STUDIES ON PIEZO-ELECTRIC PROPERTY OF PRAWN SHELLS

The piezo-electric film was developed from bio-waste Prawn Shells (PS). The absorption peak of the PS film was observed at 266 nm and 377 nm, respectively. The structural and crystallographic features of PS were studied by FT-IR spectroscopy. The co-existence of intra and inter-molecular hydrogen bonds is also evident from the vibrational bands 3145 cm^-1 and 3011 cm^-1, respectively. The cross-sectional scanning electron microscopy (SEM) image of the PS shows hierarchically organized and specially arranged layer structure of chitin nanofibers (ChNFs).

In particular, naturally abundant piezoelectric materials are the suitable choice for designing bio-medical sensors/nanogenerators that can function without any adverse reaction or toxicity. After cellulose, the second most abundant natural piezoelectric biopolymer is the chitin [poly-b-(1,4)-N-acetyl-d-glucos-amine], chitin is mechanically robust, nontoxic, biocompatible, and biodegradable. It naturally occurs as supramolecular crystalline nanofibers which are further held by strong hydrogen bonds to form fiber bundles of larger scales called chitin nanofibers (ChNFs).

The absorption spectrum of PS was studied by UV-Vis absorption spectroscopy as shown in Fig.1. The maximum absorption was observed at a wavelength of 266 nm and 377 nm, respectively. The structural and crystallographic features of PS were studied by FT-IR spectroscopy (Fig.2). The co-existence of intra and inter-molecular hydrogen bonds is also evident from the vibrational bands 3429 cm^-1 and 3251 cm^-1, respectively. The detailed surface morphologies were investigated by SEM operated at an acceleration voltage of 20 kV (Fig.3). In the X-ray diffraction (XRD) pattern, two diffraction peaks are observed at 2θ ~ 19.82º and 39.56º, respectively in the range of 15º-40º.