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The global development of electromobility and the innovation of life are becoming increasingly noticeable. A direct implication of this is the increase in demand for modern products and services, their components and thus the raw materials necessary to produce them (e.g. cobalt, lithium, rare earth metals). In the European Union (EU), raw materials related to strategic sectors – renewable energy, electric mobility, defense and aerospace and digital technologies – show a very strong dependence on import throughout the entire value chain. In the case of eleven out of thirty of the so-called critical raw materials (CRM), necessary for the energy transition, the EU’s dependence on import exceeds 85%. Global supply chains, which had already been strained, were further affected by the COVID-19 pandemic and the exacerbated geopolitical situations leading to even greater shortages of critical raw materials in Europe and leaving the industry facing challenges in securing access to resources. An implication of this was the European Parliament’s position on critical raw material legislation in September 2023, which called on the EU to increase its processing capacity across the value chain and enable the production of at least 40% of the annual consumption of strategic raw materials by 2030. Growing importance in the transition to a low-emission economy is attributed to cobalt (Co), which is an essential component both in the production of electric vehicles (EV), stationary energy storage and in the developing sectors of wind energy, fuel cell systems and hydrogen storage technolo)gies, robotics, unmanned vehicles (drones) and 3D printing as well as in digital technologies. Securing the supply of such raw material is crucial for the European Union’s economic resilience, technological advantage and strategic autonomy. The purpose of this article is to present and analyze the concept of value chains as strategic mo)dels of long-term development and ensuring efficiency from a sustainable perspective. According to the authors, a detailed analysis of value chains may enable defining strategic directions of action and identifying the risks of their disruption or interruption. To give a practical dimension to the presented analyses, the example of the cobalt value chain is provided and the determinants of its functioning on the current market along with development prospects are indicated. [ABSTRACT FROM AUTHOR]

The aim of this work was to encapsulate two drugs: 5-Fluorouracil (5-FU) with the hydrophobic properties and 5-Formyl-5,6,7,8-tetrahydropteroyl-L-glutamic acid calcium salt (leucovorin) with the hydrophilic properties into liposomes prepared by the modified reverse-phase evaporation method (mREV) from L-α-phosphatidylcholine dipalmitoyl (DPPC). The drugs are used in the anticancer multidrug therapy FLv (5-fluorouracil, leucovorin) and ELF (etoposide, leucovorin, 5-fluorouracil). We studied the competition for their encapsulation in liposomes by the use of two spectroscopies: 1H NMR and UV on the basis of the analysis of the signals of each drug in the liposome - drug system. Liposomes are highly versatile structures for research, therapeutic and analytical applications. We concluded that the liposomes obtained by the mREV method may transport more than one drug simultaneously. [ABSTRACT FROM AUTHOR]

Abstract: EPR spectroscopy was applied to determine the binding site of chloro(triethylphosphine)gold(I), (ClAuPEt3), in bovine serum albumin (BSA). The EPR spectrum of the spin marker covalently bonded to the sulphydryl group of polypeptide chain shows the presence of two 3-maleimidoPROXYL populations which differ in their way of immobilization. The first population shows the spin marker with a strongly restricted rotation due to hydrogen bonds between the oxygen of the label agent nitroxyl group and hydrogen atoms of the polypeptide chain with possible participation of water. The second population contains the spin marker bound with Cys-34 sulphydryl group located outside the crevice between helices h2 and h3, weakly immobilized by water hydrogen bonds. The addition of ClAuPEt3 results in the changes of the shape of spin labeled albumin EPR spectra. The displacement of 3-maleimidoPROXYL is observed below ClAuPEt3:BSA molar ratio 0.5:1. It is possible that above this molar ratio another bonding of the displaced spin marker takes place, having a high freedom of movement. EPR spectra, recorded after dialysis, show displacement of 3-maleimidoPROXYL molecules and the competition between AuPEt3 and the spin marker to the mutual binding site with cysteine residue. [Copyright &y& Elsevier]

