Purely inorganic reactions of silica, metal carbonates, and metal hydroxides can produce self-organized complex structures that mimic the texture of biominerals, the morphology of primitive organisms, and that catalyze prebiotic reactions. To date, these fascinating structures have only been synthesized using model solutions. We report that mineral self-assembly can be also obtained from natura...

The evolution during thermal treatment of the precursor obtained by a new method to synthezise barium hexaferrite by chemical coprecipitation is described; the method involves the precipitation froma strongly alkaline ferrate(V1) solution containing barium chloride. Barium hexaferrite may be formed by heating of the original superparamagnetic precursor at temperatures as low as 700QC as shown b...

Recent work has demonstrated that the dynamic interplay between silica and carbonate during co-precipitation can result in the self-assembly of unusual, highly complex crystal architectures with morphologies and textures resembling those typically displayed by biogenic minerals. These so-called biomorphs were shown to be composed of uniform elongated carbonate nanoparticles that are arranged ac...

News and Notes Eighth Annual Calorimetry Conference; Symposium on the Role of Proteins in Ion Transport Across Membranes.. 710 Technical Papers One-Step Preparation of C14-Cyanide from Barium Carbonate-C14: J. K. Jeanes .719 Evaluation of Oral Temperature Readings: Francis L. Harmon.. 719 Use of the Thymus Gland in Chicks to Elucidate Interrelationships Between Pteroylglutamic Acid and Biologic...

Various liquid phases for glass capillary columns have been evaluated for gas-liquid chromatographic analysis of methyl ester trimethylsilylether derivatives of bile acids from serum and bile. Bile acid analysis is rapid and exhibits high separation efficiency with a 20 X 0.3 mm glass capillary column whose internal surface is covered with a crystal layer of barium carbonate and coated with pol...

Crystallisation of barium carbonate in the presence of silica can lead to the spontaneous assembly of highly complex superstructures, consisting of uniform and largely co-oriented BaCO3 nanocrystals that are interspersed by a matrix of amorphous silica. The formation of these biomimetic architectures (so-called silica biomorphs) is thought to be driven by a dynamic interplay between the compone...

The application of barium f&:e (BaFelZO19; BaF) in the magnetic media industry requires materials with strict control of homogeneity, morphology and magnetic properties resulting from their preparation and pretreatment. Here the use of water-in-oil microemulsions for the synthesis of nanoparticles of BaF is considered. Two microen~ulsions (containmg an aqueous phase, cetyltrimethylammonium brom...