可溶盐NaCl和CaCl2对陶质文物的酥粉作用

研究可溶盐NaCl和CaCl_2复合盐破坏陶质文物过程中作用本质,在复合盐溶液的平衡结晶相分析基础上,分析陶质样品中可溶盐溶液的吸收和水分蒸发速率变化,以及采用超景深显微系统、扫描电子显微系统等检测可溶盐NaCl、CaCl_2和复合盐溶液对陶质样品的破坏过程和作用。结果表明:陶质样品破坏的本质在于可溶盐结晶受力过程中微裂纹的扩展和贯通,在环境相对湿度变化引起裂纹扩展贯通过程中,陶质样品表面逐层粉化脱落,质量、形貌和强度都发生着一定程度的改变,其中NaCl结晶体对陶质样品产生的作用力较大,破坏性最强,而NaCl溶液中加入的CaCl_2延长了盐结晶所需要的时间,间接地阻碍了NaCl的结晶析出,反而对陶质样品起到了一定的保护作用。研究结果为进一步酥粉陶质文物的保护研究提供科学依据。

The effects of the soluble salts NaCl and CaCl2 on pottery efflorescence

The process of failure due to salt-promoted efflorescence in pottery by digital and scanning electron microscopy and by analysis of the effects of NaCl and CaCl₂ on the phase equilibrium of salt water systems. These studies indicated that the growth and connection of the micro-cracks in the particles of samples under the stress of salt crystallization was the destructive cause of pottery efflorescence. Furthermore, there were significant changes in quality, morphology and flexural strength of pottery due to salt crystallization, depending on environmental relative humidity. The most devastating effect was due to crystallization of sodium chloride. Crystallization of sodium chloride could be slowed down by the addition of CaCl₂ , which therefore can play a role in preventing the destruction of pottery due to efflorescence.