Surface Microstructures and Hydrophobicity Evaluation of Allamanda cathartica (Yellow Bell) and Plumeria acuminata(Kalachuchi) Flower Petals

Abstract

Surface hydrophobicity in nature has inspired many scientists to develop innovative products that could help us in our daily lives. Together with this ongoing trend, the surface wettability and hydrophobicity of the petals selected local flowers such as Allamanda cathartica, and Plumeria acuminate were investigated. Scanning Electron Microscopy and HD digital microscope were used in the analytical imaging of the flower petal samples. On the other hand, the surface hydrophobicity of selected flower petals with ten replications was evaluated based on their actual contact angle measurements using the optical tensiometer. It was found that there was a significant difference between the contact angles of A. catharticaandP. acuminata(t=2.247;p=0.04) with mean contact angles of 129.121° and 117.179°, respectively. This implied that both flower petals were indeed hydrophobic. The obtained hydrophobicity potential was associated to the generated micrographs of the flower petal samples wherein A. cathartica, had uniform cellular structures in terms of shape, size, and textural orientation making the sample nearly super-hydrophobic while in P. acuminate, an aberration on the cellular structures was more evident which led water droplets unease and tended to spread over time. Also, the presence of cuticular wax on both petals was also identified, which probably contributed to the observed hydrophobic capacity of both petals. In conclusion, both petals could be viable models in developing hydrophobic nano-sculptured surfaces of several non-wetting products.