Polyacrylamide hybridized double networks with polysaccharides and zinc oxide nanoparticles as a Novel approach for removing animal glue stain from paper manuscripts.

Animal glue stains are commonly found in manuscripts, and their removal is a delicate process that requires selective treatment to avoid damaging the fragile cellulose fibers. Therefore, this study developed a novel hybrid double network hydrogel (HDNH) consisting of synthetic polymer (Polyacrylamide), natural polymers (Agarose or sodium alginate), and Zinc Oxide nanoparticles (ZnONPs) for removing animal glue stains from paper manuscripts. The cleaning mechanism relies on the capillary HDNH to draw the aged animal glue into the gel matrix. To establish the suitability of this HDNH as a paper-cleaning material, the gels were first characterized physicochemically and microstructurally, and the HDNH formulation was confirmed. At the same time, mechanical, physicochemical, morphological, optical, and wettability techniques were performed on the paper samples under investigation, both before and after the cleaning treatment, to evaluate the HDNHs' cleaning capabilities. The results show that the Polyacrylamide/Agarose/ZnONPs (HDNH/Ag/ZnONPs) provide superior performance in removing most of the accumulated glue layers while maintaining the structural and chemical integrity of the paper substrate. Agarose provides a very rigid, highly porous structure with a superior capacity to retain water, preventing the paper from becoming waterlogged. Polyacrylamide provides flexibility and mechanical durability, allowing the hydrogel to be peeled off in one piece.