Ag^(+)改性沸石-聚氨酯涂料用于混凝土下水道微生物诱导混凝土腐蚀行为

In vitro microbiologically-induced concrete corrosion behavior of Ag^(+) loaded zeolite-polyurethane coating for concrete sewer applications

微生物诱导混凝土腐蚀(MICC)是指硬化混凝土浆体中生物产生的硫酸与水化产物之间的化学反应,它将导致早期强度降低、劣化,甚至结构破坏。本文探讨了表面涂覆改性沸石聚氨酯胶凝材料的杀菌性能。研究了银改性沸石-聚氨酯涂层在硫氧杆菌接种的环境中8周的抗菌性能。通过分析pH值、光密度(OD)、硫酸盐产量和细菌数量来评估沸石-聚氨酯涂层在硫氧杆菌接种产生硫酸环境中的抗菌性能。对缺乏细菌附着和样品表面变形的微菌落、pH降低滞后、OD值增加和硫酸盐产量进行分析,结果表明,与未改性的聚氨酯涂层相比,加入银改性沸石的样品(不论沸石类型)均表现出抗菌性能。银改性沸石的抑菌性能是由于在水溶液中释放的银离子抑制了细菌的细胞功能,导致细胞损伤从而起到抑菌作用。

Microbiologically-induced concrete corrosion(MICC)refers to chemical reactions between biologically produced sulphuric acid and with hydration products in the hardened concrete paste,resulting in an early reduction of strength,deterioration,and very severe circumstances,structural failure.This paper explores the bactericidal characteristics of cementitious materials with surface coated with modified zeolite-polyurethane.The zeolite-polyurethane coating incorporated with silver was studied in environments inoculated with A.thiooxidans bacteria for 8 consecutive weeks.The antibacterial characteristics were evaluated in terms of pH,optical density(OD),sulphate production and bacteria count to determine the effectiveness of the zeolite-polyurethane coatings in environments inoculated with A.thiooxidans bacteria producing the sulphuric acid.The results revealed that the samples incorporated with silver modified zeolites generally showed antibacterial performance(regardless of the zeolite type)compared with unmodified polyurethane coating.This was evaluated by the lack of bacteria attachment and the deformed microcolonies on the sample surface,lag in pH reduction,increase in OD,and sulphate production.The silver zeolites gained their antibacterial performance from the release of silver ions(Ag^(+))when the sample comes into contact with aqueous solutions.This results in the inhibition of cell functions of the bacteria and subsequently causes cell damage.