Preparation of air stable nanoscale zero valent iron functionalized by ethylene glycol without inert condition

The use of nanoscale zero-valent iron has been widely studied in recent years for potential application in environmental engineering, due to its affinity for a large number of contaminants, which may be in aqueous or solid phase, and for its abundance, which makes it an attractive tool for environmental remediation. However, there exist some variables in the production of nZVI that complicate the generation of the material, such as the complex methodologies of synthesis and the cost of inert conditions like nitrogen or argon atmosphere, which have the purpose of preventing the oxidation and reducing the instability of the material under ambient conditions. As a simple and economical synthesis methodology, this work presents an optimized method to synthesize functionalized nanoscale zero-valent iron (nZVI) using ethylene glycol (EG) without need for inert conditions. The coordination of iron ions during the nZVI-EG synthesis and the functionalization mechanism of the nanoparticles were identified by UV–Vis absorption spectroscopy and Fourier transform infrared spectroscopy (FTIR). Functionalized nZVI showed increased dispersibility due to the effects of steric repulsion between the grafted polymers. Ethylene glycol functionalized nZVI showed stability against oxidation during dry atmospheric condition, while significant oxidation was observed in the case of unfunctionalized nZVI. This result was also correlated with actual capacity for contaminant reduction. Therefore, the possibility was verified of using ethylene glycol in an effective surface modification method to prepare air stable nZVI for environmental remediation.