Optimized Semi-Interpenetrated p(HEMA)/PVP Hydrogels for Artistic Surface Cleaning.

Area of Science:

• Materials Science
• Conservation Science
• Polymer Chemistry

Background:

• Artistic surfaces are susceptible to degradation from metal salts.
• Developing effective and rapid cleaning methods for delicate surfaces is crucial in conservation.

Purpose of the Study:

• To optimize the synthesis of poly-hydroxyethyl methacrylate (pHEMA) based hydrogels semi-interpenetrated with polyvinylpyrrolidone (PVP).
• To enhance the cleaning effectiveness of these hydrogels for removing copper salt deposits from artistic surfaces, particularly marble.
• To accelerate gel preparation time and improve cleaning efficiency.

Main Methods:

• Modified synthesis parameters (temperature, time, crosslinker) of pHEMA/PVP hydrogels.
• Varied PVP molecular weights, initiators, and added maleic anhydride.
• Characterized hydrogels using equilibrium water content (EWC), water uptake, conversion grade, and differential scanning calorimetry (DSC).
• Assessed cleaning effectiveness via copper salt removal from stained specimens using EPR, UV-Vis, ICP-MS, and color variation measurements on marble.

Main Results:

• Accelerated gel synthesis was achieved using PVP with a molecular weight of 360 kDa.
• Hydrogels incorporating maleic anhydride demonstrated the highest effectiveness in removing copper salt deposits.
• Maleic anhydride acted as a chelator for copper ions, enhancing the cleaning process.

Conclusions:

• Optimized pHEMA/PVP hydrogels provide a rapid and effective method for cleaning artistic surfaces.
• The inclusion of maleic anhydride is key to superior copper salt removal due to its chelating properties.
• These findings contribute to advanced conservation strategies for metal-contaminated artifacts.