scholarly journals Tuning the Activity of a Hybrid Polymer–Oxocluster Catalyst: A Composition—Selectivity Correlation

Polymers ◽  
2021 ◽  
Vol 13 (19) ◽  
pp. 3268
Author(s):  
Giulia Bragaggia ◽  
Anna Beghetto ◽  
Ferdinando Bassato ◽  
Rudi Reichenbächer ◽  
Paolo Dolcet ◽  
...  
Keyword(s):  
Solid State Nmr ◽  
Hydrolytic Stability ◽  
Polymeric Materials ◽  
Acrylic Polymers ◽  
X Ray ◽  
Ir And Raman Spectroscopies ◽  
Before And After ◽  
Ft Ir ◽  
X Ray Absorption ◽  
Ir And Raman

Zr-based oxoclusters MxOy(OR)w(OOR’)z are promising catalysts for the activation of hydrogen peroxide. However, they need to be integrated into suitable matrices to increase their hydrolytic stability and allow for their recovery after use. Polymeric materials can be successfully employed for this aim, since they modify the properties of the resulting hybrid materials, in terms of polarity and chemical affinity for the substrates, improving the catalytic activity. Herein, we report the synthesis of different acrylic polymers based on various co-monomers (methyl methacrylate (MMA), 2,2,2-trifluoroethylmethacrylate (TFMA) and 3-methacryloxypropyltrimethoxylsilane (MAPTMS)) covalently cross-linked by a Zr4-based oxocluster, whose composition was tuned to optimise the catalytic oxidation of methyl p-tolyl sulphide. To assess their properties and stability, the materials were characterised via Fourier Transform Infrared (FT-IR) and Raman spectroscopies, Thermogravimetric Analysis (TGA), Solid-State NMR (SS-NMR) and X-Ray Absorption Spectroscopies XAS, before and after catalytic turnover.

scholarly journals Mechanical Properties and Weathering Behavior of Polypropylene-Hemp Shives Composites

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Marcel Ionel Popa ◽  
Silvia Pernevan ◽  
Cecilia Sirghie ◽  
Iuliana Spiridon ◽  
Dorina Chambre ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Chemical Degradation ◽  
Accelerated Weathering ◽  
Ir And Raman Spectroscopies ◽  
Before And After ◽  
Ft Ir ◽  
Main Components ◽  
Poly Propylene ◽  
Ir And Raman

This paper presents the obtaining and the characterization of composites with polypropylene matrix and hemp shives as filler in different ratios and containing poly(propylene)-co maleic anhydride (MAH-PP) 3% wt as compatibility agent. The weathering behavior of the composite enclosing 60% hemp shives, performed after the exposure to UV radiations at different exposure times, was evaluated. The changes in the chemical and morphological structures were investigated by FT-IR and RAMAN spectroscopies and AFM microscopy. The mechanical characteristics of the composites were determined before and after an artificial aging process, and they are within the limits of the values reported for polyolefin-based composites and materials with natural fillers. During the accelerated weathering process, the correlation between the chemical degradation of the main components of the composite and the modification of the mechanical properties after the process of aging has been observed.

scholarly journals Synthesis and Impedance Spectroscopy of Poly(p-phenylenediamine)/Montmorillonite Composites

Polymers ◽  
2021 ◽  
Vol 13 (18) ◽  
pp. 3132
Author(s):  
Udit Acharya ◽  
Patrycja Bober ◽  
Muhammed Arshad Thottappali ◽  
Zuzana Morávková ◽  
Magdalena Konefał ◽  
...  
Keyword(s):  
Impedance Spectroscopy ◽  
Transport Mechanism ◽  
Oxidative Polymerization ◽  
Charge Transport Mechanism ◽  
X Ray ◽  
Ammonium Peroxydisulfate ◽  
Ir And Raman Spectroscopies ◽  
Temperature Ranges ◽  
Ft Ir ◽  
Ir And Raman

Poly(p-phenylenediamine)/montmorillonite (PPDA/MMT) composites were prepared by the oxidative polymerization of monomers intercalated within the MMT gallery, using ammonium peroxydisulfate as an oxidant. The intercalation process was evidenced by X-ray powder diffraction. The FT-IR and Raman spectroscopies revealed that, depending on the initial ratio between monomers and MMT in the polymerization mixture, the polymer or mainly oligomers are created during polymerization. The DC conductivity of composites was found to be higher than the conductivity of pristine polymer, reaching the highest value of 10−6 S cm−1 for the optimal MMT amount used during polymerization. Impedance spectroscopy was performed over wide frequency and temperature ranges to study the charge transport mechanism. The data analyzed in the framework of conductivity formalism suggest different conduction mechanisms for high and low temperature regions.

