Copolymers Of 4-vinylpyridine Research Articles

Removal of polyphenols from anthocyanin-rich extracts using 4-vinylpyridine crosslinked copolymers

In this work, new sorbents for the purification of anthocyanin-rich extracts were evaluated. Copolymers of 4-vinylpyridine crosslinked with trimethylolpropane trimethacrylate (poly(4VP-co-TRIM)) or 1,4-dimethacryloyloxybenzene (poly(4VP-co-14DMB)) were tested for their potential to capture polyphenols. Copolymers were obtained by seed swelling polymerization in the form of microspheres with permanent porous structure – attractive features of sorbents used for sample purification by dispersive solid phase extraction. The microspheres were characterized by AFM, elemental analysis, SEM, and nitrogen adsorption-desorption method. Their capacity to remove polyphenols was evaluated using spectrophotometry, HPLC-DAD, and LC-MS/MS. For proof-of-concept, the aqueous extracts of berries classified into three different groups regarding their anthocyanin composition (strawberries, raspberries, blackcurrants) were selected. It was found that studied microspheres adsorbed flavonoids more effectively compared to primary secondary amine and graphitized carbon black. Copolymers of 4-vinylpyridine also capture anthocyanins and might be used for the purification of extracts of fruits before LC-MS/MS analysis to reduce the matrix effect.

Cationic 4-Vinylpyridine Copolymer Nanospheres with Dual Active Centers for Antibacterial Coatings

Cationic 4-Vinylpyridine Copolymer Nanospheres with Dual Active Centers for Antibacterial Coatings

4-Vinylpyridine copolymers for improved LC–MS tryptophan and kynurenine determination in human serum

Tryptophan (an essential amino acid) and its clinically important metabolite—kynurenine contribute to several fundamental biological processes and methods that allow their determination in biological samples are in demand. The novelty of the work was a demonstration of the utility of two polymers: 4-vinylpyridine crosslinked with trimethylolpropane trimethacrylate (poly(4VP-co-TRIM)) or 1,4-dimethacryloyloxybenzene (poly(4VP-co-14DMB))—in terms of human serum clean-up for simultaneous LC–MS determination of tryptophan and kynurenine. The goal was to achieve a reduction of the matrix effect, which is responsible for signal suppression, with minimal capture of analytes. The adsorption properties of the polymeric beads were studied by evaluating the adsorption kinetics and isotherms in model matrices. Therefore, the adsorption capacities of both molecules were not efficient, the tested 4-vinylpyridine-based copolymers have shown great promise (especially poly(4VP-co-TRIM)) as sorbents for serum clean-up. In the model human serum matrix, poly(4VP-co-TRIM) provided good recoveries of tryptophan and kynurenine (76% and 87%, respectively) and allowed for the reduction of the matrix effect. Performances of both copolymers were compared to those of commercially available sorbents (octadecylsilane, activated charcoal, and primary secondary amine).

Pyridinium and trifluoromethanesulfonate bifunctional poly(ionic liquid)s for highly efficient and selective adsorption of anionic dyes

The efficient and selective removal of dyes from polluted water by low cost, durable, sustainable, and reusable adsorptions remain challenges. In this study, a pyridinium and trifluoromethanesulfonate bifunctional poly(ionic liquid)s, named Py-CF3SO3-PIL was prepared by co-polymerization of 4-vinyl pyridine (4VP), divinylbenzene (DVB) and styrene (ST), followed by quaternization with 1-bromobutane and anion exchange with lithium trifluoromethanesulfonate. The resulting bifunctional Py-CF3SO3-PIL exhibited remarkable adsorption capacity (2192 mg g−1) and efficiency (within 10 min) for selective removal (>99.9%) of methyl orange (MO) from (mixed) dye solutions. The superior adsorption capacity and selectivity of Py-CF3SO3-PIL towards the removal of MO was attributed to the strong electrostatic interactions and π-π stacking interaction between the adsorbent and MO dye. Detailed kinetic studies, adsorption isotherms, and thermodynamic experiments revealed an endothermic monolayer chemical adsorption mechanism of MO on Py-CF3SO3-PIL, which is perfectly matched with the Langmuir isotherm model (R2 > 0.999). Importantly, the Py-CF3SO3-PIL could be easily collected and regenerated for multiple repeated uses, highlighting its reusability. The exceptional adsorption capacity and selectivity towards anionic dyes make Py-CF3SO3-PIL a promising candidate for dye separation applications. Our findings will contribute to the rational design of functional poly(ionic liquid)s-based adsorbents for water purification.

