Layer-by-layer anchoring of copolymer of methyl methacrylate and [3-(methacrylamino)propyl] trimethyl ammonium chloride to gold surface on flexible substrate for sensing humidity

• Main Authors: Hsu, Huan-Chieh, 徐煥傑
• Other Authors: Liu, Ching-Yang
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/35353908082562875110

碩士 === 中國文化大學 === 化學系應用化學碩士班 === 101 === Novel flexible impedance-type humidity sensors were fabricated by anchoring humidity-sensitive polyelectrolyte to the gold electrode on plastic substrates using a peptide chemical protocol. A pair of comb-like Au electrodes on a polyester (PET) substrate was pretreated with 3- mercaptopropionic acid (MPA) and further reacted with a copolymer of methyl methacrylate (MMA) and [3-(methacrylamino)propyl] trimethyl ammonium chloride (MAPTAC) using N-(3-dimethylaminopropyl)-N’-ethylcarbodiimide hydrochloride (EDC) as peptide coupling reagent. The prepared humidity-sensing film was characterized by electrochemical impedance spectroscopy (EIS) and Fourier transform infrared spectroscopy (FTIR). The amount of added EDC influenced the stability of the anchored poly-MMA-MAPTAC onto the MPA/Au surface in water. The flexible impedance-type humidity sensor made of poly-MMA-MAPTAC that was anchored onto the MPA/Au surface using 200 mM added EDC had a wide working range of humidities, a high sensitivity, an acceptable linearity, a small hysteresis, high flexibility, a short response time, a weak dependence on temperature and good long-term stability. The dependence of the impedance on frequency was greater at lower RH.