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Cross-linked amino-polystyrene was reacted with thiophene-2-carboxyldehyde followed by the reaction with different metal salts [Cu(II), Mn(II), V(IV), Fe(III) and Ni(II)] to form new heterogeneous polystyrene-anchored catalysts. The structures of the immobilized catalysts were established on the basis of CHNS, DRS, FTIR, AAS, EDX and EPR techniques. The catalytic activity of polystyrene-anchored catalysts was estimated for the oxidation of benzyl alcohol using tert-butyl hydroperoxide and hydrogen peroxide as oxidants. The influence of different reaction parameters like temperature, time, oxidant and the quantity of catalyst on the oxidation were investigated. Under optimized condition, the results show that TBHP as an oxidant provides 90% conversion with the nickel catalyst. The copper catalyst, when used with TBHP, demonstrated the highest selectivity for benzaldehyde, reaching 98%. Under optimal conditions, the catalysts can be reused four times without considerable loss in its activity. [ABSTRACT FROM AUTHOR]

Biliary strictures are characterized by the narrowing of the bile duct lumen, usually caused by surgical biliary injury, cancer, inflammation, and scarring from gallstones. Endoscopic stent placement is a well-established method for the management of biliary strictures. However, maintaining optimal mechanical properties of stents and designing surfaces that can prevent stent-induced tissue hyperplasia and biofilm formation are challenges in the fabrication of biodegradable biliary stents (BBSs) for customized treatment. This study proposes a novel approach to fabricating functionalized polymer BBSs with nanoengineered surfaces using 3D printing. The 3D printed stents, fabricated from bioactive silica poly(ε-carprolactone) (PCL) via a sol–gel method, exhibited tunable mechanical properties suitable for supporting the bile duct while ensuring biocompatibility. Furthermore, a nanoengineered surface layer was successfully created on a sirolimus (SRL)-coated functionalized PCL (fPCL) stent using Zn ion sputtering-based plasma immersion ion implantation (S-PIII) treatment to enhance the performance of the stent. The nanoengineered surface of the SRL-coated fPCL stent effectively reduced bacterial responses and remarkably inhibited fibroblast proliferation and initial burst release of SRL in vitro systems. The physicochemical properties and biological behaviors, including in vitro biocompatibility and in vivo therapeutic efficacy in the rabbit bile duct, of the Zn-SRL@fPCL stent demonstrated its potential as a versatile platform for clinical applications in bile duct tissue engineering.

Supercritical carbon dioxide (CO2) has extremely important applications in the extraction of unconventional oil and gas, especially in fracturing and enhanced oil recovery (EOR) technologies. It can not only relieve water resource wastage and environmental pollution caused by traditional mining methods, but also effectively store CO2 and mitigate the greenhouse effect. However, the low viscosity nature of supercritical CO2 gives rise to challenges such as viscosity fingering, limited sand–carrying capacity, high filtration loss, low oil and gas recovery efficiency, and potential rock adsorption. To overcome these challenges, low–rock–adsorption thickeners are required to enhance the viscosity of supercritical CO2. Through research into the literature, this article reviews the solubility and thickening characteristics of four types of polymer thickeners, namely surfactants, hydrocarbons, fluorinated polymers, and silicone polymers in supercritical CO2. The thickening mechanisms of polymer thickeners were also analyzed, including intermolecular interactions, LA–LB interactions, hydrogen bonding, and functionalized polymers, and so on. [ABSTRACT FROM AUTHOR]

This article reviews the successive development of photo‐assisted electrochemical performances using functionalized polymer materials. The photoelectrochemical technologies have already been well‐established as a major tool for generating renewable energy harvesting solar power. In this regard, the research on the generation of new photoactive polymer supported units has drawn remarkable attention to improve the power conversion output and build up low‐cost advanced devices. So, starting from fundamental working principle, we have tried to overview comprehensively the key features of most of these studies, which involve the tactical schemes behind the appropriate selection of different substituents to functionalize the polymer skeleton to achieve an optimal bandgap, challenges faced specially in the index of performance in post synthetic phase, the possible routes to overcome the hurdle, so that it can harvest photons matched with the solar spectrum and of course their relevance in the broad range of application window. Apart from photovoltaic solar cell application, the idea has been logically extended to cover highly selective photoelectrochemical sensing devices,where we have disclosed briefly the role of polymers in designing innovative biosensors, the trend of development along with specific illustrative examples, and some of their successful utilization in real time assay. The overall description is entirely focused on how these strategies have emerged from the background concepts and finally shaped to a viable and significant outcome. [ABSTRACT FROM AUTHOR]