Preliminary Research on the Uptake Behavior of Ammonium Molybdophosphate for Cesium and the Corresponding Structural Transformation

2012 ◽  
Vol 535-537 ◽  
pp. 2191-2194 ◽  
Author(s):  
Zhao Ya Huang ◽  
Dong Zhang ◽  
Zhao Yi Tan
Keyword(s):  
Exchange Capacity ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ammonium Molybdophosphate ◽  
Before And After ◽  
Initial Ph ◽  
Negative Effect ◽  
Ft Ir ◽  
Ph Conditions ◽  
Ir And Raman

In this work, Ammonium Molybdophosphate (AMP) was synthesized and the adsorption of Cs onto it under different initial pH conditions was investigated. The results show the negative effect of the hydronium and hydroxyl irons on the uptake of Cs while the iron-exchange capacity can reach 144.8 mg/g. In addition, the structure differences between AMP samples before and after Cs adsorption were examined by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR) and Raman technique. The results show that the Keggin structure of AMP stayed unchanged while new bonds arose after the Cs adsorption.

scholarly journals Novel solid forms of the analgesic drug ethenzamide

2014 ◽  
Vol 70 (a1) ◽  
pp. C995-C995
Author(s):  
Duane Choquesillo-Lazarte ◽  
Cristóbal Verdugo-Escamilla ◽  
Juan Manuel García-Ruiz
Keyword(s):  
Polycrystalline Material ◽  
X Ray Diffraction ◽  
Analgesic Drug ◽  
X Ray ◽  
Solution Methods ◽  
Additional Stability ◽  
Ft Ir ◽  
Model Drug ◽  
Solid Form ◽  
Ir And Raman

The interest in multicomponent solid forms has increased in the last years within the pharmaceutical industry and also the solid-state community due to the possibility of obtaining materials with new properties [1]. Crystallization strategies, supported by solvent- and solid-based techniques, have also received attention in the search and development of methodologies for the screening of multicomponent crystals. In this work, ethenzamide, an anti-inflammatory and analgesic drug, was selected as a model drug to develop cocrystals on the basis of the synthon types using a series of phenolic coformers. Ethenzamide cocrystals and cocrystal solvates have been reported recently [2,3]. Liquid Assisted Grinding (LAG) and solution methods were used as synthetic tools. Attempts to produce cocrystals by LAG and Reaction Crystallization led to the formation of polycrystalline material. The solids obtained were then characterized by powder X-ray diffraction (PXRD), FT-IR and Raman spectroscopy. Recrystallization by slow solvent evaporation was carried out when the above-referred techniques strongly suggest the formation of a new solid form. The structure of five new multicomponent solids has been determined by single crystal X-ray diffraction. Additional stability studies have been performed at controlled relative humidity conditions and followed by PXRD.

scholarly journals Optical, Structural and Electrical Properties of Electrochemical Synthesis of Thin Film of Polyaniline

2018 ◽  
Vol 15 (1) ◽  
pp. 73-80 ◽  
Author(s):  
Baghdad Science Journal
Keyword(s):  
X Ray Diffraction ◽  
X Ray ◽  
Force Microscopy ◽  
Morphological Studies ◽  
Atomic Force ◽  
Vis Spectroscopy ◽  
Structural And Electrical Properties ◽  
A Cell ◽  
Ft Ir ◽  
Ir And Raman

Polyaniline membranes of aniline were produced using an electrochemical method in a cell consisting of two poles. The effect of the vaccination was observed on the color of membranes of polyaniline, where analysis as of blue to olive green paints. The sanction of PANI was done by FT-IR and Raman techniques. The crystallinity of the models was studied by X-ray diffraction technique. The different electronic transitions of the PANI were determined by UV-VIS spectroscopy. The electrical conductivity of the manufactured samples was measured by using the four-probe technique at room temperature. Morphological studies have been determined by Atomic force microscopy (AFM). The structural studies have been measured by (SEM).

scholarly journals Sonochemical-assisted magnesium borate synthesis from different boron sources

2017 ◽  
Vol 19 (1) ◽  
pp. 81-88 ◽  
Author(s):  
Meral Yildirim ◽  
Azmi Seyhun Kipcak ◽  
Emek Moroydor Derun
Keyword(s):  
High Efficiency ◽  
Synthesis Method ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Magnesium Borate ◽  
Ir And Raman Spectroscopies ◽  
Ft Ir ◽  
Surface Morphologies ◽  
Ir And Raman ◽  
Good Agreement

