X-ray Photoelectron Spectroscopy Evidence for the Covalent Bond between an Iron Surface and Aryl Groups Attached by the Electrochemical Reduction of Diazonium Salts

Langmuir ◽  
2003 ◽  
Vol 19 (15) ◽  
pp. 6333-6335 ◽  
Author(s):  
Kada Boukerma ◽  
Mohamed M. Chehimi ◽  
Jean Pinson ◽  
Chris Blomfield
Keyword(s):  
Electrochemical Reduction ◽  
Photoelectron Spectroscopy ◽  
Covalent Bond ◽  
Iron Surface ◽  
Diazonium Salts ◽  
X Ray

scholarly journals Cross-Linking With Diamine Monomers to Prepare Graphene Oxide Composite Membranes With Varying D-Spacing for Enhanced Desalination Properties

2021 ◽  
Vol 9 ◽  
Author(s):  
Hong Ju ◽  
Jinzhuo Duan ◽  
Haitong Lu ◽  
Weihui Xu
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Water Flux ◽  
Covalent Bond ◽  
Composite Membranes ◽  
Rejection Rate ◽  
High Water ◽  
Cross Linking ◽  
Separation Performance ◽  
X Ray

As a new type of membrane material, graphene oxide (GO) can easily form sub-nanometer interlayer channels, which can effectively screen salt ions. The composite membrane and structure with a high water flux and good ion rejection rate were compared by the cross-linking of GO with three different diamine monomers: ethylenediamine (EDA), urea (UR), and p-phenylenediamine (PPD). X-ray photoelectron spectroscopy (XPS) results showed that unmodified GO mainly comprises π-π interactions and hydrogen bonds, but after crosslinking with diamine, both GO and mixed cellulose (MCE) membranes are chemically bonded to the diamine. The GO-UR/MCE membrane achieved a water flux similar to the original GO membrane, while the water flux of GO-PPD/MCE and GO-EDA/MCE dropped. X-ray diffraction results demonstrated that the covalent bond between GO and diamine can effectively inhibit the extension of d-spacing during the transition between dry and wet states. The separation performance of the GO-UR/MCE membrane was the best. GO-PPD/MCE had the largest contact angle and the worst hydrophilicity, but its water flux was still greater than GO-EDA/MCE. This result indicated that the introduction of different functional groups during the diamine monomer cross-linking of GO caused some changes in the performance structure of the membrane.

scholarly journals Synthesis and physical properties of biodegradable nanocomposites fabricated using acrylic acid-grafted poly(butylene carbonate-co-terephthalate) and organically-modified layered zinc phenylphosphonate

2021 ◽  
Author(s):  
Yi-Fang Lee ◽  
Tzong-Ming Wu
Keyword(s):  
Acrylic Acid ◽  
Photoelectron Spectroscopy ◽  
Covalent Bond ◽  
Interlayer Spacing ◽  
X Ray Diffraction ◽  
Spectroscopy Analysis ◽  
X Ray ◽  
Nuclear Magnetic Resonance Spectra ◽  
Organically Modified ◽  
Biodegradable Nanocomposites

Abstract A set of novel biocompatible aliphatic-aromatic nanocomposites, including numerous acrylic acid-grafted poly(butylene carbonate-co-terephthalate) (g-PBCT) and organically-modified layered zinc phenylphosphonate (m-PPZn), were successfully synthesized via polycondensation and transesterification. A primary covalent linkage was produced between the biocompatible polymer and the inorganic reinforcements. Fourier transform infrared spectroscopy and 13C-nuclear magnetic resonance spectra demonstrated the successful grafting of acrylic acid into the PBCT (g-PBCT). Both wide-angle X-ray diffraction data and X-ray photoelectron spectroscopy analysis showed that the g-PBCT polymer matrix was intercalated into the interlayer spacing of the m-PPZn and was chemically interacted with the m-PPZn. The addition of m-PPZn in the g-PBCT matrix significantly improved its storage modulus. A slight increase in thermal stability was observed in all the g-PBCT/m-PPZn composites. Both results are attributed to the presence of covalent bond between g-PBCT and m-PPZn.

scholarly journals Chemical Synthesis and Characterization of Poly(poly(ethylene glycol) methacrylate)-Grafted CdTe Nanocrystals via RAFT Polymerization for Covalent Immobilization of Adenosine