To meet the demands of the market and society, the development of structured polymeric materials for application in the medical field is constantly increasing. Over the last decades, metallic silver nanoparticles have been explored due to their antimicrobial action. Here, we aimed to incorporate metallic silver nanoparticles into polymeric pieces obtained by additive manufacture via a chemical route involving silver nitrate and sodium borohydride. Polyamide 12 membranes were obtained by selective laser sintering, which was followed by washing, pretreatment, and functionalization with the alkoxides tetraethylorthosilicate and 3-aminopropyl tetraethoxysilane. For nanoparticle preparation and incorporation, a chemical route was tested under different conditions. The samples were characterized by techniques, such as X-ray diffraction, ultraviolet-visible spectroscopy, and infrared vibrational spectroscopy. Nanoparticle formation and incorporation into the polyamide 12 membranes were demonstrated by the absorbance band at 420 nm, which indicated that the particles measured between 10 and 50 nm in size; by the X-ray diffraction peaks at 2θ = 38, 44, and 64°, which are typical of crystalline silver; and by vibrational spectroscopy, which evidenced that the nanoparticles interacted with the polyamide 12 nitrogen groups. Polyamide 12 membranes containing metallic silver nanoparticles have promising biomedical applications as antimicrobial wound dressings associated with drug carriers. Highlights: Nanoparticle size and shape determine nanoparticle stabilization in a PA12 polymer. The polymer pieces obtained by additive manufacture and modified by chemical agents contribute to new applications. The sol-gel process is an important technique to functionalize polymeric materials. [ABSTRACT FROM AUTHOR]

The influence of the concentration of copper particles, compatibilizers based on low- and high-density polyethylene graft copolymers and grafted methacrylic acid chains, as well as a functionalized polymer, on the regularity of changes in the peeling resistance of copper and aluminum foil is considered. The effect of the pressing temperature of a foil-clad polymer composite on the character of adhesive destruction of the above-mentioned composites is described. It has been shown that composites with a graft copolymer of polyethylene with methacrylic acid as a polymer matrix have relatively high peeling resistance. [ABSTRACT FROM AUTHOR]

Herein, the synthesis of functionalized polymer microspheres core-shell structure is successfully fabricated by a process involving three steps: (1) preparation of superparamagnetic Fe3O4 nanoparticles through a co-precipitation method, (2) Fe3O4 nanoparticles were functionalized using polypyrrole (PPy), a natural amino acid, to graft Hg(II) and azo dyes onto the surface of the nanocomposite, and (3) immobilization of meso-tetrakis (4-carboxyphenyl) porphyrin based on Fe3O4/PPy core-shell by a facile route. To recluse investigation of the ratio effect of core and shell amounts, the adsorbent was prepared with two different percentages: 2.53 and 33. In this work, some critical factors on the efficiency of adsorbent have been studied, including concentration and time. Structural and morphological changes induced by modification were confirmed by X-ray diffraction, Fourier transforms infrared, scanning electron microscopy, and energy-dispersive X-ray spectroscopy analysis. UV-visible (UV-vis) spectra illustrate the elimination percentages of methylene blue (MB) and methyl orange (MO). Inductively coupled plasma analysis was used to investigate the removal of Hg(II) ions. The results illustrated that the adsorbent shows efficiency up to 100%. Furthermore, UV-vis spectroscopy was used to show that the prepared nanocomposite removes MB and MO dyes with a yield of 100% and 95%, respectively. The porous structure was also investigated by Brunauer–Emmett–Teller analysis, and a type VI isotherm was obtained. The magnetic nanocomposite is featured with superparamagnetism, excellent reusability, and a high anti-interfering ability to remove Hg(II) toxic ions and organic pollutants such as MB and MO in an aqueous medium at room temperature. [ABSTRACT FROM AUTHOR]