Abstract In this study, sonochemical-assisted magnesium borate synthesis is studied from different boron sources. Various reaction parameters are successfully applied by a simple and green method. X-ray diffraction (XRD), Fourier transform infrared (FT-IR) and Raman spectroscopies are used to characterize the synthesized magnesium borates on the other hand surface morphologies are investigated by using scanning electron microscope (SEM). The XRD analyses showed that the products were admontite [MgO(B2O3)3 · 7(H2O)] with JCPDS (Joint Committee on Powder Diffraction Standards) no. of 01-076-0540 and mcallisterite [Mg2(B6O7(OH)6)2 · 9(H2O)] with JCPDS no. of 01-070-1902. The results that found in the spectroscopic studies were in a good agreement with characteristic magnesium borate bands in both regions of infra-red and visible. According to SEM results, obtained borates were in micro and sub-micro scales. By the use of ultrasonication, reaction yields were found between 84.2 and 97.9%. As a result, it is concluded that the sonochemical approach is a practicable synthesis method to get high efficiency and high crystallinity in the synthesis magnesium borate compounds.

scholarly journals Direct Conjugation of Resveratrol on Hydrophilic Gold Nanoparticles: Structural and Cytotoxic Studies for Biomedical Applications

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1898
Author(s):  
Iole Venditti ◽  
Giovanna Iucci ◽  
Ilaria Fratoddi ◽  
Manuela Cipolletti ◽  
Emiliano Montalesi ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
X Ray ◽  
Conjugated Systems ◽  
Cell Vitality ◽  
Anticancer Effects ◽  
Radiation Induced ◽  
Ft Ir ◽  
Cytotoxic Studies ◽  
X Ray Absorption

Strongly hydrophilic gold nanoparticles (AuNPs), functionalized with citrate and L-cysteine, were synthetized and used as Resveratrol (RSV) vehicle to improve its bioavailability. Two different conjugation procedures were investigated: the first by adding RSV during AuNPs synthesis (1) and the second by adding RSV after AuNPs synthesis (2). The two different conjugated systems, namely AuNPs@RSV1 and AuNPs@RSV2 respectively, showed good loading efficiency (η%): η1 = 80 ± 5% for AuNPs@RSV1 and η2 = 20 ± 3% for AuNPs@RSV2. Both conjugated systems were investigated by means of Dynamic Light Scattering (DLS), confirming hydrophilic behavior and nanodimension (<2RH> 1 = 45 ± 12 nm and <2RH> 2 = 170 ± 30 nm). Fourier Transform Infrared Spectroscopy (FT-IR), Synchrotron Radiation induced X-Ray Photoelectron Spectroscopy (SR-XPS) and Near Edge X-ray Absorption Fine Structure (NEXAFS) techniques were applied to deeply understand the hooking mode of RSV on AuNPs surface in the two differently conjugated systems. Moreover, the biocompatibility of AuNPs and AuNPs@RSV1 was evaluated in the concentration range 1.0–45.5 µg/mL by assessing their effect on breast cancer cell vitality. The obtained data confirmed that, at the concentration used, AuNPs do not induce cell death, whereas AuNPs@RSV1 maintains the same anticancer effects as the unconjugated RSV.

Synthesis and characterization of the solid uranium(VI) dioxo-diacetohydroxamate complex

2007 ◽  
Vol 95 (8) ◽  
Author(s):  
Cynthia-May S. Gong ◽  
Frédéric Poineau ◽  
Kenneth R. Czerwinski
Keyword(s):  
Solid Phase ◽  
Uranyl Acetate ◽  
Proton Nuclear Magnetic Resonance ◽  
Acetohydroxamic Acid ◽  
Acetate Dihydrate ◽  
Reaction Conditions ◽  
X Ray ◽  
Ft Ir ◽  
X Ray Absorption

A novel dry synthesis for the uranium(VI) dioxo-diacetohydroxamate (UAHA) complex has been developed. The complex was generated in >80% yield by mechanically grinding solid uranyl acetate dihydrate (UAc) with solid acetohydroxamic acid in stoichiometric amounts. The resulting UOThe UAHA solid was extensively characterized by ultraviolet-visible (UV-vis), Fourier-transform infrared (FT-IR), and extended X-ray absorption fine structure (EXAFS) spectroscopies. The compound did not fluoresce after laser excitation. Proton nuclear magnetic resonance (NMR) spectra were obtained of the complex in DThe easy synthesis and purification of UAHA enables researchers to strictly control reaction conditions; to eliminate interfering salts and water; and to study the complex in the solid-phase.

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