Fire retardancy of graphene oxide/wood composite (GOW) prepared by a vacuum-pulse dipping technique

Holzforschung ◽  
2018 ◽  
Vol 72 (5) ◽  
pp. 375-378 ◽  
Author(s):  
Xiaoshuai Han ◽  
Qinqin Zhang ◽  
Yihui Yin ◽  
Junwen Pu
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
Degree Of Crystallinity ◽  
Multilayer Graphene ◽  
Layer By Layer ◽  
Fire Retardancy ◽  
X Ray Diffraction ◽  
X Ray ◽  
Natural Wood ◽  
Thermal Stability Of

AbstractGraphene oxide/wood (GOW) composite was fabricated by a vacuum-pulse dipping technique, and the resulting composites were characterized by scanning electron microscope (SEM), Raman spectroscopy and thermogravimetric analysis (TGA). As demonstrated, the wood matrix became filled by the dense multilayer graphene oxide (GO) membrane structure, which was formed by the layer-by-layer self-assembly of GO nano-sheets. X-ray diffraction (XRD) revealed that the amorphous GO decreased the composite’s relative degree of crystallinity. Additionally, the filled GO generated improvement in the thermal stability of GOW composites in comparison with that of the natural wood (NW).

scholarly journals Layer-by-Layer Self-Assembled Ferrite Multilayer Nanofilms for Microwave Absorption

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Jiwoong Heo ◽  
Daheui Choi ◽  
Jinkee Hong
Keyword(s):  
Electron Microscopy ◽  
Self Assembly ◽  
Precursor Solution ◽  
Ferrite Nanoparticles ◽  
Energy Dispersive ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Simple Method ◽  
X Ray ◽  
Scanning Electron

We demonstrate a simple method for fabricating multilayer thin films containing ferrite (Co0.5Zn0.5Fe2O4) nanoparticles, using layer-by-layer (LbL) self-assembly. These films have microwave absorbing properties for possible radar absorbing and stealth applications. To demonstrate incorporation of inorganic ferrite nanoparticles into an electrostatic-interaction-based LbL self-assembly, we fabricated two types of films: (1) a blended three-component LbL film consisting of a sequential poly(acrylic acid)/oleic acid-ferrite blend layer and a poly(allylamine hydrochloride) layer and (2) a tetralayer LbL film consisting of sequential poly(diallyldimethylammonium chloride), poly(sodium-4-sulfonate), bPEI-ferrite, and poly(sodium-4-sulfonate) layers. We compared surface morphologies, thicknesses, and packing density of the two types of ferrite multilayer film. Ferrite nanoparticles (Co0.5Zn0.5Fe2O4) were prepared via a coprecipitation method from an aqueous precursor solution. The structure and composition of the ferrite nanoparticles were characterized by X-ray diffraction, energy dispersive X-ray spectroscopy, transmission electron microscopy, and scanning electron microscopy. X-ray diffraction patterns of ferrite nanoparticles indicated a cubic spinel structure, and energy dispersive X-ray spectroscopy revealed their composition. Thickness growth and surface morphology were measured using a profilometer, atomic force microscope, and scanning electron microscope.

scholarly journals Nacre Shell Inspired Self Assembly of Graphene Oxide-Lipid Nanocomposites

2021 ◽  
Author(s):  
Greeshma Chathamkandath Raghuvaran ◽  
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
Lipid Membranes ◽  
Experimental Studies ◽  
Layer By Layer ◽  
Fabrication Method ◽  
X Ray Diffraction ◽  
Free Standing ◽  
Sem Images ◽  
Inherent Strength