Abstract: The aim of this work was to encapsulate two drugs: 1-β-d-arabinofuranosylcytosine (Ara-C) with the amphiphilic properties and 5-fluorouracil (5-FU) with the hydrophobic properties into liposomes prepared by the modified reverse-phase evaporation method (mREV) from l-α-phosphatidylcholine dipalmitoyl (DPPC). Both drugs are used together in the anticancer multidrug therapy. We studied the competition for their encapsulation in liposomes by the use of two spectroscopies: 1H NMR and UV on the basis of the analysis of the signals of each drug in the liposome–drug system. We concluded that the mREV method allows us to obtain liposomes which may transport more than one drug simultaneously. The NMR and UV studies of the drug competitive encapsulation and transport in liposomes formed from DPPC by the mREV method should be the basis for the analysis of the changes which may occur in vivo. [Copyright &y& Elsevier]

Abstract: Pathologic structure of albumin is present in blood of uremic or diabetic patients. The defective binding of albumin can cause, among others, inhibition of the metabolism of amphipathic hormones and the enhancement of the toxicity of drugs. We aim to show the alteration of the binding site of 6-propyl-2-thiouracil (PTU) in bovine serum albumin (BSA) in the presence of urea and guanidine hydrochloride. This study shows that PTU has the tendency to interact within the hydrophobic domain IIA or IB of serum albumin and to quench the fluorescence of tryptophanyl side chains by the static and collisional quenching mechanism. For the binding to the native protein, two classes of binding sites are seen. In the first one, the binding constant is equal to KbI−9.6×104 M−1, and in the second class, the binding constant is KbII−7.1×103 M−1. For the binding to the denaturated serum albumin, only one class of the binding sites can be observed. The binding constants for BSA denatured with urea and Gu·HCl are lower and are equal to 2.2×104 M−1 and 3.5×104 M−1, respectively. Evaluation of the binding ability of serum albumin is also important in case of older people because weaker drug–protein interaction can result in the increase of drug concentration in the blood serum. [Copyright &y& Elsevier]

This paper presents concepts of value chains as strategic models for long-term development and a sustainable approach for ensuring efficiency. It highlights the fact that value chains are of particular importance in the raw materials industry, where the exploration, extraction, processing and metallurgy stages are characterized by high capital expenditure and fixed costs. Additionally, it emphasizes that offering an increasingly valuable product at each stage of production or processing makes it possible to increase earnings and achieve a higher margin. In order to give a practical dimension to the presented analyses, the paper provides an example of lithium value chains and identifies the determinants of their functioning in the current market together with their prospects. The conclusion highlights Europe's need to source raw materials within business models based on value chains. [ABSTRACT FROM AUTHOR]

Properties of the polyurethane-rubber composites obtained from used products were studied. The influence of the amount of polyurethane glue and amount of isocyanate diphenylmethane 4,4′-diisocyanate (MDI) on composites selected properties was observed. The dynamic thermo-mechanical analysis allowed us to determine the glass transition temperature Tg and the course of the relaxation processes in the composites. The analysis of the changes in the storage module E′ and loss module E″as a function of temperature enabled the calculation of the activation energy for relaxation processes of various polyurethane glues and polyurethane-rubber composites. [ABSTRACT FROM AUTHOR]

Polymer materials packagings are quickly deposited in dumps due to the short life time as a useable product. Recycling of polymer waste, mainly polyolefines, which constitute 60% of them, on the technological lines operating according to the Polish technology seems to be a long-term solution. According to this technology, the used polymers after melting flow down to the reactor, where they undergo thermal degradation in the presence of catalyst. A product which can be processed in refineries for fuel is obtained. The studies leading to the improvement of the properties of the obtained product are still conducted. [ABSTRACT FROM AUTHOR]