Self-healing elastomers from supramolecular random copolymers of 4-vinyl pyridine

For the first time hydrogen bonding complexes between poly(4-vinyl pyridine) (P4VP) and its copolymers were employed as a healing concept for building supramolecular materials with self-healability. P4VP and its random copolymers with stearyl acrylate and stearyl methacrylate were first synthesized via UV light-mediated metal-free polymerization using 4-(10H-phenothiazin-10-yl)-N,N-diphenylaniline as organic photocatalyst. Three complexes between the P4VP homopolymer and the obtained copolymers bearing “hairy” side groups with 3,3′-dithiodipropionic acid (DTDP) as a proton donor crosslinker were studied. Owing to the “solvent”-like mantle formed by lowly ordered stearyl side groups, the complex of poly(4-vinyl pyridine-random-stearyl methacrylate) and DTDP exhibited efficient self-healability of complete cuts at room temperature after 30 min, with tensile strength recovery of above 80%. The results of this work suggested that this dynamic supramolecular concept based on P4VP is promising for developing self-healing materials for various applications.

Continuous-Flow Suzuki-Miyaura Coupling in Water and Organic Solvents Promoted by Blends of Stabilized Convoluted Polymeric Palladium Catalysts and Polymeric Auxiliary Materials.

Given that heterogeneous palladium-catalyzed C-C bond formation reactions under continuous-flow conditions are well suited for the efficient and safe production of pharmaceuticals and functional materials, the development of active and durable catalysts for this purpose is a matter of high practical significance. Here, a previously established molecular convolution methodology was used to synthesize catalysts for Suzuki-Miyaura coupling under flow conditions by blending convoluted polymeric palladium catalysts (prepared from copolymers of 4-vinylpyridine and 4-tert-butylstyrene) and crosslinked polymeric auxiliary materials (prepared from copolymers of divinylbenzene and 4-tert-butylstyrene). The optimal catalyst exhibited high performance and durability and allowed numerous biaryl products such as liquid-crystalline materials, organic electroluminescent materials, and pharmaceuticals to be continuously synthesized with turnover frequencies of up to 238 h-1 . In a demonstration of practical utility, the developed catalytic system was used for the continuous synthesis of two pharmaceuticals (felbinac and fenbufen) in water as the sole solvent.

Structural Features of 4-VP-HEMA-SiO<sub>2</sub> Hybrid Membranes and Their Proton Conductivity

Hybrid organic-inorganic membranes based on tetraethoxysilane and orthophosphoric acid-doped copolymers of 4-vinylpyridine (4-VP) and 2-hydroxyethyl methacrylate (HEMA) were formed by the sol-gel synthesis method. The membranes are characterized by high values of exchange capacity and proton conductivity. An increase in the proton conductivity of hybrid organo-inorganic membranes compared to the initial copolymer can be associated with the generation of water of crystallization during the formation of a silicon dioxide fragment, which follows from quantum-chemical modeling of the local structure of the membrane, which includes an organic part from the copolymerization product of 4-VP with HEMA (44 atoms) and an inorganic part of 27 atoms, repeating the structure of the silicon dioxide block.

Histidine-mediated dendritic mesoporous magnetic ion-imprinted polymer toward effective and recoverable cadmium removal

In this study, a magnetic dendritic mesoporous silica nanoparticle material (MDMS@MAH-Cd-IIP) was prepared via surface ion-imprinted technique for selective removal of Cd(Ⅱ) from aqueous solution. The material was based on an ion-imprinted copolymers of 4-vinyl pyridine (4-VP) and N-methacryloyl-L-histidine (MAH), a synthesized ligand monomer to complex with cadmium ions as ion recognition layer. The obtained polymer was characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), and magnetic measurement system. The adsorption experiments exhibited MDMS@MAH-Cd-IIP showed fast (within 35 min) and selective capture of Cd(Ⅱ) with maximum uptake capacity of 21.04 mg g−1. The adsorption process followed pseudo-second order kinetic and Langmuir adsorption isotherm models, indicating monolayer chemisorption on homogeneous sites was the rate-limiting step. Meanwhile, the MDMS@MAH-Cd-IIP also showed a specificity recognition ability for Cd(Ⅱ) using analogues Co(Ⅱ), Pb(Ⅱ), Zn(Ⅱ) and Ni(Ⅱ) as interference. Moreover, the MDMS@MAH-Cd-IIP based magnetic SPE can extract approximately 90.0–102.0% of Cd (Ⅱ) in real water samples with a RSD of 3.34–8.23%, which indicated the polymer had the high stability and reproducibility and presented itself a promising material for the Cd(Ⅱ) adsorption and detection from aqueous solution.

