Microscopy image analysis techniques

Angus, S.D., Davis, T.P. Polymer surface design and informatics facile microscopy/image analysis techniques for self-organizing microporous polymer film characterization. Langmuir 18, 9547-9553 (2002)... 

The particles can be visualized using optical or electron microscopy, and specific dimensions can be measured with less subjectivity. The advent of computers also allows particles to be sized by image analysis techniques based on optical or electron photomicrographs. 

Microscopy. Characterization of particulate from suspensions using microscopic methods is an effective method for establishing the size distribution of the particles and also their composition. Using properly prepared samples, automated image analysis techniques can be used that significantly reduce data collection times. Although the size distribution and composition of the suspended particles are important, the real strength of microscopic methods is the ability to observe particles in suspension and to determine how they interact and associate. There is little difference in microscopic methods applied to solids in suspension or to oil droplets in suspension (emulsions). As a result, the bulk of this discussion is borrowed from a similar chapter on emulsion characterization found in reference 19. 

Optical microscopy on phase contrast mode allows observation of the different morphologies obtained for each PP/interfacial modifier/PA6 blend. By image analysis techniques, it is possible to carry out statistical field measurements not only of the mean number of particles on the dispersed phase but also of their preferential geometry, mean size, and size distribution. 

If the orientation can be examined by optical microscopy, it can be quantified using computerized image analysis techniques. Anisotropy can be studied by applying an ultrasonic, electrical or radiation signal, which penetrates into the test material in different directions. Gross fibre waviness can be checked by visual inspection. 

Laser ablation technology for industrial applications has first come to prominence in 1965. For example, chlorinated rubber (CR) coatings were removed from concrete surfaces using a 60 W high power laser diode [59]. The ash particles were investigated by optical microscopy, image analysis, DTA/DTG, ESEM and EDX techniques. 

The lateral resolution (perpendicular to the optical axis) is about 200 nm, typical for optical microscopy. Because of limitations of the optics, the vertical resolution is only 500 nm. Appheation of image analysis techniques [29,30] improves the resolution for the location of the center of the particles by about an order of magnitude. A typical time to scan a stack of planes through a sample is a few seconds. 

Analytical electron microscopy permits structural and chemical analyses of catalyst areas nearly 1000 times smaller than those studied by conventional bulk analysis techniques. Quantitative x-ray analyses of bismuth molybdates are shown from lOnm diameter regions to better than 5% relative accuracy for the elements 61 and Mo. Digital x-ray images show qualitative 2-dimensional distributions of elements with a lateral spatial resolution of lOnm in supported Pd catalysts and ZSM-5 zeolites. Fine structure in CuLj 2 edges from electron energy loss spectroscopy indicate d>ether the copper is in the form of Cu metal or Cu oxide. These techniques should prove to be of great utility for the analysis of active phases, promoters, and poisons. 

Vukjovic et al.199 recently proposed a simple, fast, sensitive, and low-cost procedure based on solid phase spectrophotometric (SPS) and multicomponent analysis by multiple linear regression (MA) to determine traces of heavy metals in pharmaceuticals. Other spectroscopic techniques employed for high-throughput pharmaceutical analysis include laser-induced breakdown spectroscopy (LIBS),200 201 fluorescence spectroscopy,202 204 diffusive reflectance spectroscopy,205 laser-based nephelometry,206 automated polarized light microscopy,207 and laser diffraction and image analysis.208... 

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