scholarly journals Sunlight-Driven Photothermal Effect of Composite Eggshell Membrane Coated with Graphene Oxide and Gold Nanoparticles

2019 ◽  
Vol 9 (20) ◽  
pp. 4384
Author(s):  
Ling Wang ◽  
Bin Tang ◽  
Ji Zhou ◽  
Hai Zhao ◽  
Wu Chen ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Chemical Elements ◽  
Membrane Surface ◽  
Composite Membranes ◽  
Eggshell Membrane ◽  
Photothermal Effect ◽  
Photothermal Conversion ◽  
3D Network

Eggshell membrane (ESM), which consists of unique interwoven shell membrane fibers, provides a unique supporting platform for functional nanoparticles in catalysis and sensing. This work reports a novel strategy for fabricating sunlight-driven photothermal conversion composite membranes by loading graphene oxide (GO) and gold nanoparticles (AuNPs) on the three-dimension (3D) network structured eggshell membrane. Surface morphologies and chemical elements were characterized by scanning electron microscopy and X-ray photoelectron spectroscopy. High photothermal conversion under simulated sunlight irradiation, which may be caused by the synergistic effect of GO and AuNPs, was achieved by coating both GO and AuNPs onto ESM. The temperature of ESM modified with AuNPs, and then GO increased from 26.0 °C to 49.0 °C after 10 min of light irradiation. Furthermore, the nanoscaled GO and AuNPs could add benefit to the heating localization of the obtained composite membrane. It is expected this biocompatible ESM modified with GO and AuNPs would have great potential in drug release and photothermal therapy applications.

scholarly journals Synthesis and Characterization of Composite Membranes Based on Carbon Functionalized with Gold Nanoparticles

2019 ◽  
Vol 56 (2) ◽  
pp. 309-314
Author(s):  
Alexandra Georgiana Vatui (Moise) ◽  
Sorina Nicoleta Valsan ◽  
Corneliu Fratila ◽  
Andreea Nicoleta Ghita ◽  
Arcadii Sobetkii ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Cross Sections ◽  
Self Assembly ◽  
Carbon Nanostructures ◽  
Chemical Reduction ◽  
Membrane Surface ◽  
Composite Membranes ◽  
The Matrix ◽  
Experimental Laboratory

The purpose of this experimental laboratory work is to obtain composite membranes having carbon and gold nanoparticles in the matrix. Consideration was made of using graphene oxide, a material which, under certain conditions, can generate membranes by a self-assembly process under vacuum in an aqueous or organic medium. The cellulose acetate (CA) - graphene oxide (GO) composite membranes have been functionalized with gold nanoparticles (AuNP) by two technological processes: thermal evaporation and ultrasonic mixing of stable graphene oxide and gold suspensions. The stable suspensions containing gold nanoparticles were obtained by chemical reduction of aqueous solutions of Tetrachloroauric acid trihydrate (HAuCl4) precursors with sodium citrate under high temperature conditions. Dispersibility of carbon nanostructures and precious metal nanoparticles has been studied with a DLS granulometer - Malvern Instruments Zetasizer ZS90. It was determined the mean particle size and Zeta potential function of the suspensions pH. The graphite based membranes were further subjected to various characterizations techniques. It was found that both the surfaces and the cross-sections were functionalized with gold particles. The presence of Au particles was revealed both on the membrane surface and also inside its structure. Hydrophilic tests demonstrate that the membrane filters have potential to be used in various applications.

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 Simultaneous Detection of Dihydroxybenzene Isomers Using Electrochemically Reduced Graphene Oxide-Carboxylated Carbon Nanotubes/Gold Nanoparticles Nanocomposite

Biosensors ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 321
Author(s):  
Angélica Domínguez-Aragón ◽  
Rocio B. Dominguez ◽  
Erasto Armando Zaragoza-Contreras
Keyword(s):  
Carbon Nanotubes ◽  
Gold Nanoparticles ◽  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Tap Water ◽  
Simultaneous Detection ◽  
3D Network ◽  
Reduced Graphene ◽  
Electrochemically Reduced Graphene Oxide ◽  
Carboxylated Carbon Nanotubes

