Szczotki polimerowe jako materiały funkcjonalne.

W pracy omówiono problemy badawcze odnoszące się do syntezy i właściwości szczotek polimerowych o zróżnicowanej topologii pojedynczej molekuły, wynikającej z geometrii zastosowanego inicjatora. Powyższe materiały otrzymano metodą polimeryzacji rodnikowej z przeniesieniem atomu (ATRP), stosując jako inicjatory odpowiednio liniowe polimery, płaskie powierzchnie oraz sferyczne cząstki.In this thesis, the topics, related to the synthesis and properties of polymer brushes with different single molecule topology resulting from the varied initiators used, have been discussed. Polymer brushes were synthesized by atom transfer radical polymerization (ATRP) using linear, flat and spherical particles with covalently anchored ATRP initiators, respectively

Sustainable polyhydroxyalkanoate production from food waste via Bacillus mycoides ICRI89: Enhanced 3D printing with poly (methyl methacrylate) blend

ABSTRACT: In view of implementing green technologies for bioplastic turning polices, novel durable feedstock for Bacillus mycoides ICRI89 used for efficient polyhydroxybutyrate (PHB) generation is proposed herein. First, two food waste (FW) pretreatment methods were compared, where the ultrasonication approach for 7 min was effective in easing the following enzymatic action. After treatment with a mixture of cellulase/amylases, an impressive 25.3 ± 0.22 g/L of glucose was liberated per 50 g of FW. Furthermore, a notable 2.11 ± 0.06 g/L PHB and 3.56 ± 0.11 g/L cell dry eight (CDW) over 120 h were generated, representing a productivity percentage of 59.3 wt% using 25% FW hydrolysate. The blend of polyhydroxybutyrate/poly (methyl methacrylate) (PHB/PMMA = 1:2) possessed the most satisfactory mechanical properties. For the first time, PHB was chemically crosslinked with PMMA using dicumyl peroxide (DCP), where a concentration of 0.3 wt% had a considerable effect on increasing the mechanical stability of the blend. FTIR analysis confirmed the molecular interaction between PHB and PMMA showing a modest expansion of the C=O stretching vibration at 1725 cm⁻¹. The DCP-PHB/PMMA blend had significant thermal stability and biodegradation profiles comparable to those of the main constituent polymers. More importantly, a 3-Dimetional (3D) filament was successfully extruded with a diameter of 1.75 mm, where no blockages or air bubbles were noticed via SEM. A new PHB/PMMA “key of life” 3D model has been printed with a filling percentage of 60% and a short printing time of 19.2 min. To conclude, high-performance polymeric 3D models have been fabricated to meet the pressing demands for future applications of sustainable polymers

Impact of ionic liquids on the processing and photo-actuation behavior of SBR composites containing graphene nanoplatelets

The effects of butylpyridinium bromide-based ionic liquids (ILs) on the vulcanization kinetics, mechanical properties and photo-actuation ability of styrene-butadiene rubber (SBR) composites filled with graphene nanoplatelets (GnPs) were investigated. Two different ILs, 1-butylpyridinium bromide (BBP) and 4-methyl-1-butylpyridinium bromide (BMBP), were introduced into rubber compounds. The methodology of IL incorporation into the rubber compounds was studied as well. The ILs were added either directly as a single component or after immobilization onto the GnPs surface. High values of the modulus and tensile strength, which are important mechanical properties, were observed for the composites filled with immobilized BMBP. Freely dispersed BBP resulted in composites with the fastest scorch time, highest thermal and electrical conductivity, and best photo-actuation response of 0.230 mm. © 2020 The AuthorsMinistry of Education, Youth and Sports of the Czech republic - DKRVO [RP/CPS/2020/003]; National Science Centre, Poland through POLONEZ project [UMO-2016/23/P/ST5/02131]; European Unions's Horizon 2020 research and innovation program under Marie Sklodowska -Curie [665778]; Qatar University [QUCGCAM-19/20-2