Nanoscale graphene oxide-lipid composites have shown wide applications in the field of biosensing and nanosafety. Macroscopic free-standing membranes of this combination potentially offer excellent mechanical properties which can be attributed to the inherent strength of graphene oxide(GO). Previous experimental studies have mostly dealt with monolayer or bilayer interactions of lipids with graphene and graphene oxide surfaces. In our study, we report for the first time, a simple and scalable fabrication method where Small Unilamellar Vesicles (SUVs) of 1,2-dioleoyl-sn-glycero-3-phosphocholine(DOPC) combine with graphene oxide to produce stable nanocomposites via self-assembly. Scanning Electron Microscopy (SEM) images of the composite revealed layer-by-layer structures, reconfirmed by X-Ray Diffraction(XRD) results which show a proportional increase in the interlayer separation with an increasing ratio of lipid in graphene oxide. The nanocomposite thus fabricated mimics naturally occurring nacre shell structures where graphene oxide substitutes the strong aragonite layers, and the intermediate lipid layers provide the necessary elasticity pertaining to protein chitin in nacre. The addition of lipids to graphene-based nanocomposites also serves as a biodegradable alternative to using polymers as a popular reinforcement agent. The ease of fabrication method reported facilitates the production of stable GO-Lipid membranes in variable scales and geometries.

Study on Crystal Structure and Thermal Stability of Hexaaquanickel (II) Bis[4-amino-3-methyl-benzenesulfonate]

2013 ◽  
Vol 643 ◽  
pp. 64-67
Author(s):  
Li Hua Wang
Keyword(s):  
Self Assembly ◽  
Water Molecules ◽  
X Ray Diffraction ◽  
Complex Molecules ◽  
X Ray ◽  
Dimensional Network ◽  
Distorted Octahedral ◽  
Coordinated Water ◽  
Light Green ◽  
Thermal Stability Of

Light green crystals of the Ni (II) complex material, [Ni(H2O)6](C14H16N2O6S2), were obtained by the self-assembly of Ni(H2O)6·6H2O, 4-amino-3-methyl-benzenesulfonic acid and NaOH. The result of X-ray diffraction shows that each Ni (II) atom is six-coordinated in a distorted octahedral environment by six oxygen atoms from the water molecules. The complex molecules are connected by hydrogen bonds to form two dimensional network structure. The thermal analysis shows that the complex has a enothermic peak at 302 C, indicating that coordinated water molecules are in the complex.

Self-Assembly of Cobalt/Bipyridine Multilayers Modeled After Hofmann Clathrate Compounds

1994 ◽  
Vol 351 ◽  
Author(s):  
Michael A. Ansell ◽  
Astrid C. Zeppenfeld ◽  
William K. Ham ◽  
Catherine J. Page
Keyword(s):  
Self Assembly ◽  
Grazing Angle ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Grown Layer ◽  
Multilayered Films ◽  
X Ray ◽  
Clathrate Compounds ◽  
Micro Analysis ◽  
Ordered Layers

ABSTRACTProgress has been made towards the development of inorganic-organic multilayered films modeled after Hofmann clathrate compounds. Cobalt-bipyridine multilayers were grown layer by layer on a silicon substrate. The resulting films were characterized using ellipsometry, grazing angle X-ray diffraction, Auger electron spectroscopy and EPMA (Electron Probe Micro- Analysis). Results indicate that moderately well ordered layers have been synthesized, but cross-linking with M(CN)42(M = Ni, Pd, or Pt) to simulate the model structure does not significantly occur.

scholarly journals How exfoliated graphene oxide nanosheets organize at the water interface: evidence for a spontaneous bilayer self-assembly

Nanoscale ◽  
2017 ◽  
Vol 9 (34) ◽  
pp. 12543-12548 ◽  
Author(s):  
Nathalie Bonatout ◽  
François Muller ◽  
Philippe Fontaine ◽  
Ignacio Gascon ◽  
Oleg Konovalov ◽  
...  
Keyword(s):  
Graphene Oxide ◽  
Self Assembly ◽  
Oxide Films ◽  
Grazing Incidence ◽  
Water Interface ◽  
X Ray Diffraction ◽  
Graphene Oxide Nanosheets ◽  
X Ray ◽  
Exfoliated Graphene ◽  
Air Water Interface

In this study, we have characterized graphene oxide films formed at the air–water interface by X-ray reflectivity and grazing incidence X-ray diffraction using synchrotron sources.

