Poly 4-vinylpyridine Research Articles

Polymer-templated supramolecular co-assemblies of proteins and metal oxide clusters as versatile platform for chemo-enzymatic catalysis

The hybridization of enzymes and inorganics in controlled manner is challenging, however, critical for the development of chemo-enzymatic cascade catalyst with high efficiency and selectivity. Here, proteins and metal oxide clusters can be facilely co-assembled on the surface of colloid of poly(4-vinylpyridine) (P4VP) via hydrogen bonding, due to their enriched surface hydrogen bonding donors. The co-assembly method can be generally applied for preparing chemo-enzymatic catalyst within the selected database of various proteins and metal oxide clusters while the assembly units retain their structures and activities. Typically, a 2.5 nm metal oxide cluster {Mo72Fe30}, with peroxidase-like activity, are complexed with glucose oxidase (GOX) on P4VP for the catalysis against the oxidization of o-dianisidine (ODA) with the existence of glucose. Due to the synergistic effects of chemical and enzymatic catalysis, the co-assemblies show even higher ODA oxidation activity compared to GOX/catalase bi-enzymatic system, confirming the effectiveness of the co-assembly protocol for cascade catalysis and enabling its applications in rapid glucose detection and biomass conversion.

Linear-Organic-Polymer-Supported Iridium Complex as a Recyclable Auto-Tandem Catalyst for the Synthesis of Quinazolinones via Selective Hydration/Acceptorless Dehydrogenative Coupling from o-Aminobenzonitriles.

A linear-organic-polymer-supported iridium complex Cp*Ir@P4VP, which is designed and synthesized by the coordinative immobilization of [Cp*IrCl2]2 on poly(4-vinylpyridine), was proven to be an efficient heterogeneous autotandem catalyst for synthesizing quinazolinones via selective hydration/acceptorless dehydrogenative coupling from o-aminobenzonitriles. Furthermore, the synthesized catalyst was recycled five times without an obvious decrease in the catalytic activity.

Synthesis of color-responsive polydiacetylene assemblies and polydiacetylene/zinc(II) ion/zinc oxide nanocomposites in water, toluene and mixed solvents: Toward large-scale production

Polydiacetylenes (PDAs) are well-known materials that can be utilized as colorimetric sensors of various stimuli. PDA-based materials are normally synthesized via a self-assembly in an aqueous medium. In this study, we explored important experimental parameters including concentration, incubating temperature, and solvent media, that affected the self-assembly of monocarboxylic PDA and reversible thermochromic PDA/Zn2+/ZnO nanocomposites. The critical concentration (C*), the lowest concentration for topotactic photopolymerization in each system, was determined. We achieved, for the first time, direct synthesis of PDA/Zn2+/ZnO nanocomposites in toluene. Furthermore, it was possible to synthesize the nanocomposites at ambient conditions, simplifying the process for large-scale production. The addition of co-solvent, ethanol, resulted in a significant increase in blue-phase concentration. The presence of ethanol in the solvent medium also caused the morphological change from sheet-like to ribbon-like structures. The ability to synthesize the nanocomposite in nonpolar media allowed the fabrication of solid-state sensors by mixing with various polymers such as polyethylene, polystyrene, poly(methyl methacrylate), and poly(4-vinylpyridine). Reversible thermochromic smart inks were prepared by simple mixing with acrylic paint. Our study extends the utilization of PDA-based materials as colorimetric sensors.

Ligand Exchange Reaction in [Co4O4]-Cobalt Cubane: A Versatile Strategy Towards the Preparation of Cobalt Cubane-based Functional Small Molecules and Polymeric Materials

Herein, we report the mechanistic and application study of ligand exchange reaction in Co4O4-cobalt cubane, a well-known water oxidation catalyst (WOC). The ligand exchange reaction involves the instantaneous dissociation of attached pyridine ligand and replacement of target ligand in an appropriate solvent. The kinetic and thermodynamic parameters were quantified for the ligand exchange reaction under mild conditions. Activation parameters revealed that the ligand exchange mechanism follows dissociative (D) or interchange-dissociative (Id) pathway in case of Co4O4, as it is evident by the high activation enthalpy (ΔH‡) and the positive activation entropy (ΔS‡) values. The effects of ligand derivatization, reaction temperature and type of the solvent on the exchange kinetics and the product purity were also investigated in detail. Furthermore, our theoretical studies disclosed the most probable ligand exchange pathway in case of Co4O4. Finally, this methodology was successfully applied to the preparation of Co4O4-containning functional poly-4vinylpyridine (P4VP) and cross-linked heterogeneous polymeric catalysts. The present mechanistic study clearly demonstrates that the ligand exchange method is an efficient and versatile method for the preparation of Co4O4-based functional materials.

