scholarly journals Micro/Mesoporous Fe3O4/Fe-Phthalocyanine Microspheres and Effects of Their Surface Morphology on the Crystallization and Properties of Poly(Arylene Ether Nitrile) Composites

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1356 ◽  
Author(s):  
Kui Li ◽  
Dengxun Ren ◽  
Xianzhong Tang ◽  
Mingzhen Xu ◽  
Xiaobo Liu
Keyword(s):  
Electron Microscope ◽  
Surface Morphology ◽  
Composite Films ◽  
Surface Characteristics ◽  
Excellent Thermal Stability ◽  
Arylene Ether ◽  
Transmission Electron ◽  
Interfacial Compatibility ◽  
Surface Morphologies ◽  
Mesoporous Structures

The surface morphology of nanoparticles significantly affects the final properties and interfacial characteristics of their composites. Thus, investigations on the surface morphology of the nanoparticles is essential to fabricate improved nanoparticle-reinforced composites. Fe3O4/Fe-phthalocyanine (FePc) hybrid microspheres with micro/mesoporous structures were prepared via a solvothermal process and solvent etching method. The surface morphology and compositional distribution were respectively investigated using a scanning electron microscope (SEM) and a transmission electron microscope (TEM) to rule out that FePc monomers have been blended with Fe3O4 to form Fe3O4/FePc hybrid microspheres without serious agglomeration. The surface roughness of Fe3O4/FePc microspheres was investigated by the scanning probe microscope (SPM), and confirmed by the adsorption and desorption isotherms of N2. The effects of the various surface morphologies on the crystallization behavior of crystallizable poly(arylene ether nitrile) (c-PEN) were first employed to confirm the surface characteristics of the resulted microspheres. Results indicated that the etched Fe3O4/FePc microspheres would improve the crystallization degree of c-PEN, due to their much more micro/mesoporous structures than that of original Fe3O4/FePc. Then, Fe3O4/FePc hybrid microspheres reinforced PEN composite films were prepared and their interfacial compatibility was monitored using an SEM. Excellent thermal stability and improved mechanical properties were obtained by combining the etched Fe3O4/FePc and PEN matrix. The excellent surface properties and micro/mesoporous structures make the novel Fe3O4/FePc an excellent candidate of organic/inorganic hybrid fillers and micro/mesoporous materials.

Defect morphology in thick relaxed layers of InGaAs on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 668-669
Author(s):  
R H Dixon ◽  
P Kidd ◽  
P J Goodhew
Keyword(s):  
Electron Microscopy ◽  
Surface Morphology ◽  
Growth Conditions ◽  
X Ray Diffraction ◽  
Double Crystal ◽  
Strained Layers ◽  
Good Surface ◽  
Transmission Electron ◽  
Device Structures ◽  
Surface Morphologies

Thick relaxed InGaAs layers grown epitaxially on GaAs are potentially useful substrates for growing high indium percentage strained layers. It is important that these relaxed layers are defect free and have a good surface morphology for the subsequent growth of device structures.3μm relaxed layers of InxGa1-xAs were grown on semi - insulating GaAs substrates by Molecular Beam Epitaxy (MBE), where the indium composition ranged from x=0.1 to 1.0. The interface, bulk and surface of the layers have been examined in planar view and cross-section by Transmission Electron Microscopy (TEM). The surface morphologies have been characterised by Scanning Electron Microscopy (SEM), and the bulk lattice perfection of the layers assessed using Double Crystal X-ray Diffraction (DCXRD).The surface morphology has been found to correlate with the growth conditions, with the type of defects grown-in to the layer (e.g. stacking faults, microtwins), and with the nature and density of dislocations in the interface.

Atomic oxygen effects on polymers containing silicon or phosphorus: Mass loss, erosion yield, and surface morphology

2018 ◽  
Vol 31 (8) ◽  
pp. 969-976 ◽  
Author(s):  
Wang Chunbo ◽  
Jiang Haifu ◽  
Tian Dongbo ◽  
Qin Wei ◽  
Chen Chunhai ◽  
...  
Keyword(s):  
Surface Morphology ◽  
Mass Loss ◽  
Atomic Oxygen ◽  
Low Earth Orbit ◽  
Relative Order ◽  
Oxygen Effects ◽  
Arylene Ether ◽  
Inorganic Coatings ◽  
Oligomeric Silsesquioxane ◽  
Surface Morphologies

