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Phosphorus-containing polymers are very promising because of the versatility of their applications. Polyphosphates and polyphosphonates are well-known for their excellent fire-retardant properties. In this work, a cotton fabric was grafted by oxygen-tolerant photochemically induced atom transfer radical polymerization (photoATRP) of dimethyl(methacryloyloxymethyl) phosphonate (MAPC1) in order to prepare flame resistant fabric. The photoATRP of MAPC1 was first optimized in solution and subsequently used for surface-initiated polymerization from of cotton fabric pre-functionalized by ATRP initiator in order to achieve PMAPC1 brushes onto the surface. The modified cotton fabrics were characterized by attenuated total reflection–Fourier transforms infrared spectroscopy and X-ray photoelectron spectroscopy to prove successful grafting. Minimal effect of grafting on mechanical properties of the cotton fabric was confirmed by tensile tests. The thermal properties and flammability of the modified fabric were tested by thermogravimetric analysis, horizontal and vertical flame tests. Limiting oxygen index and microscale cone calorimeter were performed as well. The results show that modified fabric has a high flame resistance making it a good candidate for flame-retardant application. Washing tests confirmed that the grafted layer on the fabric has good durability from the point of view of retention of high flame resistance.

Carbon nanotube (CNT)-based materials allow for the direct conversion of light into heat and then into mechanical force in the so-called photo-mechanical effect. This effect has been observed almos...

A modification of the cotton fabric surface using surface-initiated oxygen-tolerant photochemically induced atom transfer radical polymerization (SI-photoATRP) of 2-(dimethylamino)ethyl methacrylate (DMAEMA) with subsequent quaternization to impart antibacterial properties is reported. First, the photoATRP of DMAEMA was optimized by investigating the effect of reaction conditions on the control of polymerization kinetics and molecular characteristics of poly(2-(dimethylamino)ethyl methacrylate) (PDMAMEA). Subsequently, the optimized conditions were applied for surface modification of cotton fabric pre-functionalized with an ATRP initiator. Cotton-grafted-PDMAEMA (cell-g-PDMAEMA) with different grafting yields was produced and reacted with benzyl bromide to obtain quaternized-grafted cotton fabric (cell-g-QPDMAEMA), which has an antibacterial function. The structure and morphology of cell-Br, cell-g-PDMAEMA, and cell-g-QPDMAEMA have been characterized by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and scanning electron microscopy. The quaternized-grafted cotton fabric showed high antibacterial efficiency and a good laundry resistance, while the mechanical properties of the modified fabrics did not deteriorate dramatically by the surface modification.

A concept initially intended for mechanically controlled atom transfer radical polymerization (hereinafter referred to as “mechano-ATRP”) was extended in order to modify magnetic nanoparticles (NPs) with poly(methyl acrylate) (PMA) grafts, resulting in NPs@PMA hybrids which served as efficient additives in magnetorheological (MR) suspensions. In a novel procedure, magnetic NPs with an ATRP initiator anchored on their surfaces were added into a mechano-ATRP mixture, bringing about surface-initiated growth of the PMA chains after exposure to ultrasonication (35 kHz, 45 °C). The reaction proceeded with low concentration (at hundreds of “ppm”) of the CuBr2 catalyst, thereby providing the PMA chains with low dispersity of molar masses and high monomer conversions. Investigation was conducted as to the effect of hexagonal micro-ZnO and cubic-phase BaTiO3 piezoelectric transducers on the feasibility of the process. The presence of PMA on the surfaces of NPs@PMA hybrids was proven by infra-red spectroscopy, as well as thermal and magnetization analyses. The NPs@PMA hybrids were subsequently applied as additives to fabricate a bidisperse MR suspension, in which they unexpectedly enhanced accessible shear stress and yield stress values by up to ∼840 Pa under a magnetic field (of up to 432 kA m−1). Notably, the MR suspension supplemented with the NPs@PMA hybrids synthesized by mechano-ATRP exhibited no sign of sedimentation when left undisturbed for 2 days, although sedimentation of the reference sample occurred within a few hours. Such enhancements were attributed to the effects of friction, formation of a 3D gel-like network and the reduced density of the NPs@PMA hybrids.

The alumina wafer pre-annealed in dry air manifests chemiresistive behaviour: the electrical resistivity is highly sensitive to trace concentrations of acetone vapours even at room temperature. The response suggests that the alumina can be applicable in the role of a room-temperature operated acetone sensor in the ppm range. The elemental analysis of the alumina surface suggests that the sensing mechanism is governed by interaction of adsorbed acetone molecules with alkaline impurities such as sodium and/or magnesium ions naturally occurring in the α-Al2O3.

