Cryo-Transmission Electron Microscopy Confirms Controlled Synthesis of Cadmium Sulfide Nanocrystals within Lecithin Vesicles

1998 ◽  
Vol 10 (8) ◽  
pp. 2116-2119 ◽  
Author(s):  
Michael T. Kennedy ◽  
Brian A. Korgel ◽  
Harold G. Monbouquette ◽  
Joseph A. Zasadzinski
2008 ◽  
Vol 58 ◽  
pp. 27-31 ◽  
Author(s):  
Yu Liang An ◽  
Yan Qiu Liu ◽  
Xia Yuan

A novel and practical route for preparing carbon nanocapsules using biomass – starch as the starting materials was presented. Carbon nanocapsules can be effectively synthesized by catalytic carbonizing starch in hydrogen flow. The carbohydrate was carbonized in a controllable way that leads to a large amount of carbon cages nanoparticles under Fe catalyst. Transmission electron microscopy (TEM), energy dispersive X-ray (EDX) and X-ray diffraction (XRD) were employed to characterizing carbon nanomaterials. The growth mechanism of carbon nanocapsules is briefly discussed in term of composition of precursor.


2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
A. Shokuhfar ◽  
S. S. S. Afghahi

In this research the size controlled synthesis of FeCo nanoparticles was done using a quaternary microemulsion system. X-ray diffraction and high resolution transmission electron microscopy of as-synthesized nanoparticles confirm the formation of FeCo alloy nanoparticles. The effects of two process parameters, namely, water to surfactant molar ratio and molar concentration of metal salts, on the size and size distribution of nanoparticles were discussed by the aid of transmission electron microscopy. The size dependency of magnetic properties was also investigated using a room temperature vibrating sample magnetometer. The superparamagnetic-ferromagnetic and single domain-multidomain transition sizes were determined. Then the specific absorption rates at transition sizes were calculated and the best sample for magnetic hyperthermia treatment was introduced.


2006 ◽  
Vol 6 (3) ◽  
pp. 818-822 ◽  
Author(s):  
Xiyan Dong ◽  
Xingtang Zhang ◽  
Bing Liu ◽  
Hongze Wang ◽  
Yuncai Li ◽  
...  

Novel reverse micelles of high CTAB concentration were successfully developed to synthesize MnOOH (manganese oxyhydroxide) nanorods with uniform diameters of about 10 nm and up to 200 nm in length under mild solution conditions and Mn3O4 nanorods with the same morphology could be obtained by calcining the precursors at 450 °C. The morphology and microstructure of the nanorods were investigated by transmission electron microscopy (TEM and HRTEM), XRD and TGA. The results showed that the concentration of CTAB was a key factor for the formation of MnOOH nanorods and only above 0.2 M the nanorods could be obtained. Moreover, the length of nanorods increased with the increase of CTAB concentration, while the diameter of nanorods retained steadily. In this way, the length of nanorods could be easily controlled from tens nanometers to hundreds nanometers by increasing the CTAB concentration from 0.35 M to 1.25 M. In addition, in our experiment the products were almost entirely rod-like shape, which indicated this method should be suitable for mass-producing.


Nanoscale ◽  
2019 ◽  
Vol 11 (36) ◽  
pp. 16801-16809 ◽  
Author(s):  
Shih-Ting Wang ◽  
Yiyang Lin ◽  
Michael H. Nielsen ◽  
Cheng Yu Song ◽  
Michael R. Thomas ◽  
...  

Understanding the mechanisms behind crystal nucleation and growth is a fundamental requirement for the design and production of bespoke nanomaterials with controlled sizes and morphologies.


