关键词: 传感器, 电化学阻抗谱, 电化学噪声, 实罐, 饮料包装

Abstract: An electrochemical sensor was designed to detect the corrosion degree of metal cans for beverage packaging, and the effective testing area of the sensor was determined. Electrochemical impedance spectroscopy (EIS) and electrochemical noise (EN) were performed to detect the corrosion degree of beverage cans which have been stored for 1 month(named s1), 3 month(named s2), 27 month(named s3) and 43 month(named s4). EIS results showed that the EIS plot of s1 had not developed to a characteristic of two time-constants and the coating resistance was higher than 108Ω?cm2, indicating that the coating showed good protective performance. The EIS plots of s2, s3 and s4 showed characteristics of two time-constants and the coating resistance was lower than 108Ω?cm2, indicating that the organic coatings of s2,s3,s4 had lost their protective performance. EN results showed that quantities and amplitudes of transient peaks increased with the increasing storage time, indicating that the increasing local corrosion occurred in the cans. The designed electrochemical sensor was successfully applied to detect the performance of beverage cans and further provided scientific proof to evaluate the shelf life of metal cans for packaging.

Key words: sensor；electrochemical impedance spectroscopy；electrochemical noise, cans；beverage packaging