scholarly journals ELECTROCHEMICAL DISPERSION OF GRAPHITE IN 58% NITRIC ACID TO PRODUCE MULTILAYER GRAPHENE OXIDE

2021 ◽  
Vol 64 (3) ◽  
pp. 59-65
Author(s):  
Elena V. Yakovleva ◽  
Andrey V. Yakovlev ◽  
Ivan N. Frolov ◽  
Anton S. Mostovoy ◽  
Vitaly N. Tseluikin
Keyword(s):  
Graphene Oxide ◽  
Graphite Powder ◽  
Multilayer Graphene ◽  
X Ray Diffraction ◽  
X Ray ◽  
Graphene Layers ◽  
Intercalated Compounds ◽  
Fold Reduction ◽  
Electrochemical Dispersion ◽  
Oxidized Graphite

Electrochemical oxidation of graphite powder in 58% HNO3 was studied. Samples of oxidized graphite were obtained with a imparting of the amount of electricity 500, 700, 1500 mAh g-1. The character of the galvanostatic dependencies allows to select a region of the formation of intercalated compounds of graphite prior to the accumulation of quantity of electricity of 500 mA h g-1. It was found that when the quantity of electricity of over 700 mA h g-1 the process of electrochemical peroxidation of intercalated graphite begins with the formation of multilayer graphene oxide, as confirmed by comprehensive studies using X-ray diffraction, scanning electron microscopy, FTIR spectroscopy, laser diffraction. The synthesized multilayer graphene oxide is characterized by the presence of a spectrum of oxygen-containing functional groups, mainly hydroxyl, as well as carboxyl, epoxy and alkoxyl. X-ray images show a peak at 2θ = 11.45° which intensity increases for re-oxidized graphite compounds and also indicate the formation of a multilayer graphene oxide with an interlayer distance of 7.8 Å. The synthesized material in aqueous suspensions under the action of ultrasound is dispersed with a 7-11-fold reduction in particle size. Graphene layers remains layered structure but the degree of their deformation increases, and the thickness of the layers decreases with an increase in the imparted amount of electricity. 

Preparation and characterization of poly(3-hydroxybutyrate)/ Cloisite25A nanocomposites

e-Polymers ◽  
2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Matko Erceg ◽  
Dražan Jozić
Keyword(s):  
Crystallization Rate ◽  
Nucleating Agent ◽  
Degree Of Crystallinity ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Tg Analysis ◽  
Solution Intercalation ◽  
X Ray ◽  
Thermal Stability Of

Abstract Poly(3-hydroxybutyrate)/Cloisite25A (PHB/25A) nanocomposites were prepared by solution-intercalation method. The intercalation of PHB chains between the layers of Cloisite25A was observed by X-ray diffraction (XRD). Differential scanning calorimetry (DSC) and non-isothermal thermogravimetry (TG) analysis were performed to study the thermal properties, crystallization and the thermal degradation of the prepared nanocomposites. DSC analysis indicates that Cloisite25A acts as a nucleating agent and increases the crystallization rate of PHB, but due to intercalation reduces its overall degree of crystallinity. TG analysis shows that addition of Cloisite25A enhances the thermal stability of PHB.

A nanocomposite constructed by intercalating iron porphyrin into layered tantalotungstate with exfoliation/self-assembly method utilized for electrocatalytic oxidation of nitrite

2019 ◽  
Vol 12 (05) ◽  
pp. 1950069 ◽  
Author(s):  
Mengjun Wang ◽  
Jinpeng Li ◽  
Zichun Fan ◽  
Shining Wu ◽  
Juanjuan Ma ◽  
...  
Keyword(s):  
Self Assembly ◽  
Electrocatalytic Oxidation ◽  
Colloidal Suspension ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
Electrochemical Behaviors ◽  
X Ray ◽  
Assembly Method ◽  
Cyclic Voltammetry Method ◽  
Pulse Voltammetry

