A novel approach to consolidation of historical limestone: the calcium alkoxides

作者：Favaro M^*; Tomasin P; Ossola F; Vigato P A

来源：Applied Organometallic Chemistry, 2008, 22(12): 698-704.

DOI：10.1002/aoc.1462

• stone consolidation
• calcium alkoxides
• limestone
• calcium carbonate deposition
• building heritage

Potential utilization of calcium alkoxides as stone consolidants was considered. Reaction of Ca(OCH(3))(2), Ca(OCH(2)CH(3))(2)(CH(3)CH(2)OH)(4) and Ca[OCH(CH(3))(2)](2) with the atmosphere in different experimental conditions was studied. The reaction produced CaCO(3) and two different pathways seem to be involved, the first taking place through CO(2) insertion into the Ca-O bond of Ca(OR)(2) species with formation of an alkylcarbonate derivative, subsequently transformed into CaCO(3) through ROH elimination; the second takes place through hydrolysis of Ca(OR)(2) to Ca(OH)(2), which is then carbonated to CaCO(3). The vaterite/calcite ratios found in the final CaCO(3) vary considerably with the experimental conditions adopted. Investigations demonstrated the potentiality of Ca(OCH3)2 to act as a stone consolidant. in fact, impregnation of a porous substrate, simulating the deteriorated stone, with a methanol solution of Ca(OCH3)2, produced a crystalline vaterite film, which gradually filled all the pores and cavities of substrate and seems to fulfil the necessary requirements for a consolidant.

• 出版日期2008-12