Enhancement of corrosion resistance of waterborne epoxy resin using Ti3C2Tx MXene nanosheets modified with L-glutamic acid: preparation, performance and mechanism

Ti3C2Tx MXene, a two-dimensional material with abundant functional groups, can effectively fill the holes and flaws of coating, but its intrinsic agglomeration reduces the dispersibility in organic coatings. To solve this problem, modified MXene/epoxy coating (L-MX/WEP) was synthesized by using L-Glutamic acid (L-Glu) to modify Ti3C2Tx MXene and incorporating them into waterborne epoxy (WEP) resin. Its structure and anticorrosion performance were analyzed and anti-corrosive mechanism was revealed. The results showed that NTi and N-H bonds existed in L-MX, with a D-spacing of 0.82 & Aring;, which was greater than that in the original Ti3C2Tx MXene. The |Z|0.01 Hz value of L-MX/WEP coating (2.51 x 106 Omega & sdot;cm2) was significantly larger than that of WEP coating (4.54 x 104 Omega & sdot;cm2) after 45 d of immersion in 3.5 wt % NaCl solution. The total elemental content of Fe and Sn on the substrate surface was the highest (96.46 wt %). After 600 h of salt spray testing, LMX/WEP coating had the least amount of corrosion products in the scratches. L-MX exhibited remarkable dispersion and corrosion inhibition in the WEP, enhancing the physical barrier and anti-corrosion performance of composite coating. The toxicity experiments of L-MX/WEP coating showed 78 % SR and 93 colonies of Escherichia coli. The development of environmentally friendly multifunctional coating offers a novel approach for designing green, safety and durable anti-corrosion materials.