Eco-Friendly Production of AuNPs and Their Impact on the Oil Oxidative Stability

Abstract

Vegetable oils have been used for different applications and, more recently, as an active host medium to obtain nanoparticles for employment in bionanotechnological applications. Nevertheless, oils are very susceptible to oxidation during production, storage, and transportation because of their chemical composition. Consequently, any modification in their production must be accompanied by an analysis of the oxidative stability. In this study, naked and biocompatible gold nanoparticles (AuNPs) were grown on sunflower oil during sputtering deposition using different deposition times. Size and morphology were determined by transmission electron microscopy (TEM) and their concentrations were found by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Rancimat® method was employed to evaluate the AuNPs influence on the oxidative stability of the vegetable oil. Well-dispersed quasi-spherical NPs were produced with a mean diameter in the 2.9–3.7 nm range and they were concentration-dependent on the deposition time. A concentration of about 11 mg/L, 38 mg/L, and 225 mg/L of AuNPs was obtained for a deposition time of 5 min, 15 min, and 30 min, respectively. The results also revealed that AuNPs negatively affected the oxidative stability of the sunflower oil and exponentially reduced the induction period (IP) with the increase in AuNPs content. IP reductions of 63%, 77%, and 81% were determined for the AuNPs containing samples at 11 mg/L, 38 mg/L, and 225 mg/L. For the first time, it is reported that naked AuNPs promote the rapid degradation of vegetable oil and this points out the need for attention relative to the quality of vegetable oils used to host metal nanoparticles.

Sputtering onto liquids: how does the liquid viscosity affect the formation of nanoparticles and metal films?

“…16 Changes in the UV-vis spectra might also be related to the fact that oils containing Au NPs dry more quickly within the storage time. 21…”

“…16 Changes in the UV-vis spectra might also be related to the fact that oils containing Au NPs dry more quickly within the storage time. 21 The size of Au NPs obtained by magnetron sputtering was measured by three different methods. The size distribution and morphology of the individual NPs were analysed by TEM, and the results are shown in Fig.…”

Magnetron sputtering onto nonionic surfactant for 1-step preparation of metal nanoparticles without additional chemical reagents

“…Most of the known host liquids suitable for the SoL process are hydrophobic e.g. vegetable [8][9][10][11][12] and silicone [13][14][15] oils, or liquids that are very sensitive to humidity and should be stored in glove boxes like, for example, ionic liquids [7,[16][17][18][19] that were used in more than 50% of the published research works so far [1]. The only reported hydrophilic host liquids are glycerol and polyethylene glycols (PEGs with MW = 200-600 g mol −1 ) [4,5,[20][21][22].…”