Microwave-mediated synthesis of silver nanoparticles on various metal-alginate composites: evaluation of catalytic activity and thermal stability of the composites in solvent-free acylation reaction of amine and alcohols

Abstract

This work demostratres the synthesis of different metal (Ca, Zn, Ni and Cu) alginate-supported silver nanoparticles (Agnp-MA, M and A for metal and alginate respectively) by using microwave irradiation process. The characterization of these composites has been carried out through UV-vis spectra, XRD, HRTEM and FESEM analysis which confirms the formation of spherical and crystalline nanoparticles in all MA supports with particles size range of 5-8 nm. All MAs show excellent reducing and stabilizing capabilities towards Agnp and act as support for nanoparticles too. The catalytic activities of all Agnp-MAs are tested in acylation reactions of various amines and alcohols in solvent-free medium using acetic acid as green acylating agent. The detail ionic mechanism of acylation reaction has been demonstrated. Thermal stability of all catalysts was investigated through TGA analysis and the reusability of the catalysts in a reaction is explained in terms of their thermal stability. The order of stability is Agnp-CaA > Agnp-ZnA > Agnp-NiA > Agnp-CuA. Consequently, Agnp-CaA shows best reusability property than other Agnp-MAs in the reaction and can perform well up to 5th run. Heterogeneous kinetic models are proposed for the reaction.

Antibacterial, Antioxidant Activities, GC-Mass Characterization, and Cyto/Genotoxicity Effect of Green Synthesis of Silver Nanoparticles Using Latex of Cynanchum acutum L

“…Several metals have been used to synthesize nanomaterials, such as copper, zinc, titanium [ 35 ], magnesium, gold [ 36 ], and silver, for biological activities; in addition, alginate is a polysaccharide used as catalyst support [ 37 ]. Specifically, silver nanoparticles have proved to be most effective due to their specific characteristics of chemical stability, excellent conductivity, and most importantly, antibacterial, antiviral, antifungal, and anti-inflammatory features [ 38 ].…”

Fabricating Antibacterial and Antioxidant Electrospun Hydrophilic Polyacrylonitrile Nanofibers Loaded with AgNPs by Lignin-Induced In-Situ Method

“…Thus, several green methods for AgNPs synthesis using plant extracts were investigated [ 28 , 29 , 30 , 31 , 32 , 33 ]. Synthesis of AgNPs using UV radiation [ 34 ], gamma radiation [ 35 ], microwave [ 36 ], and laser irradiation pulse [ 37 ] was also studied by several researchers in recent years. However, these reports focused on the synthesis of AgNPs only rather than synthesis on electrospun nanofibrous structures.…”