The differences among polymers containing silicon or phosphorus, 20% polyhedral oligomeric silsesquioxane polyimide (20%-POSS-PI), 30% polysiloxane- block-polyimides (30%-PSX-PI), poly(siloxane imide) homopolymer (PSX-PI), and arylene ether phosphine oxide homopolymer (P-PPO), on mass loss, erosion yield, and surface morphology were elucidated. The tolerance against atomic oxygen (AO) was improved versus Kapton®H after introducing silicon or phosphorus to the polymers. The relative order of the mass loss was PSX-PI < P-PPO < 20%-POSS-PI < 30%-PSX-PI. In contrast, the erosion yields of 30%-PSX-PI, 20%-POSS-PI, and P-PPO decreased by orders of magnitude (PSX-PI declined by about two orders). The surface of Kapton®H was seriously eroded by AO exhibiting a “carpet-like” shape, and the roughness of the surface of Kapton®H became remarkable as the AO fluence increased. PSX-PI, P-PPO, 20%-POSS-PI, and 30%-PSX-PI at an AO fluence of 5.2 × 1020 atoms/cm2 had different surface morphologies, and the relative order of the surface roughness was PSX-PI < 30%-PSX-PI < 20%-POSS-PI < P-PPO. The 30%-PSX-PI and PSX-PI had minor mass losses and a smooth surface. This kind of material might replace inorganic coatings for applications in low earth orbit.

Corrosion Resistance of Ni-Y2O3 Composite Coating Prepared by Electrodeposition under Ultrasonic Condition

2010 ◽  
Vol 97-101 ◽  
pp. 1235-1238 ◽  
Author(s):  
Yu Jun Xue ◽  
Chen Shen ◽  
Ji Shun Li ◽  
Hang Li ◽  
Dong Hong Si
Keyword(s):  
Aqueous Solution ◽  
Corrosion Resistance ◽  
Electron Microscope ◽  
High Resolution ◽  
Surface Morphology ◽  
Composite Coatings ◽  
Nanocomposite Coating ◽  
Transmission Electron ◽  
Superior Corrosion Resistance ◽  
Electronic Microscope

Ni-Y2O3 nanocomposite coating was electrodeposited from a nickel sulfamate solution containing Y2O3 particles and ultrasonic was applied during the process of the electrodeposition. The surface morphology and microstructure of the composite coatings were analyzed by a scanning electronic microscope (SEM) and a high-resolution transmission electron microscope (HRTEM). The corrosion resistence of the coatings was evaluated in the solution of 10 wt.% HCl aqueous solution. The results indicate that the Ni-Y2O3 nanocomposite coating shows a refined crystal grain and improved corrosion resistance compared with pure Ni coating. The Ni-Y2O3 nanocomposite coating prepared under ultrasonic condition exhibits a superior corrosion resistance due to the formation of denser structure and finer-grain scale.

Microstructure and Erosion Behavior at Elevated Temperature of Thermal Sprayed Fe-Al/WC Coating

2010 ◽  
Vol 105-106 ◽  
pp. 455-458
Author(s):  
Bao Hong Tian ◽  
Yong Liu
Keyword(s):  
Electron Microscope ◽  
Elevated Temperature ◽  
Incidence Angle ◽  
Arc Spraying ◽  
Image Analyzer ◽  
Cored Wire ◽  
Erosion Behavior ◽  
Transmission Electron ◽  
Coating Microstructure ◽  
Surface Morphologies

A Fe-Al/WC composite coating was fabricated by using high velocity arc spraying (HVAS) and cored wire. The elevated temperature erosion behaviors of the coating were investigated with a grit blasting type erosion tester. The coating microstructure and eroded surface morphologies were analyzed by energy dispersion spectroscope (EDS), X-ray diffraction (XRD), scanning electron microscope (SEM) , transmission electron microscope (TEM) and image analyzer. The effects of incidence angle and test temperature on the erosion behavior were determined.

scholarly journals Poly(arylene ether nitrile) Composites with Surface-Hydroxylated Calcium Copper Titanate Particles for High-Temperature-Resistant Dielectric Applications

Polymers ◽  
2019 ◽  
Vol 11 (5) ◽  
pp. 766 ◽  
Author(s):  
Junyi Yang ◽  
Zili Tang ◽  
Hang Yin ◽  
Yan Liu ◽  
Ling Wang ◽  
...  
Keyword(s):  
High Temperature ◽  
High Performance ◽  
Temperature Stability ◽  
Dielectric Materials ◽  
Excellent Thermal Stability ◽  
Arylene Ether ◽  
Calcium Copper Titanate ◽  
Interfacial Compatibility ◽  
Surface Hydroxylation ◽  
Effective Path