2010 ◽  
Vol 2010 ◽  
pp. 1-6 ◽  
Author(s):  
Gong Jiangfeng ◽  
Dou Zhaoming ◽  
Ding Qingping ◽  
Xu Yuan ◽  
Zhu Weihua

We present here a systematic study on the synthesis of various ZnO nanostructures by electrodeposition method withZnCl2solution as starting reactant. Several reaction parameters were examined to develop an optimal procedure for controlling the size, shape, and surface morphology of the nanostructure. The results showed that the morphology of the products can be carefully controlled through adjusting the concentration of the electrolyte. The products present well-aligned nanorod arrays when the concentration is low. However, they act as anomalous hexangular nanoplates when the concentration ofZnCl2is higher than 5 mM. Transmission electron microscopy and select area electron diffraction results show that the product presents good crystallinity. A possible formation process has been proposed.


2008 ◽  
Vol 58 ◽  
pp. 55-58
Author(s):  
Jing Hui Wang ◽  
Xin Li ◽  
Jun Wei Ye ◽  
Yuan Lin ◽  
Gui Ling Ning

In this paper, magnesium hydroxide (Mg(OH)2) nanoparticles with tunable morphologies have been selectively synthesized via a facile template-free solvothermal route. The as-synthesized samples were characterized by instrumental analyses such as transmission electron microscopy (TEM) and X-ray powder diffraction (XRD). It was found that the morphology and size of the final products strongly depended on the reaction temperature and duration time. By manipulating the temperature and time in the solvothermal treatment, fiber-like, sphere-like and garland-like magnesium hydroxide nanoparticles were obtained. The described method without any catalysts or templates for preparing magnesium hydroxide nanoparticles is promising for industrial production in competition with other approaches.


Author(s):  
G. G. Shaw

The morphology and composition of the fiber-matrix interface can best be studied by transmission electron microscopy and electron diffraction. For some composites satisfactory samples can be prepared by electropolishing. For others such as aluminum alloy-boron composites ion erosion is necessary.When one wishes to examine a specimen with the electron beam perpendicular to the fiber, preparation is as follows: A 1/8 in. disk is cut from the sample with a cylindrical tool by spark machining. Thin slices, 5 mils thick, containing one row of fibers, are then, spark-machined from the disk. After spark machining, the slice is carefully polished with diamond paste until the row of fibers is exposed on each side, as shown in Figure 1.In the case where examination is desired with the electron beam parallel to the fiber, preparation is as follows: Experimental composites are usually 50 mils or less in thickness so an auxiliary holder is necessary during ion milling and for easy transfer to the electron microscope. This holder is pure aluminum sheet, 3 mils thick.


Author(s):  
R. W. Anderson ◽  
D. L. Senecal

A problem was presented to observe the packing densities of deposits of sub-micron corrosion product particles. The deposits were 5-100 mils thick and had formed on the inside surfaces of 3/8 inch diameter Zircaloy-2 heat exchanger tubes. The particles were iron oxides deposited from flowing water and consequently were only weakly bonded. Particular care was required during handling to preserve the original formations of the deposits. The specimen preparation method described below allowed direct observation of cross sections of the deposit layers by transmission electron microscopy.The specimens were short sections of the tubes (about 3 inches long) that were carefully cut from the systems. The insides of the tube sections were first coated with a thin layer of a fluid epoxy resin by dipping. This coating served to impregnate the deposit layer as well as to protect the layer if subsequent handling were required.


Author(s):  
S. Fujishiro

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.


Author(s):  
Nakazo Watari ◽  
Yasuaki Hotta ◽  
Yoshio Mabuchi

It is very useful if we can observe the identical cell elements within the same sections by light microscopy (LM), transmission electron microscopy (TEM) and/or scanning electron microscopy (SEM) sequentially, because, the cell fine structure can not be indicated by LM, while the color is; on the other hand, the cell fine structure can be very easily observed by EM, although its color properties may not. However, there is one problem in that LM requires thick sections of over 1 μm, while EM needs very thin sections of under 100 nm. Recently, we have developed a new method to observe the same cell elements within the same plastic sections using both light and transmission (conventional or high-voltage) electron microscopes.In this paper, we have developed two new observation methods for the identical cell elements within the same sections, both plastic-embedded and paraffin-embedded, using light microscopy, transmission electron microscopy and/or scanning electron microscopy (Fig. 1).


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