Reusable Pd-PolyHIPE for Suzuki-Miyaura Coupling.

Palladium was immobilized on a highly porous copolymer of 4-vinylpyridine and divinylbenzene (polyHIPE—poly(high internal phase emulsion)) using palladium(II) acetate to obtain PolyPy-Pd with 6.1 wt % or 0.57 mmol Pd/g. The immobilized catalyst was able to catalyze the coupling of iodobenzene and phenylboronic acid in ethylene glycol monomethyl ether/water (3:1) within 4 h at rt and complete conversion was observed when 2.5 mol % of Pd per PhI was used. The reaction tolerated a wide range of substituents on the aromatic ring. Iodobenzene derivatives with electron-withdrawing substituents showed higher reactivity, while the opposite was true for the phenylboronic acid series. The polyHIPE-supported Pd catalyst was also used for the direct conversion of phenylboronic acid to biphenyl through an iodination/coupling reaction sequence. The recyclability of the heterogeneous catalyst was also optimized, and by finding a suitable combination of solvents for the loading of Pd, the reaction, and the isolation of the product, the solid-supported catalyst was completely regenerated and used in the next reaction with the same activity.

Facile synthesis and characterization of macromolecular Eu(III) complexes with β-diketone ligands and poly(4-vinyl pyridine-co-methyl methacrylate)

Poly(4-vinyl pyridine-co-methyl methacrylate), PVM, was synthesized by radical copolymerization of 4-vinyl pyridine with methyl methacrylate. Afterward, the macromolecular Eu(III) complexes of general formula [Eu(β-diketonate)3(PVM)(H2O)], where β-diketonate = benzoylacetonate (BA), 1; dibenzoylmethanate (DBM), 2; thenoyltrifluoroacetonate (TTA), 3, were prepared and fully characterized by means of element analysis, thermal analysis, SEM, 1H NMR, 13C NMR, FT-IR, and UV-vis spectra. The macromolecular complexes can dissolve in many ordinary organic solvents (e.g. dimethylformamide, dimethylsulfoxide, and tetrahydrofuran), as well as emit strong red luminescence under ultraviolet light excitation. The room-temperature 5D0 lifetime and fluorescence quantum yield of 3 are 391 μs and 37%, respectively, which are far more than those of 1 (194 μs, 16%), 2 (160 μs, 18%), and Eu(TTA)3(H2O)2 (224 μs, 22%). The CIE coordinates of 1–3 are calculated as (0.49, 0.33), (0.62, 0.33) and (0.65, 0.34), respectively, demonstrating the promising utilization future of these complexes, especially the latter two, as luminescent functional materials used in large-area optical display.

Sorption properties of silica gel with adsorbed copolymers of 4-vinylpyridine and styrene with respect to Cu(II), Pb(II) and Fe(III) ions

A number of new organo-mineral composites in different mass ratios of organic and inorganic components were obtained by adsorption on the silica gel surface of 4-vinylpyridine–styrene copolymer. The fact of the copolymer immobilization on the silica gel surface was confirmed by Fourier transform infrared spectroscopy (FTIR) spectroscopy and thermogravimetry combined with mass-spectrometry analysis. Thermogravimetric analysis was employed for estimation of copolymers mass content in the composite obtained. It has been established that all the synthesized composites exhibit sorption activity toward traces of Cu (II), Pb (II) and Fe (III) ions in neutral aqueous medium.

Adsorption properties of silica gel <em>in situ</em> modified with copolymers of 4-vinylpyridine and styrene towards ions of toxic metals

Adsorption properties of silica gel <em>in situ</em> modified with copolymers of 4-vinylpyridine and styrene towards ions of toxic metals

Facile and efficient removal of Pb(II) from aqueous solution by chitosan-lead ion imprinted polymer network

A new chitosan based imprinted polymer was prepared by copolymerization of 4-Vinylpyridine (VP) as a functional monomer and N,N′-Methylenebisacrylamide (MBA) as a crosslinker in the presence of Potassium peroxodisulfate (KPS) as an initiator to eliminate Pb(II) from aqueous solutions. The template ions were removed from ion imprinted polymer (IIPs) particles by leaching with 0.1 M nitric acid (HNO3) that leaves cavities in the particles with the capability of selective extraction of the Pb(II) ions. Some properties of the bioadsorbent were further identified using Field Emission Scanning Electron Microscopy (FE-SEM), Fourier Transform Infrared Spectroscopy (FT-IR) and Thermal Gravimetric Analysis (TGA). In addition, the equilibrium adsorption data were examined through Langmuir and Freundlich isotherm models and it was found that adsorption data fit well with the Freundlich isotherm. The competitive adsorption studies clearly showed that the Pb(II)-IP has a much higher adsorption capacity for Pb(II) than the non-imprinted polymer (NIP) with the same chemical composition; furthermore, it has excellent selectivity for the targeted ion. In addition, the studies regarding the regeneration and reuse studies revealed that the Pb(II)-IP beads showed no significant decrease in their adsorption capacities.

