Enhanced dispersibility and improved paper deacidification in fluorocarbon solvent by immobilization of nano-MgO with polyvinylpyrrolidone.

Paper deacidification is one of the most important tasks in the conservation of cultural relics. Recently, fluorocarbon solvents which are safe, environment-friendly, and do not react with paper have attracted extensive attention and have been used as the deacidification solvent. However, as one of the most commonly used deacidification agents, the poor dispersibility of nano-MgO in organic solvent has greatly restricted the paper deacidification effect. Herein, by introducing polyvinylpyrrolidone (PVP, K30) as a guiding agent during the process of nano-MgO electrolysis synthesis, we enhanced the dispersibility of nano-MgO in fluorocarbon solvent (C5H3F9O) with stable suspension time extended to 1.5 h, then optimized deacidification performance of paper in Qing Dynasty. The nano-MgO immobilized with PVP (MgO/PVP) is flaky. Compared with MgO synthesized directly without surfactant, its suspension stability increased from 30 min to 1.5 h. Moreover, nano-MgO immobilized with PVP exhibited the best paper deacidification effect. Other than pH 7.8 and 7.9 in groups of MgO and MgO-PVP (PVP addition after MgO synthesis), the pH of the paper after deacidification reached 8.85 for MgO/PVP. In addition, tensile strength of the treated paper is increased 16.3% and the color of the paper is slightly influenced. Overall, We have improved the electrolysis method, and realized the uniform dispersion of nano-MgO in fluorocarbon solvent, which brought the good deacidification effect to the paper and had certain significance in the protection of cultural relics. [ABSTRACT FROM AUTHOR]