Hydrocarbon particle size influence

Figure 5. The influence of the Ru particles size on the hydrocarbon selectivities Curve 1, distribution for a mean-particle size of 1.5 nm Curve 2, distribution for a mean-particle size of 10 nm initial pressure, 20 bar HJCO = 4/1 reaction temperature,200°C...

The influence of mixed coupling on the properties of Cl Pigment Yellow 12 has been studied recently [12]. Carboxy- or sulpho- substituted derivatives of acetoacetanilide were evaluated as co-coupling components and analysis revealed that the state of the crystal and the particle size were changed and new diffraction peaks were observed. When these modified pigments were treated with a fatty amine such as stearylamine, the hydrocarbon chains enclosed the anionic groups in the co-coupler so that properties such as flowability, wettability and dispersibility in nonpolar solvents were greatly improved. 

Aromatic hydrocarbons Natural sediments Partition coefficient showing the influence of particle size [43,47,48,51,53 - 63] ... 

Based on experiments with pure hydrocarbons and synthetic silica-alumina catalyst, it has been estimated that the cracking-rate constant at 932°F. should decrease by a factor of to when particle diameter is increased from about 0.5 mm. to 4 mm. (74). The influence of particle size on effective activity is especially pronounced at very high cracking temperatures (49). This behavior is in line with predictions because, with increasing temperature, reaction rate on the catalyst surface increases more rapidly than the rate of diffusion of reactants into the pores. Cracking of unsymmetrical diarylethanes is an exceptional case in which the reaction appears to depend entirely upon the number of collisions of the hydrocarbon with the external area of the catalyst particles (208). 

Some aspects of the particle size, alloying effect, and metal-support interaction in nano-sized supported metal particles are presented for the oxidation of ethylene, the hydrogenolysis of alkanes, and the hydrogenations of unsaturated hydrocarbons and a,j8-unsaturated aldehydes. The influence of these phenomena is highlighted on the... 

It is therdbre possible to predict, with some confidence, the stability of a dispersion from readily obtainable parameters, and this has been done for hydrocarbon media for a range of particle size and surface potential. The validity of the DLVO theory has been demonstrated both by qualitative and by rigorous experimental tests on systems in which there is no significant influence of the interaction of adsorbed layers of surface-active material, i.e. only the charge mechanism is operative. However the origin of the charge on the particles is still subject to debate. 

Inverse emulsion polymerization is used for the preparation of polymers with ultrahigh molecular masses. For this type of polymerization, the expression dispersion polymerization is often used in the literature [410]. A concentrated monomer solution (about 40% monomer in water) is dispersed under intensive stirring in aliphatic or aromatic hydrocarbons in the presence of additives (emulsifiers, protective colloids). Polymerization can be initiated by either water-soluble or oil-soluble initiators [411-418]. The advantage of this process is based on the constant viscosity of the reaction mixture, as the increase of viscosity takes place only in the dispersed phase. By the use of additives (tensides), the dispersion inverts when the emulsion is stirred into water. Precipitation from the aqueous solution yields a polymer with ultrahigh molar mass. The quality of polymer made by inverse emulsion polymerization is influenced by the following factors (1) species and concentration of initiator, (2) species and concentration of additives (emulsifiers, protective colloids), (3) type of oil phase, and (4) particle size of the dispersed water phase. Because of the easy modification of all these parameters, much attention has been given in recent years to water-in-oil emulsion polymerization of AAm and MAAm. 

Carbon Black (CB) is a colloidal form of elemental carbon, which usually consists of spherical particles. Size of these molecules is less than few dozen nanometers. Particles create agglomerations with different spatial configuration. Structure and configurations of particles influence properties of carbon black. The genesis of obtaining carbon black is mainly based on incomplete combustion of carbonaceous materials. The main precursors include wood, coal, natural gas and hydrocarbons. The basic production methods for this material include furnace method, lamp method, and now more widely used plasma method. Commercially available carbon black fillers have varying level of structure, particle size, chemical reactivity and pH that lead to different levels of reinforcement. 

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