Synthesis of Sodium Alginate–Silver Nanocomposites Using Plasma Activated Water and Cold Atmospheric Plasma Treatment

• Published in: Nanomaterials (Basel, Switzerland) Vol. 11; no. 9; p. 2306
• Main Authors: Sharmin, Nusrat, Pang, Chengheng, Sone, Izumi, Walsh, James Leon, Fernández, Cecilia Górriz, Sivertsvik, Morten, Fernández, Estefanía Noriega
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 05-09-2021; MDPI
• Subjects: Acids; Alginic acid; Antiinfectives and antibacterials; Antimicrobial activity; Atmospheric pressure; Cold; cold plasma; Cold plasmas; Cold treatment; Coliforms; Drinking water; E coli; Food packaging; Gram-negative bacteria; mechanical properties; Modulus of elasticity; Molecular weight; Nanocomposites; Nanoparticles; Nitrates; Nitrogen; Plasma; plasma activated water; Reducing agents; Rheology; Shear thinning (liquids); Silver; silver nanoparticles; Silver nitrate; Sodium; Sodium alginate; Spectroscopy; Stabilizers (agents); Storage modulus; Synthesis; Tensile strength; Ultraviolet spectroscopy; Norway
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano11092306

In this study, sodium alginate (SA)-based, eco-friendly nanocomposites films were synthesized for potential food packaging applications using silver nitrate (AgNO3) as the metal precursor, reactive nitrogen and oxygen species (RNOS) created within plasma activated water (PAW), or through cold plasma treatment (CP) as reducing agent and SA as stabilizing agent. The formation of silver nanoparticles (AgNPs) was confirmed via the absorption peaks observed between 440 and 450 nm in UV-vis spectroscopy. The tensile strength (TS) and tensile modulus (TM) of the nanocomposite films were significantly higher than those of the SA films. An increase in the TS was also observed as the AgNP concentration was increased from 1 to 5 mM. The storage modulus (G’) of the nanocomposite solution was higher than that of the SA solution. The synthesis of AgNPs resulted both in a higher solution viscosity and a more marked shear-thinning effect. The synthesized AgNPs showed antimicrobial activity against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The AgNPs were spherical in shape with an average size of 22 nm.