Dispersion composition

Each oil-dispersant combination shows a unique threshold or onset of dispersion [589]. A statistic analysis showed that the principal factors involved are the oil composition, dispersant formulation, sea surface turbulence, and dispersant quantity [588]. The composition of the oil is very important. The effectiveness of the dispersant formulation correlates strongly with the amount of the saturate components in the oil. The other components of the oil (i.e., asphaltenes, resins, or polar substances and aromatic fractions) show a negative correlation with the dispersant effectiveness. The viscosity of the oil is determined by the composition of the oil. Therefore viscosity and composition are responsible for the effectiveness of a dispersant. The dispersant composition is significant and interacts with the oil composition. Sea turbulence strongly affects dispersant effectiveness. The effectiveness rises with increasing turbulence to a maximal value. The effectiveness for commercial dispersants is a Gaussian distribution around a certain salinity value. 

Dispersant compositions for the treatment of oil spills at the surface of the water consist of a mixture of water, a hydrocarbon solvent, and a mixture of surfactants consisting of 55% to 65% by weight of emulsifiers and 35% to 45% by weight of dioctyl sodium sulfosuccinate. The emulsifying agents consist of a mixture of various sorbitan oleates [351-354]. 

A proteinaceous particulate material has been described that is effective as an oil spill-dispersant composition [1450]. The material is a grain product (such as oats) from which lipids are removed through organic solvent extraction. When such compositions are applied to an oil spill, they will adsorb oil, emulsify it, and finally, disperse it. Moreover, the compositions are substantially nontoxic. 

J. B. Bloys, W. N. Wilson, E. Malachosky, R. D. Bradshaw, and R. A. Grey. Dispersant compositions comprising sulfonated isobutylene maleic anhydride copolymer for subterranean well drilling and completion. Patent US 5360787,1994. 

A. Charlier. Dispersant compositions for treating oil slicks on the surface of water (compositions dispersantes pour le traitement de nappes d huile a la surface de I eau). Patent EP 254704, 1988. 

A. Charlier. Dispersant compositions for treating oil slicks on cold water. Patent EP 398860, 1990. 

Y. Inoue, Photocatalytic activity of the Ru02-dispersed composite p-block metal oxide LiInGe04 with d10-d10 configuration for water decomposition,... 

An additional opportunity that arises from applying polymer-based materials is the preparation of water-dispersible composites, which is an essential feature for biomedical purposes, as it is possible to attach bio-active molecules to the poly-mer/CNTs systems and specifically deliver them to cells. In this manner, plasmid DNA, siRNA (Fig. 3.11) and several anticancer agents have been successfully bound and delivered [61]. The stratagem to generate materials with good solubility in aqueous media usually involves the presence of water-soluble polar groups (e.g. phosphates, protonated amines etc.) embedded in the polymer chain. 

CNT randomly dispersed composites Many soft and rigid composites of carbon nanotubes have been reported [17]. The first carbon-nanotube-modified electrode was made from a carbon-nanotube paste using bromoform as an organic binder (though other binders are currently used for the paste formation, i.e. mineral oil) [105]. In this first application, the electrochemistry of dopamine was proved and a reversible behavior was found to occur at low potentials with rates of electron transfer much faster than those observed for graphite electrodes. Carbon-nanotube paste electrodes share the advantages of the classical carbon paste electrode (CPE) such as the feasibility to incorporate different substances, low background current, chemical inertness and an easy renewal nature [106,107]. The added value with CNTs comes from the enhancement of the electron-transfer reactions due to the already discussed mechanisms. 

The possibility to obtain a uniformly dispersed composite powder was shown for the a-Fe-Al203 system where metal particles with an average size of 55 nm were formed in an amorphous/nano alumina matrix.18 Other studies attempting to obtain dense bulk composites based on the sol-gel route using conventional pressure-assisted sintering ( 1400°C and an applied force of 10 MPa) resulted in a coarse microstructure.16 However, if reaching theoretical density is not a necessary requirement, a porous ceramic microstructure containing nanometer-sized metal particles can be used as a catalytic material.19 Certain combinations of composite materials demand... 

Several forensic laboratories in the United States and in other countries have SEM facilities, many of which are equipped for energy dispersive compositional analysis (EDA). This paper will describe selected actual recent applications of SEM-EDA techniques performed at the New York State Police Scientific Laboratory and Electron Microanalysis Laboratory at Rensselaer Polytechnic Institute. 

It should be noted that an expression similar to (47) was recommended by Budianski [50] and Hill [51] for description of the dependence of the relative modulus of disperse composites on concentration. A more elaborate expression was obtained by Lee [53], who used Vand s concepts of the immobilized liquid for the description of the behavior of dispersions in terms of the mechanics of three bodies ... 

Equations, similar to Hatschek s empirical equation (11) can be found in calculations by Ishai and Cohen [54] or Narkis [55] for describing the dependence of relative modulus on concentration for disperse composites ... 

Fig. 10. Dependence of the packing factor of highly-loaded coarse-dispersion composites on vibration time. Numbers on the curves correspond to numbers of composites in Table 2...

R. J. Lo, J. L. Chen, and H. B. Scher, Dry Water-Dispersible Compositions of Mieroencap-sulated Pesticides, United States Patent 6,358,520,2002. 

For example, there is a 500% rate difference for the photoreduction of CO2 using 10 different samples of Pd colloids Wilner, I. Mendler, D. J. Am. Chem. Soc. 1989, 111, 1330. Also, see Kohler, J. U. Bradley, J. S. Catal. Lett. 1997, 45,203, wherein they describe a 670% variation in the rate of hydrogenation with PVP-protected Phj colloids (due to a widely dispersed composition, with varying numbers of surface groups). 

CNT randomly dispersed composites Many soft and rigid composites of carbon... 

A transparent film prepared from a poorly dispersed composite by the same method is shown in Figure 6. Chunks of carbon black, about 2irin diameter are readily visible. During micronization, fracture could conceivably occur in the middle of a large carbon black chunk, leaving the uncoated surface exposed. In the well dispersed material, fracture through the smaller carbon black aggregates seems less likely, thus the surface of this sample powder probably has less exposed carbon black. 

Cleaning and soil dispersing compositions comprising ethoxylated/propoxylated polyalkyleneamine polymers... 

Stability of disperse composition, that is, stability with respect to change in dispersity (particle size distribution). 

Many properties of disperse systems, such as those described above and those analyzed in subsequent chapters, are defined by the degree to which substance is dispersed and by the type of particle size distribution. Various methods for the investigation of dispersion composition of dispersed phase (idispersion analysis) have been developed. Many of these methods utilize the concepts of transfer phenomena discussed in previous sections of this chapter. 

The subtype is a lower unit, including a transient group of soils with a character mainly of a certain type but with some characteristics which belong to another type. Each soil type is characterized by a certain typical stratigraphy of the soil profile, i.e. by a sequence, thickness and development of particular horizons. The horizons may be differentiated from each other on the basis of morphologic features and results of analyses, such as the dispersion composition, mineralogical and chemical composition. 

Figure 1. Electrode potential curves obtained from the (intermittent) galvanostatic charge-discharge curves of the carbon-dispersed composite electrodes of (a) Lii. sNiOa, (b) Lii Co02, (c) Li6V20s, (d) Lii+6[Ti5/3Li /3]04, and (e) graphite. Reprinted from (1999), (2001), and (2001), with permission from Elsevier Science.

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