FE荧光探针在线检测土质文物中水分形态及其挥发行为

Online Detection of Water Forms and Moisture Volatilization Behavior in Earthen Relics Based on FE Fluorescence Probe

土质文物众多病害都与水有关,土体多孔结构中自由水和吸附水对其病害的影响存在显著差异性,在水分挥发过程中,自由水易挥发,有利于土体保持干燥,而吸附水挥发缓慢,是盐害和酥粉等病害的主要成因。因此,检测土质文物中不同形态水的挥发行为对预防土质文物盐害及酥粉病害具有积极作用。由于自由水和吸附水存在化学上的极性差异,而FE荧光双发射峰对极性和氢键具有敏感性,可用于指示极性差异。以FE作为荧光探针,将其引入到不同吸潮时间的土质文物模拟样中,通过在线检测样品水分挥发过程中表面荧光光谱,根据荧光特征峰位置及变化,揭示土样中水分的存在形态及自由水和吸附水挥发行为特征;通过在线检测加固土样荧光光谱变化,揭示加固对土样中不同形态水挥发行为的影响规律。FE荧光探针拥有波段可分的双发射波峰,激发波长在可见光区,避开了土壤具有强吸收的紫外区,以FE为荧光探针识别土体中水分的不同形态具有灵敏性。同时,在识别不同形态水基础上,可在线检测土体中不同形态水分挥发演变过程,这对评价土质文物加固后文物透气性能具有指导价值。

Numerous diseases in ancient earthen cultural relics are relative to water.Free water and absorbed water in earthen cultural relics’pore structure bring different influences.During the evaporation of water,free water easily evaporates from soil in favor of drying soil.Relatively,the volatilization of absorbed water is slow,leading to salt damage.Therefore,it is the foundation for relic protection to identify free water and absorbed water in earthen relics and study volatilization behavior.The free water and absorbed water have different polarities in chemistry.FE fluorescence substance with double emission peaks is sensitive to the change of chemical polarity and hydrogen bond,used to indicate polarity difference.This paper introduced FE as florescence probe into the stimulated soil samples with different moisture time.By detecting fluorescence characteristic peaks online during water evaporation,the water form and the volatilization behavior of free water and bound water in soil samples were revealed.In the same way,the fluorescence spectra of the stimulated soil samples before and after consolidation were determined to research the effect of consolidation treatment on the volatilization behavior of different forms of water.FE probe has separable double emission peaks,and the excitation wavelength is in the visible region,avoiding soil’s highly absorptive ultraviolet region.The method proposed in this paper can sensitively detect the water form in earthen cultural relics and evaluate the properties in breathability and water resistance for consolidated earthen cultural relics through the volatilization behavior of different forms of water.