In Situ Preconcentration and Quantification of Cu2+ via Chelating Polymer-Wrapped Multiwalled Carbon Nanotubes.

Trace analysis of heavy metals in complex, environmentally relevant matrices remains a significant challenge for electrochemical sensors employing stripping voltammetry-based detection schemes. We present an alternative method capable of selectively preconcentrating Cu2+ ions at the electrode surface using chelating polymer-wrapped multiwalled carbon nanotubes (MWCNTs). An electrochemical sensor consisting of poly-4-vinyl pyridine (P4VP)-wrapped MWCNTs anchored to a poly(ethylene terephthalate) (PET)-modified gold electrode (r = 1.5 mm) was designed, produced, and evaluated. The P4VP is shown to form a strong association with Cu2+ ions, permitting preconcentration adjacent to the electrode surface for interrogation via cyclic voltammetry. The sensor exhibited a detection limit of 0.5 ppm with a linear range of 1.1–13.8 ppm (16.6–216 μM) and a relative standard deviation (RSD) of 4.9% at the Environmental Protection Agency (EPA) limit of 1.3 ppm. Evaluation in tap water, lake water, ocean water, and deionized water rendered similar results, highlighting the generalizability of the presented preconcentration strategy. The advantages of electrochemical analysis paired with polymeric chelation represent an effective platform for the design and deployment of heavy metal sensors for continuous monitoring of natural waters.

Self-Assembly of Polymer End-Tethered Gold Nanorods into Two-Dimensional Arrays with Tunable Tilt Structures

We demonstrated a facile yet effective strategy for self-assembly of polymer end-tethered gold nanorods (GNRs) into tunable two-dimensional (2D) arrays with the assistance of supramolecules of hydrogen bonded poly(4-vinyl pyridine) (P4VP) and 3-n-pentadecylphenol (PDP). Well-ordered 2D arrays with micrometer size were obtained by rupturing the assembled supramolecular matrix with a selective solvent. The formation of long-range ordered 2D arrays during a drying process was observed via small-angle X-ray scattering. Interestingly, the packing structure of the ordered arrays strongly depends on the molecular weight (Mw) of the polymer ligands and the size of the GNRs. By increasing Mw of the polymer ligands, tilted arrays can be obtained. The average angle between GNRs and the surface normal direction of the layered 2D arrays changes from 0 to 37° with the increase in Mw of the polymer ligands. A mechanism for assembly behavior of dumbbell shapes with a soft shell structure has been proposed. The resulting GNR arrays with different orientations showed anisotropic surface-enhanced Raman scattering (SERS) performance. We showed that the vertically ordered GNR arrays exhibited ∼3 times higher SERS signals than the tilt ordered arrays. The results prove that the polymer end-tethered GNRs can be used as a building block for preparing the tilted 2D arrays with tunable physicochemical properties, which could have a wide range of potential applications in photonics, electronics, plasmonics, etc.

Mn, N, P-tridoped bamboo-like carbon nanotubes decorated with ultrafine Co2P/FeCo nanoparticles as bifunctional oxygen electrocatalyst for long-term rechargeable Zn-air battery

