A study on the zeolite 13X and transition metals iron, nickel composites and hybrid electrically conductive polyaniline/polyurethane foams

Recent synthetic work at Albany has focused on preparing composites of nanometer porous inorganic silicate matrices interpenetrated or filled by neutral or conductive macromolecules. These composites bracket in pore size, nature of the porous matrix, and certain properties of the previously prepared hybrid inorganic/organic composites. Two composites of two different molecular sieve zeolites and transition metals iron and nickel ions were synthesized. Zeolite and iron composites were prepared by following the two steps: absorption of iron pentacarbonyl by 13X and 5A zeolites and thermal decomposition of the iron pentacarbonyl within the zeolite framework at various temperatures. One composite was reduced by hydrogen at elevated temperature. Morphological studies showed that zeolite 13X is an excellent candidate as host for the transition metals. Iron was successfully incorporated into the zeolite pore and channel system as Fe3+ and Fe2+ ions and it is in an amorphous state. Fe₂O₃ was also one of the main components of the composite. The iron oxides were extremely small in their sizes (less than 10 Å). The hydrogen reduction did impact the charge state and symmetry of the iron ions. Utilizing ion-exchange technique and then followed by hydrogen reduction at temperature over 400°C, nickel was successfully introduced into the zeolite 13X channels but not the 5A zeolite. Metallic nickel was the predominant components of the composites.; Flexible and rigid polyurethane foams were synthesized by following known commercial formulations. The absorbed aniline was oxidatively polymerized within the foams. Polyaniline was doped by hydrochloric acid during the polymerization. Different polymerization solution acidities resulted in different polyaniline molecular weights. The polyaniline average molecular weight obtained by GPC increases as the polymerization acidity increases. The conductivity of the polyaniline salt increases with increasing molecular weight as a result of the increasing of the dopant HCI acidity. The PANI/PU flexible foam showed a conductivity ranging from 1 × 10−2 Scm −1 to 1.6 × 10−1 Scm−1 . The hybrid foam was very stable during D.C. conductivity measurement and showed surprising measurement reproducibility. The pore system of the rigid foams does not allow for free percolation of the PANI.