Preparation and characterization of acetylated starch mediated silver nanoparticles: The effect of solution ratio and time-varying exposure

Plastic packaging is widely used in food industry to protect and maintain food freshness. However, plastic packaging also contributes to solid waste problem and can become the contamination area of microbial activities which in turn affecting the shelf-life of the food product and may causing food-borne illness towards consumer. Thus, the demands on biodegradable polymer as plastic packaging has grown widely especially among the food industry. The employment of silver nanoparticles (AgNPs) can improve physical properties of biopolymer as well as promoting antimicrobial properties on the plastic packaging. The aim of this study is to synthesize of AgNPs by utilising acetylated starch (AS) as reducing agent with different parameters via microwave irradiation method. The effect of different ratio of acetylated starch and microwave time-varying exposure is evaluated. The synthesized silver nanoparticles were characterized via UV-VIS spectroscopy (UV-VIS), X-Ray Diffraction (XRD) and Fourier Transform Infrared (FTIR) analysis. The absorbance peak emerges at 420nm on UV-VIS shows that silver nanoparticles is successfully produced. 15 minutes microwave time exposure and 1:1 ratio is identified as the optimum condition to produce silver nanoparticles. The peak emerges on FTIR spectra shows the involvement of starch in reduction process in synthesizing AgNPs. The XRD results shows the amorphous structure of starch and crystalline peak of silver appear in 2Θ regions 37.4°, 43.4°, 63.1° and 75.7°. In conclusion, the significant outcome from the study is the AgNPs were successfully synthesized via microwave irradiation method and be a function of time varying exposure and acetylated starch ratio.