N-(4-iodo-1,3-diphenylbutyl) acrylamide (NIAM) is a potential hydrophobic monomer for preparation of hydrophobically modified polyacrylamide largely used for enhanced oil recovery. Moreover, it has an iodine group as substitute allowing further modification reactions. This monomer was synthesized via Ritter reaction as described in the literature and characterized by nuclear magnetic resonance (NMR), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). DSC analysis of monomer showed two endothermic peaks referring to the melting points of a mixture of diastereoisomers. Conventional radical homopolymerization of NIAM was investigated, and the polymer was characterized by NMR, TGA, DSC and size-exclusion chromatography. The polymerization was successfully performed only in the presence of large amounts of radical initiator 2,2′-azobis(2-methylpropionitrile) (AIBN) suggesting an iodine transfer polymerization mechanism. The polymer showed low degree of polymerization, dispersity lower than 1.1 and glass transition temperature of 19.5 °C. [ABSTRACT FROM AUTHOR]

Currently, research in nanoparticles as a drug delivery system has broadened to include their use as a delivery system for bioactive substances and a diagnostic or theranostic system. Nanogels, nanoparticles containing a high amount of water, have gained attention due to their advantages of colloidal stability, core-shell structure, and adjustable structural components. These advantages provide the potential to design and fabricate multifunctional nanosystems for various biomedical applications. Modified or functionalized polymers and some metals are components that markedly enhance the features of the nanogels, such as tunable amphiphilicity, biocompatibility, stimuli-responsiveness, or sensing moieties, leading to specificity, stability, and tracking abilities. Here, we review the diverse designs of core-shell structure nanogels along with studies on the fabrication and demonstration of the responsiveness of nanogels to different stimuli, temperature, pH, reductive environment, or radiation. Furthermore, additional biomedical applications are presented to illustrate the versatility of the nanogels.

A new and sensitive preconcentration procedure was developed for the determination of trace amount of Mn(II) in environmental water samples. Amberlite XAD-4 resin was functionalized with N,N-bis(salicylidene)cyclohexanediamine (SCHD) to preconcentrate and separate Mn(II) at the trace level concentrations. Mn(II) ion in environmental water samples was determined by the formaldoxime spectrophotometric method. The influences of analytical parameters including pH and volume of sample, type and concentration of elution solution, flow rate of sample and elution solution, etc. were investigated on the recoveries of Mn(II) ion. The adsorption was achieved quantitatively for Mn(II) on XAD-4-SCHD resin at the pH range of 3–10 and 3 mL min–1 sample flow rate. Elution was performed with 0.5 mol L–1 nitric acid solution. Under the optimized conditions, calibration curve was found to be linear in the concentration range of 0.1–5 mg L–1 with a limit of detection of 0.65 μg L–1. The effect of foreign ions on the perconcentration and determination of Mn(II) was studied and no adversely affecting ion was observed even at high ionic media. The recovery value was above 90%, with an enrichment factor of 100. The per cent relative standard deviation (%) value was found to be 1.8 for twenty repetitive measurements containing 1 mg L–1 of Mn(II). Sorption capacity of the Mn(II) ion on the XAD-4-SCHD resin was found to be 29.217 μg. The accuracy of the presented preconcentration and determination method was checked by the analysis of TMDA-70.2 Ontario lake Water certified reference material and synthetic water sample. The method was applied for the analyses of tap water and industrial wastewater samples for Mn(II). Almost the similar results were observed for the Mn(II) determination in different environmental water samples using both the proposed and ICP-MS methods. [ABSTRACT FROM AUTHOR]

