“雾霾”风化作用下钠钙硅玻璃的损伤行为与机理研究

As an important architecture/industry material, soda-lime-silica (SLS) glass surface would suffer more serious damage when it is exposed to haze ambient conditions with high concentration of water-soluble ions and micro-scale solid particles for long-term, compared to that in normal ambient conditions. But so far, understanding of the damage behavior and its mechanism of SLS glass under haze ambient conditions is very poor. By the combination of macro-scale and micro-scale studies, the proposed project aims to investigate the surface damage behavior and its mechanism of SLS glass at haze ambient conditions systemically. At macro-scale, the typical haze ambient is composed of water-soluble ions and micro-scale solid particles, which can be formed of a salt-frog box system; then the weathering of SLS glass at real haze ambient conditions could be stimulated, and the effect of chemical compositions of haze on the corrosion and damage of SLS glass will be addressed. At micro-scale, the contact and wear between glass and single solid particle from haze ambient can be stimulated by using an Atomic Force Microscopy (AFM), the micro-wear behavior and it mechanism of SLS glass at haze ambient with water-soluble ions can be revealed by understanding the single-asperity induced corrosion and micro tribochemical wear. As a result, by combining the perspective of macro-scale and micro-scale, the technical procedure for reducing the damage of glass material at haze conditions will be proposed. In summary, the proposed research effort is very helpful for improving the lifetime of glass materials at engineering application. It can also contribute to the fundamental theory of micro-tribology.

钠钙硅玻璃作为重要的建筑/工业材料，当其长期暴露在由高浓度水溶性酸碱离子和固体微细颗粒混合的“雾霾”大气下，会遭受比普通大气下更严重的风化损伤，但目前对其损伤机理还认识还不足。为此，本项目拟采用宏观与微观相结合的方式，系统的开展“雾霾”风化作用下钠钙硅玻璃损伤行为和机理研究。宏观上，利用盐雾箱引入水溶性离子和微细颗粒以形成典型的“雾霾”环境，并模拟玻璃在其中遭受的真实“雾霾”风化过程，揭示“雾霾”化学组分对钠钙硅玻璃表面腐蚀和磨损的宏观作用机理；微观上，利用原子力显微镜（AFM）实现单固体颗粒在“雾霾”环境中的接触与磨损，从单点腐蚀与单点摩擦化学磨损的角度，揭示存在水溶性离子的“雾霾”大气下玻璃的微观损伤规律和机理。最后，从宏观和微观相结合的角度，提出减小玻璃在“雾霾”中风化损伤的技术措施。该项目研究成果不仅有助于提升玻璃材料在工程应用中服役寿命，还能为丰富微观摩擦学的基础理论做出贡献。

本项目针对钠钙硅玻璃在“雾霾”大气下的损伤现象，从宏观和微观相结合的角度，通过模拟研究玻璃不同外部环境下的损伤行为，阐述了玻璃在不同条件下的损伤机理。主要进展包括：（1）揭示了外部环境对钠钙硅玻璃表面腐蚀和磨损的宏观作用机理。在宏观尺度上，载荷对钠钙硅玻璃锡面在潮湿空气下损伤程度的影响大于空气面损伤的影响。随着滑动速度的增加，钠钙硅玻璃在干燥空气中的磨损量逐渐增加，而在潮湿空气中，钠钙玻璃的磨损量却随着滑动速度的增加逐渐减小。经SO2气氛风化处理后，钠钙硅玻璃在潮湿空气下的摩擦化学损伤加剧，但其维氏压痕等性能明显提升。而在液体环境下，钠钙硅玻璃在酸性溶液（pH=3）和碱性溶液 （pH=11）中的磨损量均小于在纯水环境下，此外，当溶液中存在带正电的聚合电解质时，钠钙硅玻璃的摩擦损伤程度大幅度降低，最大可达97%。（2）揭示了载荷和湿度对钠钙硅玻璃在微观尺度的损伤机理。借助原子力显微镜（AFM）发现，随着载荷和环境湿度的增加，钠钙硅玻璃在微观尺度的摩擦损伤逐渐增大，同时AFM针尖的摩擦损伤也增加。这些现象同钠钙硅玻璃表面与环境（特别是水分子）的相互作用密切相关。（3）基于钠钙硅玻璃在不同环境下的损伤规律与机理，提出了玻璃在相应工况下的调控措施。相关结果有望完善玻璃材料损伤与去除机理的理论，并促进玻璃在不同工程应用中的损伤调控。