Simultaneous Deacidification and Reinforcement of Aged Paper via In Situ Polymerization of Inorganic Ionic Oligomers

ABSTRACT The acidification and degradation of paper, a primary carrier of human civilization, pose a significant challenge to cultural heritage conservation. Here, we introduce for the first time a biomimetic conservation strategy based on volatile organic base modified inorganic ionic oligomers, which act as a dual‐function agent for simultaneous deacidification and reinforcement. Triethylamine (TEA)‐capped calcium phosphate oligomers (CPOs), stabilized at the molecular level, are utilized to ensure deep penetration into the cellulose fiber network. Upon application, the volatile TEA provides a transient and mild deacidification effect. As TEA is gradually removed, an in situ polymerization of the CPOs is subsequently initiated. Guided by the cellulose fibers of the paper as a natural template, these oligomers mineralize in situ into a continuous hydroxyapatite (HAP) network through inorganic ionic crosslinking, becoming intimately integrated with the paper structure. When tested on aged handmade bamboo paper, this integrated treatment yielded a neutral pH, a uniformly distributed alkaline reserve, and markedly improved tensile strength, all without altering the original appearance of the paper. This study demonstrates a novel paradigm for paper conservation, shifting from conventional particle deposition to in situ network formation, and establishes inorganic ionic oligomers as a promising platform for developing advanced, multifunctional materials for the preservation of cultural heritage.