Electron microscopy sample preparation

Electron microscopy samples were prepared by techniques similar to that of Kato (8). Film samples were fixed with OSO4, potted in polymethyl methacrylate and then microtomed into thin sections ( 100 nm) for transmission examination using a Philips 100B electron microscope. 

Samples for transmission electron microscopy were prepared in the following manner. Films were grown with different current rates up to various thicknesses on platinum working electrodes. The film thickness was controlled by the period of current flow. The films were transferred onto carbon coated electron microscope grids by stripping with formvar and subsequently removing the formvar with methylene chloride. As-synthesized films were directly used for scanning electron microscopy. 

Samples for transmission electron microscopy were prepared in the following manner. A 50/50 blend was potted in an acrylic resin (London Resin Co. Ltd.) and subsequently microtomed in thin films of approximately 600 angstrom thickness and transferred onto electron microscope grids. These sections were then doped with iodine vapor (stained) and were ready for transmission electron microscopy. The blends of other compositions were not examined in this manner for reasons discussed later. 

Optical and Electron Microscopy. Samples of film for optical and electron microscopy were prepared by microtoming. The samples for optical phase contrast microscopy were approximately 15-20jU thick whereas those for electron microscopy were ultra microtomed with a diamond knife to about 0.05-0. lju, thickness. A Leitz Ortholux microscope was used for the phase contrast microscopy and an RCA-EMU-36 electron microscope at 40,000 X magnification was used for the electron microscopy. 

Ultrastructural Analysis. Samples to be examined by electron microscopy were prepared as described by Persi and Burnham (19). All samples were fixed using the following schedule glutaral-dehyde (4% (w/v), 6h), osmium tetroxlde (20% (w/v), 6h) tannic acid (10% (w/v), 3h), and osmium tetroxlde (20% (w/v), 2h). Each fixative was prepared In 0.2M cacodylate buffer, pH 7.2, and samples were washed between fixations with cacodylate buffer. Subsequently, all cells were treated with uranyl acetate, washed, dehydrated through a graded ethanol series, and finally embedded In Maraglas (Polysciences, Inc.). Ultrathln sections were cut, post-stained with lead citrate and examined in a Phillips 300 transmission electron microscope operating at 60 Kv. 

Scanning Electron Microscopy. Samples of unweathered and weathered untreated and formaldehyde-treated wools were mounted or specimen stubbs using conducting silver paint and coated with two thin layers of silver. Scanning electron micrographs of the samples were prepared and examined for changes In the fiber surface (Fig. 1). 

Ultrafiltration. Microscopy Applications Environmental Light Microscopy Electron Microscopy Specimen Preparation for Electron Microscopy Scanning Electron Microscopy Atomic Force and Scanning Tunneling Microscopy. Particle Size Analysis. Sampling Theory. 

Fig. IX-4. An electron micrograph of reconstituted DNA-clupeine complexes. The complexes, formed by the slow-binding method from native herring sperm DNA and whole clupeine, were dissolved in 4 M ammonium acetate. Samples for electron microscopy were prepared according to the method of Kleinschmidt et al. (1962) and shadow-casted with platinum-palladium (80 20, v/v) (from Inoue and Fuke, 1970)... 

Our research on these subjects began more than 25 years ago with Yeh s examination of the morphology and properties of amorphous poly(ethylene terephthalate) (PET) and the effect thereon of crystallization and deformation. Both thick and thin (i.e., > 10 i and ca. 1,000 A, suitable for transmission electron microscopy) samples were used, the samples being either quenched from the melt or cast from solution into the amorphous state. The films, as prepared, were amorphous by x-ray or electron diffraction. 

Electron Beam Techniques. One of the most powerful tools in VLSI technology is the scanning electron microscope (sem) (see Microscopy). A sem is typically used in three modes secondary electron detection, back-scattered electron detection, and x-ray fluorescence (xrf). AH three techniques can be used for nondestmctive analysis of a VLSI wafer, where the sample does not have to be destroyed for sample preparation or by analysis, if the sem is equipped to accept large wafer-sized samples and the electron beam is used at low (ca 1 keV) energy to preserve the functional integrity of the circuitry. Samples that do not diffuse the charge produced by the electron beam, such as insulators, require special sample preparation. 

A variety of instmmental techniques may be used to determine mineral content. Typically the coal sample is prepared by low temperature ashing to remove the organic material. Then one or more of the techniques of x-ray diffraction, infrared spectroscopy, differential thermal analysis, electron microscopy, and petrographic analysis may be employed (7). 