2-Isopropenyl-2-oxazoline (IPOx) is an important double functional monomer with multiple potential applications. However, until now, the attempts at reversible-deactivation radical polymerization (...

Electrically conductive materials that are fabricated based on natural polymers have seen significant interest in numerous applications, especially when advanced properties such as self-healing are introduced. In this article review, the hydrogels that are based on natural polymers containing electrically conductive medium were covered, while both irreversible and reversible cross-links are presented. Among the conductive media, a special focus was put on conductive polymers, such as polyaniline, polypyrrole, polyacetylene, and polythiophenes, which can be potentially synthesized from renewable resources. Preparation methods of the conductive irreversible hydrogels that are based on these conductive polymers were reported observing their electrical conductivity values by Siemens per centimeter (S/cm). Additionally, the self-healing systems that were already applied or applicable in electrically conductive hydrogels that are based on natural polymers were presented and classified based on non-covalent or covalent cross-links. The real-time healing, mechanical stability, and electrically conductive values were highlighted.

Engineered nanoparticles (ENPs) have potential application in precision farming and sustainable agriculture. Studies have shown that ENPs enhance the efficiency of the delivery of agrochemicals and thus, have the potential to positively affect the environment, thereby improving the growth and health of the crops. However, the majority of the research on the effects of ENPs on plants and in agricultural applications have been limited to controlled laboratory conditions. These conditions do not fully consider various aspects inherent to the growth of agricultural plants in fields under changing weather and climate. Some of the most investigated ENPs in the agricultural research area are ZnO nanoparticles (ZnO NPs) and TiO2 nanoparticles (TiO2 NPs). ZnO NPs have the potential to increase crop production and stress resistance, mainly by the slow release of Zn ions to crops. Unlike ZnO NPs, TiO2 NPs have less well-understood means of action, and are generally considered as plant growth promoter. This mini review presents information compiled for ZnO and TiO2 NPs, their influence on agricultural plants with emphasis on particularly effect on plant growth, nutrient distribution and pollution remediation under field conditions. It is concluded that in order to gain a broader perspective, more field studies are needed, particularly multigeneration studies, to fully understand the effects of the ENPs on agricultural plants’ growth and improvement of their health.

From environmental aspects, the recovery of keratin waste is one of the important needs and therefore also one of the current topics of many research groups. Here, the keratin hydrolysate after basic hydrolysis was used as a filler in plasticized polylactic acid/poly(3-hydroxybutyrate) blend under loading in the range of 1–20 wt%. The composites were characterized by infrared spectroscopy, and the effect of keratin on changes in molar masses of matrices during processing was investigated using gel permeation chromatography (GPC). Thermal properties of the composites were investigated using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The effect of keratin loading on the mechanical properties of composite was investigated by tensile test and dynamic mechanical thermal analysis. Hydrolytic degradation of matrices and composites was investigated by the determination of extractable product amounts, GPC, DSC and NMR. Finally, microbial growth and degradation were investigated. It was found that incorporation of keratin in plasticized PLA/PHB blend provides material with good thermal and mechanical properties and improved degradation under common environmental conditions, indicating its possible application in agriculture and/or packaging.

From the environmental point of view, there is high demand for the preparation of polymeric materials for various applications from renewable and/or waste sources. New lignin-based spun fibers were produced, characterized, and probed for use in methylene blue (MB) dye removal in this study. The lignin was extracted from palm fronds (PF) and banana bunch (BB) feedstock using catalytic organosolv treatment. Different polymer concentrations of either a plasticized blend of renewable polymers such as polylactic acid/polyhydroxybutyrate blend (PLA-PHB-ATBC) or polyethylene terephthalate (PET) as a potential waste material were used as matrices to generate lignin-based fibers by the electrospinning technique. The samples with the best fiber morphologies were further modified after iodine handling to ameliorate and expedite the thermostabilization process. To investigate the adsorption of MB dye from aqueous solution, two approaches of fiber modification were utilized. First, electrospun fibers were carbonized at 500 °C with aim of generating lignin-based carbon fibers with a smooth appearance. The second method used an in situ oxidative chemical polymerization of m-toluidine monomer to modify electrospun fibers, which were then nominated by hybrid composites. SEM, TGA, FT-IR, BET, elemental analysis, and tensile measurements were employed to evaluate the composition, morphology, and characteristics of manufactured fibers. The hybrid composite formed from an OBBL/PET fiber mat has been shown to be a promising adsorbent material with a capacity of 9 mg/g for MB dye removal.

The study demonstrates that resistivity of an alumina wafer is highly sensitive to trace concentrations of acetone vapors at room temperature. Though, a thermal pretreatment is necessary to precede the room-temperature sensing of acetone vapors, whilst the sensitiveness increases with the pretreatment temperature. This advocates the alumina being suitable for an adequate acetone sensor in the ppm range. A plausible mechanism of the response is discussed.

