수용액내에서 Mg/Al-NO₃ 및 Ca/Al-NO₃ 층상이중수산화물(LDHs)의 염소이온 고정화 특성에 관한 실험적 연구

Chloride ions ingress continuously in reinforced concrete through pores of it by Cl - . Finally, it causes a localized corrosion of the rebar and then it generates cracks on concrete structures. Recently, new materials removing harmful anions have been developed. Layered double hydroxides(LDHs) has an excellent ability to remove harmful anions because various anions can be adsorbed in the interlayer space between divalent and trivalent cations. Thus, LDHs has been applied in various fields. Especially, LDHs is expected to be effective adsorbent binding chloride ions. In this study, Ca/Al-NO₃ and Mg/Al-NO₃ LDHs were prepared by using a co-precipitation method. Ca/Al-NO₃ and Mg/Al-NO₃ LDHs were compared and analyzed by using XRD, SEM analysis. Many nano size hexagonal crystals were observed by SEM. Experiments for binding chloride ions of LDHs were conducted by using potentiometric method. The experimental data were measured every 15 minutes. It was observed that the chloride ion content is reduced by increasing of LDHs mass fraction and the reaction rate of Mg/Al-NO₃ is faster than Ca/Al-NO₃. In future studies, binding chloride capacity in cement materials will be evaluated based on results of this study.