COPVDF MEMBRANES FOR PROTECTION OF CULTURAL HERITAGES

The study focuses on the possibility of using polymeric membranes to p rotect cultural heritages from biological degradation and from corrosi ve action exhibited by atmospheric agents. These membrane systems may be utilized as intelligent coatings on the porous lithoid material sur faces, which constitute a great part of the heritage and in recent yea rs have suffered from an increase in attack phenomena. In particular v inylidene fluoride copolymer has been used in this study. The hydropho bic character of CoPVDF membranes has been used to avoid direct Liquid water contact with Serena stone surfaces. The Pietra Serena is a poro us sandstone which has been frequently used to construct balconies, st airs and decorations of Italian monuments. The possibility of modifyin g the gas and liquid permeability by introducing a mixture of liquid c rystals in the CoPVDF polymeric matrix has been also analyzed. In part icular, a mixture of liquid crystals has been introduced in the nemati c phase in a polymeric matrix. Because of their fluidity and nematic i ntrinsic anisotropy, those materials are applicable in the electro-opt ical field, but their gas transport behaviour is also interesting. The y can control and facilitate the gas passage through a polymeric film. We have characterized the selectivity of modified CoPVDF membranes fo r several gases (O-2,N-2,CO2).