Series of superabsorbent hydrogels derived from renewable α-methylene-γ-butyrolactone (MBL), known as a Tulipalin A, was prepared and examined with respect on their swelling properties and stimuli responsive character. Hydrogels were synthesized by copolymerization of either sodium or potassium 4-hydroxy-2-methylenebutanoate, products resulted from saponification of MBL, with acrylamide in the presence of N,N′-methylenebis(acrylamide) as cross-linker. Hydrogels with various comonomers composition, feed monomers content and variable cross-linking density represent materials with highly tunable characteristics. The effect of temperature, pH and ionic strength of solutions on swelling behavior of the hydrogels was examined. Reversible swelling character of hydrogels in buffer and water was proved as well. Experiments demonstrated reversible ability of hydrogels to swell upon immersing to ultrapure water and deswell in buffer solution.

Changes in mechanical and thermal properties of biodegradable mulches based on plasticized PLA/PHB filled with 3 wt% of carbon black were investigated during natural ageing in real soil environments after application for one season. The natural ageing process changes were evaluated under three different conditions of the mulching films: (a) buried in the soil, (b) exposed to sunlight, and (c) shadowed by plants. In a parallel study, the film was irradiated by a UV–Vis lamp under laboratory controlled test conditions at constant temperature and humidity. All samples were analyzed using GPC, DSC, DMTA and tensile tests. The plasticized PLA/PHB/CB film buried in soil lost its tensile properties faster than when shadowed by plants or exposed to sunlight. The deterioration of mechanical properties during degradation resulted in significant decreases elongation at break, while Young’s modulus values and tensile stress increased. Assessment of the mulching effect on the harvest of sweet pepper fruits, as well as carotenoids and vitamin C contents, was also performed. The obtained results showed that plasticized PLA/PHB/CB film has the potential for application for one season mulches.

Surface-initiated atom transfer radical polymerization (SI-ATRP) was used to modify graphene oxide (GO) particles with poly(butyl methacrylate) (PBMA) chains. This procedure facilitated the single-step fabrication of a hybrid material with tailored conductivity for the preparation of a suspension in silicone oil with enhanced sedimentation stability and improved electrorheological (ER) activity. PBMA was characterized using various techniques, such as gel permeation chromatography (GPC) and 1H NMR spectroscopy. Thermogravimetric analysis through on-line investigation of the Fourier transform infrared spectra, together with transmission electron microscopy, X-ray photoelectron microscopy, and atomic force microscopy, were successfully used to confirm GO surface modification. The ER performance was investigated using optical microscopy images and steady shear rheometry, and the mechanism of the internal chain-like structure formation was elucidated. The dielectric properties confirmed enhanced ER performance owing to an increase in relaxation strength to 1.36 and decrease in relaxation time to 5 × 10−3 s. The compatibility between GO and silicone oil was significantly influenced by covalently bonded PBMA polymer brushes on the GO surface, showing enhanced compatibility with silicone oil, which resulted in the considerably improved sedimentation stability. Furthermore, a controlled degree of reduction of the GO surface ensured that the suspension had improved ER properties.

Well-defined poly(methyl acrylate) (PMA) and poly(n-butyl acrylate) (PBA) are prepared via photochemically induced atom transfer radical polymerization (photoATRP) using ppm amounts of CuBr2/tris[2-(dimethylamino)ethyl]amine (Me6TREN) catalyst complex without degassing of the polymerization mixture. The effect of light intensity and partial replacement of the excess of expensive Me6TREN ligand with cheaper tertiary amines on kinetics of the polymerization was investigated in various solvents. The addition of triethylamine to photoATRP system resulted in both significant shortening the induction period and increasing the polymerization rate. High livingness of the oxygen tolerant photoATRP system containing triethylamine was proved by chain-extension polymerizations resulting in formation of PMA-b-PBA copolymer. The presented photoATRP system can have tremendous importance from an industrial point of view since the well-defined polyacrylates can be prepared almost without any induction period and in short polymerization time without necessity of both air removal and using the excess of expensive ligand.