In order to develop high-performance dielectric materials, poly(arylene ether nitrile)-based composites were fabricated by employing surface-hydroxylated calcium copper titanate (CCTO) particles. The results indicated that the surface hydroxylation of CCTO effectively improved the interfacial compatibility between inorganic fillers and the polymer matrix. The composites exhibit not only high glass transition temperatures and an excellent thermal stability, but also excellent flexibility and good mechanical properties, with a tensile strength over 60 MPa. Furthermore, the composites possess enhanced permittivity, relatively low loss tangent, good permittivity-frequency stability and dielectric-temperature stability under 160 °C. Therefore, it furnishes an effective path to acquire high-temperature-resistant dielectric materials for various engineering applications.

scholarly journals Fabrication and characterization of Ni-decorated h-BN powders with ChCl-EG ionic liquid as addition by electroless deposition

2018 ◽  
Vol 5 (5) ◽  
pp. 180146
Author(s):  
Qionglian Yang ◽  
Juanjian Ru ◽  
Peng Song ◽  
Mingyu Hu ◽  
Jing Feng
Keyword(s):  
Ionic Liquid ◽  
Electron Microscope ◽  
Electroless Plating ◽  
Choline Chloride ◽  
Nickel Particle ◽  
Additive Concentration ◽  
Plating Bath ◽  
Transmission Electron ◽  
Average Size ◽  
Surface Morphologies

Ni-decorated h-BN powders are fabricated with ChCl-EG as additive via electroless plating in the paper. As comparison, the different additive concentration of choline chloride-ethylene glycol (ChCl-EG) ionic liquid (0 g l −1 , 30 g l −1 , 60 g l −1 , 90 g l −1 ) is presented. The effects of ChCl-EG concentration are studied, including the surface morphologies, phase analysis of Ni-decorated h-BN powders and the residual Ni 2+ concentration is measured in electroless plating bath. It is demonstrated that the deposition phenomena of nickel particles on h-BN surface is changed with the addition of ChCl-EG. When the concentration of ChCl-EG is 30 g l −1 , the Ni particles on h-BN surface are in dispersed and spheroid state with the average size of 10–1000 nm. It can be found that 30 g l −1 ChCl-EG is conducive to the arise of deposition phenomena, which is the formation of the single nickel particle on h-BN surface. Besides, more Ni particles are deposited on h-BN surface with the increase of nickel plating times, which is characterized with scanning electron microscope and transmission electron microscope. Furthermore, the deposition phenomenon and growth mechanism are proposed without and with ChCl-EG as additive to further elaborate the formation of Ni particles on h-BN surface.

Nanometer-area diffraction of small iron crystallites in single crystalline Fe-MgO composite films

1988 ◽  
Vol 46 ◽  
pp. 706-707
Author(s):  
N. Tanaka ◽  
K. Mihama ◽  
H. Ou ◽  
J.M. Cowley
Keyword(s):  
Phase Transformation ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Carbon Film ◽  
Composite Films ◽  
High Resolution Electron Microscopy ◽  
Scanning Transmission Electron Microscope ◽  
Specimen Preparation ◽  
Single Crystalline ◽  
Transmission Electron

Nanometer-sized iron(Fe) crystallites can be prepared in a single crystalline magnesium oxide(MgO) film by a simultaneous vacuum deposition of Fe and MgO. The crystallites are grown epitaxially and almost coherently in the film, the orientation being (001) [110]Fe//(001)[100]MgOand (011) [100]Fe//(001) [100]MgO. A heat treatment of the as-grown composite films at 500-1000°C brings about a phase-transformation from α -iron(b.c.c.) to γ -iron(f.c.c.). In the present study, the phase-transformation and the structure of the γ-iron crystallites are studied by nanometer-area electron diffraction(nanodiffraction) in TEM and STEM as well as high-resolution electron microscopy.The specimens were single crystalline Fe-MgO composite films prepared on a NaCl (001 ) surface by co-evaporation of Fe and MgO. The films were separated from the substrate in water and mounted on a perforated carbon film. Nanodiffraction in TEM was performed in a 200 kV transmission electron microscope(JEM- 2000FX)2 and that in STEM3was carried out in a 100 kV scanning transmission electron microscope (VG-HB5) equipped with a specimen-preparation chamber.

scholarly journals Structurally Designed Imine Skeletal Pyrenyl Pendant Pyridine Core Polybenzoxazine nSiO2/PBZ Hybrid Polymer Nanocomposites

2021 ◽  
Vol 33 (4) ◽  
pp. 793-801
Author(s):  
S.G. Gunasekaran ◽  
L. Devaraj Stephen ◽  
V. Arivalagan ◽  
M. Soundarrajan
Keyword(s):  
Electron Microscope ◽  
Sol Gel ◽  
Hybrid Nanocomposites ◽  
Spectral Studies ◽  
Fluorescent Properties ◽  
Excellent Thermal Stability ◽  
Transmission Electron ◽  
Ft Ir ◽  
Hydrophobic Nature ◽  
Nanosilica Particles

