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Size and Properties

Although we have shown a number of micrographs, it is beyond the scope of this treatment to discuss the details of experimental methodology and the tremendous art and craft that sometimes goes into sample preparation. Nevertheless, before finishing this section with a description of the morphology of fibers and block copolymers, it is useful to summarize the relative size of [Pg.234]

FIGURE 8-63 Schematic diagram illustrating chain folding in a spherulite. [Pg.234]

FIGURE 8-64 Summary of the relative size of different structures. [Pg.235]

Properties will also depend upon the nature of the amorphous domains, whether they are glassy or rubbery, and so on. So, struc-ture/property relationships is a big, complex snbject, but certain rules of thumb can be summarized, as shown in Table 8-3. [Pg.235]

Optical Clarity Generally increases with density. Semi-crystalline polymers usually appear opaque because of the difference in refractive index of the amorphous and crystalline domains, which leads to scat- altering. Will depend upon crystallite size. [Pg.236]


Petit C and Pileni M P 1997 Nanosized oobalt boride partioles oontrol of the size and properties J. Magn. Magn. Mater. 166 82... [Pg.2916]

The total lanthanide contraction is of a similar magnitude to the expansion found in passing from the first to the second transition series, and which might therefore have been expected to occur also in passing from second to third. The interpolation of the lanthanides in fact almost exactly cancels this anticipated increase with the result, noted in preceding chapters, that in each group of transition elements the second and third members have very similar sizes and properties. [Pg.1234]

Symplectin, 208-210, 347 isolation and purification, 208 molecular size and properties, 209 regeneration with... [Pg.469]

One of the insidious disadvantages of certain plastics is their tendency to absorb moisture from ambient air and then change their size and properties. There are protective measures that can be taken with these plastics such as coatings, chemical treatments, additives, and so on. To be practical, the best way to circumvent problems of this type is to select a plastic with the lowest possible absorption rate. [Pg.106]

In an attempt to create particles with different sizes and properties, ligands other than dodecanethiol were used to create polydispersed colloids from the SMAD method. Thus, dodecylamine, trioctyl phosphine, and dodecyl alcohol were used in addition to dodecanethiol. The results of these studies led to nearly monodispersed stable colloids for the phosphine protected particles at 6.3 nm in diameter (Figure 13). [Pg.240]

Either a liquid or a gas can be used as the carrier fluid, depending on the size and properties of the particles, but there are important differences between hydraulic (liquid) and pneumatic (gas) transport. For example, in liquid (hydraulic) transport the fluid-particle and particle-particle interactions dominate over the particle-wall interactions, whereas in gas (pneumatic) transport the particle-particle and particle-wall interactions tend to dominate over the fluid-particle interactions. A typical practical approach, which gives reasonable results for a wide variety of flow conditions in both cases, is to determine the fluid only pressure drop and then apply a correction to account for the effect of the particles from the fluid-particle, particle-particle, and/or particle-wall interactions. A great number of publications have been devoted to this subject, and summaries of much of this work are given by Darby (1986), Govier and Aziz (1972), Klinzing et al. (1997), Molerus (1993), and Wasp et al. (1977). This approach will be addressed shortly. [Pg.447]

Clearly, the definitive characteristic of any nanoparticulate drug delivery system will be its submicrometer diameter. Sizing such particles in the suboptical region can be difficult as the measuring technique itself may alter size and properties by either hydrating or aggregating the particles. This will have a profound influence on the size of the particle [59]. Haskell [134] has discussed the various optical techniques available to measure the size of nanoparticles. [Pg.8]

Volumes of the suspensions to be handled vary from the extremely large quantities involved in water purification and ore handling in the mining industry to relatively small quantities, as in the fine chemical industry where the variety of solids is considerable. In most industrial applications it is the solids that are required and their physical size and properties are of paramount importance. Thus, the main factors to be considered when selecting equipment and operating conditions are ... [Pg.372]

The tunability in size and properties of the materials described in the previous sections is so large that we expect them to find applications in different fields such as optoelectronics, pigments, molecular probes, and educational tools. We focus on five applications among these. Some of them are already feasible, whereas others require further development. [Pg.339]

The sizes of the droplets in the initial emulsion significantly affect the size and properties of the microspheres (Table 6)36). As the mixing rate used to produce the emulsions is increased, the average size of the droplets decreases whereas the microsphere size increases. Very dispersed emulsions seem to be more likely to coalesce, thus yielding larger droplets and hence larger microspheres after the heat treatment. This method can produce spherical unicellular particles with diameters of200-400 pm, densities of 260-700 kg/m3, and space factors of up to 59% 35 36). [Pg.73]

Chen (1980, p. 7) suggested that the use of bulk phase properties, such as those in Equations 3.1 through 3.3, may be satisfactory only in qualitative analyses. Microscopic critical clusters contain several tens to thousands of molecules, and as such have a spectrum of sizes and properties, which may be difficult to quantify with a single number on a macroscopic scale. [Pg.127]


See other pages where Size and Properties is mentioned: [Pg.237]    [Pg.1510]    [Pg.283]    [Pg.91]    [Pg.931]    [Pg.216]    [Pg.22]    [Pg.230]    [Pg.477]    [Pg.9]    [Pg.56]    [Pg.47]    [Pg.60]    [Pg.237]    [Pg.313]    [Pg.717]    [Pg.635]    [Pg.267]    [Pg.497]    [Pg.51]    [Pg.253]    [Pg.659]    [Pg.219]    [Pg.3]    [Pg.4]    [Pg.6]    [Pg.8]    [Pg.10]   


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