The aim of this study is to encapsulate two drugs: 5-fluorouracil (5-FU) with the hydrophobic properties and 1-β-D-arabinofuranosylcytosine (Ara-C) with the amphiphilic properties into liposomes prepared by the modified reverse-phase evaporation method (mREV) from L-α-phosphatidylcholine dipalmitoyl (DPPC). We studied the thermotropic phase behavior of liposome entrapped 5-FU and Ara-C. It is known that the stability of liposomes depends not only on the method of chemical gradient loading, the use of membrane stabilizer such as sterols, but also on the phase transition temperature ( T) of phospholipids, which undergoes an alteration after encapsulation of drugs to liposomes. The competition of these two drugs entrapped in liposomes was analyzed by the use of two spectroscopies: H NMR and UV on the basis of the analysis of the signals of each drug in the liposome-drug system. The percent of encapsulation in DPPC/Ara-C/5-FU liposome obtained by the use of UV spectroscopy amounted 93.84 and 96.05% for 5-FU and Ara-C, respectively. Phase transition temperature T of liposomes containing Ara-C did not significantly change while for the liposomes containing 5-FU it increased in comparison with T of the reference liposomes formed from DPPC. [ABSTRACT FROM AUTHOR]

In this study waste polystyrene foam and virgin polystyrene as a reference materials were converted by chemical reactions under heterogeneous conditions into useful products. Polymeric flocculants were obtained from polystyrene during the sulfonation with sulfuric acid as the sulfonating agent and Ag2SO4 as the catalyst. The influence of temperature and time of reaction on the properties of the products were studied. The products were successfully used as flocculants in the treatment of the waste water. Solid silica sulfuric acid was also used to convert polystyrene. In comparison with the conventional sulfonation methods this sulfonating agent simplifies the reaction and makes easier separation of products from acid and solvent. The obtained products were cross-linked and exhibited cation-exchange properties. The batch method was used to study purification of solutions of Zn2+ and Cu2+ by the yielded resins. The performed study proved the usefulness of waste polystyrene derivatives for water treatment process. [ABSTRACT FROM AUTHOR]

The aim of the investigation was the dynamic thermo-mechanical analysis (DMTA) study of the polyurethane-rubber composites obtained from used polymer products. Polyols obtained in the glycolysis process from used semi-rigid polyurethane foams, hardened by diphenylmethane 4,4'-diisocyanate (MDI) and rubber granules obtained from mechanical granulation of used car tyres were used to receive polyurethane-rubber composites. On the basis of the DMTA spectra the glass transition temperature Tg was determined. The analysis of loss module E'' allowed us to observe two relaxation processes for polyurethane-waste rubber composites α - originating from the rubber and α' - from the polyurethane glue. The dependence of the changes of activation energy of relaxation processes with the change of weight ratio of polyurethane glue in polyurethane-waste rubber composites was observed. [ABSTRACT FROM AUTHOR]

Used polymer plastics have high fuel values (approximately 40 MJ/kg for polyolefines). Therefore, they constitute perfect energy materials. Thermodestruction of used products and wastes of polymer plastics on specialized installations seems to be a long-term method to manage this group of wastes in chemical recycling with the destination to obtain fuel ingredients. Application of this technology allows for reduction the quantity of municipal waste. This enables also to obtain the valuable fuel components. In the Department of Environment Chemistry and Technology of Institute of Chemistry at the University of Silesia and in enterprises using the installation for the thermodestruction of used polymer plastics it was studied influence of different catalyst on course of thermodestruction. According to an innovatory technology elaborated in the enterprise called “Speranda-1” Sp. z o.o. the dirty used products of polymer plastics and wastes after melting flow down to the bottom part of the reactor, where they undergo thermal degradation due to a contact with the catalyst. It was ascertained that type of catalyst influences the course of the primary and secondary destruction processes and is of fundamental importance for capacity of this process and for the composition of the obtained products. [ABSTRACT FROM AUTHOR]