Polymers ◽  
2019 ◽  
Vol 11 (1) ◽  
pp. 77 ◽  
Author(s):  
Trinh Duy Nguyen ◽  
Hieu Vu-Quang ◽  
Thanh Sang Vo ◽  
Duy Chinh Nguyen ◽  
Dai-Viet N. Vo ◽  
...  
Keyword(s):  
Ethylene Glycol ◽  
Photoelectron Spectroscopy ◽  
Raft Polymerization ◽  
Condensation Reaction ◽  
Covalent Bond ◽  
Poly Ethylene Glycol ◽  
X Ray ◽  
Glycol Methacrylate ◽  
Cdte Qds ◽  
Poly Ethylene

This paper describes the functionalization of poly(poly(ethylene glycol) methacrylate) (PPEGMA)-grafted CdTe (PPEGMA-g-CdTe) quantum dots (QDs) via surface-initiated reversible addition–fragmentation chain transfer (SI-RAFT) polymerization for immobilization of adenosine. Initially, the hydroxyl-coated CdTe QDs, synthesized using 2-mercaptoethanol (ME) as a capping agent, were coupled with a RAFT agent, S-benzyl S′-trimethoxysilylpropyltrithiocarbonate (BTPT), through a condensation reaction. Then, 2,2′-azobisisobutyronitrile (AIBN) was used to successfully initiate in situ RAFT polymerization to generate PPEGMA-g-CdTe nanocomposites. Adenosine-above-PPEGMA-grafted CdTe (Ado-i-PPEGMA-g-CdTe) hybrids were formed by the polymer shell, which had successfully undergone bioconjugation and postfunctionalization by adenosine (as a nucleoside). Fourier transform infrared (FT-IR) spectrophotometry, energy-dispersive X-ray (EDX) spectroscopy, thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy results indicated that a robust covalent bond was created between the organic PPEGMA part, cadmium telluride (CdTe) QDs, and the adenosine conjugate. The optical properties of the PPEGMA-g-CdTe and Ado-i-PPEGMA-g-CdTe hybrids were investigated by photoluminescence (PL) spectroscopy, and the results suggest that they have a great potential for application as optimal materials in biomedicine.

Preparation of Poly(diallydimethyl ammonium chloride) (PDDA)/Au Nanocomposite Film by In Situ Electrochemical Reduction and its Electrocatalytic Properties

2010 ◽  
Vol 123-125 ◽  
pp. 189-192
Author(s):  
Hong Wei Shi ◽  
Li Zhang ◽  
Cong Wang ◽  
Ke Ying Zhang
Keyword(s):  
Electrochemical Reduction ◽  
Ammonium Chloride ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Composite Films ◽  
Nanocomposite Films ◽  
Layer By Layer ◽  
X Ray ◽  
Assembly Technique

Nanocomposite films containing Au nanoparticles were fabricated by alternating adsorption of poly(diallydimethyl ammonium chloride) (PDDA) and HAuCl4 using layer-by-layer self-assembly technique and subsequent in situ electrochemical reduction of the AuCl4- ions. The composition and properties of the composite films were characterized by ultraviolet-visible spectroscopy (UV-vis), X-ray photoelectron spectroscopy (XPS), and cyclic voltammetry (CV).The UV-vis characteristic absorbances of PDDA and Au increase almost linearly with the number of bilayers, which suggests a progressive deposition with almost an equal amount of the PDDA and Au in each cycle. X-ray photoelectron spectroscopy further confirms the presence of the main components (such as PDDA and Au) of the nanocomposite films. Furthermore, the nanocomposite films also exhibit good electrocatalytic activity for the oxidation of ascorbic acid (AA), which may be used in electrochemical biosensors.

The interaction of diazomethane and its decomposition products with a polycrystalline iron surface, studied by X-ray photoelectron spectroscopy

1987 ◽  
Vol 184 (1-2) ◽  
pp. L339-L344
Author(s):  
Peter M. Loggenberg ◽  
Laurence Carlton ◽  
Richard G. Copperthwaite ◽  
Graham J. Hutchings
Keyword(s):  
Photoelectron Spectroscopy ◽  
Iron Surface ◽  
Decomposition Products ◽  
Polycrystalline Iron ◽  
X Ray