The conducting polymer poly(2-(1H-pyrrole-1-yl)ethyl methacrylate (PPEMA) was synthesized by conventional atom transfer radical polymerization for the first time from free as well as surface-bonded alkyl bromide initiator. When grafted from the surface of carbonyl iron (CI) a substantial conducting shell on the magnetic core was obtained. Synthesis of the monomer as well as its polymer was confirmed using proton spectrum nuclear magnetic resonance (H-1 NMR). Polymers with various molar masses and low dispersity showed the variability of this approach, providing a system with a tailorable structure and brush-like morphology. Successful grafting from the CI surface was elucidate by transmission electron microscopy and Fourier-transform infrared spectroscopy. Very importantly, thanks to the targeted nanometer-scale shell thickness of the PPEMA coating, the magnetization properties of the particles were negligibly affected, as confirmed using vibration sample magnetometry. Smart elastomers (SE) consisting of bare CI or CI grafted with PPEMA chains (CI-PPEMA) and silicone elastomer were prepared and dynamic mechanical properties as well as interference shielding ones were investigated. It was found that short polymer chains grafted to the CI particles exhibited the plasticizing effect, which might be interesting from the magnetorheological point of view, and more interestingly, in comparison to the neat CI-based sample, it provided enhanced electromagnetic shielding of nearly 30 dB in thickness of 500 mu m. Thus, SE containing the newly synthesized CI-PPEMA hybrid particles also exhibited considerably enhanced damping factor and proper mechanical performance, which make the material highly promising from various practical application points of view., Ministry of Education, Youth and Sports of the Czech Republic-DKRVO [RP/CPS/2022/003]; Internal Grant Agency of Tomas Bata University in Zlin [IGA/CPS/2021/003]; Integrated Infrastructure Operational Programme - ERDF [313021T081]; Slovak Research and Development Agency [APVV-19-0338]; Slovak Grant Agency VEGA [2/0129/19]; Qatar University Grant [QUCG-CAM-22/23-504], RP/CPS/2022/003; Slovenská Akadémia Vied, SAV: 313021T081; Tomas Bata University in Zlin, TBU: IGA/CPS/2021/003; Qatar University, QU: QUCG-CAM-22/23-504; Agentúra na Podporu Výskumu a Vývoja, APVV: APVV-19-0338; Vedecká Grantová Agentúra MŠVVaŠ SR a SAV, VEGA: 2/0129/19; European Regional Development Fund, ERDF

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.

Synthesis of a new family of polymers having a polydisulfide structure can be conducted from sulfobetaine-based derivative of natural (R)-lipoic acid. A polydisulfide backbone of polymer can be depolymerized by response to external stimuli and sulfobetaine pendant groups ensure the upper critical solution temperature (UCST) behaviour temperatures that can be modulated according to the nature of the solvent and concentration.Sulfobetaine-bearing polydisulfides were synthesized from dithiolane derivatives and then characterized. UCST behavior of the polymers in water and in mixtures containing different alcohols (methanol, ethanol, isopropanol) was investigated. The regeneration of monomers from the polymers in response to external stimuli was examined using UV-vis and circular dichroism (CD) spectroscopy. Tunable surface wettability were shown on the grafted polymers.Decreasing polarity and/or increasing alcohol percentage in the water mixtures induced an increase in the cloud points of the polymers in the solutions. Thermoresponsive behaviour were repeatable and fully reversible with negligible hysteresis from aggregate to unimer state. The regeneration of monomers by depolymerization was tunable by temperature and sunlight. A thickness dependence on surface wettability was observed on wafers covalently modified with polydisulfides. This is the first report of sulfobetaine-based polydisulfides showing tunable UCST behavior and surface wettability.

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]

This paper reports the utilization of the controllable coating via SI-ATRP technique as a promising approach for controlling stimuli-responsive capabilities of graphene oxide (GO) based nanocomposites. Various polymer brushes with controlled molar mass and narrow dispersity were grown from the surface of GO particles. Modification of GO with poly(methyl methacrylate) and poly(n-butyl methacrylate) was proved by transmission electron microscopy, thermogravimetric analysis with online FTIR recording and finally by X-ray photoelectron spectroscopy (XPS). Densities of GO-based materials were investigated and conductivity measurements showed the increase values. XPS and Raman shift was used to confirm the GO particles reduction. A compatibility of the filler with propylene-based elastomer was elucidated by melt rheology. The light-induced actuation capability was investigated on composite samples to show, that polymer hybrid particles based on GO have better compatibility with the polymer matrix and thus their proper dispersibility was significantly improved. In addition the plasticizing effect of the short polymer grafts present on the GO filler surface has the crucial impact on the matrix stiffness and thus the ability of composite material to reversibly respond to the external light stimulation.

