Kinetic and morphological studies on water and organo-dispersible gold nanoparticle formation and the influence of synthesis media on dispersibility and plasmonic features

Despite numerous reports on the successful preparation of organo-dispersible gold nanoparticles (AuNPs), complicated multi-step synthetic procedures and poor colloidal stability are still the main drawbacks. Poly (N,N-dimethylaminoethyl methacrylate) (PDMAEMA) is a polymer which is potent for reducing Au³⁺ to Au(0) with diverse dispersibility in organic solvents. With respect to these advantages, PDMAEMA was employed as both a reducing and stabilizing agent for the direct synthesis of AuNPs in water and some protic and aprotic organic solvents in this study. Notably, there was no need for any extra reducing agent or phase transfer material here. The kinetic of AuNPs formation and the effect of medium type on the size, shape, and dispersibility of AuNPs were studied by using TEM and UV–Vis results. Comprehensive analyses revealed that binding of PDMAEMA onto the gold precursor, established interactions, and conformation of PDMAEMA chains with consequent coverage of AuNPs surface are influential on the nucleation and growth rates, size, shape, dispersibility, and assembly of nanoparticles. This in-situ method will develop the exploitation of organo-dispersible metal nanoparticles, especially in the field of catalysts and sensors.