Rational synthesis of cost-effectiveness, ultra-stable and high-efficiency bifunctional oxygen catalysts are pivotal for Zn-air batteries. Herein, fine Co2P/FeCo nanoparticles (NPs) anchored on Mn, N, P-codoped bamboo-like carbon nanotubes (Co2P/FeCo/MnNP-BCNTs) are constructed in the coexistence of melamine, poly(4-vinylpyridine) and adenosine-5′-diphosphate disodium salt (ADP) by convenient pyrolysis and follow-up acid treatment. The as-prepared catalyst exhibits the higher onset potential (Eonset = 0.97 V vs. RHE) and half-wave potential (E1/2 = 0.88 V vs. RHE) for oxygen reduction reaction (ORR), coupled with excellent oxygen evolution reaction (OER) with the lower overpotential of 324 mV at 10 mA cm−2. Notably, the home-made Zn-air battery delivers the greater peak power density of 220 mW cm−2, together with the outstanding cycling stability. The excellent performances of Co2P/FeCo/MnNP-BCNTs catalyst are mainly attributed to the highly conductive carbon nanotubes and the synergistic effects between carbon nanotubes and Co2P/FeCo NPs. This work offers a novel strategy to explore advanced bifunctional oxygen catalysts for high-efficiency metal-air batteries.

Suzuki–Miyaura Coupling and C–H Arylation Catalyzed by Poly(4-vinylpyridine)–Palladium Composite

Suzuki–Miyaura Coupling and C–H Arylation Catalyzed by Poly(4-vinylpyridine)–Palladium Composite

Synthesis and self-assembly of star multiple block copolymer of poly(4-vinylpyridine)-block-polystyrene

Star multiple block copolymer of poly (4-vinylpyridine)-block-polystyrene (s-P4VP-b-PS) is synthesized via initial synthesis of linear poly (4-vinylpyridine)-block-polystyrene (l-P4VP-b-PS) by dispersion RAFT polymerization to form l-P4VP-b-PS nano-assemblies and then cross-linking within the l-P4VP-b-PS nano-assemblies. The synthesized s-P4VP-b-PS has a high molecular weight and exists 25–47 nm nanospheres in the common solvent of N,N-dimethylformamide. The self-assembly of s-P4VP-b-PS in two block selective solvents, e.g., toluene and methanol, is investigated, and great difference from l-P4VP-b-PS is demonstrated. In methanol, s-P4VP-b-PS forms core-corona nanospheres. In toluene, s-P4VP-b-PS forms dispersed nanoparticles or nanoparticle clusters dependent on polymer concentration. In the s-P4VP-b-PS nanoparticle clusters, poly (4-vinylpyridine) forms dispersed nano-domains, the size of which is firmly dependent on the degree of polymerization of the P4VP block. It is thought that the great difference between s-P4VP-b-PS and l-P4VP-b-PS will arouse new interest on self-assembly of block copolymers.

Poly 4-Vinylpyridine and Polystyrene Based Interpenetrating Polymer Networks (IPNs): Synthesis and Characterization

A study on synthesis of thin film of interpenetrating polymer network (IPN), of poly(4-vinylpyridine) (PVP) and polystyrene was carried out. A series of IPN was synthesized, using divinyl benzene (as cross linker) and benzoyl peroxide (as an initiator) and characterized using FT-IR spectroscopy, scanning electron microscopy (SEM), thermal (DSC, TGA) and fluorescent techniques. FTIR spectra revealed the presence of PVP at 1584 cm–1 and polystyrene at 1609 cm–1. Shifting in band positions depicts formation of IPN. SEM images show a clear dual phase morphology. DSC thermogram reveals glass transition temperature (Tg) value of the polymer network at 350 ºC. TGA graph depicts thermal stability of IPN upto 400 °C. The XRD pattern of IPN indicates semi crystalline nature. The properties such as average molecular weight between crosslinks (Mc), percentage swelling is found to be the direct function of initiator (BPO) and inverse function of concentration of cross linker (DVB) and styrene. Fluorescence spectra of IPN observed in visual range of 506 nm.