A simple, robust, and eco‐friendly technique for the fabrication of functionalized Jeffamine polymer in an aqueous medium is developed. The polymer is prepared by post polymerization modification of Jeffamine ED‐2003 of molecular weight 2000. The structure of the modified polymer was studied in detail using FTIR and NMR (1H and 13C NMR) spectroscopic methods. The thermal properties and degradation of the polymer were examined by DSC and TGA techniques. The polymer exhibited glass transition temperature (Tg) at 115°C. The functionalized polymeric compound showed good antimicrobial activity against gram‐negative bacterium Escherichia coli, a tubercular variant Mycobacterium smegmatis, and gram‐positive bacterium Staphylococcus aureus with a zone of inhibition of 6 to 12, 9, and 5 to 9 mm diameter, respectively. The compound also showed good activity against the fungus, Candida albicans, with a zone of inhibition of 6 to 11 mm diameter. The morphology of the polymer films and interaction of the microbes with functionalized Jeffamine polymer were investigated by using scanning electron microscopy (SEM). [ABSTRACT FROM AUTHOR]

Abstract: BACKGROUND: The nuclear power industry and other high‐tech industries require increasing quantities of uranium and rare‐earth elements (REEs). There is a need for materials that can competitively recover these metals from ore leachates (such as produced in the leaching of Egyptian ores). RESULTS: A sorbent based on the chemical grafting of glutamine moieties on a magnetic polyacrylonitrile support was synthesized: polyacrylonitrile, crosslinked with 10% divinyl benzene in the presence of magnetite, was chemically modified by a series of grafting steps to produce a magnetic polyglutamine sorbent (MGLU). The sorbent was characterized by titration, elemental analysis, X‐ray diffraction (XRD), thermogravimetric analysis, Fourier‐transform infra‐red (FTIR) spectrometry and scanning electron microscopy (SEM). The sorption properties were tested as a function of pH; the sorption isotherms were modeled using the Langmuir equation (maximum sorption capacities: 2 mmol U g‐1 and up to 3.5 mmol g‐1 for Nd(III) and Dy(III)). The equilibrium is achieved within 1 h of contact. Metal desorption and sorbent recycling are highly efficient using acidic solutions; sorption/desorption performance remains stable for a minimum of 5 cycles. MGLU was tested for metal binding in multi‐metal solutions at different pH values. CONCLUSION: This sorbent could be used for the recovery of REEs and uranium from simulated ore leachates. © 2017 Society of Chemical Industry [ABSTRACT FROM AUTHOR]

The main object of this study is to analyse the effects of different functional groups on the thermal and microbial properties of nanocomposites of poly(methyl methacrylate) (PMMA). For this, amino functionalized PMMA were synthesized by using post polymer functionalization method. In this method, PMMA was treated with four different amino compounds to obtain functionalized PMMA. To determine the structural features, functionalized PMMA was characterized with Fourier transform infrared (FTIR) spectroscopy. These functionalized PMMA were used to prepare functionalized polymer nanocomposites with addition of nanoclay and Ag nanoparticles into the polymer matrix. These nanocomposites were further studied against thermal and antibacterial properties. Sophisticated analytical techniques i.e., thermal gravimetric analysis (TGA), differential thermal analysis (DTA), and derivative thermogravimetric curve (DTG) were used to characterize the thermal properties of nanocomposites. Antibacterial study was performed by using disc diffusion method against bacteria E. coli. The thermal results showed that, the maximum degradation temperature ( T ) increases up to 85.5°C in air atmosphere in case of sample HM2. Antibacterial study showed that, the bacteria have least effect on the silver containing functionalized polymer nanocomposites. [ABSTRACT FROM AUTHOR]