In the present study, the sulfobetaine-based copolymer bearing a dopamine functionality showed gel formation adjusted by the application of metal salts for gelation and various values of pH. Normally, the liquid-like solution of the sulfobetaine-based copolymer and metal cross-linkers is transformed to a gel-like state upon increasing the pH values in the presence of Fe3+ and Ti3+. Metal-induced coordination is reversible by means of the application of EDTA as a chelating agent. In the case of Ag+ ions, the gel is formed through a redox process accompanied with the oxidative coupling of the dopamine moieties and Ag0 particle formation. Mussel-mimicking and metal-dependent viscoelastic properties were observed for Fe3+, Ti3+, and Ag+ cross-linking agents, with additionally enhanced self-healing behavior in comparison with the covalently cross-linked IO4 − analogues. Antibacterial properties can be achieved both in solution and on the surface using the proper concentration of Ag+ ions used for gelation; thus, a tunable amount of the Ag0 particles are formed in the hydrogel. The cytotoxicity was elucidated by the both MTT assay on the NIH/3T3 fibroblast cell line and direct contact method using human dermal fibroblast cell (F121) and shows the non-toxic character of the synthesized copolymer. © 2017 The Authors, Qatar University [QUUG-CAM-2017-1]; Ministry of Education, Youth and Sports of the Czech Republic - Program NPU I [LO1504]; Maersk Oil R&TC Qatar project; Qatar National Research Fund (Qatar Foundation) [9 - 219-2-105]

The synthesis of functional copolyesters that contain pendant double bonds in their structures is reported by ring-opening copolymerization of renewable monomer Tulipalin A (α-methylene-γ-butyrolactone, MBL) and e-caprolactone (CL) using either coordination–insertion or monomer activated mechanisms. Aluminum tris(isopropoxide) (Al(OiPr)3) was successfully used as a cheap and commonly available catalyst for the coordination–insertion ring-opening copolymerization, and functional copolyesters with dispersities below 1.2 and with contents of MBL units in the copolymer up to 25 mol % were prepared. In addition, linear or multiarm copolymers of MBL with CL were synthesized by cationic ring-opening copolymerization that was conducted using protic acid as a “metal-free” catalyst in combination with mono- or multihydroxyl alcohols as initiators. The molecular characteristics and composition of the functional copolyesters were determined by GPC, NMR, two-dimensional NMR, and MALDI-TOF spectroscopy. The effect of M...

This article is focused on the controllable reduction of the graphene oxide (GO) particles as a simultaneous process during surface initiated atom transfer radical polymerization (SI-ATRP) providing hybrid particles with tailored conductivity and substantial polymer shell on the particles tunable by SI-ATRP conditions. The main advantage of such approach is that both the compatibility improvement, due to the polymer layer, and conductivity tuning, due to partial GO reduction, were simply achieved in single-step reaction providing electrorheological (ER) system with enhanced performance in comparison to either neat GO or similar non-covalently bonded GO-polymer hybrids. The presence of the poly(glycidyl methacrylate) (PGMA) on the surface of GO was investigated using FTIR spectrometry, transmission electron microscopy and thermogravimetric analysis and their chain length ( M w ) and polydispersity index (PDI) were determined by 1 H NMR and GPC, respectively. Two different GO-PGMA particle systems varied in M w and PDI and also in electrical conductivities were prepared and their electro-responsive capabilities were investigated. The reduction of GO particles was confirmed by Raman shift as well as conductivity measurements. Electrorheological (ER) performance was investigated at various electric field strengths and repeatability of the phenomenon was confirmed by 10 on/off field cycles. Finally, with the help of dielectric measurements of GO-PGMA based ER suspensions, fitted by Havriliak–Negami model, the relaxation processes were properly investigated and the results were correlated with those obtained from electrorheological measurements.

A facile synthesis of multifunctional hindered phenolic macromolecular antioxidants based on hyperbranched polyglycerol (HbPG) nanoparticles as cores with different molecular weights is reported. The structure of the resulting polymers was verified by 1 H NMR and UV–Vis spectroscopies indicating 64–77% antioxidant functionalizations of the hydroxyl groups of the HbPGs. GPC analyses show that polymeric antioxidants with PDI of 1.33–1.66 are formed. DSC and TGA measurements revealed T g of ∼40 °C and high thermal stability up to ∼300 °C of the multifunctional HbPG-antioxidant conjugates, respectively, confirming that these materials are liquids and stable at usual polymer processing temperatures. The efficiency of the synthesized antioxidants in thermooxidative stabilization of PVC was investigated, keeping in mind that although the importance and wide application of PVC, especially in biomedical fields are incontestable, the utilization of macromolecular antioxidants for the stabilization of PVC has not been examined so far. It was found that the macromolecular antioxidants show similar stabilizing efficiency as the tetrafunctional industrial Irganox1010. Very low extent of leaching of the HbPG-antioxidant from PVC, investigated by extraction tests in both water and hexane, was observed in both extracting agents in contrast to the case of the low molecular weight hindered phenolic antioxidant. Thus, the obtained results confirm the advantages, i.e. high efficiency and highly suppressed leaching, of HbPG-based macromolecular antioxidants in a variety of application fields.

