Polymorphic transformation of seashell waste to develop smart composite films: An environmentally benign and sustainable approach

Unremitting escalation in global population has compounded the overall demand for food, including seafood, leading to an accumulation of waste seashells causing landfills, which poses serious environmental concerns. To confront this challenge, the present work aims to utilize seashells as a potential candidate to serve as fillers during the fabrication process of polymer films. This study presents an extensive high-energy ball-milling process of seashells using planetary ball-milling for 36h. The study demonstrates a polymorphic transformation of calcium carbonate (CaCO₃) present in the seashell from calcite to aragonite. Furthermore, these processed seashells are incorporated as fillers in the polyvinyl alcohol (PVA) matrix to create a composite film using the electrospinning technique. The milled seashells and the corresponding fabricated films are systematically evaluated through various physicochemical evaluations, including microscopic and spectroscopic methods, to demonstrate the accumulation of finer seashell particles within the hollow fiber. The formation of seashell particles as a function of processing time has been comprehensively studied in this work. Additionally, the fabricated films were also examined for their antibacterial activities. The work demonstrates an environmentally benign and sustainable approach to making biocompatible and antibacterial films, with applications in the fields of agriculture, food packaging, and food science.