scholarly journals Graphene oxide chemically decorated with hybrid Ag-Ru/chitosan nanoparticles: fabrication and properties

2015 ◽  
Author(s):  
Murugan Veerapandian ◽  
Suresh Neethirajan
Keyword(s):  
Graphene Oxide ◽  
Chitosan Nanoparticles ◽  
Hybrid Nanoparticles ◽  
Spectroscopic Techniques ◽  
Wet Chemical ◽  
Amine Groups ◽  
Oxygenated Functional Groups ◽  
Coordination Reaction

Hybridization of distinct materials into a single nanoplatform is relevant to advance material’s properties for functional application such as biosensor platform. We report the synthesis and characterization of nanosheets of graphene oxide decorated with hybrid nanoparticles of silver-ruthenium bipyridine complex (Ag@[Ru(bpy)3]2+) core and chitosan shell. Hybrid nanoparticles were first obtained through a sequential wet-chemical approach using in situ reduction, electrostatic and coordination reaction. Oxygenated functional groups of graphene oxide and abundant amine groups of chitosan layer on the surface of hybrid nanoparticles allowed the functionalization reaction. Changes in intrinsic optical, chemical and structural properties of graphene oxide due to hybrid nanoparticles were studied in depth using spectroscopic techniques and an electron microscope. Electrodes modified with nanosheets of graphene oxide-hybrid nanoparticles retain the biocompatibility and displayed an amplified redox property suitable for a broad range of sensing studies.

Synthesis of sandwich type acyclic tetra-nuclear silver(I)-N-heterocyclic carbene complexes for wound healing applications

2020 ◽  
Vol 75 (9-10) ◽  
pp. 369-376
Author(s):  
Ayesha Riaz ◽  
Muhammad Adnan Iqbal ◽  
Haq Nawaz Bhatti ◽  
Muhammad Shahid
Keyword(s):  
Alkyl Halides ◽  
Wound Contraction ◽  
Spectroscopic Techniques ◽  
Open Chain ◽  
Standard Drug ◽  
Sandwich Type ◽  
Benzimidazolium Salts ◽  
Multistep Reaction

AbstractTwo meta-xylyl linked tetrakis-benzimidazolium salts (L1-L2) as multidentate ligands and two respective silver complexes (C1 and C2) were synthesized. A multistep reaction was done at room temperature, starting with simple benzimidazole and alkyl halides, going through precursors and salt formation by reflux and finally in situ deprotonation of tetrabenzimidazolium salts with Ag2O to yield respective tetra-nuclear Ag(I)-N-heterocyclic Carbene (NHC) complexes. Propyl and butyl groups were bonded at the terminal positions of tetra-azolium open chain salts. Characterization of compounds was done by analytical and spectroscopic techniques. On the basis of spectroscopic data, a chemical structure with open chains having four Ag(I) ions sandwiched between NHC layers was established. Potential of synthesized complexes (C1 & C2) for wound contraction was evaluated and compared with standard wound contraction gel. Percentage wound contraction of both complexes was found very close to that of standard drug used in parallel.

Supported optically active poly(amide-imide) on magnetic graphene oxide/Fe3O4 for Hg2+ adsorption from aqueous solution

2019 ◽  
pp. 089270571988909
Author(s):  
Sedigheh Khalili ◽  
Zahra Rafiee
Keyword(s):  
Graphene Oxide ◽  
Sem Analysis ◽  
Optically Active ◽  
X Ray Diffraction ◽  
One Pot ◽  
Thermal Stabilities ◽  
Magnetic Graphene Oxide ◽  
Methyl Phenyl

The ternary superparamagnetic nanocomposites consisting of graphene oxide (GO), Fe3O4 nanoparticles, and optically active poly(amide-imide) (PAI) were fabricated in three steps consisting of a facile one-pot in situ growth of Fe3O4 on GO, resulted in the preparation of the magnetic Fe3O4@GO, modification of Fe3O4@GO by 3-aminopropyltriethoxy silane to introduce amino groups on its surface, and subsequently its compositing by various levels of 5, 10, and 15 wt% with chiral PAI derived from 3,5-diamino- N-(4-(di(1H-indol-3-yl)methyl)phenyl)benzamide and N, N′-(4,4′-carbonyldiphthaloyl)-bis-l-phenylalanine diacid through ultrasonic irradiation. Characterization of the resulting nanocomposites was performed by Fourier transform infrared spectroscopy, X-ray diffraction, vibrating sample magnetometer, scanning electron microscope (SEM), and thermogravimetric analysis (TGA). The SEM analysis showed Fe3O4 nanoparticles with 30 nm size successfully decorated the GO nanosheets. The TGA analysis established the expected thermal stabilities for PAI/Fe3O4@GO nanocomposites. Furthermore, incorporation of Fe3O4@GO in polymer matrix improved the mechanical properties substantially. PAI/Fe3O4@GO 10 wt% was used to evaluate the sorption properties of Hg2+ at pH 7.

