dye MB using AMAs Al 87 Gd 5 Ni 4 Fe 4 were suggested.

Polymer Bulletin, Dec 4, 2018

Several alkali metal salts that activated 18-crown-6 were applied as initiators of β-butyrolacton... more Several alkali metal salts that activated 18-crown-6 were applied as initiators of β-butyrolactone anionic ring-opening polymerization in tetrahydrofuran at room temperature. Some of them, i.e., Ph 2 PK, Ph 3 HBK, (Me 3 Si) 2 NK, and t-BuOK, deprotonate the monomer which results in macromolecules with trans-crotonate starting group. Other salts, for example, MeOK, i-PrOK, PhCH 2 OK, and CbK (Cb denotes carbazolyl group), deprotonate monomer or open its ring in the acyl-oxygen position. After ring-opening KOH forms as intermediate and initiates further polymerization. Ph 3 CK and monopotassium salt of ethylenediaminetetraacetic acid also deprotonate monomer and open its ring, however, in the alkyl-oxygen position. Monopotassium salts of glycolic acid, diglycolic acid, or malonic acid initiate polymerization mainly by ring opening in the alkyl-oxygen position. It results in the formation of polymers with two reactive terminal groups. The salts used react with the monomer as strong bases, nucleophilic bases, or nucleophiles. It determines unsaturation of the polymers obtained in the wide range of 2-100 mol%.

Electrochimica Acta, Mar 1, 2017

Highlights  New 4,4'-bipyridine derivatives C-substituted with bithiophene groups were prepared.... more Highlights  New 4,4'-bipyridine derivatives C-substituted with bithiophene groups were prepared.  Their polymerisation afforded novel polymers with 4,4'bipyridine and viologen groups in the main chain.  Conjugation disruption in 4,4'-bipyridine copolymers stabilises doping induced polarons.  4,4'-bipyridine copolymer chain topology promotes intermolecular π-π interactions.  The viologen repeating unit copolymer demonstrates strong charge trapping/detrapping effects.

Journal of Polymer Research, Nov 20, 2019

Several monosubstituted oxiranes were polymerized with suspension of potassium hydride (KH) in te... more Several monosubstituted oxiranes were polymerized with suspension of potassium hydride (KH) in tetrahydrofuran (THF) at room temperature. This heterogeneous process resulted in polyethers with various starting groups depending on the kind of monomer. The macromolecules formed in ring-opening polymerization of monosubstituted oxiranes were analyzed by Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS). It was stated, that initiation of propylene oxide (PO) polymerization with KH proceeded via three ways, i.e. cleavage of oxirane ring in the β-position, monomer deprotonation and deoxygenation. Potassium isopropoxide, potassium allyloxide and potassium hydroxide were the real initiators. The main reactions, which occur in the initiation step, depend on the type of monomer used. In the case of allyl glycidyl ether (AGE) and phenyl glycidyl ether (PGE) deprotonation of the monomer did not occur. During initiation of glycidyl ethers oxirane ring was opened and also linear ether bond between glycidyl group and oxygen atom was cleaved under influence of KH. Interestingly, formation of new kinds of macromolecules was observed in the systems containing glycidyl ethers, which do not possess mers of the monomers used. Mechanisms of the studied processes were presented and discussed. Carbon-13 Nuclear Magnetic Resonance (13 C NMR) was used as supporting technique for analysis of the obtained polymers. Number average molar masses of the polymers (M n) determined by Size Exclusion Chromatography (SEC) were about two times higher than calculated ones. It indicated that half of used KH did not take part in the initiation step.