γ-Butyrolactone (γ-BL) derivatives are reviewed from the point of view of their ability to form polymers by ring-opening polymerization. The thermodynamic limitations for polymerization of γ-BL are discussed. Polymerizability of naturally available unsaturated and synthetic functional γ-BL derivatives enabling postfunctionalization of final polyesters is presented. Homopolymerization of γ-BL derivatives with significant effect of the substituent on the γ-BL ring strain is shown.

Biodegradable oligolactide derivatives based on α-, β- and γ-cyclodextrins (CDs) were synthesized by a green procedure in which CDs play the role of both the initiator and the catalyst. The synthetic procedure in which CDs and L-lactide (L-LA) are reacting in bulk at relatively high temperature of 110 °C was investigated considering the structural composition of the products. The obtained products were thoroughly characterized via mass spectrometry methods with soft ionization like matrix-assisted laser desorption ionization (MALDI) and electrospray ionization (ESI). Liquid chromatography (LC) separation with evaporative light scattering detection (ELSD) and NMR analysis were employed in order to elucidate the structural profiles of the obtained mixtures. The results clearly demonstrate that the cyclodextrins were tethered with more than one short oligolactate chain per CD molecule, predominantly at the methylene group, through ring opening of L-LA initiated by primary OH groups.

The synthesis and characterization of isotropic magnetorheological elastomer (MRE) with significantly enhanced utility properties is presented. Common drawbacks of classical MREs, such as poor particle wettability, dispersibility, low thermo-oxidative stability, low chemical stability, and insufficient durability, were eliminated by grafting the carbonyl iron (CI) particles with poly(trimethylsilyloxyethyl methacrylate) (PHEMATMS) using surface-initiated atom transfer radical polymerization (ATRP). Two sets of the MREs were prepared containing bare CI and CI grafted with PHEMATMS chains (CI-g-PHEMATMS). The effects of the coating on magnetorheological behavior in oscillatory shear, as well as the sensing properties of the prepared MREs, were evaluated. The mechanical properties in tensile mode and the particle filler/polydimethylsiloxane (PDMS) matrix interactions were investigated using a dynamic mechanical analysis. The PHEMATMS grafts considerably improved the CI particles’ mobility, probably by preven...

Ageing of foils made from poly(lactic acid)/poly(3-hydroxybutyrate) PLA/PHB blends, unfilled or filled with 1 wt% of carbon black is presented. The foils were either buried in the soil or exposed to the sunlight for 4 months to imitate the behavior of the material when applied as mulching foils. In addition, UV-vis irradiation and hydrolysis over water vapor were studied under laboratory conditions. Finally, the effect of the ageing under the mentioned conditions on mineralization of the foils at room temperature was investigated in order to simulate plowing the material after its application. The degradation was studied by gel permeation chromatography and structural changes were investigated using differential scanning calorimetry. The changes in mechanical properties were investigated by dynamic-mechanical thermal analysis and a tensile test. Addition of carbon black to PLA/PHB resulted in improved photochemical stabilization of the foils, preventing supplemental crystallization during ageing and provided longer retention of the mechanical properties during ageing.

Montmorillonite modified with a grafted polyacrylamide layer (Mt-g-PAm) was used as an effective compatibilizer for the blends of ethylene propylene diene (EPDM) and methyl vinyl silicone (MVQ) rubbers. PAm was prepared by surface-initiated atom transfer radical polymerization (SI-ATRP) in such a way that varied PAm content and Mt. surface coverage was achieved, which was confirmed by FTIR, TGA, XRD and TEM measurements. The morphology of the hybrid compatibilizers influenced the elastic behavior of the composite blends during samples deformation which was due to varied polymer-filler-rubber network interactions as well as the varied chains entanglements effects. The selective location of Mt-g-PAm within MVQ phase as well as at the EPDM/MVQ interphase affected the dynamic mechanical properties of the composites (storage and loss modulus G', G" and tan delta values). Tan delta values were used to investigate the damping properties of the composites. The highest values were observed for hybrid compatibilizers grafted with dense brushes. Compared to the values of the neat matrix, an improvement of 118% and 161% was reported for long dense and short dense brushes, respectively.