X-ray and thermal analysis of selected drugs containing acetaminophen

Studies carried out by X-ray and thermal analysis confirmed that acetaminophen (paracetamol), declared by the manufacturers as an Active Pharmaceutical Ingredient (API), was present in all studied medicinal drugs. Positions of diffraction lines (2θ angles) of the studied drugs were consistent with standards for acetaminophen, available in the ICDD PDF database Release 2008.ID2θI values were lower than 0.2°, confirming the authenticity of the studied drugs. Also, the values of interplanar distances dhkl for the examined samples were consistent with those present in the ICDD. Presence of acetaminophen crystalising in the monoclinic system (form I) was confirmed. Various line intensities for API were observed in the obtained diffraction patterns, indicating presence of the preferred orientation of the crystallites in the examined samples. Thermal analysis of the studied substances confirmed the results obtained by X-ray analysis. Drugs containing only acetaminophen as an API have melting point close to that of pure acetaminophen. It was found that presence of other active and auxiliary substances affected the shapes and positions of endothermal peaks significantly. A broadening of endothermal peaks and their shift towards lower temperatures were observed accompanying an increase in the contents of additional substances being “impurities” in relation to the API. The results obtained by a combination of the two methods, X-ray powder diffraction (XRPD) and differential scanning calorimetry/thermogravimetry (DSC/TGA), may be useful in determination of abnormalities which can occur in pharmaceutical preparations, e.g., for distinguishing original drugs and forged products, detection of the presence of a proper polymorphic form or too low content of the active substance in the investigated drug

From brush to dendritic structure: Tool for tunable interfacial compatibility between the iron-based particles and silicone oil in magnetorheological fluids

Comprehensive magnetic particle stability together with compatibility between them and liquid medium (silicone oil) is still a crucial issue in the case of magnetorheological (MR) suspensions to guarantee their overall stability and MR performance. Therefore, this study is aimed at improving the interfacial stability between the carbonyl iron (CI) particles and silicone oil. In this respect, the particles were modified with polymer brushes and dendritic structures of poly(2-(trimethylsilyloxy)ethyl methacrylate) (PHEMATMS), called CI-brushes or CI-dendrites, respectively, and their stability properties (corrosion, thermo-oxidation, and sedimentation) were compared to neat CI ones. Compatibility of the obtained particles and silicone oil was investigated using contact angle and off-state viscosity investigation. Finally, the magneto-responsive capabilities in terms of yield stress and reproducibility of the MR phenomenon were thoroughly investigated. It was found that MR suspensions based on CI-brushes had significantly improved compatibility properties than those of neat CI ones; however, the CI-dendrites-based suspension possessed the best capabilities, while the MR performance was negligibly suppressed.Ministerstvo Školství, Mládeže a Tělovýchovy, MŠMT, (RP/CPS/2022/003); Grantová Agentura České Republiky, GA ČR, (23-07244S); Narodowa Agencja Wymiany Akademickiej, NAWA, (PPM/ULM/2019/1/00102

The usefulness of X-ray diffraction and thermal analysis to study dietary supplements containing iron

X-ray powder diffraction (XRPD) and thermal analysis (differential scanning calorimetry/ derivative of thermogravimetry (DSC/DTG)) are solid-state techniques that can be successfully used to identify and quantify various chemical compounds in polycrystalline mixtures, such as dietary supplements or drugs. In this work, 31 dietary supplements available on the Polish market that contain iron compounds, namely iron gluconate, fumarate, bisglycinate, citrate and pyrophosphate, were evaluated. The aim of the work was to identify iron compounds declared by the manufacturer as food supplements and to try to verify compliance with the manufacturer’s claims. Studies performed by X-ray and thermal analysis confirmed that crystalline iron compounds (iron (II) gluconate, iron (II) fumarate), declared by the manufacturers, were present in the investigated dietary supplements. Iron (II) bisglycinate proved to be semi-crystalline. However, depending on the composition of the formulation, it was possible to identify this compound in the tested supplements. For amorphous iron compounds (iron (III) citrate and iron (III) pyrophosphate), the diffraction pattern does not have characteristic diffraction lines. Food supplements containing crystalline iron compounds have a melting point close to the melting point of pure iron compounds. The presence of excipients was found to affect the shapes and positions of the endothermic peaks significantly. Widening of endothermic peaks and changes in their position were observed, as well as exothermic peaks indicating crystallization of amorphous compounds. Weight loss was determined for all dietary supplements tested. Analysis of the DTG curves showed that the thermal decomposition of most food supplements takes place in several steps. The results obtained by a combination of both simple, relatively fast and reliable XRPD and DSC/DTG methods are helpful in determining phase composition, pharmaceutical abnormalities or by detecting the presence of the correct polymorphic form

