Beata Schmidt

Modified acrylamide copolymers as flocculants for model aqueous suspensions

Modified acrylamide copolymers as flocculants for model aqueous suspensions Two groups of acrylamide copolymers have been obtained by inverse microemulsion polymerization using: (i) acrylamide (AAm) with [2-(acryloyloxy)ethyl]trimethylammonium chloride (AETAC) in the presence of sodium montmorillonite (MMT), and (ii) acrylamide with acrylic acid (AA) in the presence of aluminum sulphate. The received materials were characterised by capillary viscometry and the DSC methods, as well as the flocculation performances of the modified copolymers in the treatment of aqueous model suspensions of talc and calcium montmorillonite have been investigated. The effectiveness of the acrylamide flocculants was evaluated on the basis of the suspension extinction reduction and the sludge volume. The obtained results have been compared while using the modified materials and appropriate anionic and cationic AAm copolymers.

PANI/NaTaO3 composite photocatalyst for enhanced hydrogen generation under UV light irradiation

Abstract A PANI/NaTaO3 composite was successfully synthesized by an oxidative polymerization of aniline monomer in hydrochloric acid solution containing sodium tantalate. NaTaO3 at a monoclinic structure was produced via hydrothermal method. The photocatalytic activities of the unmodified NaTaO3 and PANI/NaTaO3 were evaluated for hydrogen generation from an aqueous HCOOH solution and under UV light irradiation. The results showed that the evolution rate of H2 increased significantly when NaTaO3 was modified with PANI. The enhancement of the photocatalytic activity of PANI/NaTaO3 composite was ascribed to the effective charge transfer and separation between NaTaO3 and PANI, which reduced their recombination. This indicates that PANI modification of tantalate photocatalysts may open up a new way to prepare highly efficient catalytic materials for H2 generation.