Solutions, colloidal conductivity

Zhukov, A.N., Zviaguilskaya, Y.V. and Benndorf, C., Effect of the surface conductance on electrokinetic potential calculated from electrophoretic mobilities of the diamond particles in ethanol electrolyte solutions. Colloids Surf. A, 222, 341, 2003. 

The author studied the temporal evolution of a /iN solution of zirconoxychloride. The electrical conductivity increased during 7 days continuously to up to 30%. After cooking the solution, the conductivity increased further, to a final value about double the initial one. After heating, the reactivity of solutions of zirconoxychloride changed. Precipitation after Na2S04 addition was observed only in heated solutions. The changes were explained based on the formation of a colloidal hydroxide, the presence of which was identified by dialysis techniques. Potential polymer formation as a precursor of colloid formation has not been discussed in this paper. 

Inoue, T. Ebina, H. Dong, B. Zheng, L. Q. (2007). Electrical conductivity study on micelle formation of long-chain imidazolium ionic liquids in aqueous solution. /. Colloid Interface Sci, 314,236-241. 

The most familiar type of electrokinetic experiment consists of setting up a potential gradient in a solution containing charged particles and determining their rate of motion. If the particles are small molecular ions, the phenomenon is called ionic conductance, if they are larger units, such as protein molecules, or colloidal particles, it is called electrophoresis. 

The reduction of K2TaF7 can also be performed using sodium vapors [584]. This process is conducted at an Na pressure as low as 0.1 torr, which enables the removal of interferring gases such as N, O and H20. The interaction begins at 350°C. The temperature further increases up to 800°C to prevent the condensation of sodium and the formation of colloidal tantalum powder. The product of the interaction is removed from the reactor after cooling and treated with boiled HC1 and HF solutions. The method enables the production of coarse grain tantalum powder with 99.5% purity. 

A DEA is basically a compliant capacitor where an incompressible, yet highly deformable, dielectric elastomeric material is sandwiched between two complaint electrodes. The electrodes are designed to be able to comply with the deformations of the elastomer and are generally made of a conducting material such as a colloidal carbon in a polymer binder, graphite spray, thickened electrolyte solution, etc. Dielectric elastomer films can be fabricated by conventional... 

Stigter, D, Kinetic Charge of Colloidal Electrolytes from Conductance and Electrophoresis. Detergent Micelles, Poly(methacrylates), and DNA in Univalent Salt Solutions, Journal of Physical Chemistry 83, 1670, 1979. 

The role of reversed micelles in the manufacture of fine chemicals with enzymes also needs to be assessed and analysed. An outstanding example is lipase catalysed interesterification to produce cocoa butter substitute from readily available cheap materials (Luisi, 1985). This example of reversed micelles is sometimes referred to as a colloidal solution of water in organic systems. A number of water insoluble alkaloids, prostanoids, and steroids have been subjected to useful transformations (Martinek et al., 1987). Peptide synthesis has also been conducted. The advantages of two liquid phases are retained to a very great extent the amount of water can be manipulated to gain advantages from an equilibrium viewpoint. 

Fig. 24. Plot of the specific rate of interfacial electron transfer k vs. the pH of the solution. Experiments were conducted with colloidal solutions of TiOj (R = 10 nm) in the presence of 10" M...

A similar study was conducted by Dimitrijevi6 et al. with neutral solutions of a-Fe203. The yield of Fe was found to be very low. However, a large Fe yield was found after dissolution of the colloid by hydrochloric acid under an argon atmosphere. This showed that electrons donated by the free radicals penetrated deep into the colloidal particles to reduce iron to F, . Buxton et al. observol in a study on the reductive dissolution of colloidal Fe304 that Fe ions in this material are less readily released into the aqueous phase than reduced Fe ions. 

Ionic (electrolytic) conduction of electric current is exhibited by electrolyte solutions, melts, solid electrolytes, colloidal systems and ionized gases. Their conductivity is small compared to that of metal conductors and increases with increasing temperature, as the resistance of a viscous medium acts against ion movement and decreases with increasing temperature. 

The conductance of several Au-acetone colloids was measured and compared to pure acetone, and Nal-acetone solutions. As expected the Nal-acetone solutions (0.00075 M up to 1.5 ft) shewed greatly increased conductivities (130 to >20,000 yohm s 1 cm1). However, the Au-acetone colloid solutions showed-approximately the same conductivities (2.5 to 7.4 yohm s cm 1) as acetone itself (4.5 yohm s cm ). We conclude that very little "electrolyte (ion pairs) was present in the purple Au-acetone colloidal solutions. 

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