Polymer Bulletin, Oct 13, 2018

Various alkali metal salts were applied as initiators for ε-caprolactone anionic ringopening poly... more Various alkali metal salts were applied as initiators for ε-caprolactone anionic ringopening polymerization in tetrahydrofuran at room temperature. It was observed that potassium methoxide (MeOK), potassium isopropoxide (i-PrOK) and potassium tert-butoxide (t-BuOK) nonactivated or activated by 18-crown-6 (18C6) initiated polymerization mainly by deprotonation of the monomer. In the case of potassium hydride (KH), its basicity increased with the ability of the ligand for cation complexation. For example, KH without ligand or with weak ligands for K + as 12C4 reacted exclusively by ring opening. However, in the presence of strong ligands, as 15C5, 18C6 or cryptand C222, basicity of H − increased with the ability of the ligand for cation complexation. In the last case, ~ 32% of the monomer was deprotonated. In these systems, gaseous H 2 evolved during the initiation. Deprotonation of the monomer by some initiators resulted in macromolecules with reactive aldehyde group or lactone ring as starting groups. They took part in the reaction with potassium alkoxide active centers of growing chains leading to the formation of branched poly(ε-caprolactone)s. Sodium hydride (NaH) was inactive, but in the presence of 15-crown-5 or 18-crown-6 initiated polymerization exclusively by ring opening. MALDI-TOF mass spectrometry supported with 13 C NMR and SEC was used for analysis of the polymers obtained. Mechanism of the studied processes was proposed and discussed.

Journal of Luminescence, Dec 1, 2017

Abstract Six novel azomethines with substituted thiophene central core were synthesized and their... more Abstract Six novel azomethines with substituted thiophene central core were synthesized and their properties are reported. They were obtained by the condensation reaction between 2,5-diamino-thiophene-3,4-dicarboxylic acid diethyl ester and various aldehydes. The imines were characterized by NMR and FTIR spectroscopies and by elemental analysis. DSC measurements revealed that the prepared compounds are molecular glasses (except for one) with high T g varying from 94 and 183 °C. Their redox properties were investigated in solution by cyclic voltammetry and differential pulse voltammetry. It was found that all imines were electrochemically active and showed low values of energy band gap ranging from 1.61 to 1.78 eV. Photoluminescence measurements indicated that they emitted light in solution with quantum yield (Φ PL ) in the range of 1.2–14.3% and in solid state as film and blend with poly(methyl methacrylate) and binary blend with poly(9-vinylcarbazole) (PVK) and (2-(4-tert-butylphenyl)-5-(4-biphenylyl)-1,3,4-oxadiazole) (PDB) with Φ PL form 0.24–1.77% and from 0.52% to 1.66%, respectively. The density functional theory (DFT) was applied for calculating their geometries and frontier molecular orbitals. Their electroluminescence ability was examined in guest-host diode with structure ITO/PEDOT:PSS/PVK:PBD:imine / Al and emission of light with maximum of emission band from 626 to 674 nm was observed. This work demonstrates, to the best of our knowledge, the first example of light emitting devices based on thiophene azomethines as active layer component.

Materials, Oct 10, 2022

This article is an open access article distributed under the terms and conditions of the Creative... more This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY

Materials Science Forum, Nov 1, 2010

A series of various C3-symmetric molecules were synthesized by Stille cross-coupling procedure. M... more A series of various C3-symmetric molecules were synthesized by Stille cross-coupling procedure. Monomers have been characterized by 1 H NMR, 13 C NMR. Received oligomers in the process of electropolymerization, containing thienyl, furyl, and EDOT groups provide good conductivity and show stability in common organic solvents such as CHCl 3 , toluene, and CH 2 Cl 2 and exhibit thermal stability. Electrochemical results suggest that obtained materials can be successfully used in wide scale of organic-electronic devices such as organic light-emitting diodes (OLEDs), organic field-effect transitors (OFETs), and organic solar cells.

Polymer Testing, Jul 1, 2017

Experimental and numerical investigation of yielding phenomena in a shape memory polymer subjecte... more Experimental and numerical investigation of yielding phenomena in a shape memory polymer subjected to cyclic tension at various strain rates,

Dyes and Pigments, Feb 1, 2015

A series of star-shaped carbazole derivatives were prepared via Suzuki-Miyaura and Stille couplin... more A series of star-shaped carbazole derivatives were prepared via Suzuki-Miyaura and Stille coupling procedures. Received monomers were characterized by UV-Vis spectroscopy, fluorescence spectroscopy and cyclic voltammetry in order to estimate their basic spectral, electrochemical and electronic properties important for wide scale of applications in organic electronics and photovoltaics. Experimental results were supported by DFT calculations. Synthesised compounds were also used as monomers in the electrodeposition of conjugated polymers. Spectroelectrochemical EPR and UV-Vis-NIR measurements were carried out in order to study the influence of structure on charge carrier formation.

