Iron oxide-entrapped solid lipid nanoparticles and poly(lactide-co-glycolide) nanoparticles with surfactant stabilization for antistatic application

Polymers with very low surface conductivity can easily accumulate an electric charge through surface friction. If the charged entities are grounded with conductive materials, they may discharge electricity associated with sparks that will interrupt the production process, and more seriously, cause industrial disasters. In order to avoid damage from electrical sparks, an antistatic agent (ASA) is employed with the polymer during production. In this study, conductive iron oxide (Fe3O4) nanoparticles (NPs) with hydrophobic modification by oleic acid (OA) were prepared using a co-precipitation method. Fourier transformed infrared spectra and thermogravimetric analysis confirmed that OA-Fe3O4 was formed through chemisorption interactions between OA and Fe3O4. Fe3O4 NPs were entrapped in solid lipid NPs (SLNs) and poly(lactide-co-glycolide) NPs through hydrophobic interactions to obtain new composite antistatic NPs (CANs). Surfactants and their concentration played a decisive role in the zeta potential and particles size of CANs. Sodium dodecyl sulfate (SDS) created some regular-shaped CANs, and didodecyldimethylammonium bromide (DMAB) and glycerol monostearate (GMS) created irregular-shaped CANs. 10% methanol and 1% Tween 80 yielded an appropriate contact angle with polymer films. The surface electrical resistance value of CANs was found to be in the order of SDS > DMAB > GMS. GMS-based CANs reached a lower electrical resistance value of around 108 Ω/Sq, and can be used as an ASA in engineering practice.