Investigations of Tll Suspensions

Thallous iodide suspensions were obtained by direct mixing of TlN03 and Na! solutions. The amount of TH was kept constant in the systems, while the concentrations of Na! (in excess), laurylamine nitrate (LAN) or myristylamine nitrate (MAN) were varied. Tyndallometric values were recorded as the function of Na!, LAN, and MAN concentrations respectively, for suspensions aged for various times. Particle sizes of differently aged TH in \u27Suspensions containing Na! and Eu(N03)a in solution were determined. Tyndal.:. lometry and electronmicroscopy showed fast particle growth of TH in suspension. After about 10 minutes the TH particle grew up to 1.3 μ. The zero point of charge, determined by microelectrophoresis, was attained at 0.001-0.005 M Na! and 0.0001-0.0005 M LAN depending on the conditions under which the system had been prepared. The results of radiometrically recorded adsorption- desorption equilibria show a constant increase of the adsorption capacity as the electrolyte concentration increases

On Some Properties of Silver Iodide

In order to obtain the relation between several factors affecting the colloido-chemical properties of silver iodide in the heterogeneous exchange processes, the following measurements were carried out: determination of the adsorption capacity of silver iodide (radiometry) tempered from 20 up to 400 °c, dry aged for 20 days to 5 years, pressed at 500 and 1500 kg cm-2 (on dried isoelectric precipitate); determination of the relation between particle size (electron microscopy) and crystallite size (X-ray diffraction analysis), and of the adsorption capacity of AgI (formed by dilution of KI + AgI complex solution) in the presence of sodium laurylsulphate (SLS); determination of the surface area (BET) of the tempered isoelectric dried silver iodide; determination of particle size and determination of the volume fraction of cubic and hexagonal modifications of AgI in the tempered samples. In conclusion, the effect of the inner surface as a possible relevant factor for the elucidation of the influence of surface active substances on acceleration of the exchange rate is pointed out. Interactions with sodium laurylsulphate are also discussed

Radiometric Determination of Agl-TlI-(1311), Agl-HgI2-(1311), and HgI2-TlI-(1311) Systems

The principle and procedure for radioanalytical determination of intermolecular interactions in a polycomponent system of »Solid- liquid: type is described. As models AgI-TlI-(131!), AgI-Hglr( 131!), and HgI2-TlI-(131I) systems were used. The AgI-TlI-(1311) system was analysed in detail and radioanalytical results obtained were compared using X-ray analysis, conductivity and micro differential thermal analysis. Of the other two systems the results obtained were compared only with the remlts of X-ray analysis. As all the results obtained agree with literature data, it is concluded that the described radioanalytical method is applicable for adequate analysis of intermolecular interactions in mixed systems

On »Silver Iodide + Surfactant« Systems

The effects of three different groups of surfactants are discussed: the ionic nonconstituent, the ionic constituent and the nonionic nonconstituent surfactants. On the basis of graphs: electrophoretic mobility vs. concn., turbidity vs. concn. and fraction of exchange vs. log of exchange time, four different types of systems can be distinguished

Radiometric Analysis of Silver Iodide Sols

With the ultimate goal to investigate (a) the formation of the solid phase by precipitation from electrolytic solutions, and (b) processes characteristic of the interaction between the solid phase and the electrolytic solution, the well-known radiometric methods of analyses have been applied, as well as new radiometric methods for the analysis of colloidal system developed. The methods applied are extremely sensitive, selective, and accurate. The new methods have been checked up by comparison of the obtained results with the standard classical methods, such as X-ray diffraction, turbidimetry, conductometry, differential thermic analysis, and also by published data