K. G. Mayhan

A study of medium and high internal phase ratio water/polymer emulsions

Abstract Medium and high internal phase ratio water/polymer emulsions were studied utilizing scanning electron microscope techniques. Results are reported for the geometry and distribution of droplets for water/polymer ratios from 1 1 to 9 1 . Electron micrographs confirm those models which predicts polyhedral droplet formation at high internal phase ratios.

Organic desorption from carbon—III. The effect of solvent in the desorption of phenol from dry carbon

Abstract The desorption of phenol from active carbon was studied using cyclic and continuous flow desorbers. A wide difference in desorption capabilities was shown among ten solvents. The system employed was complex, with water being present in addition to phenol on the carbon. An attempt to correlate the desorption data with the physical properties of the phenol and solvent and regular solution theory is made. A thermodynamic approach using the linear free energy—enthalpy relationship produced a reasonable correlation of the heat of formation of the phenol—solvent hydrogen bond with the desorption data. This indicates that the desorption of the phenol from carbon in this complex system is dependent upon the ability of the solvent to form hydrogen bonds with the phenol.

A study of variant silicone rubber heart valve poppets by thermogravimetry-differential thermal analysis

Abstract Thermal analyses were used to assist in the characterization of forty selected silicone elastomer heart valve poppets which have been implanted in humans for time periods varying from 22 to 79 months. Three distinct types of thermograms were obtained which were related to the amount and general type of constituents absorbed by the poppets during implants. These results are analyzed and discussed in terms of other analytical results from solvent extraction, gas chromatographic and thin-layer chromatographic analyses.

The transition-metal chemistry of quinuclidinone-containing ligands. Part VI. A study of the thermal properties of several complexes with trans-2-(2-quinolyl)methylenequinuclidin-3-one

A thermochemical determination of the relative solid-state stabilities of the yellow [{Ni(qnqn)Cl2}2] and violet [Ni(qnqn)Cl2] isomers (where qnqn is trans-2-(2-quinolyl)methylenequinuclidin-3-one) has indicated that the violet isomer is the metastable isomer at room temperature. D.t.a.-t.g. measurements have been obtained for the iron, cobalt, nickel, and copper chloride and nickel bromide complexes of qnqn and reveal in the case of the nickel chloride isomers an endothermic structural transformation of the yellow dimer to the violet monomer at 230 °C. No related transformation is observed in the remaining complexes. The unusual inter-related thermal properties of the nickel chloride isomers are discussed in terms of the various properties of the two complexes.