Graffiti coating eco-remover developed for sensitive surfaces by using an optimized high-pressure homogenization process

Nanostructured fluids (NSFs), such as water-in-oil (w/o) nanoemulsions (NEs), comprise one of the best examples of new, ecological products dedicated to removing various graffiti coatings (so-called eco-removers) from sensitive surfaces without causing damage underneath. These contemporary acceptable formulations are intended to be more efficient in removing undesirable graffiti coatings than traditional organic solvent-based preparations. In this paper, systematic studies were performed on the selective and controlled removal of paint and ink coatings from substrates that were sensitive to mechanical cleaning by using innovative graffiti coating removers in the form of “brush on, wipe off” detergents. The w/o NEs were fabricated by using a high-pressure homogenization process (HPH) from the following ingredients from sustainable sources of raw materials: esterified used cooking oils (Oil-PEG-8-ester), ethyl lactate (EL), water and saccharide-derived surfactants, such as alkyl polyglucosides (APGs), which have excellent wetting and detergent activities. The most efficient formulations achieved during the HPH process were determined by optimization through response surface methodology (RSM). The optimized w/o nanoemulsions were tested for the selective removal and wetting ability of graffiti coatings from selected sensitive surfaces, such as plastics, ceramics, or painted metal surfaces. Additionally, in studies of interaction with graffiti coatings, evaluating their surface properties (topography, wettability) on a real paint coating allowed for the assessment of the mechanism of graffiti paint removal by the proposed ecological remover. Using the "brush on, wipe off" cleaning procedure based on the developed w/o nanoemulsion systems has the potential to remove safely rough and heterogeneous graffiti coatings. Therefore, nanotechnological detergents are an outstanding environmentally friendly alternative to conventional graffiti coating removers.