In-situ growth synthesis of nanolime/kaolin nanocomposite for strongly consolidating highly porous dinosaur fossil

Due to the excellent compatibility and ageing-resistant performance, nanolime (NL) as a promising inorganic material is applied to consolidate aged sandstones and other arenaceous rocks based cultural heritage, such as wall paintings and stone relics. However, sometimes, NL does not assure a good consolidation strength for cultural relics. The existing researches on enhancing its consolidation strength are costly, time-consuming or still involving organic polymers. Here, utilizing inexpensive kaolin nanosheets as platform, we design and facilely synthesize a new nanolime/kaolin (N-K) nanocomposite by in-situ growth of Ca(OH)2 nanoparticles on the surface of kaolin nanosheets. The kinetic stability of this nanocomposite is comparable to the NL. Application experiment shows that the consolidation strength of the N-K nanocomposite in the highly porous pterosaur fossil (65%, porosity) is stronger than that of NL. The reason is due to the incorporation of kaolin nanosheets into the CaCO3 network after carbonation. For the first time, this work reports a new N-K inorganic nanocomposite and will facilitate the development of NL-based inorganic materials for the conservation of cultural heritage.