Influence of spin coating rate on the thickness, surface modification and optical properties of water dispersed PPy composite thin films

Abstract

Water dispersed polypyrrole was chemically synthesized with Dodecylbenzene sulfonic acid (DBSA) as dopant and Poly (4-styrenesulfonic acid (PSS) as co-dopant. The 10wt% of PSS doped polypyrrole composite shows higher processability. The prepared composites aqueous solution was deposited to get thin films by spin coating technique at various spin rates of 1000rpm, 2000rpm and 3000rpm. The paper reports on effect of spin coating rate, thickness, surface roughness, and photoluminescence of water dispersed DBSA / PSS /PPY composite thin films. The transmittance is found to be decreased with increasing spin rates. Surface roughness of the films were analyzed by atomic force microscopy. The Root Mean Square (RMS) and Roughness (Ra) values were found as (22.5nm, 89nm), (135nm and 18nm), and (70nm and 113nm) values. The super hydrophilic nature of the composite films was studied by water contact angle measurements. The contact angle values were found to be 8.6°, 9.4° and 10° for different spin rates. Photoluminescence (PL) of DBSA/PSS/PPY composite films reveals the emission with high intensity at high spin rates. Thickness of the composite films was found as 378nm, 333nm and 304nm at 1000rpm, 2000rpm and 3000rpm.