In the present research, the concept of developing a novel system based on polymer-enzyme macromolecules was tested by coupling carboxylic acid functionalized poly(vinyl alcohol) (PVA-COOH) to glucose oxidase (GOx) followed by the bioconjugation with CdS quantum-dots (QD). The resulting organic-inorganic nanohybrids were characterized by UV-visible spectroscopy, infrared spectroscopy, Photoluminescence spectroscopy (PL) and transmission electron microscopy (TEM). The spectroscopy results have clearly shown that the polymer-enzyme macromolecules (PVA-COOH/GOx) were synthesized by the proposed zero-length linker route. Moreover, they have performed as successful capping agents for the nucleation and constrained growth of CdS quantum-dots via aqueous colloidal chemistry. The TEM images associated with the optical absorption results have indicated the formation of CdS nanocrystals with estimated diameters of about 3.0 nm. The “blue-shift” in the visible absorption spectra and the PL values have provided strong evidence that the fluorescent CdS nanoparticles were produced in the quantum-size confinement regime. Finally, the hybrid system was biochemically assayed by injecting the glucose substrate and detecting the formation of peroxide with the enzyme horseradish peroxidase (HRP). Thus, the polymer-enzyme-QD hybrid has behaved as a nanostructured sensor for glucose detecting.

Polymeric thin films represent an emerging industrial area driven by their enormous technological and commercial potential in interdisciplinary sectors such as chemistry, material science, engineering, and physics. The large selection in terms of materials/composites and the wide range of technological solutions that could be used for their fabrication could create confusion for the final user requiring a quantitative characterization of their properties. This analysis could be even more complex in the case of functionalized polymeric films such as the samples reported in this work. Here we present how thin polymer films can be wholly characterized by applying a multiplicity of optical methods. Films were realized by a special liquid one-step process. Moreover, such polymer films were functionalized here for the first time by mesoporous silica nanoparticles. The nanoparticles were added to a polymeric matrix. We show that a full characterization was achieved by employing three different microscope techniques, i.e., scanning electron microscope, digital holography (DH), and space-time DH. Exploiting such a multimodal methodology can be of great benefit for characterizing the functionalized polymeric thin films. In fact, multiple characterization in different conditions was possible. The results reported in terms of morphological information, thickness distribution, three-dimensional (3D) mapping, large field of view, high magnification, and super resolution of the zoomed area offer a good solution for testing materials and obtaining a quantitative characterization and whole inspection in the case of complex polymeric samples. [ABSTRACT FROM AUTHOR]

We have prepared cobalt sulfide (CoxSy) nanoparticles through a successive ionic layer adsorption and reaction (SILAR) method at room temperature. Co(NO3)2 ? 6H2O aqueous solution was used as a cobalt precursor, Na2S ? 9H2O and thiourea [(NH2)2CS] aqueous solutions were used as sulfur precursors. Functionalized nitrile butadiene rubber (FNBR) was used as a stabilizing agent for the formation of nanoparticles and contains -PO(OH)2 and -(O)PO(OH)2 acid groups. Obtained CoxSy/FNBR nanocomposites were annealed at 100°C in a vacuum for 6 h. The prepared nanocomposites were characterized by XRD, SEM, EDX, UV-Vis and FT-IR spectrometer. In case thiourea is used as asulfur source, mixed phases of Co3S4, CoS1.097 and CoS2 were obtained with the dominance of Co3S4 phase. A possible formation mechanism, physical and chemical stabilization into the functional polymer matrix (FNBR) for the growth processes have been discussed. [ABSTRACT FROM AUTHOR]

Diphenylphosphinated poly(vinyl alcohols) (DPP-PVA) were synthesized by the insertion of chlorodiphenylphosphine to PVA in the presence of triethyl amine as base. The structure of this new polymer was confirmed by FT-IR and NMR spectroscopy. This polymer can be used as ligand fo r the preparation of nanoparticles of palladium. The complexation of PVA-grafted phosphinite with palladium(II) acetate was carried out to obtain the heterogeneous catalytic system. X-ray diffraction techniques, X-ray photoelectron spectroscopy, and transmission electron microscopy imaging revealed that palladium was dispersed into the nanometer scale through the support. This catalytic system showed excellent activity in the cross-coupling Heck reactions of olefinic compounds with aryl iodides, bromides cl5 well as chlorides and gave high yields within short reaction times. Elemental analysis of Pd by the inductively coupled plasma technique on the supported catalyst exhibited low leaching of the metal into the solution. The catalyst can be reused several times in the repeated Heck reaction cycles without considerable loss in its activity. [ABSTRACT FROM AUTHOR]