STUDY OF DILUTED SOLUTIONS OF PORPHYRIN-CONTAINING POLYMERIC SYSTEMS BASED ON POLY-4-VINYLPYRIDINE

The dynamic light scattering method was used to determine the diffusion coefficients and hydrodynamic radius of particles in diluted dimethylformamide solutions of poly-4-vinylpyridine, polystyrene, styrene and 4-vinylpyridine copolymers with different comonomer compositions and poly-4-vinylpyridine modified by zinc meso-tetraphenilporphrine. The temperature range was from 20 °C to 25 °C. The copolymers were obtained in different conditions - by thermal and microwave heating. In order to determine the optimal conditions for the behavior of macromolecular reactions involving these polymers, diluted solutions of all samples were studied by the viscometric method. For these systems, a solvent of appropriate quality was selected, the structure of the solution was studied, the interaction of the solvent with the polymer was evaluated, the parameters of the macromolecular ravel were calculated: characteristic viscosities, Huggin’s constants, root-mean-square distances between the ends of the chains and the specific indicator of the system taking into account the molecular weight of the polymers was presented. It is shown, that the values of characteristic viscosity fall with increasing temperature, the Huggin’s constant, on the contrary increases. These data indicate that the "quality" of the solvent for the systems under study is deteriorating, that is, the tangle of macromolecules in dimethylformamide shrinks with increasing temperature. This behavior is typical for systems with a lower critical temperature of dissolution. The introduction of the porphyrin fragment into the polymer macromolecule loosens the macromolecular coil, but does not change the behavior of the system in the solution as a whole. The results obtained by the quasi-elastic light scattering method are consistent with the data obtained by the viscometric method. The surface morphology and elemental composition of poly-4-vinylpyridine and coordination-related porphyrin polymers on its basis were studied by scanning electron microscopy.

ОСАДОВА КОПОЛІМЕРИЗАЦІЯ 4-ВІНІЛПІРИДИНУ ЗІ СТИРОЛОМ

The determination of the copolymers of 4-vinylpyridine with styrene copolymers real composition, formed under the conditions of precipitation copolymerization in CCl4, is described. For this, 4-vinylpyridine with styrene was copolymerized in different ratios. The composition of the obtained copolymers was determined according to 1H NMR spectroscopy. A comparison of the real copolymers composition with the theoretically calculated ones was performed as well. The copolymerization of styrene with 4-vinylpyridine was carried out in sealed ampoules in argon medium. Solutions of a concentration of 1.02 mol/l in CCl4 were prepared. The initiator azobisisobutyronitrile in the amount of 0.00106 mol/l was added. The copolymerization was carried out in a thermostat C1823 at T = 75 ± 0.5°C. The copolymerization time was 3 hours. The original ratio of monomers (4-vinylpyridine:styrene) = 6:1; 5:1; 4:1; 3:1; 2:1; 1:2; 1:3; 1:4; 1:5; 1:6. The composition of the obtained copolymers was determined according to 1H NMR spectroscopy. It was determined that copolymers of 4-vinylpyridine with styrene obtained by precipitation copolymerization in CCl4 were enriched by 4-vinylpyridine bonds. On the contrary, the calculation of the instant composition of the copolymers according to the literature shows that under the conditions of classical copolymerization in 4-vinylpyridine solution is less active than styrene. We calculated the theoretical relative constants of copolymerization of styrene with 4-vinylpyridine: r1 = 1.97; r2 = 0.93. Therefore, under the conditions of classical copolymerization in solution 4-vinylpyridine is less active than styrene (r2 < r1). It was also found out that for the original molar content of styrene if it is greater than 0,85, it is not possible to synthesize by means of precipitation polymerization into CCl4 the copolymers of 4-vinylpyridine:styrene.

