Inadequate surface preparation of mild steel panels prior to painting could be the leading cause of the paint film failure. This work evaluated the surface preparation treatments in order to improve the paint integrity and thereby increasing the corrosion resistance of the steel panel in artificial sea water. The AISI 1020 steel ground and grit blasted samples were prepared followed by applying zinc based epoxy primer and top coat. The degradation mechanism was devised by immersing the samples in 3.5% NaCl solution. The degradation due to blistering within the paint was analyzed by following ASTM D-610 and ASTM D-714. Energy Dispersive Spectroscopy of corrosion product revealed a correlation with the degradation mode of painted sample. It was deduced that degradation of paint depends on surface morphology of substrate.

A molecularly imprinted polymer (MIP), with special molecule recognition properties of different phenylurea herbicides namely liuron (LU), isoproturon (IPU), diuron (DU), fenuron (FU) and methiuron (MU), was prepared by thermal polymerization in which phenylureas acted as the template molecules, methacrylic acid (MAA) acted as the functional monomer and ethylene glycol dimethacrylate (EGDMA) acted as the crosslinker. A biomimetic potentiometric field monitoring device was developed for the assessment of these phenylurea herbicides based on these newly synthesized imprinted polymers. The sensing elements were fabricated by the inclusion of phenylurea imprinted polymers in polyvinyl chloride (PVC) matrix. The sensors showed a high selectivity and a sensitive response to the template in an aqueous system. Electrochemical evaluation of these sensors revealed near-Nernstian response with slopes of 66.1±0.5 (r2 = 0.998), 59.6±1.3 (r2 = 0.997), 62.3±0.6 (r2 = 0.998), 67.1±0.3 (r2 = 0.998) and 71.5.0±0.4 (r2 = 0.998) mV decade-1 with a detection limit of 1.0 × 10-5, 7.1 × 10-6, 1.3 × 10-5, 1.8 × 10-5 and 1.6 × 10-5 mol L-1 with MIP/LU, MIP/IPU, MIP/DU, MIP/FU and MIP/MU membrane based sensors plasticized with DOP, respectively. The sensors were easily used in a double channel flow injection system and compared with a tubular detector. The method had the requisite accuracy, sensitivity and precision to assay phenylureas in water samples.