@PHDTHESIS{ 2022:1021299922,
 	title = {Head-to-Tail and Head-to-Head Molecular Chains of Poly(p-anisidine):  Combined Experimental and Theoretical Evaluation},
 	year = {2022},
 	url = "https://tede.ufam.edu.br/handle/tede/9413",
 	abstract = "Poly(p–anisidine) (PPA) is a polyaniline presenting a methoxy (–OCH3) group at the para
 position of the phenyl ring. Considering the important role of conjugated polymers in novel
 technological applications, a systematic, combined experimental and theoretical investigation
 had been performed to get more insight into the crystallization process of PPA. Conventional
 oxidative polymerization of p–anisidine monomer was based on a Central Composite Rotational
 Design (CCRD). The effect of the concentration of the monomer, ammonium persulfate (APS)
 and HCl on the percentage of crystallinity was considered. Several experimental techniques
 such as X-Ray diffraction (XRD), Scanning Electron Microscopy (SEM), Multifractal Analysis,
 Nuclear Magnetic Resonance (13C NMR), Fourier-transform Infrared Spectroscopy (FTIR),
 Complex Impedance Spectroscopy analysis besides Density Functional Theory (DFT) were
 employed to perform a systematic investigation of PPA. The experimental treatments resulted
 in different crystal structures with the percentage of crystallinity ranging from (29.2 ± 0.6) %
 (PPA1HT) to (55.1 ± 0.2) % (PPA16HT-HH). The XRD patterns of PPA1HT and PPA16HT-HH were
 clearly correlated, but more defined in PPA1HT. A broad hallo in the PPA16HT-HH pattern from 2θ
 = 10.0° – 30.0° suggested reduced crystallinity. Basically, two types of morphology were
 observed in both samples: needles and globular particles. SEM images suggested that the
 needles morphology might be related to the crystalline contribution. Multifractal analysis
 showed that the PPA surface became more irregular and complex when the crystallinity was
 reduced. The proposed molecular structures of PPA were supported by the high-resolution 13C
 NMR results, allowing to access the percentage of head–to–tail (HT) and head–to–head (HH)
 molecular structures: PPA1HT was fully (100%) constituted of HT polymer chains (PPAHT),
 while PPA16 was formed predominantly by HT molecular structure [(62.0 ± 0.5) %; PPAHT-HH).
 Comparing calculated and experimental FTIR spectra, the most pronounced changes were
 observed in ν(C–H), ν(N–H), ν(C–O) and ν(C–N–C) due to the influence of counter ions, as well
 as by the different mechanisms of polymerization. Finally, a significant difference in electrical
 conductivity values was observed in the range of 1.00 x 10-9 S.cm-1 and 3.90 x 10-14 S.cm-1,
 respectively, for PPA1HT and PPA16HT-HH.",
 	publisher = {Universidade Federal do Amazonas},
 	scholl = {Programa de Pós-graduação em Física},
 	note = {Instituto de Ciências Exatas}
}