Bioelectrochemistry, Apr 1, 2022

Current trends in the field of neural tissue engineering include the design of advanced biomateri... more Current trends in the field of neural tissue engineering include the design of advanced biomaterials combining excellent electrochemical performance with versatile biological characteristics. The purpose of this work was to develop an antibacterial and neuroprotective coating based on a conducting polymer - poly(3,4-ethylenedioxypyrrole) (PEDOP), loaded with an antibiotic agent - tetracycline (Tc). Employing an electrochemical technique to immobilize Tc within a growing polymer matrix allowed to fabricate robust PEDOP/Tc coatings with a high charge storage capacity (63.65 ± 6.05 mC/cm2), drug release efficiency (629.4 µg/cm2 ± 62.7 µg/cm2), and low charge transfer resistance (2.4 ± 0.1 kΩ), able to deliver a stable electrical signal. PEDOP/Tc were found to exhibit strong antimicrobial effects against Gram-negative bacteria Escherichia coli, expressed through negligible adhesion, reduction in viability, and a characteristic elongation of bacterial cells. Cytocompatibility and neuroprotective effects were evaluated using a rat neuroblastoma B35 cell line, and were analyzed using MTT, cell cycle, and Annexin-V apoptosis assays. The presence of Tc was found to enhance neural cell viability and neurite outgrowth. The results confirmed that PEDOP/Tc can serve as an efficient neural electrode coating able to enhance charge transfer, as well as to exhibit bifunctional biological characteristics, different for eukaryotic and prokaryotic cells.

European Journal of Inorganic Chemistry, Dec 7, 2018

New mononuclear osmium complexes M1-M4 with various NCN-cyclometalating pyrene ligands were synth... more New mononuclear osmium complexes M1-M4 with various NCN-cyclometalating pyrene ligands were synthesized and thoroughly characterized with particular emphasis on the nature of NCNcyclometalating pyrene ligands on the properties of target compounds. Structural properties were achieved by using the theoretical studies (DFT). Moreover, spectroscopic and theoretical studies (TD-DFT) show the character of transitions and allow to understand the behavior of molecules during the stepwise oxidative titrations by using the cerium ammonium nitrate (CAN) solutions what resulted in M1 +-M4 +. The obtained experimental and theoretical data show the significant differences between the mononuclear osmium complexes M1-M4 in reference to used pyrene ligands.

European Journal of Inorganic Chemistry, Apr 16, 2018

New ruthenium (Ru), osmium (Os), and iridium (Ir) complexes bridged by cyclometalating 1,3,6,8-te... more New ruthenium (Ru), osmium (Os), and iridium (Ir) complexes bridged by cyclometalating 1,3,6,8-tetra(4-(2,2dimethylpropyloxy)-2-pyridyl)pyrene with terminal 4'-(4metoxynaphthalene-1-yl)-2,2':6',2''-terpyridine ligands were synthesized and characterized to exhibit diverse properties with respect to used metal. Thermal measurements showed that obtained complexes retain high thermal stability. Structural properties were achieved by using the density functional theory (DFT) calculations. What is more, spectroscopic and theoretical studies (TD-DFT) showed the character of transitions, especially metal-to-ligandcharge-transfer (MLCT) excitation predominant in the case of Ru and Os complexes and weakly observed in Ir complex. Electrochemical research showed the considerable differences between complexes with various metals.

Journal of Materials Chemistry C, 2019

Novel dyes based on the phenothiazine system D/A–π–D–π–A exhibit that elongation of π-conjugation... more Novel dyes based on the phenothiazine system D/A–π–D–π–A exhibit that elongation of π-conjugation is advantageous in the design of efficient photosensitizers.

