ZIF-8 Modified Ce–Sol–gel Film on Rebar for Enhancing Corrosion Resistance

• Published in: Acta metallurgica sinica : English letters Vol. 37; no. 12; pp. 2121 - 2135
• Main Authors: Zeng, Yanwei, Xu, Peng, Liu, Guoqiang, Wang, Tianguan, Lei, Bing, Feng, Zhiyuan, Zhang, Ping, Meng, Guozhe
• Format: Journal Article
• Language: English
• Published: Beijing The Chinese Society for Metals 01.12.2024; Springer Nature B.V
• Subjects: Cathodic protection; Cement; Characterization and Evaluation of Materials; Chemistry and Materials Science; Chloride resistance; Concrete; Concrete blocks; Corrosion and Coatings; Corrosion effects; Corrosion inhibitors; Corrosion resistance; Corrosion resistant steels; Curing; Electrochemical impedance spectroscopy; Electrodes; Hot rolling; Interfacial bonding; Materials Science; Metallic Materials; Nanoparticles; Nanotechnology; Organometallic Chemistry; Rebar; Reinforced concrete; Reinforcing steels; Resistance factors; Scale (corrosion); Sol-gel processes; Spectroscopy/Spectrometry; Tribology; Corrosion resistance; Oxide scale; Rebar; Sol–gel; Chloride corrosion
• ISSN: 1006-7191; 2194-1289
• DOI: 10.1007/s40195-024-01768-z

Chloride-induced corrosion of steel reinforcement is the key factor leading to the degradation of reinforced concrete building durability. Improving the corrosion resistance of oxide scale of rebar has always been a research hotspot in the field of civil engineering materials. A ZIF-8 modified Ce–Sol–gel (ZCS) film was prepared on oxide scale of plain steel rebars by sol–gel method. It is observed that the | Z | 0.01 Hz value of the ZCS film reached 320 kΩ cm 2 , which is about 29 times higher than that of blank rebar in simulated concrete pore (SCP) solution with 0.1 M NaCl. Then, they were inserted into mortar block and curing them in a curing box at T  = 20 ± 2 °C and RH = 95 ± 2% for 28 days. Subsequently, these samples were subject to electrochemical impedance spectroscopy in 3.5 wt% NaCl. The | Z | 0.01 Hz value of the rebar with the ZCS film was six times higher than that of the blank rebar after immersing for 20 days, resulting in an overall increase in corrosion resistance for rebar. The results indicated that the modification by ZIF-8 could reduce the porosity of Ce–sol–gel (CS) film and improved the “labyrinth effect” of the film. Additionally, the negative charge on the surface of ZIF-8 in alkaline condition increased the repulsion effect with Cl − , significantly reducing the sensitivity of rebar to Cl − .