Doped carbon dots reinforced flexible nanocomposite active polymer film for antibacterial and antioxidant activities

Abstract

Utilizing nanoparticles in packaging materials has proven to be an effective method for enhancing the longevity and security of food products. Carbon dots (CDs) have a wide variety of potential applications in food packaging. A flexible film made of thermoplastic chitosan (TPC) and heteroatom-doped CDs has been created using a wet chemical blending technique. These CDs reinforced TPC based hybrid films exhibit flexibility, antioxidant properties, biodegradability, and resistance to UV radiation. The mechanical strength of the films was assessed through uniaxial tensile testing, while their low-temperature flexibility was evaluated by measuring the sub-ambient (∼-30°C) glass transition temperature (Tg). Additionally, the presence of CDs directly influences the permeability of oxygen and moisture, resulting in a reduction in comparison to neat chitosan films, a vital characteristic for packaging materials. Over a span of three weeks, the TPC-based hybrid films demonstrated a progressive weight loss (∼75 %), indicating their biodegradability. Furthermore, these films have shown promise as antibacterial and antioxidant materials. The durability of the films and the absence of chemical release from the embedded CDs within the TPC matrices were also verified, underscoring their considerable potential as antibacterial, biodegradable, and antioxidant packaging materials within the food industry.