Sorption properties of saponite clay, in situ modified by poly(4-vinylpyridine-co-styrene), towards Cu(II), Cd(II), Pb(II), Mn(ІІ) and Fe(III) ions

In situ modification with copolymer of 4-vinylpyridine and styrene (molar ratio 3:1) of natural mineral saponite from deposit Tashkivske(Ukraine) by radical polymerization was carried out. Anchorage of organic polymer 4-vinylpyridine-co- styrene on the mineral surface was proved by IR spectroscopy, mass spectrometry and scanning electron microscopy. The amount of immobilized copolymer in the synthesized composite material according to the thermogravimetric analysis is 8.5 wt.%. The recorded adsorption capacity of the composite with respect to Cu(II), Pb(II) and Fe(III) ions was increased in comparison with native mineral saponite.

Magnetic molecularly imprinted polymer prepared by microwave heating for confirmatory determination of chloramphenicol in chicken feed using high-performance liquid chromatography-tandem mass spectrometry

A magnetic molecularly imprinted polymer (MMIP) for chloramphenicol was prepared using a surface-imprinted and microwave-heating-induced polymerization method. The surfaces of the magnetic particles were first double-bond functionalized with 3-(trimethoxysilyl)propyl methacrylate (γ-MPS), followed by the copolymerization of 4-vinyl pyridine (4-VP) and trimethylolpropane trimethacrylate (TRIM) in the presence of chloramphenicol as a template and 1,1-azobis(cyclohexane-carbonitrile) (ABCN) as an initiator in a mixture of dimethyl sulfoxide and water with microwave heating at 80°C. The magnetic polymer possesses supraparamagnetic properties and was used to concentrate and cleanup chicken feed extract, followed by chromatographic separation using a Lichrospher®100 RP C8 column and detection with two multi-reaction monitoring transitions at m/z 321→ 152 and m/z 321→ 257. The mean recoveries obtained at two spiking levels were in the range of 94.6–100% The relative intra- and inter-day standard deviations were in the range of 1.4–2.6% and 5.1–5.7%, respectively. The detection limit of the method was 0.12 µg kg−1. This confirmatory method was successfully applied to determine chloramphenicol in chicken feed samples.

Influence of chain microstructure of acrylic acid and 4-vinylpyridine copolymers on their aggregative stability and adsorption from aqueous solutions

The behavior of acrylic acid–4-vinylpyridine copolymers of different architectures, namely, with gradient and block distributions of comonomer units in a chain as well as with quaternized 4-vinylpyridine units, is studied. It is shown that all the copolymers are prone to aggregation in acidic and alkaline media and that the sizes of aggregates and the regions of their stability are determined by chain microstructure. The aggregates formed in acidic media exhibit temperature sensitivity. The kinetics and mechanism of copolymer adsorption from solutions on the surface of nylon membranes are explored. It is shown that the block distribution of units substantially increases the adsorption efficiency, while the quaternization of 4-vinylpyridine units decreases the monolayer adsorption parameters.

Synthesis and Adsorption Properties of 4-Vinylpyridine and Styrene Copolymer In Situ Immobilized on Silica Surface

Copolymer of 4-vinylpyridine with styrene was in situ immobilized on silica gel surface via the heterogeneous radical polymerization. Anchorage of the copolymer on the surface layer was confirmed by IR spectroscopy. The quantity of copolymer on the silica gel surface was evaluated as 25.73 wt.% by TG and DSC-MS analysis. “Islet” location of polymer layer on the silica surface was confirmed by the scanning electron microscopy. A high adsorption activity of silica gel with immobilized copolymer towards microquantitatives of Cu(II), Cd(II), Pb(II), Fe(III), and Ni(II) ions in steady state conditions as well as of Ni(II) ions in dynamic regime was found.

Adsorption of platinum(IV) by a composite based on silicon dioxide and copolymer of 4-vinylpyridine and 2-hydroxyethylmethacrylate

The adsorption of platinum(IV) solutions by a composite based on silicon dioxide and copolymer of 4-vinylpyridine and 2-hydroxyethylmetacrylate in hydrochloric acid solutions has been studied. The maximum efficiency of extraction of platinum(IV) ions has been detected in a solution of HCl with a concentration of 1 mol L–1 at a temperature of 338 K (sorption capacity equal to 188 mg g–1). The interaction of platinum (IV) with the surface of the composite is a result of chemisorption. The models of Langmuir, Freundlich, and Dubinin–Radushkevich have been used to describe the nature of adsorption. Adsorption kinetics was assessed using the models of Boyd–Adamson, pseudofirst and pseudosecond orders, and Elovich.