Dodecane black

Initial studies were made with the Rank Bros, electrophoresis unit, using the dilute supernatant suspension over a dispersion of 3.33g of carbon black per liter of dodecane equilibrated for 24 hours with the added 0L0A-1200. The electrophoretic mobility (u) of 1-3 pm clumps of particles was observed at a field of 100 volts per centimeter. The zeta-potentials ( ) were calculated... 

Figure 8. Conductivity of stirred 10% suspensions of carbon black in dodecane with OLOA-1200 dispersant. Triangles- 5 minutes after dispersant added circles- 45 minutes after addition and squares- 12 hours after addition. Reproduced with permission from Ref. (16). Copyright 1983, Elsevier Science Publishers.

Figure 11.1 Fish diagrams of the systems hbO-n-dodecane-C-B/is E5 ((a), dark grey circles), H2 0/NIPAm/BisAm-n-dodecane-Ci3/i5E5 ((a) and (b), black circles), hbO/NIPAm/BisAm-...

The catalysts were prepared by reducing the cobalt acetylacetonate dissolved in benzene, under a inert atmosphere of argon, using a known quantity of triethylaluminium (as a function of the desired Al/Co ratio). The solution immediatly became black and the metallic particles formed were able to be stabilized by butadiene at 0°C. The solvent employed during the hydrogenation reaction was dodecane or propylene carbonate. The benzene was then evaporated under a controlled atmosphere and the degradation products were then removed and analyzed, the temperature being increased up to 200°C. The catalyst thus obtained was used "in situ". 

Fig. 37.12 In vitro skin penetration of tetracycline hydrochloride from three preparations based on the same content of dodecane and water but differing in the proportion of decanol. Black circles, microemulsion, hollow circles, gel phase, squares, cream-like phase. Redrawn from Ziegenmeyer and Fuhrer. ...

Initial experiments were done in water and resulted in low cyclohexene conversions, low product selectivities, and extensive palladium deactivation by Pd black formation. The low cyclohexanone yield originated from overoxidation of cyclohexanone to 2-cyclohexenone, which undergoes further oxidation to a plethora of by-products. The low cyclohexene conversion can be attributed to the aforementioned low reactivity of the internal double bond as well as the low solubility of cyclohexene in water. Several reaction media have been described in which higher alkenes are oxidized to ketones in organic solvent-based systems. Some typical examples are DMF [4], water mixtures with chlorobenzene, dodecane, sulfolane [5], 3-methylsulfolane andM-methylpyrrolidone [6], or alcohols [7]. These solvent systems indeed lead to increased cyclohexene conversions but still suffer from overoxidation and catalyst deactivation by Pd black formation. Hence, the goal of our research was to find a variation to the Wacker oxidation without over-oxidation of the product and deactivation of the palladium catalyst. 

Figure 2.19 Phase diagrams of dodecane-water-Brij 92/96 mixtures. 0,W,S = 100% oil, water, surfactant, respectively. HLB values of the surfactant mixtures are shown to the right of each diagram. Phase boundaries for Li, L2, G, and M2 phases shown. Other symbols represent 2L, two-phase oil-water system (emulsions of varying stability) M, microemulsion I, isotropic elastic I +, isotropic elastic + disperse oil phase. Filled black regions stable emulsion zones. From Lo et al. [37] with permission.

Figure 2.27 Tetrahedral model of the system at 25°C looking towards the CgEe-octanol-dodecane face. The 3L region may just be seen as a line between the black and the white 2L regions. The small light coloured volume extending from the octanol-water-CgE face is a liquid plus liquid crystal region. From Marland and Mulley [44] with permission.

Figure 4.9 TEM micrographs recorded on a platinum shadowed replica prepared by FFET. (a) Sample prepared on 5 % dispersion of overbased calcium didodecylbenzene sulfonate in dodecane. Spherical nanoparticles of 10 nm diameter are easily visible, (b) Extractive replica prepared on the same dispersion. (c) X-ray analysis of the selected area (black circle) reveals the composition of the particles (Ca, S, O) corresponding to the sulfonate. The presence of Pt is due to the shadowing layer and copper to the copper support grid, (d) Radial distribution functions (from EXAFS studies) uncorrected from phase shifts obtained on caldte, and two OCABS dispersions in oil. The presence of a single peak corresponding to the first Ca-0 distance points out the amorphous structure of the mineral part of the OCABS particles...

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