Exfoliation/restacking route was utilized to investigate layer-by-layer self-assembly of FeTMPyP/TaWO6 [5, 10, 15, 20-tetrakis (N-methylpyridinium-4-yl) porphyrinato iron (III)] nanocomposite in this paper. The colloidal suspension of [Formula: see text] nanosheet was tested by Zeta potential and proved to be in a well-dispersed statement. Analysis technologies such as X-ray diffraction Scanning electron microscope (SEM) infrared UV-Vis were used to characterize the final product. The results showed that FeTMPyP molecules were introduced into the lamellar space of host material successfully. The electrochemical behaviors of FeTMPyP-TaWO6 nanocomposite were tested by cyclic voltammetry method, and the nanocomposite showed excellent electrocatalytic properties to the oxidation of nitrite with the anodic peak shifts from 0.122 to 0.860[Formula: see text]V. Besides, the detection limit of nitrite can be calculated to be [Formula: see text][Formula: see text]M with the concentration of nitrite ranging from 0.1 to 3.61[Formula: see text]mM by different pulse voltammetry (DPV) analyzation.

scholarly journals Preparation and Investigation of the Microtribological Properties of Graphene Oxide and Graphene Films via Electrostatic Layer-by-Layer Self-Assembly

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Yongshou Hu ◽  
Haibing Ma ◽  
Wei Liu ◽  
Qianqian Lin ◽  
Bin Liu
Keyword(s):  
Graphene Oxide ◽  
Photoelectron Spectroscopy ◽  
Self Assembly ◽  
Adhesion Force ◽  
Strong Dependence ◽  
Layer By Layer ◽  
Crystal Silicon ◽  
X Ray ◽  
Graphene Films ◽  
Self Assembled

Graphene oxide (GO) films with controlled layers, deposited on single-crystal silicon substrates, were prepared by electrostatic self-assembly of negatively charged GO sheets. Afterward, graphene films were prepared by liquid-phase reduction of as-prepared GO films using hydrazine hydrate. The microstructures and microtribological properties of the samples were studied using X-ray photoelectron spectroscopy, Raman spectroscopy, X-ray diffraction, UV-visabsorption spectroscopy, water contact angle measurement, and atomic force microscopy. It is found that, whether GO films or graphene films, the adhesion force and the coefficients of friction both show strong dependence on the number of self-assembled layers, which both allow a downward trend as the number of self-assembled layers increases due to the interlayer sliding and the puckering effect when the tip slipped across the top surface of the films. Moreover, in comparison with the GO films with the same self-assembled layers, the graphene films possess lower adhesion force and coefficient of friction attributed to the difference of surface functional groups.

scholarly journals Synthesis of Magnetic Nanocomposite Fe3O4@ZIF-8@ZIF-67 and Removal of Tetracycline in Water

2021 ◽  
Author(s):  
Xu Song ◽  
Jingqian Mo ◽  
Yuting Fang ◽  
Shumin Luo ◽  
Jingjing Xu ◽  
...  
Keyword(s):  
Self Assembly ◽  
Environmental Remediation ◽  
Advanced Characterization ◽  
Magnetic Nanocomposite ◽  
Layer By Layer ◽  
X Ray Diffraction ◽  
High Adsorption ◽  
X Ray ◽  
Before And After ◽  
High Adsorption Capacity

Abstract We prepared a double-layer magnetic nanocomposite Fe3O4@ZIF-8@ZIF-67 by layer-by-layer self-assembly. Fe3O4@ZIF-8@ZIF-67 was used to remove tetracycline from aqueous solution via a combination of adsorption and Fenton-like oxidation. Depending on the outstanding porous structure of the Fe3O4@ZIF-8@ZIF-67, a high adsorption capacity for tetracycline was 356.25 mg g− 1, with > 95.47% removal efficiency within 100 min based on Fenton-like oxidation. To better understand the mechanisms involved in integrated adsorption and Fenton-like oxidation, various advanced characterization techniques were used to monitor the changes in morphology and composition of Fe3O4@ZIF-8@ZIF-67 before and after removal of tetracycline. Scanning electron microscopy/energy dispersive X-ray spectroscopy (SEM/EDS), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD) all supported adsorption and Fenton oxidation of tetracycline. This study extends the application of Fe3O4@ZIF-8@ZIF-67 for environmental remediation.

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