Kartick Mondal

Polymer-encapsulated metal nanoparticles: optical, structural, micro-analytical and hydrogenation studies of a composite material.

A single-step synthesis route is described for the preparation of a metal-polymer composite in which palladium acetate and meta-amino benzoic acid were used as the precursors for palladium nanoparticles and poly(meta-amino benzoic acid) (PABA). The palladium nanoparticles were found to be uniformly dispersed and highly stabilized throughout the macromolecule matrix. The resultant composite material was characterized by means of different techniques, such as IR and Raman spectroscopy, which provided information regarding the chemical structure of the polymer, whereas electron microscopy images yielded information regarding the morphology of the composite material and the distribution of the metal particles in the composite material. The composite material was used as a catalyst for the ethylene hydrogenation reaction and showed catalytic activity at higher temperatures. TEM studies confirmed the changed environment of the nanoparticles at these temperatures.

Formation of metal nanoparticles in a polymer nanofiber: a hybrid material for gas-phase catalytic reactions

This paper describes the synthesis and characterization of a metal–polymer hybrid material formed by the combination of palladium nanoparticles and poly-o-phenylenediamine (poly-PDA). The preparation technique is based on an in situ, one-pot chemical synthesis route using palladium acetate and o-phenylenediamine as precursors. The composite material was characterized by optical, thermal and micro-analytical techniques. The characterization techniques show the successful synthesis of the hybrid material. This composite material was used as a catalyst for a model gas-phase hydrogenation reaction. The activation and deactivation of the catalyst is discussed in relation to the effect of temperature and the phase transition of the polymer.

Palladium-polyaniline type composite polymers: using catalysis as a monitor of palladium location

The location of nanosized (2-4 nm) palladium particles in two palla- dium-polyaniline-based composites, synthesized by the redox coupling route using monomer and palladium(II) acetate, have been revealed using ethene hydrogenation as a heterogeneously catalysed reaction, together with differential scanning calorimetry. The two palladium composites were synthesized using m-amino- benzoic acid (ABA) or o-phenylenediamine (PDA), leading to Pd-PABA or Pd-PPDA, respectively. The temperature sensitivity of catalytic activity related to the polymer melting temperature, as revealed by DSC, assists in understanding the location of the palla- dium particles. The structures of the metal-polymer composite at the micrometre and nanometre levels are revealed using scanning and transmission electron microscopy, respectively.