Factors affecting fractal patterns obtained by electroless deposition in polymer

Abstract

Electroless deposition of silver has been studied experimentally in a polymer (chitosan) with different molecular weight (∼50 000–190 000 Da and ∼600 000 Da). Transport of ions in polymers involves various dynamical processes having different time scales. The time scale of ion dynamics depends on the number of monomer chains in the polymer, i.e., the molecular weight of the polymer. Polymers of high molecular weight contain regular arrangement of long chains of monomers which generally leads to high crystallinity. Copper, zinc and aluminum wires have been used for different reaction rates in the polymer-Ag salt solution. Anisotropy of the polymer-salt solution varies due to the change in the ion dynamics in high molecular weight polymer as compared to the low molecular weight polymer. Varying anisotropy leads to different aggregation patterns around the reactive metal wires. X-ray diffraction has been performed to determine the crystallinity while the voltage-time measurement has been done to validate the aggregation process. Effect of air exposure/oxidation on the growth patterns has also been considered as the adsorption of oxygen ions changes with the change in the crystallinity of the polymer.