Optical scanning electron microscopy

Physical testing appHcations and methods for fibrous materials are reviewed in the Hterature (101—103) and are generally appHcable to polyester fibers. Microscopic analyses by optical or scanning electron microscopy are useful for evaluating fiber parameters including size, shape, uniformity, and surface characteristics. Computerized image analysis is often used to quantify and evaluate these parameters for quaUty control. 

Perhaps the most significant complication in the interpretation of nanoscale adhesion and mechanical properties measurements is the fact that the contact sizes are below the optical limit ( 1 t,im). Macroscopic adhesion studies and mechanical property measurements often rely on optical observations of the contact, and many of the contact mechanics models are formulated around direct measurement of the contact area or radius as a function of experimentally controlled parameters, such as load or displacement. In studies of colloids, scanning electron microscopy (SEM) has been used to view particle/surface contact sizes from the side to measure contact radius [3]. However, such a configuration is not easily employed in AFM and nanoindentation studies, and undesirable surface interactions from charging or contamination may arise. For adhesion studies (e.g. Johnson-Kendall-Roberts (JKR) [4] and probe-tack tests [5,6]), the probe/sample contact area is monitored as a function of load or displacement. This allows evaluation of load/area or even stress/strain response [7] as well as comparison to and development of contact mechanics theories. Area measurements are also important in traditional indentation experiments, where hardness is determined by measuring the residual contact area of the deformation optically [8J. For micro- and nanoscale studies, the dimensions of both the contact and residual deformation (if any) are below the optical limit. 

Some limitations of optical microscopy were apparent in applying [247—249] the technique to supplement kinetic investigations of the low temperature decomposition of ammonium perchlorate (AP), a particularly extensively studied solid phase rate process [59]. The porous residue is opaque. Scanning electron microscopy showed that decomposition was initiated at active sites scattered across surfaces and reaction resulted in the formation of square holes on m-faces and rhombic holes on c-faces. These sites of nucleation were identified [211] as points of intersection of line dislocations with an external boundary face and the kinetic implications of the observed mode of nucleation and growth have been discussed [211]. 

In this study, we report on the GaN nanorod growth by HOMVPE technique with or without using a new precursor, tris(N,N-dimethyldithiocarbamato)gallium(III) (Ga(mDTC)3). The structural and optical properties of GaN nanorods were characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL). 

Figure 3. Images of a cross-section of carbon fibers after propylene pyrolysis. 3a Scanning Electron Microscopy of a piece of the carbon cloth. 3b optical microscopy (crossed polarizers with a wave retarding plate).

Image Formation in Low-Voltage Scanning Electron Microscopy, L. Reimer (SPIE-Intemational Society for Optical Engineering)... 

Tg (-22 °C) of a homogeneous 70/30 PNIPAM-water mixture. Observation of samples by scanning electron microscopy and optical microscopy revealed that the morphology of the polymer-rich phase is preserved only if the polymer solutions are brought to zone C. Polymer solutions heated to zone B undergo demixing upon quench-cooling [160]. Aqueous solutions of PVCL, PNIPMAM, and PNIPMA exhibit similar behaviour [157,158,369,370]. 

Particle morphology can be examined with optical microscopy and scanning electron microscopy. A discussion of both techniques is presented. 

Figure 2.8. Scanning electron microscopy (SEM) photomicrographs of (a) a micro-diffractive optical element mold fabricated by a focused ion beam (FIB) and (b) the transferred optical element on a sol-gel film. [Reprinted with permission from Ref. 98.]... 

The minerals of the solid tailings and evaporites were assessed qualitatively with X-ray diffraction, optical, and scanning electron microscopy. 

The samples were air-dried at room temperature, sieved to < 63 pm and analysed by x-ray diffraction (XRD) and scanning electron microscopy combined with an energy dispersive system (SEM-EDS). For chemical analysis, samples were submitted to an extraction with Aqua Regia and analysed by inductively coupled plasma-optical emission spectrometry (ICP/OES). Firing experiments were performed following the procedure described by Brindley Brown (1980). 

Microscopic techniques, 70 428 Microscopists, role of, 76 467 Microscopy, 76 464-509, See also Atomic force microscopy (AFM) Electron microscopy Light microscopy Microscopes Scanning electron microscopy (SEM) Transmission electron microscopy (TEM) acronyms related to, 76 506-507 atomic force, 76 499-501 atom probe, 76 503 cathodoluminescence, 76 484 confocal, 76 483-484 electron, 76 487-495 in examining trace evidence, 72 99 field emission, 76 503 field ion, 76 503 fluorescence, 76 483 near-held scanning optical,... 

The melt mixed 80/20 PS/iPP blend displays a set of exotherms, where the amount of the iPP component that was heterogeneously nucleated is substantially reduced as indicated by the decrease of the crystallization enthalpy in the temperature region where the iPP crystallizes in bulk, i.e., at 109-111 °C (exotherm labeled A). This effect is due to the confinement of iPP into a large number of droplets. If the number of droplets of iPP as a dispersed phase is greater than the number of heterogeneities present in the system, fractionated crystallization occurs. The number of droplets for this composition is known (by scanning electron microscopy observations) to be of the order of 1011 particles cm-3 and polarized optical microscopy (POM) experiments have shown that this iPP contains approximately 9 x 106 heterogeneities cm-3. In fact, it can be seen in Fig. 1 that the fractionated crystallization of the iPP compon-... 

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