Huaiyu Yang

Experimental and theoretical investigation on corrosion inhibitive properties of steel rebar by a newly designed environmentally friendly inhibitor formula

In order to mitigate the corrosion of steel rebar in concrete, a new environmentally friendly corrosion inhibitor formula (WKI) was designed and the corrosion inhibitive effects of WKI on steel rebar were studied by gravimetric method, electrochemical impendence spectroscopy (EIS), potentiodynamic polarization and Mott–Schottky scanning in simulated concrete pore solution. Furthermore, surface analysis and quantum chemical calculations were conducted in order to illustrate the corrosion inhibitive mechanism. The results indicate that WKI exhibits excellent corrosion inhibitive activities on steel rebar in simulated concrete pore solution. By the presence of WKI, local corrosion was significantly suppressed and no pitting could be detected during the whole experimental period. The total corrosion resistance was increased from 5469 Ω cm2 to 64 440 Ω cm2 and the corrosion current density was reduced from 3.23 μA cm−2 to 0.21 μA cm−2 for the sample immersed in the corrosion medium for 7 d with WKI. The corrosion potential of the steel rebar electrode moved to a higher level and the charge transfer resistance increased, indicating that the anti-corrosion properties of the steel rebar were enhanced. The corrosion inhibitive mechanism of WKI can be attributed to the fact that it can promote the formation of a passive film and reduce its defect concentration via its adsorption and interaction with the metal surface, consequently inhibiting the corrosion of steel rebar caused by chloride ions.

Preparation of Size Controllable MgO Nanoparticles via Reverse Microemulsion Method

Nanoparticles of MgO were successfully prepared in Triton X-100/n-hextnol/cyclohexane/water W/O microemulsion system. Basic preparation conditions were determined. TG-DTA showed that the proper calcination temperature was 450 oC. The nanoparticles were characterized by XRD and IR measurements in order to determine the crystal phase and component of the products. The morphological feature of the nanoparticles has been investigated by TEM. The result of XRD pattern demonstrated that the particles were exactly indexed to a cubic rock salt structure of MgO. There are no organic or inorganic impurities appeared after 450 oC calcination. The result of TEM showed that the MgO nanoparticles were spherical and uniform. The UV-visible spectra demonstrated the phenomenon of absorption blue shift, which is the evidence of quantum confinement effect, with the decrease of water/surfactant(R) value. Average size of the nanoparticles increased with increasing R value.

Synergistic Effect of Inhibitors of an Imidazoline Derivative and Tetraethylenepentamine on Corrosion Inhibition of Steel Rebar in an Artifial Concrete Pore Solution

Inhibition performance and synergistic effect of an imidazoline derivative, namely 1-[N, Nbis(hydroxylethylether)aminoethyl]2stearicimidazoline (HASI) with tetraethylenepentamine (TEPA) on the corrosion inhibition of steel rebar in an artificial concrete pore solution containing 3.5%NaCl were investigated using linear polarization, potentialdynamic polarization and electrochemical impedance spectroscopy (EIS) techniques, while molecular dynamics (MD) simulation was employed to explore the co-adsorption behavior of the composite inhibitors on the metallic iron surface. Results indicate that after the addition of inhibitors, the corrosion current density of steel rebar was reduced and the corrosion resistance of steel rebar was enhanced. With increasing content of HASI in the composite inhibitors, the inhibition efficiency gradually increased, the corrosion potential shifted significantly to negative, and therewith a more positive pitting potential and a wide 定稿日期:2014-11-13 基金项目:国家自然科学基金项目 (51071161)和输变电设备防腐材料开发及应用关键技术研究项目 (521820130014)资助 作者简介:冯丽娟,女,1983年生,博士 通讯作者:杨怀玉,E-mail:hyyang@imr.ac.cn,研究方向为金属腐蚀与防护 DOI:10.11902/1005.4537.2014.115