Novel polybenzoxazine-silica (nSiO2/PBZ) hybrid nanocomposites were designed and synthesized using carbazole terminal pyrenyl pyridine core imine skeletal benzoxazine monomer (PYCBZ) and nanosilica (nSiO2) through in situ sol-gel method. The FT-IR and Raman spectral studies ascertained the formation of nanosilica reinforced polybenzoxazine hybrid nanocomposites. The nSiO2/PBZ hybrid nanocomposites exhibited excellent thermal stability and higher char yield than that of neat PBZ. The elevation in glass transition temperature of the nanocomposites was evidenced by the limited motion of the polymeric network with the introduction of nanosilica particles in the PBZ matrices. The hydrophobic nature of a less polar nSiO2 in the composites zipped the water uptake behaviour of (nSiO2/PBZ) hybrid nanocomposites to low percentage. The shift in the absorption peak reveals that the nanosilica particles were successfully incorporated through thermal ring opening polymerization of benzoxazine. The homogeneous reinforcement of nSiO2 particles retains the fluorescent properties of polybenzoxazine. The uniform molecular level dispersion of nano SiO2 onto polybenzoxazine networks were confirmed from transmission electron microscope and scanning electron microscope images.

Surface Morphology of Single-Crystal Ceramics

1986 ◽  
Vol 82 ◽  
Author(s):  
D.W. Susnitzky ◽  
C.B. Carter
Keyword(s):  
Electron Microscope ◽  
Surface Morphology ◽  
Single Crystal ◽  
Total Energy ◽  
Transmission Electron Microscope ◽  
Thin Foil ◽  
Crystalline Materials ◽  
Step Movement ◽  
Thin Foils ◽  
Transmission Electron

ABSTRACTSurfaces of crystalline materials generally facet and form steps and ledges on low-index planes to reduce their total energy. A conventional wedge-shaped transmission electron microscope (TEM) thin foil, prepared slightly misoriented with respect to a low-index plane, provides a suitable geometry for the study of surface ledges, steps and facets. This TEM study characterizes the surface features of annealed thin foils prepared from various oxides with a range of nominally low-index orientations. Observations from single-crystal α-A12O3 and MgAl2O4 (spinel) will be included.The steps and facets typically form along energetically favorable, low-index planes and bound terraces of low-index orientation. The structure of these features are discussed. In addition, surface step movement has been observed and monitored through a series of reannealing experiments on the same foil.

scholarly journals Multifunctional Composite Film Based on Biodegradable Grape Skin and Polyvinyl Alcohol

2021 ◽  
Author(s):  
Zhe Qiu ◽  
Weidong Niu ◽  
Shuo Wang ◽  
Fanjun Yu ◽  
Yang Yu ◽  
...  
Keyword(s):  
Polyvinyl Alcohol ◽  
Composite Film ◽  
Color Change ◽  
Cellulose Nanofibers ◽  
Composite Films ◽  
Antimicrobial Properties ◽  
Grape Skin ◽  
Excellent Thermal Stability ◽  
Transmission Electron ◽  
Ultraviolet Shielding

Abstract In winemaking, large amounts of grape skin (GS) are produced as by-products, which contain not only abundant degradable cellulose, hemicellulose, and pectin but various functional polyphenols. In contrast to most studies focusing on the utilization of extractives, the current study investigates the use of an ultrasonicated grape skin (UGS) containing all components to develop a multifunctional composite film. Owing to dissociation during ultrasonication, all GS components were well dispersed in water to obtain the UGS suspension. Transmission electron microscopy (TEM) indicated that the celluloses were successfully transformed into cellulose nanofibers (CNFs), which can improve the uniformity of the composite film. Subsequently, biodegradable and multifunctional composite films were fabricated by combining the UGS and polyvinyl alcohol (PVA). The UGS and PVA formed a good interface owing to strong hydrogen bonds, and the resulting films exhibited excellent thermal stability and moisture-sensitive mechanical properties. The polyphenols in the UGS suspension endowed the composite film with multiple functions, including pH-responsive color change, excellent antioxidant activity, ultraviolet shielding, and antimicrobial properties. The use of PVA enhanced the flexibility, strength, and elongation of the UGS film. The easily prepared, tailored, multifunctional, and biodegradable UGS/PVA composite film exhibits excellent potential for application in agriculture, cosmetics, and healthcare.

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