Thin films of metals, alloys and compounds of a few micrometres diickness, which play an important part in microelectronics, can be prepared by die condensation of atomic species on an inert substrate from a gaseous phase. The source of die atoms is, in die simplest circumstances, a sample of die collision-free evaporated beam originating from an elemental substance, or a number of elementary substances, which is formed in vacuum. The condensing surface is selected and held at a pre-determined temperature, so as to affect die crystallographic form of die condensate. If diis surface is at room teiiiperamre, a polycrystalline film is usually formed. As die temperature of die surface is increased die deposit crystal size increases, and can be made practically monocrystalline at elevated temperatures. The degree of crystallinity which has been achieved can be determined by electron diffraction, while odier properties such as surface morphology and dislocation sttiicmre can be established by electron microscopy. 

In contrast to many other surface analytical techniques, like e. g. scanning electron microscopy, AFM does not require vacuum. Therefore, it can be operated under ambient conditions which enables direct observation of processes at solid-gas and solid-liquid interfaces. The latter can be accomplished by means of a liquid cell which is schematically shown in Fig. 5.6. The cell is formed by the sample at the bottom, a glass cover - holding the cantilever - at the top, and a silicone o-ring seal between. Studies with such a liquid cell can also be performed under potential control which opens up valuable opportunities for electrochemistry [5.11, 5.12]. Moreover, imaging under liquids opens up the possibility to protect sensitive surfaces by in-situ preparation and imaging under an inert fluid [5.13]. 

Here, we will describe experimental studies on capillary filling of CNTs. Because of the focus of this chapter, we have taken examples from the work in our own laboratory certainly we may have inadvertently ignored other exciting work from other laboratories in the world. Still the preparation of a sample of purified and filled CNTs have yet to be developed, so that the study of filled tubes have been and can only be performed by electron microscopy and associated techniques. We have tried to describe in detail all the steps involved in the procedure of capillary filling, such as CNT production, opening, filling and final thermal processing. 

In this case, the elements of the crosslinked structure exhibit higher mobility, the permeability of the crosslinked structure depends on the degree of hydration. It should be noted that the pore size in hydrated crosslinked copolymers is determined by small-angle X-ray scattering or with the aid of electron microscopy using special methods of preparation for the CP samples [15],... 

Glad [37] studied the micro deformations of thin films prepared from DGE-BA/MDA by electron microscopy. His results are also shown in Fig. 7.5. The deformation of the sample with high strand density was small and consequently its image in the EM rather blurred. Therefore, the result on Mc = 0.5 kg/mol should perhaps have been omitted. 

Also a good interface resolution is obtained with transmission electron microscopy (TEM), where, however, a dedicated sample preparation and treatment are necessary to achieve nanometer resolution and suitable contrast [64]. Thus the... 

Scanning electron microscopy and replication techniques provide information concerning the outer surfaces of the sample only. Accurate electron microprobe analyses require smooth surfaces. To use these techniques profitably, it is therefore necessary to incorporate these requirements into the experimental design, since the interfaces of interest are often below the external particle boundary. To investigate the zones of interest, two general approaches to sample preparation have been used. 

The authors wish to acknowledge the work of Paul McCarthy in scanning electron microscopy, Michael Saculla in x-ray radiography, and Steven Buckley and Chuck Chen in sample preparation and modulus measurement. This work was performed under the auspices of the U.S. Department of Energy by the Lawrence Livermore National Laboratory under Contract No. W-7405-ENG-48. 

MgO-supported model Mo—Pd catalysts have been prepared from the bimetallic cluster [Mo2Pd2 /z3-CO)2(/r-CO)4(PPh3)2() -C2H )2 (Fig. 70) and monometallic precursors. Each supported sample was treated in H2 at various temperatures to form metallic palladium, and characterized by chemisorption of H2, CO, and O2, transmission electron microscopy, TPD of adsorbed CO, and EXAFS. The data showed that the presence of molybdenum in the bimetallic precursor helped to maintain the palladium in a highly dispersed form. In contrast, the sample prepared from the monometallie precursors was characterized by larger palladium particles and by weaker Mo—Pd interactions. ... 

Scattering experiments can be performed to help determine the size and shape of the vesicles without the need for the extensive sample preparation required for electron microscopy and AFM. Dynamic (DLS) and static light scattering (SLS) are widely used to determine the size and possible shape of vesicle systems [40,42,48,49,51,... 

Suhtnicion nickel powders luive been synthesized successfully from aqueous NiCh at various tempmatuTKi and times with ethanol-water solvent by using the conventional and ultrasonic chemical reduction method. The reductive condition was prepared by flie dissolution of hydrazine hydrate into basic solution. The samples synthesized in various conditions weae claractsiz by the m ins of an X-ray diffractometry (XRD), a scanning electron microscopy (SEM), a thermo-gravimetry (TG) and an X-ray photoelectron spectroscopy (XPS). It was found that the samples obtained by the ultrasonic method were more smoothly spherical in shape, smaller in size and narrower in particle size distribution, compared to the conventional one. 

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