The study of polymer properties requires the synthesis and analysis of simple model compounds. The aim of this work was the synthesis and investigation one of model compounds are needed to perform the physicochemical characteristics of linear, branched and dendrite polyesters. The description of relaxations processes of model oligoesters can make it easier to interpret the dependence between the useful properties of polyesters and the molecular structure of their macromolecules. Instrumental methods as NMR, FTIR and dielectric spectroscopy, calorimetry (DSC), thermogravimetric analysis and mechanical spectroscopy are used to this goal. The structure of the synthesized tetrakis(5-hydroxypentyl)piromelite (oligoester) was confirmed with the use of NMR, FTIR spectroscopy and elemental analysis. A detailed study of the relaxation properties using broadband dielectric spectroscopy and Dynamic Mechanical Thermal Analysis (DMTA) was also performed. A description of different dielectric and DMTA α-relaxation processes for the oligoester are indispensable to determine the relaxation properties of the suitable polyesters. For the synthesized oligoester glass temperature (Tg), relaxation time (τ) and activation energy (Ea) were determined from the results of DSC, DMTA and dielectric spectroscopy. [ABSTRACT FROM AUTHOR]

Waste-expanded polystyrene (EPS) and virgin polystyrene (VPS) were converted into ion exchangers by chemical modification. For this purpose, we used silica sulfuric acid as the sulfonating agent and conducted sulfonation under heterogeneous conditions. For VPS, the influence of the quantity of the sulfonating agent, the temperature, and the reaction time on the product properties were studied. As it appeared, silica sulfuric acid simplifies the reaction in comparison with the conventional sulfonation methods. Fourier transform-infrared (FT-IR) spectra and elemental analysis revealed that products were cross-linked and the content of sulfonate groups in a polymer chain varied. Some of the yielded polymers exhibited good water absorption and cation-exchange properties. The ion-exchange capacity (IEC) for chosen products was also determined, and it turned out to be similar to the commercial resin. The batch method was used to study the purification of solutions of Zn2+ and Cu2+ by the obtained resins. The performed study proved the usefulness of waste PS derivatives for the water treatment process. [ABSTRACT FROM AUTHOR]

Transmission electron micrographs (TEM) showed that liposome vesicles prepared from DL-α-phosphatidylcholine dimyristoyl (1,2-ditetradecanoyl-rac-glycerol-3-phosphocholine) (DMPC) by the modified reverse-phase evaporation method (mREV) were spherical in shape and in majority of them were less than 100 nm in diameter. Differential scanning calorimetry (DSC) method was used to determine the influence of cholesterol content and pH of Tris-HCl buffer used for the preparation of liposomes on the temperature of phase transition T C of phospholipids which form the investigated liposome vesicles. The use of DSC method made it possible to determine not only the temperature of the main phase transition of phospholipids but also the temperature of the phospholipid phase transition from the tilted gel phase( L β′) to the ripple gel phase( P β′). The results were compared with those obtained with EPR study. EPR study was carried out in the temperature range from 284 to 310 K i.e. below and above the phase transition temperature T C of DMPC. On the basis of EPR spectra of spin marker 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) incorporated into the liposome, the values of parameters f were determined. Hence TEMPO can be used to observe the change in partition between aqueous and fluid lipid regions. The change in the relative values of f determined for DMPC as a function of temperature shows that this phospholipid undergoes a transition from a ‘gel phase’ to a lamellar smectic liquid crystalline phase in the presence of excess water. The EPR study of TEMPO allowed us to determine the transition temperature T C. The results were compared with those obtained with DSC method. [ABSTRACT FROM AUTHOR]

