Study of Morphology

The morphology of the particles in rocks and soils means the size or size distribution, shape of the particles and pores, and the specific surface area of the external and internal surfaces. 

Size and size distribution can be studied by classical sedimentation techniques. The classification of soils is based on particle sizes (Chapter 1, Section 1.1.3, Table 1.6). The size and shape of the particles can be observed by different microscopes, from the traditional light microscopes to scanning and transmission electron microscopes. The nanometer-sized particles can be observed by the atomic force microscope. This microscope, equipped with a microprobe (scanning and transmission microscope), is suitable for the chemical analysis of the sample. 

The size distribution of solid samples can be determined by static and dynamic light-scattering techniques the size ranges from a few nanometers to a few microns. The concept uses the idea that small particles in a suspension move in a random pattern called Brownian motion. When the moving particles are irradiated by a 

The porosity of solid samples can be quantitatively studied by mercury poro-simetry. The total volume, specific surface area of the pores, bulk density, and particle size can be determined in 1.8 nm-300 pm pore size and 15 nm-3 mm particle size. The principle of the method is that there is a relationship between the pressure of mercury and the size of the pores filled with mercury. The pressure of mercury (p) required for its introduction into the pores of a given radius (r) can be expressed by Washburn s equation  

The measurements of external and internal specific surface area have already been discussed in Chapter 1, Section 1.1.3. The principles and the isotherm equation of the BET method to measure external specific surface area, including macro- and mesopores, have been presented in Chapter 1, Section 1.3.4.1.5. The external specific surface area is usually determined by nitrogen gas adsorption at the temperature of liquid nitrogen. Both static (one-point) and dynamic (five-point) methods are applied. The calculations are made by Equation 1.75 (Chapter 1), using one or five different pressure values. The external specific surface area is calculated from the maximum number of surface sites, that is, monolayer and the cross-sectional area of nitrogen molecules. 

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Crystallization has been investigated for other block copolymers, in particular those containing poly(e-caprolactone) (Tm = 57°C). Experimental results for these materials are also summarized here. A study of morphology in block copolymers where both blocks are crystal lizable is also discussed. 

Baschong, W., Baschong-Prescianotto, C., and Kellenberger, E. 1983. Reversible fixation for the study of morphology and macromolecular composition of fragile biological structures. Eur. J. Cell Biol. 32 1-6. 

Studies of morphology First principles calculations on sample systems... 

Thiedemann, K.U., Holubarsch, C., Medugorac, I., and Jacob, R. 1983. Connective tissue content and myocardial stiffness in pressure overload hypertrophy. A combined study of morphologic, morphometric, biochemical, and mechanical parameters. Basic Res. Cardiol. 78 140-155. 

Several fundamental studies of morphology and glass transition temperatures of poly(urethane-seq-diene) networks have been published 144,211 216). Phase separation was characterized by electron microscopy. 

Grain formation occurs when temperatures in the expanding envelope of red giants (RGs) or in SN ejecta are low enough for the condensation of minerals. Many late-type stars are observed to be surrounded by dust shells of grains whose mineral compositions reflect the major chemistry of the gas (e.g., Little-Marenin, 1986). The study of morphological features of pristine grains, of internal... 

The study of cells. Implies the use of light or electron microscopic methods for the study of morphology. 

B. G. Ranby, Inst. Phys. Chem., Univ. Uppsala, Arkiv Kemi, 4, 241 (1952). Fine structure and reactions of native cellulose. Electron microscope study of morphology of celluloses from wood, cotton, bacteria, tunicates, and algae behavior of samples on swelling in sodium hydroxide and hydrolytic degradation. 

Detailed study of morphology and dissolution of six powders obtained by different methods based on Atkinson recipe [I486]. TEM image available [248,585,723], SEM image available [1468,1484,1485,1558,1561], 100 face predominant [1534,1574], 90% of 110 face, 10% of 021 face [629], XRD pattern available [536,602,1318], TGA results available [1468], Mossbauer spectrum available [1318], IR spectra available [1574]. 

Fluorescence quenching techniques (1) provide a battery of useful tools for the study of morphology in complex polymer systems. One of the most important applications of these techniques is to the study of interfaces and interphases in polymer systems. 

In this study, the imperfection of the networks was varied by varying the stoichiometry of an Epon 828-methylene dianiline system. Related studies of morphology, other properties, and creep as a function of molecular weight and distribution of the prepolymer are described elsewhere (9-13). 

P. Eisenberger, and S. R. Forrest, In situ studies of morphology, strain, and growth modes of a molecular organic thin film, Phys. Rev. B 56(6), 3046-3053(1997). 

Figure 2 shows how glass transition temperatures (Tg) obtained by dynamic mechanical spectroscopy (DMS), percent crystallinities obtained by wide angle x-ray scattering (WAXS) or differential scanning calorimetry (DSC), experimental diffusion coefficients, and information on tortuosity obtained by studies of morphology, can be useful in applying both the theory of V D and the model of P D. The Williams-Landel-Ferry (WLF) parameters [18] c % and C2 , which can be determined by DMS, are needed as additional input for the theory of V D. Densities and thermal expansion coefficients are needed as additional input for the model of P D. 

In the past few years the study of morphology changes undergone by supported Rh particles during oxidation / reduction thermal treatments has attracted considerable attention (refs 1-4). These phenomena are of particular importance in the deactivation of automotive exhaust catalysts for which rhodium is the main active ingredient for the reduction of NO. 

Microphase separation and domain formation in block copolymers, which are the result of incompatibility of block chains, have been studied extensively (1,2). In addition to being incompatible, block chains in a copolymer generally have different thermal transition temperatures. The surface tensions of molten block chains also differ. When a crystalline block chain is incorporated into a block copolymer, it is expected that crystallization of the crystalline block chain causes considerable change in resultant morphology. Surface properties of a block copolymer and of its blend with a homopolymer should also be modified by the surface tension difference between block chains and the homopolymer. Since these factors determine the morphological features of a block copolymer both in bulk and at surface, a unified study of morphology, crystallization, and surface activity of any block copolymer is important to our understanding of its physical properties. 

Amorphous PA (20) / S-IPO (1% IPO) (80) internal mixer at 200°C / torque rheometry / selective solvent extraction / SEM study of morphology development in reactive and in non-reactive blends Scott and Macosko, 1995... 

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