Study on pH sensitive optical film and its responsive performance in pH oscillation reaction
LIU Wenjun1, YANG Shan2, HU Daodao1*
（1 School of Materials Science and Engineering, Shaanxi Normal University, Xi′an 710119,Shaanxi, China; 2 College of Chemistry and Environment, Weinan Normal University, Weinan 714099, Shaanxi, China）
Abstract:
The pH sensitive optical film (CCM) with a thickness of about 10 μm was prepared by embedding Congo red in cellulose acetate. The composition, structure and morphology of CCM were characterized by scanning electron microscope, infrared spectrophotometer, UV adsorption spectrometer and contact angle analyzer, respectively. In addition, the responsive performance of CCM was evaluated. The following results were obtained. The CCM has excellent responsive performance for pH change, and excellent synchronous responsivity with pH oscillation reaction. The excellent responsive performance is attributed to the abundant interaction between cellulose acetate and Congo red. Additionally, the hydrolysis of cellulose acetate in alkaline condition can increase the amount of hydroxyl groups, which enhances the CCM responsive performance due to increasing swelling property and wettability.
KeyWords:
cellulose acetate; Congo red; pH sensitive film; pH oscillation reaction
