"Nanocomposites and nanomaterials"

Preparation of metal-doped carbon/silica composites by mechanochemical grinding
Charmas B. 1, Kucio K. 1, Zięzio M. 1 
1Department of Chromatographic Methods, Faculty of Chemistry, Maria Curie - Sklodowska University, Maria Curie-Sklodowska Sq.3, 20-031 Lublin, Poland
E-mail: barbara.charmas@poczta.umcs.lublin.pl 

Mechanochemistry is an innovative method of different materials synthesis. This unconventional method of preparation is based on the conversion of mechanical energy created during collisions of grinding balls in the heat allowing the overlap of chemical reactions. This enjoys a great interest because it has many advantages. Products obtained by the mechanochemical treatment are characterized by high purity and stability. 
In the presented studies mechanochemistry was used to prepare carbon-silica composites (carbosils) which are adsorbents of a very wide variety of applications. Their usefulness results from the original properties of the surface, combining features of both non-polar carbon and the polar mineral parts of the material. Owing to these properties such composites can be used in the adsorption of both polar and non-polar substances from the aqueous media and are often used also as catalysts or catalyst supports. By incorporation of some metals (e.g., nickel) into the structure of such composites, the catalytic materials can be obtained. Such materials used as catalysts should have adequate physical and chemical properties (high thermal resistance, mechanical strength, proper sorption capacity, phase composition, well-defined and stable nature of the surface, etc.).
The aim of the presented study was the preparation of a new series of composites of various nickel contents, based on different silicas (as a matrix) and determination of their basic physical and chemical properties. Composite materials were prepared using of two silicas: precipitated (porous) as well as aerosil (fumed silica - non-porous). Potato starch was used as a carbon precursor. The materials were differentiated using various amounts of Ni2+ ions. 
In order to characterize the structural and thermal properties of the tested carbon-silica adsorbents the N2 adsorption, thermal analysis, DSC, FTIR/ATR, SEM and XRD methods were applied.