Research on the conductivity of circuit on fabrics based on inkjet printing and electroless deposition technology

Traditional silicon semiconductor substrate based electronic manufacturing has the shortcomings of non-bending, poor biocompatibility, and high cost. Fabric is more suitable for wearable electronic substrate due to its advantages of flexibility, air permeability, and skin-friendliness. We studied the manufacture of the conductive circuit based on inkjet printing and electroless deposition technology and got excellent conductivity and high dimensional accuracy circuit on fabric substrates. Three kinds of commonly used fabric materials cotton, polyester/cotton and polyester are selected to study the key work of surface pre-treatment, inkjet printing circuit pattern, and electroless deposition. The synergetic effect of SU-8 and P4VP (poly-4-vinylpyridine) on fabric ensures that the pattern retains its original size rather than diffusing. The distance between adjacent electric lines is no less than 0.3mm. With the extension of copper deposition time, the copper deposition layer becomes more and more uniform and dense. Sheet resistance reached 0.01Ω after 2 hours of copper deposition. The performance of all three kinds of fabric is similar. And cotton fabric had the best water lock performance. This technology has great potential for promotion and development in the application of intelligent textiles in the future.

10-(pyren-1-yl)-10h-phenothiazine and pyrene as organic catalysts for photoinitiated ATRP of 4-vinylpyridine

Abstract The UV light-mediated metal-free polymerizations of 4-vinylpyridine (4VP) have been successfully performed by using 10-(pyren-1-yl)-10H-phenothiazine (PPTh) and pyrene as photocatalysts. The preparation of narrow polydispersity poly (4-vinyl pyridine) (P4VP) with high conversions was enabled in both protic as well as unprotic reaction media at ambient temperature. Additionally, copolymerizations of 4VP with acrylate and methacrylate monomers were also demonstrated, affording metal-free copolymer products.

A hydrogen bond cross-linked luminescent supramolecular network polymer and its application for the detection of alkyl iodides with differentiation capabilities from aromatic iodides

A luminescent supramolecular polymer consisting of poly(4-vinyl pyridine) and perylene diimide was prepared through a H-bond cross-linking strategy and used for alkyl iodide sensing.

Combining CROP and ATRP to synthesize pH-responsive poly(2-ethyl-2-oxazoline-b-4-vinylpyridine) block copolymers

Herein, we present the synthesis and characterization of block copolymers based on the biocompatible and stealth polymer poly(2-ethyl-2-oxazoline) and the polydentate ligand and pH-responsive poly(4-vinylpyridine).

Superparamagnetic iron oxide nanoparticles functionalized with a binary alkoxysilane array and poly(4-vinylpyridine) for magnetic targeting and pH-responsive release of doxorubicin

The reported supramolecular arrangement offers an attractive strategy for the pH-sensitive and magnetically-guided release of doxorubicin, which could allow exploring novel therapeutic schemes against cancer.

Synthesis of pH-Responsive Block Copolymer By ATRP

The block copolymer, poly(4-vinylpyridine)-b-poly(tert-butylmethacrylate) (P4VP-b-PtBMA), was synthesized by atom transfer radical polymerization (ATRP) in two steps. Firstly, macroinitiator P4VP-Cl was prepared via ATRP with the conversion of monomer 66.3%. The result of GPC illustrated that the Mn of P4VP-Cl could be controlled by adjusting polymerization conditions. Then, P4VP-b-PtBMA was synthesized by ATRP using P4VP-Cl as macroinitiator. The effects of polymerization reaction parameters such as solvent and polymerization time on the M n and M W/M n were investigated. Then the pH-responsive block copolymer poly(4- vinylpyridine)-b-poly(methacrylic acid) (P4VP-b-PMAA) was obtained by hydrolyzing the P4VP-b-PtBMa copolymer.

Hairy silica nanosphere supported metal nanoparticles for reductive degradation of dye pollutants.

Hairy materials can act as a sort of scaffold for the fabrication of functional hybrid composites. In this work, silica nanospheres modified with covalently grafted poly(4-vinylpyridine) (P4VP) brushes, namely, “hairy” silica spheres, were utilized as a support for the anchorage of metal nanoparticles (MNPs), thus resulting in the hierarchical SiO2@P4VP/MNP structure. In this triple-phase boundary heteronanostructure, the SiO2-supported MNPs are well stabilized by the P4VP matrix to avoid aggregation and leaching. These SiO2@P4VP/MNP nanocomposites exhibit good catalytic activity in the reductive degradation of organic dyes, i.e., 4-nitrophenol and rhodamine B and possess excellent stability and recyclability for five successive cycles.

