Effects of dispersion hydrophobized MgO nanoparticles in low polarity solvent on aged paper

Abstract Paper documents hold significant cultural and historical value, with acidification being a primary factor in their degradation. To protect acidic paper, a deacidifying dispersion was developed using oleyl alcohol-modified magnesium oxide (MgO) nanoparticles in a mixture of hexamethyldisiloxane and ethanol (8:2). The results showed that ethanol can form a solvation layer on the particle surface, provided short-range solvation repulsion, and improved the dispersion stability of the particles. The modified nano MgO changed from hydrophilic to lipophilic in hexamethyldisiloxane and ethanol (8:2) for 12 h with good dispersibility. The use of these sustainable dispersions was implemented for paper deacidification, and experiments were performed to evaluate the effectiveness of this innovative approach. The results showed that the pH value of the paper surface increased to about 8 after treatment, and the pH value of the paper was retained to 7 after aging, and the tensile strength did not decrease significantly under the condition of accelerated aging. It is important to note that the deacidification process has a negligible effect on the visual appearance of the paper as well as the integrity of the ink on its surface and the paper’s hydrophobicity.