Tetrahedron Letters, May 1, 2010

Dyes and Pigments, Jul 1, 2019

Two novel 2,4-difluorenylquinoline derivatives with different length of alkyl chain at fluorene u... more Two novel 2,4-difluorenylquinoline derivatives with different length of alkyl chain at fluorene unit (Q-F1 with methyl and Q-F2 with octyl chain) of donor-acceptor (D-A) type were synthesized and comprehensively characterized. The compounds exhibited bright emission in the blue spectral region at 400 nm and high fluorescence efficiency of 63-97% in solution. The EL measurements of OLEDs with Q-F1, and for comparison 2,4-dicarbazolylquinoline (Q-C1) were performed to determine any correlations between the device performance and the different D units at quinoline core. These fluorenyl and carbazolyl substituted quinolines (Q-F1 and Q-C1) were found to display good thermal stability with a decomposition temperature of 301 and 416 ºC, respectively. A molecule with carbazole units (Q-C1) dispersed in a host matrix exhibited higher PL quantum yield (15%) compared to Q-F1 (11%). The devices with structure ITO/PDOT:PSS/PVK:PBD:compound/Al with 15 (Q-F1) and 2 (Q-C1) wt. % of compound content in a blend were constructed. The diode based on Q-C1 emitted green light with EL maximum at 550 nm under an applied external voltage. Furthermore, by incorporation of a layer of plasmonically active silver nanowires into the device based on Q-C1

Dyes and Pigments, 2019

Donor-acceptor (D-A) system based on 2,4-dicarbazolyl-substituted quinolines (Q2-Q5) with differe... more Donor-acceptor (D-A) system based on 2,4-dicarbazolyl-substituted quinolines (Q2-Q5) with different length of alkyl chain at carbazole, viz-CH 3 (Q3),-C 8 H 17 (Q4),-C 10 H 21 (Q5), and different attachment of carbazole to quinoline core, and in addition a 4-bromo-(9H-carbaz-2yl)-quinoline (Q1) was designed and synthesized via Suzuki-Miyaura cross-coupling reaction to examine the influence of alkyl chain length on their photophysical behavior. The study shows a strong dependence of optical and electrochemical properties on the number of carbazole units in the molecule as well as the position of substitution of carbazole and mainly length of alkyl chain on carbazole units of studied quinoline derivatives. Emission (PL) spectra exhibit that the extension of alkyl chain length to-C 8 H 17 enhances the fluorescence quantum yield and lifetime of compounds but the introduction of-C 10 H 21 into molecule results in a significant reduction of luminescence ability. Additional PL spectra at 77 K of Q4 (-C 8 H 17) and Q5 (-C 10 H 21) reveal that intersystem crossing takes place with higher efficiency in Q5 and plays a superior role than possible intramolecular photoinduced electron transfer (PET) mechanism than in the case of Q4. The study of the geometry of the first singlet (S 1) and triplet (T 1) excited states of Q4 and Q5 demonstrate that the energy of the excited state in Q5 may be mostly spread as a result of the oscillations within the aliphatic hydrocarbons and in Q4 the intersystem crossing processes amplify the deactivation in the radiative path. The electrochemical investigation indicates that the oxidation potential is lower for molecules with carbazole substituted at 2-than 3-position, and among Q3-Q5 decreases significantly from

Russian Journal of Electrochemistry, Jul 1, 2018

In this work novel bisheterocyclic derivatives of alkylcarbazole with A–CZ–A architecture are inv... more In this work novel bisheterocyclic derivatives of alkylcarbazole with A–CZ–A architecture are investigated (CZ stands for alkylcarbazole). The study presents their opto-electronic and electrochemical properties which influence on the possibility of their prospective application. Monomers undergo electropolymerisation with formation of conducting layer of polythiophene derivatives, while presence of chalcone moiety hampers the process. Two-step oxidation processes of polymers results in generation of polaron and bipolaron types of charge carriers on the macromoleculs’ chains. The charge is delocalized over center and side subunits (bithiophene or bithiazole one) in first stage of oxidation. It is possible to influence on the properties of the polymers and their composition by variation of synthesis condition like solvent polarity and applied potential boundaries. Obtained conducting polymers show high stability under ambient conditions. Their energy gap values are estimated with electrochemical and spectroscopic methods.

International Journal of Molecular Sciences, Mar 1, 2023