Hafnium oxide layer-enhanced single-walled carbon nanotube field-effect transistor-based sensing platform

Single-walled carbon nanotube-based field effect transistors (SWCNT-FETs) are ideal candidates for fabricating sensors and have been widely used for chemical sensing applications. SWCNT-FETs have low selectivity because of the environmentally sensitive electronic properties of SWCNTs, and SWCNT-FETs also show a high noise signal and poor sensitivity because of charge trapping from Si–OH hydration of the SiO2/Si substrate on the SWCNTs. Herein, poly (4-vinylpyridine) (P4VP) was used for noncovalent attachment to SWCNTs and selective binding to copper ions (Cu2+). Importantly, the introduction of a hafnium-oxide (HfO2) layer through atomic layer deposition (ALD) overcame the charge trapping by SiO2 hydration and remarkably decreased the interference signal. The sensitivity of the P4VP/SWCNT/HfO2-FET sensor for Cu2+ was 7.9 μA μM−1, which was approximately 100 times higher than that of the P4VP/SWCNT/SiO2-FET sensor, and its limit of detection (LOD) was as low as 33 pmol L−1. Thus, the P4VP/SWCNT/HfO2-FET sensor is a promising candidate for the development of Cu2+-selective sensors and can be designed for the large-scale manufacturing of custom-made sensors in the future.

Isothermal, Kinetic, and Thermodynamic Studies on the Adsorption of Molybdenum by a Nanostructured Magnetic Material

In this study, the magnetic 3-(trimethoxysilyl) propyl methacrylate (TMSPMA) – poly (4-vinylpyridine) (P4VP) was synthesized and characterized. Removal of Molybdenum (Mo) from aqueous solutions using prepared material as nanosorbent was investigated. The magnetic P4VP was prepared by copolymerization of P4VP with TMSPMA. The prepared adsorbent was characterized by various techniques including the X-ray powder diffraction (XRD), scanning electron microscopy (SEM), and Fourier-transform infrared spectroscopy (FTIR). The batch adsorption technique was applied and the effect of several important parameters such as pH of the aqueous solution, adsorbent dose, initial Mo(VI) concentration, contact time, and temperature was evaluated. Desorption behavior of Mo(VI) and the effect of foreign ions (Cd2+, Ca2+, Co2+, Fe3+, Ba2+ and Pt4+) in real samples were also investigated. Co (II) and Pt (IV) had a greater impact on the adsorption process than other foreign ions. The maximum capacity for Mo(VI) adsorption on the prepared adsorbent was 4.87 mg/g, which was obtained at a temperature of 40°C with an initial concentration of 10 mg/L of Mo(VI). The adsorption isotherms were best fitted with the Weber Van Vliet isotherm model. The kinetic data were fitted well with the pseudo-second-order equation with a high correlation coefficient (R2 > 0.99). Based on the negative standard Gibbs free energy change (ΔG° < 0) and the positive standard enthalpy change (ΔH° > 0), it was found that the adsorption was an endothermic and a spontaneous process in nature.

A chemiresistive methane sensor

A chemiresistive sensor is described for the detection of methane (CH4), a potent greenhouse gas that also poses an explosion hazard in air. The chemiresistor allows for the low-power, low-cost, and distributed sensing of CH4 at room temperature in air with environmental implications for gas leak detection in homes, production facilities, and pipelines. Specifically, the chemiresistors are based on single-walled carbon nanotubes (SWCNTs) noncovalently functionalized with poly(4-vinylpyridine) (P4VP) that enables the incorporation of a platinum-polyoxometalate (Pt-POM) CH4 oxidation precatalyst into the sensor by P4VP coordination. The resulting SWCNT-P4VP-Pt-POM composite showed ppm-level sensitivity to CH4 and good stability to air as well as time, wherein the generation of a high-valent platinum intermediate during CH4 oxidation is proposed as the origin of the observed chemiresistive response. The chemiresistor was found to exhibit selectivity for CH4 over heavier hydrocarbons such as n-hexane, benzene, toluene, and o-xylene, as well as gases, including carbon dioxide and hydrogen. The utility of the sensor in detecting CH4 using a simple handheld multimeter was also demonstrated.