Recycled bacterial nanocellulose membranes as novel green gels for the cleaning of cultural heritage surfaces

Gels allow the removal of extraneous materials from cultural heritage surfaces without changing artifacts' properties, thanks to solvent retention and its controlled release. In recent years, nanotechnologies and green chemical approaches created great interest in restoration and conservation field. The aim and innovation of this paper is to use bacterial nanocellulose (BNC) as a green gel in cleaning operations. Recycled BNC, a by-product from the fermented beverage Kombucha, is used. Purified by-products are investigated by means of different analytical techniques to characterize the chemical structure, crystallinity, microstructure, thermal and tensile behaviours, retention capacity of water (WRC) and organic solvents (OSRC). Materials show good mechanical behaviour, diffuse nanodimension and high WRC and OSRC. One gel is used in the removal of wax, a widespread deposit of dirt. It proved cleaning efficiency for removing beeswax after one hour and a weak removal of microcrystalline wax, showing BNC’s potential as green gel.