A Comprehensive Investigation On Electrochemical Copolymerization Of O-aminophenol With O-toluidine,O-aminophenol With O-anisidine,and Indole With O-anisidine

Polyaniline?PANI?may be considered as one of the most interesting and oldest conducting polymers because of its interesting properties and the numerous possibilities of applications.However,PANI limited its utilization on industrial scale because of its low solubility in most organic solvents.From previous works,in order to improve the properties of polyaniline,lots of endeavors have been made.The first approach was using functionalized acids as dopants?such as sodium dodecyl benzene sulfonate,sodium dodecyl sulfate and camphor sulfonic acid,etc.?.The second was the polymerization of aniline derivatives by substitution of ortho,meta and para position.The third was copolymerized aniline with its derivatives to synthesize the copolymers with better electrochemical properties than polyaniline.This article integrated above three methods,obtained have better electrochromic properties than homopolymers by copolymerization of aniline derivatives o-aminophenol?OAP?with o-toluidine?OT?or o-anisidine?OA?,respectively.We discussed the influence of different proportions of the copolymerization system on the electrochromic properties of the resulting copolymer films.In addition,based on the above copolymerization system,anionic surfactant sodium dodecyl sulfate?SDS?was used as a dopant,the resulting polymer films with more orderly structure and longer of the polymer chain,and better electrochromic properties.In addition,the copolymerization behavior of the nitrogen-containing heteroaromatic molecule Indole and the aniline derivatives OA was preliminarily studied.The electrochemical and electrochromic behavior of the polymer films were studied,and the obtained copolymer films with wider electrochromic range.According to DFT computational and experimental study of indole preliminarily confirmed that the polymerization site of indole was 2,3-position.The main investigations of this work are as follows.?1?Study on electrochemical copolymerization of o-aminophenol with o-toluidine and the properties of their resulting copolymersHomopolymers and copolymers were synthesized electrochemically with 0.1 M OT and different OAP concentrations deposited on ITO-coated glass in 0.5M H₂SO₄solution.The obtained homopolymers and copolymers were characterized with in situ UV-vis spectroelectrochemistry,scanning electron microscopy?SEM?,MALDI-TOF mass spectrometry,FT-IR spectroscopy,cyclic voltammetry and double step chronoamperometry methods.In situ UV-Vis spectroelectrochemical method was used to trace the electrochemical homopolymerization and copolymerization processes of OAP and 0.1M OT deposited on ITO-coated glass at a potential of 1.1V.Mechanism of copolymerization of OAP and OT was proposed.The experimental results may demonstrate that new copolymers could be formed with OT and OAP units and the feed concentration of OAP strongly influence on the properties of the copolymer.The copolymers exhibited better electrochromic properties than homopolymers.But,addition of 0.5mM OAP concentration in the comonomer feed,copolymer CTP0,which have better electrochromic properties than those of other homo-/copolymers.?2?Study on electrochemical copolymerization of o-aminophenol with o-anisidine and the properties of their resulting copolymersIn situ UV-vis spectroelectrochemistry method was used to trace the electrochemical homo-/copolymerization of different OAP concentrations and 50mM OA deposited on ITO-coated glass in 0.5M H₂SO₄ solution at 1.1V.The different concentrations of OAP copolymerized with OA or OT was probably due to the electron donating ability of the methoxy group was stronger than the methyl group.The obtained polymers were characterized with SEM,MALDI-TOF mass spectrometry,FT-IRspectroscopy,cyclicvoltammetryanddoublestep chronoamperometry methods.The experimental results may demonstrate that new copolymers could be formed with OA and OAP units.The copolymers exhibited widerelectrochromicrangeandbetterelectrochromicperformancethan homopolymers.And,addition of 0.5m M OAP concentration in the comonomer feed,copolymer CAP0,which have better electrochromic properties than those of other homo-/copolymers.?3?Study on electrochemical copolymerization of o-aminophenol with o-toluidine or o-anisidine in the presence of surfactants and the properties of their resulting copolymers0.5mM anionic surfactant SDS was added to the copolymerization system with different concentrations of OAP and OT or OA,respectively.The obtained polymers were characterized with in situ UV-vis spectroelectrochemistry,SEM,MALDI-TOF mass spectrometry methods.The role of SDS in the polymerization process was studied.The results showed that in the presence of SDS,the polymerization rate is significantly faster,the structure of the resulting polymer is more stable and orderly,the molecular weight is larger,and the electrochromic properties is better.It may be because the micellar medium formed by the SDS molecules has a hydrophobic micro effect,which will increase the local concentration of the monomer and play a role of solubilization.In addition,the SDS anion can be fixed on the polymer backbone to make the polymer chain more stable.?4?Study on electrochemical copolymerization of Indole with o-anisidine and the properties of their resulting copolymersIn situ UV-vis spectroelectrochemistry method was used to trace the electrochemical homo-/copolymerization of different Indole concentrations and50mM OA deposited on ITO-coated glass in 0.5M H₂SO₄ solution at 1.1V.The polymerization position of Indole via the 2,3-position was preliminary verified through the combination of Gaussian 09 quantum calculations and experiments.The obtained polymers were characterized with MALDI-TOF mass spectrometry and FT-IR spectroscopy methods.The experimental results may demonstrate that new copolymers could be formed with OA and Indole units.The copolymers exhibited widerelectrochromicrangeandbetterelectrochromicperformancethan homopolymers.And,addition of 0.1mM Indole concentration in the comonomer feed,copolymer CAI1,which have better electrochromic properties than those of other homo-/copolymers.