Some oligoesters were synthesized in order to study changes of the useful properties of hyper-branched unsaturated polyesters. The determination of the polymer relaxation properties allows for characterization of their structure. Useful properties of the polymers such as stability and persistence depend on their structure. The aim of the investigation was to obtain model oligoesters with low molecular weight and to study their properties by spectroscopic and the dynamic mechanical thermal analysis (DMTA) methods. The synthesis was performed with the use of ethylene glycol and the mixture of maleic anhydride and phthalic acid which allowed us to obtain linear unsaturated polyesters. The cross-linking process of synthesized model oligoesters was performed using styrene as a cross-linking agent. The NMR and IR spectroscopy and elemental analysis were used for the description of purity and the structure of the obtained products. Relaxation properties of the synthesized oligoesters, course of their cross-linking and relaxation properties of the cross-linked products were studied by DMTA methods. In the synthesized oligoesters and cross-linked products α and β-relaxation processes were observed. [ABSTRACT FROM AUTHOR]

Albumin, a major transporting protein in the blood, is the main target of modification that affects the binding of drugs to Sudlow's site I and II. These modification of serum protein moderates its physiological function, and works as a biomarker of some diseases. The main goal of the paper was to explain the possible alteration of human serum albumin binding properties induced by modifications such as glycation, oxidation and ageing, their origin, methods of evaluation and positive and negative meaning described by significant researchers. [ABSTRACT FROM AUTHOR]

Pathological states in the organism, e.g., renal or hepatic diseases, cataract, dysfunction of coronary artery, diabetes mellitus, and also intensive workout, induce the structural modification of proteins called molecular ageing or N-A isomerization. The aim of this study was to analyze the structural changes of serum albumin caused by alkaline ageing using absorption, spectrofluorescence, and circular dichroism spectroscopy. The N-A isomerization generates significant changes in bovine (BSA) and human (HSA) serum albumin subdomains--the greatest changes were observed close to the tryptophanyl (Trp) and tyrosyl (Tyr) residue regions while a smaller change was observed in phenyloalanine (Phe) environment. Moreover, the changes in the polarity of the Trp neighborhood as well as the impact of the ageing process on α-helix, β-sheet content, and albumin molecule rotation degree have been analyzed. Based on the spectrofluorescence study, the alterations in metoprolol binding affinity to the specific sites that increase the toxicity of the drug were investigated. [ABSTRACT FROM AUTHOR]

The degree of encapsulation of 5-fluorouracil (5-FU) and vinorelbine (VIN) to dipalmitoylphosphatidylcholine (DPPC) liposomes was estimated using UV-vis spectroscopy. The phase transition temperature was determined by the differential scanning calorimetry (DSC). 5-FU incorporates in more extend to liposomes than VIN and affects phase transition temperature of phospholipide forming liposomal membrane. There is only a slight influence of VIN on the 5-FU encapsulation in liposome vesicle while 5-FU affects significantly the VIN content in the liposome vesicles. The binding sites of VIN and 5-FU in HSA determined by fluorescence quenching method were confirmed by computer simulation. [ABSTRACT FROM AUTHOR]

The EPR spectroscopy was used to determine the structure and physicochemical properties of liposomes prepared from L-α-phosphatidylcholine dipalmitoyl (DPPC) by the modified reverse-phase evaporation method (mREV). EPR study was carried out in the temperature range from 297 K to 340 K i.e. below and above the phase transition temperature TC of DPPC. On the basis of EPR spectra of spin marker 2,2,6,6-tetramethyl-1-piperidinyloxy (TEMPO) incorporated into the liposome, the parameter f was determined. TEMPO dissolves easily in water and in the fluid lamellar smectic liquid-crystaline phase of lipid bilayer but is largely excluded from the solid, gel-phase. Thus TEMPO can be used to observe the change in the partition between aqueous and fluid lipid regions. The change in the relative value of f as a function of temperature for DPPC shows that, in the presence of water excess, this phospholipids undergoes a transition from a “gel phase” to a lamellar smectic liquid crystalline phase. On the basis of EPR spectra of spin marker 2-(3carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinloxyl (5-DOXYL) incorporated into liposome, the parameter a′N was determined. The isotropic 14N-hyperfine coupling constant a′N of nitroxide spin label depends on the local environmental polarity. The increase of a′N value reflects the rise of polarity of spin label environment. Temperature, cholesterol and pH dependent structural changes were also described. [ABSTRACT FROM AUTHOR]

