Effect of heating rate and plant species on the size and uniformity of silver nanoparticles synthesized using aromatic plant extracts

Abstract

Mixing aqueous silver solutions with aqueous leaf aromatic plant extracts from basil, mint, marjoram and peppermint resulted in the synthesis of quasi-spherical silver nanoparticles in a range of size between 2 and 80 nm in diameter as analyzed by analytical high-resolution electron microscopy. The average size could be controlled by applying heat to the initial reaction system at different rates of heating, and by the specific botanical species employed for the reaction. Increasing the rate of heating resulted in a statistically significant decrease in the size of the nanoparticles produced, regardless of the species employed. This fact was more evident in the case of marjoram, which decreased the average diameter from 27 nm at a slow rate of heating to 8 nm at a high rate of heating. With regard to the species, minimum sizes of \10 nm were obtained with basil and peppermint, while marjoram and mint yielded an average size between 10 and 25 nm. The results indicate that aromatic plant extracts can be used to achieve the controlled synthesis of metal nanoparticles.

Green synthesis of silver nanoparticles using Thymbra spicata L. var. spicata (zahter) aqueous leaf extract and evaluation of their morphology-dependent antibacterial and cytotoxic activity

“…Nanoparticles can be non-biologically synthesized by either physical methods or chemical methods, which follow the top-down and the bottom-up approaches, respectively. Typically, non-biological methods for fabrication of nanoparticles involve external reducing agents and toxic organic solvents, which pose potential environmental and biological risks even though chemical and physical methods may successfully produce pure nanoparticles [4]. Therefore, the use of plant extracts in the development of fast, clean, non-toxic and eco-friendly process for nanoparticle synthesis has gained great importance [5,6].…”

Ulvan as novel reducing and stabilizing agent from renewable algal biomass: Application to green synthesis of silver nanoparticles

“…A further investigated strategy was based on the use of heating to favor the process of reduction of silver ions to AgNPs possibly promoted by ulvan (Hernández-Pinero et al, 2016;Prathna, Raichur, Chandrasekaran, & Mukherjee, 2013). Solutions of different ulvan/silver (wt/wt) ratios selected over the saturation limit were heated at 90 °C in dark conditions and analyzed at regular time intervals by UV-vis spectroscopy in order to detect the formation of AgNPs.…”

Formation and selected catalytic properties of ruthenium, rhodium, osmium and iridium nanoparticles

“…Successive decreasing of the heating rate leads to formation of larger nanoparticles with a broader size distribution. 44 This can be connected with a less dened nucleation threshold. As a result, more nuclei can be formed during a longer time, what leads to a broader size distribution.…”