The effect of short polystyrene brushes grafted from graphene oxide on the behavior of miscible PMMA/SAN blends

A new concept of utilization of particle-polymer hybrids as multifunctional additives for polymer blends was introduced in this study. Graphene oxide particles with short densely grafted polystyrene brushes (GO-g-PS) were prepared by surface-initiated atom transfer radical polymerization (SI-ATRP). Melt rheology studies revealed that GO-g-PS suppressed the phase separation of miscible poly(methyl methacrylate)/poly(styrene-co-acrylonitrile) (PMMA/SAN) blends. The studies suggested specific interactions of GO-g-PS with the PMMA phase and this was confirmed based on calculations of activation energies of segmental relaxations by broadband dielectric spectroscopy (BDS). These unusual interactions of GO-g-PS with PMMA phase were assigned to the specific and precise architecture of the GO-g-PS particles as well as chemical nature of PS polymer brushes. The short chains of PMMA and PS provide miscibility originating from UCST behavior of PMMA/PS blend of short polymer chains. Additionally, BDS also revealed improved charge transport in PMMA/SAN blend in presence of GO-g-PS hybrid. © 2020 Elsevier LtdAction Austria - Slovakia, Co-operation in Science and Education program [56337]; National Science Centre, PolandNational Science Center, PolandNational Science Centre, Poland [UMO-2016/23/P/ST5/02131]; European Unions' Horizon 2020 research and innovation program under Marie Sklodowska-Curie grant [665778]; Research & Innovation Operational Programme - ERDF [313021T081]; project VEGAVedecka grantova agentura MSVVaS SR a SAV (VEGA) [2/0129/19]; Technology Agency of the CR [TN01000008]; Ministry of Education, Youth and Sports of the Czech Republic - DKRVO [RP/CPS/2020/003

Znaczenie przetrwałego otworu owalnego u pacjenta kwalifikowanego do zabiegu ortotopowego przeszczepienia wątroby

Persistent foramen ovale (PFO) is a congenital defect of interatrial septum, that in majority of patients stays asymptomatic. However, in conditions that lead to increased pressure in right atrium over left atrium, it may lead to blood shunt from the right to the left atrium. We are presenting a case report of 63-years-old male who was referred to the qualification for the orthotopic liver transplantation due to the decompensated liver cirrhosis. During transesophageal echocardiography with contrast PFO was detected. In the literature cases suggesting increased perioperative risk in patients with PFO are described. It is both related to air embolisms connected with the transplantation itself and possibility of crossed embolisms. For this reason, the patient was scheduled to the transcatheter PFO closure, after which he could have liver transplantation. The operation was performed a month later, uneventfully.Przetrwały otwór owalny (PFO) to wrodzona wada przegrody międzyprzedsionkowej, która w większości przypadków nie ujawnia się klinicznie. Jednak w warunkach doprowadzających do przewyższenia wartości ciśnienia w prawym przedsionku nad lewym przedsionkiem może stanowić przyczynę przecieku prawo-lewego. W artykule przedstawiono przypadek 63-letniego mężczyzny ze schyłkową niewydolnością wątroby marskiej, kwalifikowanego do zabiegu ortotopowego przeszczepienia wątroby. U pacjenta podczas przezprzełykowego badania echokardiograficznego z użyciem kontrastu stwierdzono PFO. W literaturze istnieją opisy przypadków sugerujące podwyższone ryzyko okołooperacyjne w grupie pacjentów z PFO, które ma wynikać z ryzyka powstawania zatorów powietrznych podczas transplantacji wątroby, jak i, dodatkowo, z możliwości powstania zatorów skrzyżowanych przez PFO. Z tego powodu podjęto decyzję o przezskórnym zamknięciu PFO przed planowanym przeszczepieniem. Po wykonanym zabiegu pacjenta zakwalifikowano do operacji transplantacji wątroby, która odbyła bez powikłań, miesiąc po zamknięciu ubytku