An electrochemical sensor based on electrochemically reduced graphene oxide (ErGO), carboxylated carbon nanotubes (cMWCNT), and gold nanoparticles (AuNPs) (GCE/ErGO-cMWCNT/AuNPs) was developed for the simultaneous detection of dihidroxybenzen isomers (DHB) hydroquinone (HQ), catechol (CC), and resorcinol (RS) using differential pulse voltammetry (DPV). The fabrication and optimization of the system were evaluated with Raman Spectroscopy, SEM, cyclic voltammetry, and DPV. Under optimized conditions, the GCE/ErGO-cMWCNT/AuNPs sensor exhibited a linear concentration range of 1.2–170 μM for HQ and CC, and 2.4–400 μM for RS with a detection limit of 0.39 μM, 0.54 μM, and 0.61 μM, respectively. When evaluated in tap water and skin-lightening cream, DHB multianalyte detection showed an average recovery rate of 107.11% and 102.56%, respectively. The performance was attributed to the synergistic effects of the 3D network formed by the strong π–π stacking interaction between ErGO and cMWCNT, combined with the active catalytic sites of AuNPs. Additionally, the cMWCNT provided improved electrocatalytic properties associated with the carboxyl groups that facilitate the adsorption of the DHB and the greater amount of active edge planes. The proposed GCE/ErGO-cMWCNT/AuNPs sensor showed a great potential for the simultaneous, precise, and easy-to-handle detection of DHB in complex samples with high sensitivity.

X-Ray Photoelectron Spectroscopy Characterization of Polyaniline-Cellulose Ester Composite Membranes

2010 ◽  
Vol 657 ◽  
pp. 35-45 ◽  
Author(s):  
Asif A. Qaiser ◽  
Margaret M. Hyland
Keyword(s):  
Oxidation State ◽  
Photoelectron Spectroscopy ◽  
Membrane Surface ◽  
Oxidative Polymerization ◽  
Composite Membranes ◽  
Core Level ◽  
Ring Cleavage ◽  
Cellulose Ester ◽  
X Ray

X-ray photoelectron spectroscopy (XPS) is a promising technique employed for the study of conducting polymers and their composites. XPS was used to study the surface chemistry of polyaniline-mixed cellulose ester (PANI-ME) composite membranes prepared by various chemical oxidative polymerization techniques such as insitu solution, vapour phase polymerizations and aniline polymerization using a two-compartment permeation cell. Hydrolytic degradation of surface deposited PANI and scission of cellulosic chains due to x-ray irradiation inside the XPS chamber influenced the quantification of polyaniline deposition levels as well as oxidation and doping states in PANI-ME membranes. N1s core level spectra allowed characterization of the PANI deposition level, its oxidation state and x-ray induced cellulosic ring cleavage. C1s and O1s core level spectra revealed PANI hydrolysis at the membrane surface. These degradation phenomena influence the performance of PANI composite membranes used specifically in electrodiffusion applications. It was shown that successful quantification of PANI deposition levels and its oxidation state on microporous mixed cellulose ester membranes using XPS could be realized by incorporating the degradation effects in the characterization results.

scholarly journals Photocatalytic reduction of graphene oxide with cuprous oxide film under UV-vis irradiation

2020 ◽  
Vol 59 (1) ◽  
pp. 207-214 ◽  
Author(s):  
Yao Wang ◽  
Jianqing Feng ◽  
Lihua Jin ◽  
Chengshan Li
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Low Cost ◽  
Photocatalytic Reduction ◽  
Force Microscopy ◽  
Atomic Force ◽  
Reduced Graphene ◽  
Reduction Efficiency ◽  
Metal Organic ◽  
Reduction Effect

AbstractWe have grown Cu2O films by different routes including self-oxidation and metal-organic deposition (MOD). The reduction efficiency of Cu2O films on graphene oxide (GO) synthesized by modified Hummer’s method has been studied. Surface morphology and chemical state of as-prepared Cu2O film and GO sheets reduced at different conditions have also been investigated using atomic force microscopy (AFM) and x-ray photoelectron spectroscopy (XPS). Results show that self-oxidation Cu2O film is more effective on phtocatalytic reduction of GO than MOD-Cu2O film. Moreover, reduction effect of self-oxidation Cu2O film to GO is comparable to that of environmental-friendly reducing agent of vitamin C. The present results offer a potentially eco-friendly and low-cost approach for the manufacture of reduced graphene oxide (RGO) by photocatalytic reduction.

scholarly journals Chitosan/Silver Nanoparticle/Graphene Oxide Nanocomposites with Multi-Drug Release, Antimicrobial, and Photothermal Conversion Functions

