One-Pot Exfoliation and Functionalization of Zeolite Nanosheets for Protection of Paper-Based Relics

Two-dimensional (2D) zeolite nanosheets have emerged in many applications due to their structure/surface properties through functional designing. However, the effective and low-cost preparation of functional mono/oligo-layer 2D zeolite and its application in interdiscipline fields still remain a challenge. Here, we report a facile and efficient method of liquid exfoliation by using ethanolamine (ETA) for one-pot liquid exfoliation and surface functionalization. Strikingly, the resultant 2D oligolayer MWW zeolite (denoted as ETA-OL-MWW) has discretely dispersed nanosheets with a well-maintained framework, interface-grafted ETA molecules, and accessible functional sites. The interaction between MWW nanosheets and ETA molecules is characterized and verified as a key factor to achieve, simultaneously, surface functionalization of nanosheets and high dispersion in water-organic solvents. Meanwhile, the stable colloidal ETA-OL-MWW is favorable for functional membrane fabrication via solution-based processing like spin-coating. Based on these features, we pioneer the interdisciplinary use of colloidal ETA-OL-MWW as a multifunctional protective agent for paper-based relics, which is much desirable in the field of cultural heritage preservation. The sufficient, mild, and accessible base sites of ETA-OL-MWW benefit safe deacidification and antiaging but do not damage the original nature of paper relics and color of alkali-sensitive pigments. Moreover, the paper mechanical strength is improved owing to the 2D structure and film-forming property of ETA-OL-MWW, while its antibacteria/fungus and antioxidation for paper relics are revealed and assisted by ETA-functionalized surface. This work is conducive to broadening methods and ideas for exfoliating and functionalizing MWW zeolite and has the significance of designing zeolite-based composite material with interdisciplinary applications.