The ability to control the interparticle distance in self-assembled arrays of nanoparticles plays an important role in a large number of applications, which require tunable electronic and photonic properties. Importantly, practical applications in real devices rely on arrays satisfying more stringent requirements of lateral homogeneity controlled over a large scale. Herein, the interparticle distance in ordered nanoparticle assemblies was controlled by varying the nanoparticle effective size via the molecular chemical nature and chain length of the ligand. Iron oxide nanoparticles (IONPs) were functionalized by three types of ligands, namely (i) a mixture of oleic acid/oleylamine (OA/OAm), (ii) poly(n-butyl acrylate) (PBA) and (iii) polystyrene (PS), while two different molar masses of PBA and PS were used. The polymeric ligands with narrow dispersity and bearing phosphonic chain-end groups were prepared by atom transfer radical polymerization. Functionalization of the IONPs with polymeric ligands was achieved using a ligand exchange method. Both the hydrodynamic diameter and size distribution of the nanoparticles in colloidal solution were determined by dynamic light scattering (DLS). The mean interparticle distances in Langmuir–Schaefer monolayers prepared on solid substrates were assessed by means of the pair correlation function calculated from the atomic force microscopy (AFM) images. Furthermore, the lateral ordering, homogeneity, and interparticle distances averaged over a mesoscopic scale of the ordered monolayers were studied by the grazing-incidence small-angle X-ray scattering (GISAXS) technique. We demonstrate that the (nanoparticle) centre-to-centre distance in the ordered assemblies constituted by the IONPs with the core diameter of about 6 nm can be varied from 7.6 to about 12 nm with the resulting interparticle gap change by a factor of about 4.

Graphical abstract Image of Au nanoshells with a magnetic core., The article describes preparation, characterization and further modification of hybrid magnetic particles (Au nanoshells with a magnetic core (MPs@silica@Au)) by zwitterionic molecules bearing diazonium functional groups. Such hybrid magnetic particles modified by zwitterionic molecules exhibit the following features: • Responsiveness towards external magnetic field applicable for various enrichment strategies due to magnetic core; • Golden outer layer exhibiting free surface plasmons could be used for grafting of zwitterionic molecules via diazonium functionality; • Zwitterionic interface on such particles provides resistivity towards non-specific protein binding; and at the same time such interface was applied for immobilization of antibodies against prostate specific antigen (PSA) applied for selective enrichment of PSA from serum samples with subsequent electrochemical assays. The approach presented here using hybrid magnetic particles can be easily applied for immobilization of antibodies using a highly robust surface patterning protocols i.e. by formation of a self-assembled monolayer with delivery of functional groups on the outer surface of magnetic particles. Hybrid magnetic particles with immobilized antibodies are applied for highly efficient and quick separation of protein of interest i.e. PSA from complex sample. Finally, hybrid magnetic particles with “fished-out” protein molecules could be incubated with lectins to form a sandwich configuration for glycoprofiling of PSA.

In this study, a verified process of the "grafting from" approach using surface initiated atom transfer radical polymerization was applied for the modification of a graphene oxide (GO) surface. This approach provides simultaneous grafting of poly(2-(trimethylsilyloxy)ethyl methacrylate) (PHEMATMS) chains and a controllable reduction of the GO surface. This allows the fine tuning of its electrical conductivity, which is a crucial parameter for applications of such hybrid composite particles in electrorheological (ER) suspensions. The successful coating was confirmed by transmission electron microscopy and Fourier-transform infrared spectroscopy. The molecular characteristics of PHEMATMS were characterized by gel permeation chromatography. ER performance was elucidated using a rotational rheometer under various electric field strengths and a dielectric spectroscopy to demonstrate the direct impact of both the relaxation time and dielectric relaxation strength on the ER effectivity. Enhanced compatibility between the silicone oil and polymer-modified GO particles was investigated using contact angle measurements and visual sedimentation stability determination. It was clearly proven that the modification of the GO surface improved the ER capability of the system due to the tunable conductivity during the surface-initiated atom transfer radical polymerization (SI-ATRP) process and the enhanced compatibility of the GO particles, modified by polymer containing silyl structures, with silicone oil. These unique ER properties of this system appear very promising for future applications in the design of ER suspensions., Grant Agency of the Czech Republic [16-20361Y]; Ministry of Education, Youth and Sports of the Czech Republic-program NPU I [LO1504]; European Union [CZ. 02.2.69/0.0/0.0/16_027/0008464]; Operational Program for Research, Development and Education; National Science Centre, Poland [UMO-2016/23/P/ST5/02131]; European Unions [665778]; [APVV-14-0891]; [APVV-15-0545]

In this paper several advances were implemented for glycoprofiling of prostate specific antigen (PSA), what can be applied for better prostate cancer (PCa) diagnostics in the future: 1) application of Au nanoshells with a magnetic core (MP@silica@Au); 2) use of surface plasmons of Au nanoshells with a magnetic core for spontaneous immobilization of zwitterionic molecules via diazonium salt grafting; 3) a double anti-fouling strategy with integration of zwitterionic molecules on Au surface and on MP@silica@Au particles was implemented to resist non-specific protein binding; 4) application of anti-PSA antibody modified Au nanoshells with a magnetic core for enrichment of PSA from a complex matrix of a human serum; 5) direct incubation of anti-PSA modified MP@silica@Au with affinity bound PSA to the lectin modified electrode surface. The electrochemical impedance spectroscopy (EIS) signal was enhanced 43 times integrating Au nanoshells with a magnetic core compared to the biosensor without them. This proof-of-concept study shows that the biosensor could detect PSA down to 1.2 fM and at the same time to glycoprofile such low PSA concentration using a lectin patterned biosensor device. The biosensor offers a recovery index of 108%, when serum sample was spiked with a physiological concentration of PSA (3.5 ng mL 1 ). European Regional Development Fund, Grantov Agentura ceska Republiky Scopus

