Morphological and Structural Analysis of Polyaniline and Poly(o-anisidine) Layers Generated in a DC Glow Discharge Plasma by Using an Oblique Angle Electrode Deposition Configuration.

Bogdan Butoi,Andreea Groza,Adriana Balan,Paul Dinca,Valentin Barna

doi:10.3390/polym9120732

Abstract

This work is focused on the structural and morphological investigations of polyaniline and poly(o-anisidine) polymers generated in a direct current glow discharge plasma, in the vapors of the monomers, without a buffer gas, using an oblique angle-positioned substrate configuration. By atomic force microscopy and scanning electron microscopy we identified the formation of worm-like interlinked structures on the surface of the polyaniline layers, the layers being compact in the bulk. The poly(o-anisidine) layers are flat with no kind of structures on their surfaces. By Fourier transform infrared spectroscopy we identified the main IR bands characteristic of polyaniline and poly(o-anisidine), confirming that the polyaniline chemical structure is in the emeraldine form. The IR band from 1070 cm−1 was attributed to the emeraldine salt form of polyaniline as an indication of its doping with H+. The appearance of the IR band at 1155 cm−1 also indicates the conducting protonated of polyaniline. The X-ray diffraction revealed the formation of crystalline domains embedded in an amorphous matrix within the polyaniline layers. The interchain separation length of 3.59 Å is also an indicator of the conductive character of the polymers. The X-ray diffraction pattern of poly(o-anisidine) highlights the semi-crystalline nature of the layers. The electrical conductivities of polyaniline and poly(o-anisidine) layers and their dependence with temperature are also investigated.

Highlights

Polyaniline and poly(o-anisidine) are conducting polymers that present a well-known interest in different research areas due to their high potential applications in displays and molecular devices, smart windows, energy storage systems, and as corrosion protective layers [1].The polyaniline can be synthetized in different chemical structural forms, such as leucoemeraldine, emeraldine base, pernigraniline or emeraldine salt that present specific electrical behaviors.Leucoemeraldine is electrically insulated with no double bonds between the aromatic rings andN–H groups
In this paper we present the results on the morphological and physicochemical characterization of the polyaniline (PANI) and poly(o-anisidine) (POA) layers generated in a DC glow discharge plasma
By increasing the monomer injection temperature up to 50 ◦ C and the substrate inclination angle to the anode up to 90◦, (Figure 2c–e), it can be observed that worm like interlinked structures begin to form

Summary

Introduction

Polyaniline and poly(o-anisidine) are conducting polymers that present a well-known interest in different research areas due to their high potential applications in displays and molecular devices, smart windows, energy storage systems, and as corrosion protective layers [1].The polyaniline can be synthetized in different chemical structural forms, such as leucoemeraldine, emeraldine base, pernigraniline or emeraldine salt that present specific electrical behaviors.Leucoemeraldine is electrically insulated with no double bonds between the aromatic rings andN–H groups. Polyaniline and poly(o-anisidine) are conducting polymers that present a well-known interest in different research areas due to their high potential applications in displays and molecular devices, smart windows, energy storage systems, and as corrosion protective layers [1]. The polyaniline can be synthetized in different chemical structural forms, such as leucoemeraldine, emeraldine base, pernigraniline or emeraldine salt that present specific electrical behaviors. Leucoemeraldine is electrically insulated with no double bonds between the aromatic rings and. Emeraldine base has few N–H groups in its main chain being partially oxidized and insulated. A fully-oxidized compound is the pernigraniline having no N–H groups in its main chain structure and, no conducting properties. Protonation of the emeraldine base to emeraldine salt

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Results

Conclusion