Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

2021 ◽  
Author(s):  
SongSik Pak ◽  
KwangChol Ri ◽  
Chenmin Xu ◽  
Qiuyi Ji ◽  
Dunyu Sun ◽  
...  

The g-C3N4/Y-TiO2 Z-scheme heterojunction photocatalysts were successfully synthesized. The powder X-ray diffraction, scanning electron microscopy, high-resolution transmission electron microscope, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy were used for...


1973 ◽  
Vol 56 (4) ◽  
pp. 930-943
Author(s):  
John L Brown ◽  
James W Johnson

Abstract The optical microscope has long been an important tool in forensic analysis for the comparison of firearms markings and the examination and identification of other minute bits of evidence. The electron microscope permits the examination of even smaller details and offers analytical capabilities unique to the type of instrument used. The transmission electron microscope can be used to identify very small amounts of crystalline materials through the process of electron diffraction. The scanning electron microscope can frequently supersede the optical microscope because of its superior depth of focus and range of magnification. When it is equipped with an energy dispersive X-ray analyzer, most of the chemical elements in a sample can be determined. Applications of these instruments have provided some interesting and instructive results in forensic analysis.


2013 ◽  
Vol 364 ◽  
pp. 737-741
Author(s):  
Xiao Wei Liu ◽  
Jia Jun Gu ◽  
Fang Yu Zhang

A rapid method towards nanoPbS on peacock feathers was reported and this is inspired by a hair-dyeing technology used in Ancient Egypt thousands of years ago. Original peacock feather was sulfhydrylated by 2, 3-dimercaptosuccinic acid (DMSA) dissolved in alcohol to enhance reaction sites, and then was immersed in the saturated PbO solution in calcium hydroxide and got the PbS peacock feather. The whole process is only two steps and could be completed within two hours. The morphology and structures of the sample were measured by the X-ray diffraction (XRD), Scanning electron microscopy (SEM), and transmission electron microscope (TEM) and results showed that the structure of original peacock feather was well duplicated. Compared with previous works, this method is faster and more efficient and thus has potentials to fabricate other functional sulfides.


2018 ◽  
Vol 24 (8) ◽  
pp. 5947-5952 ◽  
Author(s):  
M Ponnar ◽  
K Pushpanathan

This article focuses the synthesis and characterization of copper doped cerium oxide nanospheres synthesized by chemical precipitation method. Synthesized nanopowders were characterized by means of X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, ultraviolet-visible spectrometer and photoluminescence spectrometer. X-ray diffraction study confirmed the copper doping without disturbing the face centred cubic structure of cerium oxide. Field emission scanning electron microscope and transmission electron microscope study also confirmed the existence of sphere like nanoparticles. The optical absorption spectrum shows that the synthesized samples exhibit strong absorption in ultraviolet region and also it confirmed the decrease in energy gap of cerium oxide on copper doping. The photoluminescence study revealed that the blue emission is attributed to the fast oxygen transportation of copper doped cerium oxide nanoparticles.


2016 ◽  
Vol 36 (1) ◽  
pp. 43-52 ◽  
Author(s):  
Jowita Szymańska ◽  
Mohamed Bakar ◽  
Marcin Kostrzewa ◽  
Marino Lavorgna

Abstract The present work investigates the effect of organomodified nanoclay (ZW1) and butadiene-acrylonitrile copolymer terminated with different amine groups (amine-terminated butadiene-acrylonitrile, ATBN) on the properties and morphology of epoxy resin. The morphologies of the nanocomposites were analyzed by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). The nanocomposites structure was confirmed by Fourier transform infrared (FTIR) spectroscopy, XRD and TEM. The properties evaluation showed that the polymeric modifier and nanoclays strongly influence the fracture toughness and flexural properties of the nanocomposites. Hybrid epoxy composites containing 1% ZW1 and ATBN rubbers showed improved fracture toughness and flexural properties in comparison with unmodified epoxy resin. FTIR spectra showed an increase in the hydroxyl peak height peak height of 3360 cm-1 due to reactive rubber incorporation. SEM micrographs of hybrid epoxy resin nanocomposites showed significant plastic yielding of the polymer matrix with stratified structures and more cavitations, explaining thus the enhancement of fracture toughness and flexural strength of the nanocomposites.