The Phytotoxicological Aspects of a Novel Superabsorbent/Hydrogels: poly(acrylamide-co-sodium 4-hydroxy-2-methylenebutanoate), prepared from renewable monomer Tulipalin A, on the growth and development of monocotyledonous Avena sativa and dicotyledonous Raphanus sativus, was investigated and compared with the effect of borate-crosslinked poly(vinyl alcohol), poly(acrylamide), and poly(acrylamide-co-sodium acrylate) conventional hydrogels. Tulipalin A-based superabsorbent hydrogels revealed superior properties in terms of the combination of the tested properties. The results confirmed excellent suitability of Tulipalin A-based hydrogels for application as reservoirs of water during plant stress condition. Values of fresh matter (yield) and shoot height of the examined plants growing in soil amended with these hydrogels were ca 10% higher than those of plants growing in soil without hydrogels. Reference borate-crosslinked PVA hydrogels (containing increasing amount of borax cross-linker) revealed harmful effect on plants. The negative effect was observed on most of the investigated properties, increasing with content of the hydrogel in soil and concentration of the borax in it.

This contribution reviews synthetic approaches for functionalization of various nanoparticles (NPs) for tailoring their surface properties and improving wettability and compatibility with polymer matrices. The reactive functional groups required to be present in low molecular weight compounds and/or polymer chains are listed from the point of view of their ability to be attached onto the surface of various types of NPs. Three different methods of modification of NP surfaces by polymer chains are described in detail, separately for cationic, anionic, free radical as well as three main reversible deactivation radical polymerization techniques. Finally, examples of functionalization of modern types of NPs to obtain advanced properties of the nanocomposites are briefly presented.

The specific interactions between polyacrylamide brushes composed of polyacrylamide chains tethered to montmorillonite particles (Mt-g-PAm) and the individual components of immiscible ethylene-propylene-diene modified with sorbic acid (EPDM) and methyl vinyl silicone (MVQ) blends were studied. The effect of various lengths of PAm chains and their grafting density on montmorillonite (Mt) surface was investigated. It was determined that, due to interactions generated within the system through carboxyl and amide groups the brush particles were selectively located at the EPDM/MVQ interphase and in the EPDM phase. Furthermore, the longer PAm chains resulted in an increase of the glass transition of EPDM, unification of blend morphology, and the reduction of crystallinity of the MVQ phase. Therefore, precisely designed polymer brushes could be considered as novel functional compatibilizers, that provide a new tool for the future material designing.

A new class of superabsorbent hydrogels was synthesized by copolymerization of acrylamide with sodium 4-hydroxy-2-methylenebutanoate (SHMB). SHMB is obtained by saponification of α-methylene-γ-butyrolactone (MBL) which is a renewable monomer from tulips. Radical polymerization of SHMB was studied for the first time. The extent of side products through the ring closure depended on the pH used during the polymerization. Reactivity ratios for copolymerization of SHMB with acrylamide were estimated. Prepared hydrogels with various composition were investigated for their swelling, mechanical and thermal properties, and morphology as well as cytotoxicity. The achieved degree of swelling of the hydrogels was up to 82 000% and significantly exceeds the capacity of classical superabsorbent hydrogels made of acrylamide and salts of acrylic acid. The degree of swelling as well as mechanical and thermal properties of the hydrogels could be tuned by SHMB content.

Nanocomposites of polystyrene-block-polyisoprene-block-polystyrene triblock copolymer (SIS) and various types of neat and polystyrene-modified carbon nanotubes (CNT-PS) were prepared and distribution of the CNT-PS throughout the polymer matrix was evaluated using confocal laser scanning microscopy (CLSM). The Nanoamor MWCNT-PS with highest thickness of 25–60 nm were readily visualized using both reflection mode without necessity of fluorescent labelling and fluorescent mode after addition of free dye to the nanocomposite. Visualization of Nanocyl MWCNT-PS with thickness of 8–18 nm and SWCNT-PS was achieved after covalent labelling of the CNT-PS with benzothioxanthene fluorescent dye. The CLSM can serve as a non-invasive method for evaluation of quality of dispersion of nanofillers on quite large area and at various depth of polymer film.