In Situ Synthesis and Characterization of Poly(aryleneethynylene)-Grafted Reduced Graphene Oxide

2016 ◽  
Vol 22 (7) ◽  
pp. 2247-2252 ◽  
Author(s):  
Sai Sun ◽  
Xiaodong Zhuang ◽  
Bo Liu ◽  
Luxing Wang ◽  
Linfeng Gu ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
In Situ Synthesis ◽  
Synthesis And Characterization ◽  
Reduced Graphene

scholarly journals Synthesis and Characterization of Novel Ternary Hybrid Nanoparticles as Thermal Additives in H2O

2021 ◽  
Author(s):  
Mohammed Zayan ◽  
Abdul Khaliq Rasheed ◽  
Akbar John ◽  
Shalini Muniandi ◽  
leo bay fen ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Graphene Oxide ◽  
Hybrid Nanoparticles ◽  
Heat Transfer Medium ◽  
Low Concentrations ◽  
Reduced Graphene ◽  
Thermophysical Characterization ◽  
Newtonian Behavior ◽  
Conductivity Models

The performance of water as a heat transfer medium in numerous applications is limited by its effective thermal conductivity. In order to improve the thermal conductivity of water, herein we report the development and thermophysical characterization of a novel metal-metaloxide-carbon based ternary hybrid nanoparticles (THNp), GO-TiO2-Ag and the rGO-TiO2-Ag. The results indicate that the graphene oxide and reduced graphene oxide based ternary hybrid nanoparticles dispersed in water enhance its thermal conductivity by 66% and 83%, respectively, even at very low concentrations. Mechanisms contributing to this significant enhancement are discussed. The experimental thermal conductivity is plotted against the existing empirical hybrid thermal conductivity correlations. We found that those correlations are not suitable for the metal-metaloxide-carbon combinations, calling for the developing a new thermal conductivity models. The rheological measurements of the nanofluids display non-Newtonian behavior, and the viscosity reduces with the increase in temperature. Such behavior is possibly due to the non-uniform shapes of the ternary hybrid nanoparticles.

scholarly journals Structural Characterization of Lignin during Pinus taeda Wood Treatment with Ceriporiopsis subvermispora

2004 ◽  
Vol 70 (7) ◽  
pp. 4073-4078 ◽  
Author(s):  
Anderson Guerra ◽  
Régis Mendonça ◽  
André Ferraz ◽  
Fachuang Lu ◽  
John Ralph
Keyword(s):  
Pinus Taeda ◽  
Wood Chips ◽  
Spectroscopic Techniques ◽  
Lignin Biodegradation ◽  
Visible Spectroscopy ◽  
Ceriporiopsis Subvermispora ◽  
Wood Treatment ◽  
Biological Attack ◽  
Wet Chemical

ABSTRACT Pinus taeda wood chips were biotreated with Ceriporiopsis subvermispora under solid-state fermentation for periods varying from 15 to 90 days. Milled wood lignins extracted from sound and biotreated wood samples were characterized by wet-chemical and spectroscopic techniques. Treatment of the lignins by derivatization followed by reductive cleavage (DFRC) made it possible to detect DFRC monomers and dimers that are diagnostic of the occurrence of arylglycerol-β-O-aryl and β-β, β-5, β-1, and 4-O-5 units in the lignin structure. Quantification of these DFRC products indicated that β-O-aryl cleavage was a significant route for lignin biodegradation but that β-β, β-5, β-1, and 4-O-5 linkages were more resistant to the biological attack. The amount of aromatic hydroxyls did not increase with the split of β-O-4 linkages, suggesting that the β-O-4 cleavage products remain as quinone-type structures as detected by UV and visible spectroscopy. Nuclear magnetic resonance techniques also indicated the formation of new substructures containing nonoxygenated, saturated aliphatic carbons (CH2 and CH3) in the side chains of lignins extracted from biotreated wood samples.

Molecular and X-ray Spectroscopies for Noninvasive Characterization of Mayan Green Stones from Bonampak, Chiapas

2019 ◽  
Vol 73 (9) ◽  
pp. 1074-1086
Author(s):  
Valentina Aguilar-Melo ◽  
Alejandro Mitrani ◽  
Edgar Casanova-Gonzalez ◽  
Mayra D. Manrique-Ortega ◽  
Griselda Pérez-Ireta ◽  
...  
Keyword(s):  
Archaeological Site ◽  
Molecular Techniques ◽  
Spectroscopic Techniques ◽  
X Ray Diffraction ◽  
X Ray ◽  
Ft Ir ◽  
Noninvasive Characterization ◽  
A Minor

A burial and a rich offering were found under Room 2 in the Murals Building, Bonampak, a Mayan archaeological site situated in Chiapas, Mexico. This burial may be related with the creation of the famous mural paintings. A rich set of jewelry made of green stones was among the different objects found. Green stones have great importance in Mesoamerican cultures, those composed of jadeite being the most appreciated. To characterize the green stones, different spectroscopic techniques were used in a complementary way: Raman and infrared spectroscopies (FT-IR) were used for global mineralogical analysis, while X-ray diffraction (XRD) and X-ray fluorescence (XRF) were applied simultaneously in situ on the artifacts that were not successfully identified by these molecular techniques. In addition, XRF was used to contrasts the elemental information from pieces composed of pyroxenes that may be related to the raw sources of jade in Guatemala. The main minerals identified within the beads and earrings were jadeite with omphacite and jadeite with albite; to a minor extent, quartz, and serpentine. In this paper, the main features of the molecular and X-ray techniques are compared in order to determine the advantages and limitations of these spectroscopies for mineral identification. With this combination of techniques, it was possible to undertake a suitable characterization of the analyzed objects. This paper focuses on the XRD–XRF combined analysis for in situ noninvasive characterization.

scholarly journals Preparation and characterization of insensitive HMX/rGO/G composites via in situ reduction of graphene oxide

RSC Advances ◽  
2017 ◽  
Vol 7 (51) ◽  
pp. 32275-32281 ◽  
Author(s):  
Chunhuan Niu ◽  
Bo Jin ◽  
Rufang Peng ◽  
Yu Shang ◽  
Qiangqiang Liu
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Chemical Reduction ◽  
In Situ Reduction ◽  
Reduced Graphene ◽  
Coating Method

Composites of 1,3,5,7-tetranitro-1,3,5,7-tetrazocane/reduced graphene oxide/graphite (HMX/rGO/G) were successfully prepared via an in situ chemical reduction coating method.

Sign in / Sign up

Export Citation Format

Share Document