Novel multicomponent titanate-germanate glasses : synthesis, structure, properties, transition metal, and rare earth doping

Novel multicomponent titanate-germanate glasses singly doped with transition metal (Cr3+) and rare earth ions (Eu3+) were synthesized and the glass transition temperatures and thermal stability parameters were determined using DSC measurements. X-ray di raction analysis confirmed fully amorphous nature of the received samples. Their structural and optical properties were compared with germanate glasses without TiO2. Correlation between local structure and optical properties in titanate-germanate glasses is well evidenced by FT-IR, Raman, EPR, and luminescence spectroscopy. In particular, luminescence spectra and their decays are examined for glass samples, where GeO2 was partially substituted by TiO2

Effect of structure of polymers grafted from graphene oxide on the compatibility of particles with a silicone-based environment and the stimuli-responsive capabilities of their composites

This study reports the utilization of controlled radical polymerization as a tool for controlling the stimuli-responsive capabilities of graphene oxide (GO) based hybrid systems. Various polymer brushes with controlled molecular weight and narrow molecular weight distribution were grafted from the GO surface by surface-initiated atom transfer radical polymerization (SI-ATRP). The modification of GO with poly(n-butyl methacrylate) (PBMA), poly(glycidyl methacrylate) (PGMA), poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) and poly(methyl methacrylate) (PMMA) was confirmed by thermogravimetric analysis (TGA) coupled with online Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Various grafting densities of GO-based materials were investigated, and conductivity was elucidated using a four-point probe method. Raman shift and XPS were used to confirm the reduction of surface properties of the GO particles during SI-ATRP. The contact angle measurements indicated the changes in the compatibility of GOs with silicone oil, depending on the structure of the grafted polymer chains. The compatibility of the GOs with poly(dimethylsiloxane) was also investigated using steady shear rheology. The tunability of the electrorheological, as well as the photo-actuation capability, was investigated. It was shown that in addition to the modification of conductivity, the dipole moment of the pendant groups of the grafted polymer chains also plays an important role in the electrorheological (ER) performance. The compatibility of the particles with the polymer matrix, and thus proper particles dispersibility, is the most important factor for the photo-actuation efficiency. The plasticizing effect of the GO-polymer hybrid filler also has a crucial impact on the matrix stiffness and thus the ability to reversibly respond to the external light stimulation.Grant Agency of the Czech RepublicGrant Agency of the Czech Republic [16-20361Y]; Ministry of Education, Youth and Sports of the Czech Republic program NPU I [LO1504]; Research & Innovation Operational Programme - ERDF [313021T081]; project VEGAVedecka grantova agentura MSVVaS SR a SAV (VEGA) [2/0129/19]; European UnionEuropean Union (EU) [CZ.02.2.69/0.0/0.0/16_027/0008464]; Operational Program Research and Development for innovations; European Regional Development Fund (ERDF)European Union (EU); national budget of Czech Republic within project CPS -strengthening research capacity [CZ.1.05/2.1.00/19.0409]; National Science Centre, Poland [UMO-2016/23/P/ST5/02131]; European Unions' Horizon 2020 research and innovation programme under Marie Sklodowska-Curie grant [665778