2011 ◽  
Vol 142 ◽  
pp. 87-91 ◽  
Author(s):  
Xiao Ping Tan ◽  
Shu Quan Liang ◽  
Li Yuan Chai

Zirconia-mullite nanocomoposites were prepared from Si-Al-Zr-O amorphous bulk with diffrent content of CaO and MgO by two-step thermal treatment between 900 and 1200°C. The effects of the additives on the phase and microsturcture were studied by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM). The results show that the addition of CaO promotes cristobalite phase formation and the anisotropic growth of mullite grains. An indention micro-crack method was used to measure the fracture toughness of zirconia-mullite nanocomoposites. The results demonstrate that the fracture toughness increases with higher concentration of CaO. The improvement of fracture toughness is attributed to the anisotropic growth of grains.


Author(s):  
J. D. Hutchison

When the transmission electron microscope was commercially introduced a few years ago, it was heralded as one of the most significant aids to medical research of the century. It continues to occupy that niche; however, the scanning electron microscope is gaining rapidly in relative importance as it fills the gap between conventional optical microscopy and transmission electron microscopy.IBM Boulder is conducting three major programs in cooperation with the Colorado School of Medicine. These are the study of the mechanism of failure of the prosthetic heart valve, the study of the ultrastructure of lung tissue, and the definition of the function of the cilia of the ventricular ependyma of the brain.


Author(s):  
J. C. Russ ◽  
E. McNatt

In order to study the retention of copper in cirrhotic liver, rats were made cirrhotic by carbon tetrachloride inhalation twice weekly for three months and fed 0.2% copper acetate ad libidum in drinking water for one month. The liver tissue was fixed in osmium, sectioned approximately 2000 Å thick, and stained with lead citrate. The section was examined in a scanning electron microscope (JEOLCO JSM-2) in the transmission electron mode.Figure 1 shows a typical area that includes a red blood cell in a sinusoid, a disse, and a portion of the cytoplasm of a hepatocyte which contains several mitochondria, peribiliary dense bodies, glycogen granules, and endoplasmic reticulum.


Author(s):  
Vicki L. Baliga ◽  
Mary Ellen Counts

Calcium is an important element in the growth and development of plants and one form of calcium is calcium oxalate. Calcium oxalate has been found in leaf seed, stem material plant tissue culture, fungi and lichen using one or more of the following methods—polarized light microscopy (PLM), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and x-ray diffraction.Two methods are presented here for qualitatively estimating calcium oxalate in dried or fixed tobacco (Nicotiana) leaf from different stalk positions using PLM. SEM, coupled with energy dispersive x-ray spectrometry (EDS), and powder x-ray diffraction were used to verify that the crystals observed in the dried leaf with PLM were calcium oxalate.


Author(s):  
M. K. Lamvik

When observing small objects such as cellular organelles by scanning electron microscopy, it is often valuable to use the techniques of transmission electron microscopy. The common practice of mounting and coating for SEM may not always be necessary. These possibilities are illustrated using vertebrate skeletal muscle myofibrils.Micrographs for this study were made using a Hitachi HFS-2 scanning electron microscope, with photographic recording usually done at 60 seconds per frame. The instrument was operated at 25 kV, with a specimen chamber vacuum usually better than 10-7 torr. Myofibrils were obtained from rabbit back muscle using the method of Zak et al. To show the component filaments of this contractile organelle, the myofibrils were partially disrupted by agitation in a relaxing medium. A brief centrifugation was done to clear the solution of most of the undisrupted myofibrils before a drop was placed on the grid. Standard 3 mm transmission electron microscope grids covered with thin carbon films were used in this study.


Sign in / Sign up

Export Citation Format

Share Document