Growth of GaN by Vacuum Thermal Evaporation on Flexible Graphene/PET Substrates

2018 ◽  
Vol 10 (3) ◽  
pp. 329-336 ◽  
Author(s):  
Xinru Tong ◽  
Zhuo Zhao ◽  
Junsheng Wu ◽  
Yanwen Zhou ◽  
Peter Kelly ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Graphene Layer ◽  
Deposition Time ◽  
Thermal Evaporation ◽  
Flexible Substrate ◽  
Covalent Bond ◽  
Visible Range ◽  
Hybrid Films ◽  
X Ray ◽  
Vacuum Thermal Evaporation

The formation of GaN/graphene hybrid films through the vacuum thermal evaporation of GaN on a double layer flexible substrate consisting of a graphene layer on PET, has been studied. The thicknesses of the GaN layers and, therefore, the structure and properties of the hybrid films, were critically influenced by the deposition time. The structure of the GaN layer on graphene was amorphous, according to small angle X-ray diffraction spectra. The existence of the GaN layer on top of the graphene and the absence of a N–C covalent bond at the interface of the GaN/graphene hybrid film was confirmed by using Fourier transform infrared spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy. The free π-electrons of graphene took the conductive role in the hybrid films. A slight change in electrical properties was observed with increasing thickness of the GaN layer, due to the shunt resistance between this layer and the graphene layer. The grain size of the GaN films increased and transmittance within the visible range decreased with increasing deposition time, i.e., increasing thickness. The method presented demonstrates the feasibility of realizing transparent conductive GaN/graphene hybrid films on flexible PET, which are in high demand for fabricating optoelectronic and sensing devices.

scholarly journals Covalent Functionalization of Graphene Oxide with Fructose, Starch, and Micro-Cellulose by Sonochemistry

Polymers ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 490
Author(s):  
María Montserrat Cruz-Benítez ◽  
Pablo Gónzalez-Morones ◽  
Ernesto Hernández-Hernández ◽  
José Roberto Villagómez-Ibarra ◽  
Javier Castro-Rosas ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Organic Molecules ◽  
Chemical Characterization ◽  
Covalent Bond ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ultrasound Waves ◽  
Short Time

In this work, we report the synthesis of graphene oxide (GO) nanohybrids with starch, fructose, and micro-cellulose molecules by sonication in an aqueous medium at 90 °C and a short reaction time (30 min). The final product was washed with solvents to extract the nanohybrids and separate them from the organic molecules not grafted onto the GO surface. Nanohybrids were chemically characterized by Fourier-transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy and analyzed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD). These results indicate that the ultrasound energy promoted a chemical reaction between GO and the organic molecules in a short time (30 min). The chemical characterization of these nanohybrids confirms their covalent bond, obtaining a grafting percentage above 40% the weight in these nanohybrids. This hybridization creates nanometric and millimetric nanohybrid particles. In addition, the grafted organic molecules can be crystallized on GO films. Interference in the ultrasound waves of starch hybrids is due to the increase in viscosity, leading to a partial hybridization of GO with starch.

scholarly journals CO2 reduction to acetate in mixtures of ultrasmall (Cu)n,(Ag)m bimetallic nanoparticles

2017 ◽  
Vol 115 (2) ◽  
pp. 278-283 ◽  
Author(s):  
Ying Wang ◽  
Degao Wang ◽  
Christopher J. Dares ◽  
Seth L. Marquard ◽  
Matthew V. Sheridan ◽  
...  
Keyword(s):  
Electrochemical Reduction ◽  
Glassy Carbon ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Nanoparticles ◽  
Co2 Reduction ◽  
Surface Binding ◽  
Hydrogen Electrode ◽  
Faradaic Efficiency ◽  
X Ray ◽  
Co2 Reduction To Acetate

Monodispersed mixtures of 6-nm Cu and Ag nanoparticles were prepared by electrochemical reduction on electrochemically polymerized poly-Fe(vbpy)3(PF6)2 film electrodes on glassy carbon. Conversion of the complex to poly-Fe(vbpy)2(CN)2 followed by surface binding of salts of the cations and electrochemical reduction gave a mixture of chemically distinct clusters on the surface, (Cu)m,(Ag)n|polymer|glassy carbon electrode (GCE), as shown by X-ray photoelectron spectroscopy (XPS) measurements. A (Cu)2,(Ag)3|(80-monolayer-poly-Fe(vbpy)32+|GCE electrode at −1.33 V vs. reversible hydrogen electrode (RHE) in 0.5 M KHCO3, with 8 ppm added benzotriazole (BTA) at 0 °C, gave acetate with a faradaic efficiency of 21.2%.

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