One-Step Reinforcement and Deacidification of Paper Documents: Application of Lewis Base—Chitosan Nanoparticle Coatings and Analytical Characterization

Abstract

To delay acidification and deterioration during natural aging, deacidification and reinforcement of paper manuscripts have been the most important technologies to prolong the life of objects. Herein, a novel approach for the conservation of paper manuscripts is proposed using chitosan nanoparticles as Lewis base that leads to both deacidification and strengthening of paper in one-step. Chitosan nanoparticles were prepared through physical ball grinding method and characterized via scanning electron microscopy (SEM), X-ray diffraction (XRD), laser particle size analyzer (LPSA), Fourier transform infrared spectroscopy (FTIR), and atomic force microscope (AFM). To evaluate the resistance of chitosan nanoparticle coating, the mechanical properties of paper after artificial aging were evaluated using dry heat and hygrothermal accelerated aging methods. The SEM, EDX, and X-ray Photoelectron Spectroscopy (XPS) were used to analyze the interaction mechanism between chitosan and Shuxuan paper. The results show that the coated paper had superior durability with respect to pH, tensile strength, and folding endurance. There was a presence of protonated amines in the form of ammonium salts due to ionic bindings with free H+ in the acidified paper, and the remaining –NH2 could be used as a base reserve. Finally, the resulting coated papers displayed good antibacterial properties.

Polyelectrolyte Coatings—A Viable Approach for Cultural Heritage Protection

“…While this is happening, excessive sun exposure would accelerate UVA and UVB radiation’s breakdown of cellulose molecules. Therefore, in order to delay the degradation in the maintenance of these paper collections, preventive conservation is required [ 41 , 107 , 108 , 109 , 110 , 111 ].…”

“…Jia et al claim that four typical fungi found in libraries and museums are used to test the antibacterial effectiveness of paper covered with CH nanoparticles. The outcomes demonstrate the potent antibacterial activity of CH nanoparticles [ 108 ]. According to Totolin and colleagues, the plasma polymer P(MMA-co-EtA) film formed by low pressure non equilibrium plasma polymerization allows the creation of a “polymer-like” structure while maintaining the functions of the monomers [ 113 ].…”

Natural Ingredients in Functional Coatings—Recent Advances and Future Challenges

“…The treated papers had higher thermal and UV stability and exhibited an inferior loss of strength. For papers coated with chitosan nanoparticles, the protection is due to the formation of chitosan protective layer when the nanoparticles combined with H 2 O and H + , the deacidification of the paper being produced (a pH increase from 5 to 7 being recorded), also increasing tensile strength and folding endurance [173].…”

An Essential Role of Polymeric Adhesives in the Reinforcement of Acidified Paper Relics

“…Calcium hydroxide, calcium bicarbonate, magnesium hydroxide, magnesium bicarbonate and magnesium oxide are the most commonly used deacidification reagents [ 8 , 9 , 10 , 11 ]. As paper acidification causes paper relics to undergo embrittlement and decay, to form dregs, and even to break upon a single touch, reinforcement treatment should be an essential step for these acidic paper relics [ 12 , 13 , 14 ]. Especially, for acidic paper relics with lost mechanical strength, a back support to enhance their mechanical strength is usually required.…”