The aim of the present work was to compare the concentration changes of polyaromatic hydrocarbons (PAH) and the course of humification processes during wastewater treatment. Studies of samples from a biological-mechanical wastewater treatment plant in Sosnowiec-Zagórze (Poland) were carded out. Determination of PAH was performed both for wastewater sludge and sludge water. Observations of the course of humification processes for humic acid fractions isolated from sludges were conducted. Analysis of PAH extracted from wastewaters and from sludge was performed by means of high-performance liquid chromatography. Investigations of humification processes were conducted by electron paramagnetic resonance and nuclear magnetic resonance methods. The elementary composition changes in the structure of the extracted humic acids were determined. It was found that polyaromatic hydrocarbons appear during the processes of humification. Their content in water decreased only after the process of sludge aeration; however, sludge water leaving the settlers was PAH-enriched. [ABSTRACT FROM AUTHOR]

Abstract: The EPR and NMR spectroscopy was used to determine the structure and physicochemical properties of liposomes prepared from dl-α-phosphatidylcholine dimyristoyl (1,2-ditetradecanoyl-rac-glycerol-3-phosphocholine) (DMPC) by the modified reverse-phase evaporation (mREV). EPR study was carried out in the temperature range from 284 to 310K, i.e. below and above the phase transition temperature T c of DMPC. On the basis of EPR spectra of spin marker 2-(carboxypropyl)-4,4-dimethyl-2-tridecyl-3-oxazolidinyloxyl (5-DOXYL) incorporated into liposome, the parameters S (empirical order parameter), 2A max (line widths) and τ (rotational correlation time) were determined. Temperature and pH dependent structural changes of liposome were also described. 31P NMR study of the liposome in the temperature range from 340 to 350K allowed to suggest that the single-bilayered liposome were obtained. [Copyright &y& Elsevier]

From the TG data of rubber granulates, different polyurethane and composites it can be seen that the thermal decomposition for the rubber granulate and all of the composites start above 520 K. Two major mass losses for the rubber granulates and majority of the composites were observed and thermal decomposition is essentially complete by ~820 K. The changes of activation energies of lower and higher temperature decomposition, calculated according to the different equations were observed for a priori assumed first-order reaction for devolatilisation. Differences between determined and calculated results could suggest a possible reaction between polyurethane agents and rubber granulate during the composites formations. [ABSTRACT FROM AUTHOR]

Abstract: One of the ways of polymer waste management is its chemical modification. Waste polystyrene foam (EPS) and virgin polystyrene (VPS) as a reference material were converted into polymeric flocculants by chemical reactions. Poly(styrene sulphonate) acids (EPSS and VPSS) were obtained from EPS and VPS during the sulphonation process with sulphuric acid as the sulphonating agent and Ag2SO4 as the catalyst. Products were precipitated in the form of sodium salt (NaEPSS, NaVPSS) in the reaction with Na2CO3. The influence of temperature and the time of reaction on the properties of the products were studied. Products with determined molecular weight and number of sulphonic group per monomer units were divided into several fractions by fractional precipitation with 0.5M aqueous NaOH as the solvent and 2-propanol as the precipitant. The products were successfully used as flocculants in the treatment of the waste water discharge model colloid system, iron (III) hydroxide, which is comparable with industrial waste and water from mining companies and galvanising plants. The application of the obtained products caused a significant decrease in turbidity of the studied solutions. It was also found that the effectiveness of the flocculation depends on the number of sulphonic groups per monomer unit and the molecular weight of the polyelectrolytes. [Copyright &y& Elsevier]