Paraffinic dispersion medium

Paraffinic dispersion medium 129 Paramagnetic anionic coordination centers 177... 

Even dynamic measurements have been made on mixtures of carbon black with decane and liquid paraffin [22], carbon black suspensions in ethylene vinylacetate copolymers [23], or on clay/water systems [24,25]. The corresponding results show that the storage modulus decreases with dynamic amplitude in a manner similar to that of conventional rubber (e.g., NR/carbon blacks). This demonstrates the existence and properties of physical carbon black structures in the absence of rubber. Further, these results indicate that structure effects of the filler determine the Payne-effect primarily. The elastomer seems to act merely as a dispersing medium that influences the magnitude of agglomeration and distribution of filler, but does not have visible influence on the overall characteristics of three-dimensional filler networks or filler clusters, respectively. The elastomer matrix allows the filler structure to reform after breakdown with increasing strain amplitude. 

Mackor (1951) was perhaps the first to endeavour to calculate the free energy of repulsion between sterically stabilized particles. This work was instigated after van der Waarden (1950 1951) had shown experimentally that aromatic molecules with long-chain aliphatic substituents could have a profound effect on the stability of carbon black particles dispersed in a paraffin (see Section 2.4.2). For this reason, Mackor adopted a model in which he assumed that the aromatic nuclei were adsorbed onto the carbon black particles in a flat configuration, thus anchoring the alkyl chains to the surface. These chains were assumed to project into the dispersion medium and were modelled as rigid rods, of length L, flexibly attached to the particle surfaces by ball joints. 

Mineral oil [liquid paraffin) was also used for the formation of pre-polymerization droplets [Kempe and Kempe, 2006). Being chemically inert in nature, these liquids do not affect the non-covalent interactions in template-monomer complex when used as a dispersing medium. There are some recent reports utilizing suspension polymerization for MIP synthesis for Staphylococcus aureus protein A-imprinted polyacrylamide [Pan et al., 2009), Stlgmasterol MIP microspheres [Han et al., 2008), MIP hydrogels for the peptide hepcidin [Abbate et al., 2010) and Promethazine based MIPs [Alizadeh et al., 2012). 

It is common knowledge that the dispersion medium contains the highest content of compounds with aliphatic (paraffinic) bonds. Correlations of the activation energy E with the concentration of dispersion medium DP as well as with the carbon in paraffinic bond CP demonstrate clearly, that pyrolysis starts with the aliphatic (paraffinic) C-C-bonds. 

The reaction kinetic constants activation energy E and frequency factor A, can only be correlated with the concentration of paraffinic carbon, CP (from structural group analysis) with the concentration of dispersion medium (fiom colloid analysis) and with the H/C ratio (from elemental analysis). These functions show correlation coefficients of an acceptable magnitude. Examination of the correlation of the concentration of maltenes revealed a similar tendency but with very low coefficients of correlation. It is well known that the dispersion medium contains the highest concentration of chemical bonds, which can be cracked under the chosen reaction conditions [4-20]. In the pyrolysis experiments from distillation residues, about 92 % of the dispersion medium was converted, whereas conversion of the petroleum resins was only 83 %, despite the fact that the kinetic coefficients are of nearly the same magnitude for the two components. 

At the same time, significant changes in the state of a system can result from fairly moderate deviations in T, for example, the changes in the mutual solubility of both the disperse phase and the dispersion medium components, leading to a radical decrease in a. Typical examples include studies on systems approaching the critical point, (and yet still below the TJ, such as those carried out with binary mixtures of paraffins with moderately polar organic substances, such as oxyquinoline [26,67,68], In these works, the formation of direct, inverse, and bicontinuous microemulsions had been described and analyzed in comparison with the independently determined values of a down to 10" -10" mN/m,... 

Emulsions are a class of disperse systems consisting of two immiscible liquids [1-3], whereby the Hquid droplets (the disperse phase) are dispersed in a liquid medium (the continuous phase). Several classes of emulsion may be distinguished, namely Oil-in-Water (O/W), Water-in-Oil (W/O), and OU-in-Oil (0/0). The latter class may be exemplified by an emulsion consisting of a polar oil (e.g., propylene glycol) dispersed in a nonpolar oil (paraffinic oil), and vice versa. In order to disperse two immiscible liquids a third component is needed, namely the emulsifier. The choice of the emulsifier is cmcial in the formation of an emulsion and its long-term stability [1-3]. 

Oil-in-oil emulsion systems display a relatively strong ER effect. Examples of such ER active emulsions are chlorinated paraffin/polydimethylsiloxane [11], castor oil/polydimethylsiloxane [13], urethane-modified polypropylene glycol/dimethylsiloxane [12] etc.. The ER effect in emulsions is attributed to the stretched droplets that Ibrm fibrillation chains along the direction of the electric field. This is a typical feature for any emulsion system in which the two liquids have a quite different dielectric constant and conductivity. Figure 17 shows the water droplet chains formed in a supercritical fluid carbon dioxide medium under a 60 Hz ac field of a very low field strength, Emax=IO V/mm [115]. A synergetic effect is observed in an system composing of polyanilines dispersed in a chlorinated paraffin/silicone oil emulsion [107],... 

Solid samples for infrared spectroscopic measurements are frequently in the form of a powder. It is impossible to measure directly an infrared transmission spectrum from a powder sample, because powder strongly scatters the infrared light. To measure an infrared tfans-mission spectrum from a powder sample, it is a usual practice to disperse the powder sample in a medium (KBr, liquid paraffin, etc.) to reduce the scattering. 

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