Materials ◽  
2021 ◽  
Vol 14 (9) ◽  
pp. 2351
Author(s):  
Zheng Su ◽  
Daye Sun ◽  
Li Zhang ◽  
Miaomiao He ◽  
Yulin Jiang ◽  
...  
Keyword(s):  
Silver Nanoparticles ◽  
Graphene Oxide ◽  
Drug Release ◽  
Release Rate ◽  
Composite System ◽  
Methyl Blue ◽  
Burst Release ◽  
Fluorescein Sodium ◽  
Photothermal Conversion ◽  
Dual Drug

In this work, we designed and fabricated a multifunctional nanocomposite system that consists of chitosan, raspberry-like silver nanoparticles, and graphene oxide. The room temperature atmospheric pressure microplasma (RT-APM) process provides a rapid, facile, and environmentally-friendly method for introducing silver nanoparticles into the composite system. Our composite can achieve a pH controlled single and/or dual drug release. Under pH 7.4 for methyl blue loaded on chitosan, the drug release profile features a burst release during the first 10 h, followed by a more stabilized release of 70–80% after 40–50 h. For fluorescein sodium loaded on graphene oxide, the drug release only reached 45% towards the end of 240 h. When the composite acted as a dual drug release system, the interaction of fluorescein sodium and methyl blue slowed down the methyl blue release rate. Under pH 4, both single and dual drug systems showed a much higher release rate. In addition, our composite system demonstrated strong antibacterial abilities against E. coli and S. aureus, as well as an excellent photothermal conversion effect under irradiation of near infrared lasers. The photothermal conversion efficiency can be controlled by the laser power. These unique functionalities of our nanocomposite point to its potential application in multiple areas, such as multimodal therapeutics in healthcare, water treatment, and anti-microbials, among others.

Oxidation degree or sheet size: What really matters for the photothermal effect and ecotoxicity of graphene oxide?

FlatChem ◽  
2021 ◽  
Vol 26 ◽  
pp. 100231
Author(s):  
Caio C.C. Moreira ◽  
Ítalo A. Costa ◽  
Diego S. Moura ◽  
Cesar K. Grisolia ◽  
Carlos A.E.M. Leite ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Photothermal Effect ◽  
Oxidation Degree

scholarly journals Boron from net charge acceptor to donor and its effect on hydrogen uptake by novel Mg-B-electrochemically synthesized reduced graphene oxide

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marla V. V. Satya Aditya ◽  
Srikanta Panda ◽  
Sankara Sarma V. Tatiparti
Keyword(s):  
Graphene Oxide ◽  
Reduced Graphene Oxide ◽  
Incubation Time ◽  
Photoelectron Spectroscopy ◽  
Weight Ratio ◽  
Hydrogen Uptake ◽  
Binding Energies ◽  
Unit Cell ◽  
Net Charge ◽  
Reduced Graphene

AbstractHydrogen uptake (H-uptake) is studied in ball milled Mg-B-electrochemically synthesized reduced graphene oxide (erGO) nanocomposites at PH2 ≈ 15 bar, ~ 320 °C. B/C (weight ratio): 0, ~ 0.09, ~ 0.36, ~ 0.90 are synthesized maintaining erGO≈10wt %. B occupies octahedral interstices within Mg unit cell—revealed by electron density maps. Persistent charge donations from Mg and B to C appear as Mg-C (~ 283.2 eV), B-C (~ 283.3–283.9 eV) interactions in C-1s core X-ray photoelectron spectroscopy (XPS) at all B/C. At B/C > 0.09, charge reception by B from Mg yields Mg-B interaction. This net charge acceptor role of B renders it electron-rich and does not alter Mg unit cell size significantly. Despite charge donation to both C and B, the Mg charge is <  + 2, resulting in long incubation times (> 5 h) at B/C > 0.09. At B/C≈0.09 the minimal Mg-B interaction renders B a charge donor, resulting in Mg-B repulsion and Mg unit cell expansion. Mg-C peak shift to lower binding energies (C-1s XPS), decreases incubation time to ~ 2.25 h and enhances H-uptake kinetics. Various atomic interactions influence the reduction of incubation time in H-uptake and increase its kinetics in the order: (Mg → C; B → C)B/C≈0.09, B: donor > (Mg → C)B/C=0 > (ternary Mg → B → C)B/C>0.09, B: acceptor.

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