Temperature Dependence of Hydrogen Bond in the Redox Process of Polyaniline

The in situ rapid-scan time-resolved IR spectroelectrochemistry (RS-TR-FTIRS) method was utilized to study the structures of hydrogen bond in the redox process of polyaniline for the first time. There are two types of hydrogen bond. The first was formed between the oxygen atom of water molecule and one hydrogen atom of amine cation radical according to the O-H stretching region (3200–2100 cm−1). Another was formed between the oxygen atom of water molecule and two hydrogen atoms of different amine cation radical according to the O-H stretching region (2700–1700 cm−1). It was found that the hydrogen bond strengthen with the increase of the quantity of amine cation radical in the redox process of polyaniline. The ordered hydrogen bond intensity increases as temperature decreases. The results may be important for understanding of chemical and electric structure and full use the chemical and electronic properties of PANI.