In-situ formation of one-dimensional silica for conservation of silicate relics using cellulose nanocrystals as templates

Due to air pollution and natural weathering, many silicate relics are severely degraded and in urgent need of conservation. Generally, consolidation materials are introduced into weathered silicate relics in liquid form, then solidify within to re-strengthen the weathered heritages. Obviously, consolidation materials will fill the voids in heritages, especially voids near the surface, thus resulting in significant loss in vapor permeability. In this work, one-dimensional silica (ODS) is prepared in-situ via template method. ODS may form supporting network easily without clogging the pores. Evaluations on the mockup samples show that samples treated with appropriate ODS display high compressive strength, high air permeability and small colorimetric variation. The results show that the prepared ODS is highly potential for silicate relics conservation. Meanwhile, it is also found that the pre-reaction time in ODS preparation step has strong influences on the penetration and microstructure of the formed ODS, and eventually on the final conservation performance.