All Shapes and Sizes

Latex particles are more difficult to make and are made by emulsion polymerization for smaller particles and suspension polymerization for the larger ones. These procedures need surfactants (typically ionic sodium dodecyl sulfate), which eventually give the resulting particles a charge. Sulfuric acid groups are seen as well. Synthesis of organic nanoparticles is discussed in Chapter 4 (Section 13). 

When the colloidal suspension is titrated with sodium hydroxide (NaOH), its conductivity decreases and reaches a minimum when the surface acid groups have all been neutralized. From material balances it is possible to calculate the total number of acid head groups initially present, and eventually the area per head group, which is seen to vary from 3 to 4 nm /group. When there are two acid groups present (sulfuric and carboxylate), the conductivity plots show a feamre similar to having two minima. These steps are often required to prepare well-characterized colloids to perform controlled experiments. 

Sometimes it is necessary to strip the colloidal suspension of not only the dissolved ions but also the adsorbed ones. The ions in the dispersion medium/water are removed by washing followed by centrifugation and decanta- 

The sizes and shapes are determined using transmission electron microscopy (TEM) over a diffraction grating replica. Dynamic light scattering can also be used to obtain the dimensions (see Chapter 8). 

The approximate experimental determination of xl), is based on measurement of the velocity of a charged particle in a solvent subjected to an applied voltage. Such a particle experiences an electrical force that initiates motion. Since a hydrodynamic frictional force acts on the particle as it moves, a steady state is reached, with the particle moving with a constant velocity U. To calculate this electrophoretic velocity U theoretically, it is, in general, necessary to solve Poisson s equation (Equation 3.19) and the governing equations for ion transport subject to the condition that the electric field is constant far away from the particle. The appropriate viscous drag on the particle can be calculated from the velocity field and the electrical force on the particle from the electrical potential distribution. The fact that the sum of the two is zero provides the electrophoretic velocity U. Actual solutions are complex, and the electrical properties of the particle (e.g., polarizability, conductivity, surface conductivity, etc.) come into play. Details are given by Levich (1962) (see also Problem 7.8). 

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Carved wooden bears in all shapes and sizes overwhelmed Yngve and me at our visit to Noboribetsu in 1976. There was an afternoon to spare before the opening of the "Oji International Seminar on Theories and Ab Initio Computations of Molecular Electronic Structure" at Tomakomai, Hokkaido in the fall of 1976 so we wished to experience the hot springs. The train left us with a choice of buses, the desdnations of which were clearly indicated in Japanese writing. We found the right one and came to a city in a canyon where the sulfur fumes and hot water let themselves out. The kind reception by Kimio Ohno and Fukashi Sasaki at Hokkaido University remains a vivid memory. 

Particles come in all shapes and sizes and in large numbers. Data are presented graphically using histograms, fractional plots, or cumulative plots. These graphs are primarily useful as pictures of the size distribution of the mixture. Table 15.4 gives a typical screen analysis for a 900-g sample. The measured experimental data are the mesh sizes, and the masses of the particles on each of the sieves are the masses of the residuals or fines. The other quantities are calculated. 

Birds are not the only creatures that come to a garden to feed. An organic garden is likely to provide rich pickings for both vegetarian and carnivorous wildlife visitors of all shapes and sizes. With a little extra thought, you can provide them with even better fare. Natural foods that can easily be included on the menu for wildlife include nectar, pollen, aphids, caterpillars, slugs, berries, and seeds. 

Solids are the most obvious state of matter for us they are ubiquitous and come in all shapes and sizes. Solids are classified as either crystalline solids or amorphous solids. A crystalline solids displays a regular, repeating pattern of its constituent particles throughout the solid. At the microscopic... 

Tho vessel holding the solution is of any convenient form, and is provided with agitators of all shapes and sizes, depending upon the whim or caprice of each... 

Today, burner manufacturers have access to all kinds of designs for pilot lights, to fit all shapes and sizes of burners and burner ports and draft systems from the smallest breeze to gale-force winds—there is no longer any excuse to operate without pilot lights installed and working. 

One advantage of liposome is theirsingularability to take up material of all shapes and sizes regardles of their individual chemical peculiarities. The most relevant to this discussion is for lipid-soluble compounds, which are incorporated into the lipid bilayer of the liposome. Thus, the maximum amount taken up into liposomes is directly proportional to the quantity of membrane components, but is independent of the size of the liposomes used, except in a few cases where the structure o the encapsulated compound may restrict the Lnal size of the liposome. Theoretically, any type of liposome is suitable for the incorporation of lipid-soluble substances, but practical considerations make some choices more preferable over others. MLVs are the best choice for sustained release whereas SUVs are particularly suitable for rapid intermembrane transfer. 

Molecules come in all shapes and sizes, but those with concave surfaces1 11 (Fig. 1) have been of a special interest to chemists. In the early 1980s,12 Cram noted a paucity of cavity-containing compounds, dubbing them cavitands... 

Rollers of all shapes and sizes canbe made from polyurethanes. They vary from very soft printing rollers to hard rollers used in the steel industry. The casting and trimming of these rollers are very suited to polyurethane manufacturing. 

Nowadays I don t, but I used to get lots of it, in all shapes and sizes. Some advice was simply based on denial (such as from members of my family, who... 

Threats of aggression can come in all shapes and sizes, so defenses have to be versatile. The largest-scale threat is war between nations. Rulers of nations always seem to be wanting the resources of neighboring countries, so threatened countries have to defend themselves or suffer unpleasant consequences. In modern times, countries can have very sophisticated means of defense indeed. The United States has stockpiled atomic bombs if some other country shakes its proverbial fist at us, we can rattle our bombs at them. If threats escalate to violence and we don t wish to use atomic bombs for one reason or another, then other machines can be deployed jets that drop smart bombs, AWACS planes that monitor the air space for many miles, tanks equipped for night combat, surface-to-air-missiles that shoot down surface-to-surface missiles, and much more. To the techno-war-monger, we live in a golden age. 

Chemicals come in all shapes and sizes and derive from a variety of sources. While to many people the words chemical and indeed poison are synonymous with man-made things such as dioxin, organo-phosphates, pesticides, and nerve gas, there are many, many other chemicals that occur naturally These may be produced by plants, for example belladonna in deadly nightshade, and ricin in the castor bean, or bacteria, for example botulinum toxin. Various animals such as snakes and spiders produce toxic venoms, and some poisons occur naturally in the ground, like asbestos, cadmium, and lead. 

Gold and silver both have a face-centred cubic (fee) ciystal structure, which is illustrated in Figure 11.IS. Gold and silver are by far the most common noble metals and the most studied when it comes to metal nanoparticle thesis. The first reported nanoparticle preparation was for gold by Faraday, who theorized that the samples he prepared consisted of metals in a state of extreme eSvisiorT [46]. Today, methods for the synthesis of nanoparticles of all shapes and sizes from gold and silver are in great abundance. 

All shapes and sizes of compressed confectionery Make-up compacts, bath salt and handwash tablets, denture cleaning tablets... 

Briefs come in all shapes and sizes, and can be subject to many types of interpretation. Often the client is not exactly certain of what is wanted, or is not capable of translating the requirement into the language of perfumery. It is the work of a fragrance house to help the clients translate their gut-feel, or verbalize their inner sense of market opportunity into a viable fragrance direction for the product. 

Proteins come in all shapes and sizes, and their charges (both sign and magnitude) will depend on the particular protein and the pH used. Consequently, there is usually no way to predict where a particular... 

Innovators — like artists, musicians, and authors, cone in all shapes and sizes. But they do sean to sahre sane common attributes ... 

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