Physiochemical synthesis of Silver/Kaolinite nanocomposites and study their antibacterial properties

Abstract

Silver nanocomposites (Ag NCs) were prepared by two methods, chemical and physical synthesis using sodium borohydride and gamma irradiation as a reducing tool. A one-step silver/kaolinite nanocomposite (Ag/Kln NCs) synthesis method has been developed successfully by irradiation technique at room temperature and under ambient pressure. The Ag/Kln NCs produced by the ?-irradiation technique is pure without chemical residues, has a good distribution with enhanced antibacterial properties, and environmentally friendly. The effects of various experimental parameters on the formation of NCs, such as the concentration of Ag+ and the irradiation dose, have been investigated. A study on antimicrobial susceptibility was undertaken to determine the antibacterial properties of Ag NCs in the presence of gram-positive and gram-negative bacteria. The susceptibility of the microorganisms to varying concentrations of Ag NCs synthesized via physical synthesis using gamma irradiation was compared to those synthesized chemically. Concentrations of Ag NCs used were 0.5, 1.0, 2.0, 5.0, and 10 % for chemical synthesis and irradiation doses used for physical synthesis were 7, 13, 20, 30, 40, 50, 65 and 80 kGy. Observation on well diffusion variant showed a significantly large zone of inhibition for physically synthesized NCs, (63 to 107% relative to control) which indicates high antimicrobial activity. Chemically synthesized NCs using the same experimental set up however showed a significantly smaller zone of inhibition. The Ag/Kln NCs in 20kGy showed higher antibacterial activity against Enterococcus faecalis and Escherichia coli as gram-positive and gram-negative bacteria. These suggest that Ag/Kln NCs can be employed as an effective bacteria inhibitor and can be applied in the medical field.

A comprehensive review of recent progress of nanofluid in engineering application: Microchannel heat sink (MCHS)

“…Brownian motion influence the thermal conductivity of nanoparticles in two ways such that one way is direct manner and another way is indirect manner. The nanoparticles can facilitate the heat transfer through solidsolid transport of heat between the particles and nano convection between the nanoparticles and the surrounding fluid [32]. The former heat transfer process is known as direct manner and the latter heat transfer process is known as indirect manner.…”

Gamma Irradiation-Assisted Synthesis of Silver Nanoparticle and Their Antimicrobial Applications: A Review

“…The Ag-NPs with Cts bead hydrogel applied in drug delivery displayed enhanced antibacterial activity against E. coli and S. aureus with controlled and prolonged drug release observed [160]. In a study by S. Moosa et al [161], Ag/Kln NCs synthesized using chemical method and gamma irradiation were evaluated against E. coli, S. aureus, E. faecalis and P. vulgaris and C. albicans. The chemical synthesis Ag/Kln NPs, displayed minimum antimicrobial properties (Figure 4A) compared to the gamma synthesized Ag/Kln NPs (Figure 4B).…”

Ab-Initio and Experimental Study of the Electronic and Optical Properties of Layered 2D Molybdenum Disulphide

“…On the other hand, the computational simulation of material modelling is particularly interesting for studying the ideal 2D layered materials formation without compromising experimental drawbacks, after which measurement methods such as ellipsometry can be utilized after successful 2D layered material fabrication. In other fields, it may also be used prior to physiochemical synthesis to study materials compatibility or even used to understand formation of nanoparticles at the molecular levels [13][14][15] and hence understanding their potential properties. Ab initio study using density functional theory (DFT) calculation is a standard tool for materials modelling that can produce reliable characteristics of materials with adequate exchange-correlation functions and basis sets [16].…”