Synthesis and characterization of poly(p-aminoazobenzene) nanosheet as a new derivative of polyaniline containing azo groups under green chemistry condition and its high efficiency in solar cell
Graphical abstract
Introduction
Polymers that contain azobenzene groups have various applications including the optical devices to convert the wavelength of light, data detection, in computational optical techniques, and many other applications in other fields [[1], [2], [3], [4], [5], [6]]. The p-aminoazobenzene (PAAB)2 is one of the favorite amino aromatic compounds that can be polymerized by different methods such as electrochemical and chemical methods. However, there are few papers on the synthesis of poly(p-aminoazobenzene) (PPAAB). Abd El-Rahman et al. demonstrated that the oxidative electropolymerization of PAAB on glassy carbon in acetonitrile containing pyridine and NaClO4 as a supporting electrolyte result in porous and fibrous polymer films [7]. Jackowska et al. prepared PPAAB films on disc electrodes or Au wire (0.2 cm2 or 0.1 geometric area) from acetonitrile solution containing pyridine, LiClO4 and PAAB [8]. In 2009, Durgaryan et al. synthesized PPAAB via chemical oxidation polymerization in boiling ethanol and under the action of iodine at the equimolar reagent ratio. They also studied the dependence of the yield and the molecular mass of polymer on the acidity of the PAAB polymerization medium in the presence of potassium hydrocarbonate and calcium carbonate [9]. Huang et al. have synthesized PPAAB using ammonium persulfate at below 5 °C in HCl, and investigated the photoisomerization process of the compound by UV–vis spectrum [10]. In our best knowledge, another report on the synthesis of this homopolymer has not been provided by chemical methods, and just few primary studies have been carried out about this polymer and its various methods of synthesis. In this paper, we have synthesized the PPAAB at room temperature, in water as a solvent and without the presence of an acid, for the first time, which is the quite environmentally friendly procedure and a green chemistry method. In addition, the application of this method of synthesis resulted in nanosheet morphology using no template while such a morphology for this polymer has not ever been reported. Also, azobenzene is a famous chromophore that is sensitive to light and cis-trans isomerization can easily occur by photoisomerization. In order to meet the demands of changing the role of polymer materials from structural to functional ones, the current trend is to employ the azobenzene moiety as a “trigger’’ to induce morphological changes which can be light-driven [[11], [12], [13], [14], [15], [16], [17], [18]]. Hence, if azo chromophores are introduced into a polymer, the functional groups would endow the polymer with not only electroactivity but also photoactivity.
This kind of polymers is attractive for scientist since the property of photoactivity in polymers bearing azobenzene group leads to potential application in photonics [[19], [20], [21], [22], [23], [24], [25], [26], [27], [28], [29]]. In this paper, UV–vis spectroscopy was employed for monitoring the process of photoisomerization in the synthesized polymer and the photoisomerization behavior was observed.
Also, the azo polymers can be applied in drug delivery [30], as thin film transistors, sensors, optoelectronic devices such as optical storage [31], polymer light emitting diodes and solar cells [32]. Recently, among the applications mentioned above, solar cells are highly regarded by scientists. The compounds containing the azo groups have been widely used in the dye-sensitive solar cell [[33], [34], [35], [36], [37], [38]], but there is not any research done on the use of these polymers in single layer polymer solar cell. However, only the existing report is by Meena et al. that obtained a power conversion efficiency (PCE) of 0.53% by new polymers containing azo linkage as a part of the main chain in multilayers cell (blend with C71-PCBM as a photoactive layer in ITO/PEDOT:PSS/azo linked polymer:C71-PCBM/Al) [39]. Indeed, azo linked polymers can potentially give rise to strongly light absorbing chromophores which are suitable for use in polymer solar cells (PSCs) [39].
Due to the structure, morphology, and conductivity of the synthesized polymer, it possesses the potential to be used in various areas such as solar cells and sensors. So, the polymer solar cell was fabricated by PPAAB with FTO/TiO2/PPAAB/Al structure and the efficiency of PPAAB on the solar cell performance was investigated. Thus, in this paper, along with the synthesis and characterization of this new polymer, a report is presented on its high efficiency in the solar cell.
Section snippets
Materials and equipment
All chemical reagents were prepared from Fluka, Aldrich, and Merck and used as received except for aniline, which was distilled to purify.
FT-IR spectra of the samples were taken by a JASCO spectrophotometer between 450 and 4000 cm−1 from KBr pellets. The Shimadzu spectrophotometer was used to record the Ultraviolet-visible (UV–vis) spectra between 200 and 800 nm by preparing a dilute solution of product (0.02 g L−1) in N-methylpyrrolidone (NMP) during irradiation at about 380 nm every 30 min
FT-IR spectra
The FT-IR spectra of PAAB and PPAAB are shown in Fig. 1. In both spectra, the absorption at 3200-3500 cm−1 is assigned to the stretching of the NH bond. However, the FT-IR spectrum of the monomer shows three peaks while the PPAAB shows a single broad peak because of the stretching of the NH bond similar to the data previously reported for polyaniline [[45], [46], [47], [48], [49], [50], [51]]. The peaks at 1580-1620 cm−1 in PAAB spectra are assigned to stretching of CC or bending of the NH
Conclusions
In summary, we have prepared poly(p-aminoazobenzene) (PPAAB) a new derivative of polyaniline containing azo groups by polymerization of diazoaminobenzene as the monomer in green condition. The polymer exhibited good thermal stability, conductivity in the range of semi-conductive compounds and nanosheet morphology. Moreover, it exhibited photoinduced isomerization behavior arisen from azobenzene groups. It seems that the isomerization properties depend on the structure and morphology of the
Acknowledgments
The authors acknowledge the financial support of a grant from the Graduate Council of University of Sistan and Baluchestan and National Nanotechnology Initiative funded by the Iranian government.
References (96)
- et al.
Physics and technology of optical storage in polymer thin films
Synth. Met.
(2001) - et al.
Organic light-emitting diodes with AZO films as electrodes
Synth. Met.
(2000) - et al.
Length-scale dependence of surface relief gratings in azobenzene side-chain polymers
Synth. Met.
(2001) - et al.
Oxidative polymerization of p-aminoazobenzene in acetonitrile: a new electroactive polymer
J. Electroanal. Chem.
(1991) - et al.
The mechanism of electrodeposition and molecular structure of poly (p-aminoazobenzene)
Synth. Met.
(1995) - et al.
Amphiphilic azo polymers: molecular engineering, self-assembly and photoresponsive properties
Prog. Polym. Sci.
(2013) - et al.
Azo-group-containing polymers for use in communications technologies
Prog. Polym. Sci.
(1997) - et al.
Azo polymers for reversible optical storage: 13. Photoorientation of rigid side groups containing two azo bonds
Polymer
(1997) - et al.
Azo polymers for colon-specific drug delivery
Int. J. Pharm.
(1992) - et al.
Low band gap dyes based on 2-styryl-5-phenylazo-pyrrole: synthesis and application for efficient dye-sensitized solar cells
J. Power Sources
(2011)
Efficient bulk heterojunction solar cells based on low band gap bisazo dyes containing anthracene and/or pyrrole units
Sol. Energy Mater. Sol. Cells
The influence of materials work function on the open circuit voltage of plastic solar cells
Thin Solid Films
Electrochemical polymerization of aromatic amines: IR, XPS and PMT study of thin film formation on a Pt electrode, J. Electroanal
Chem. Interfacial Electrochem.
IR absorption spectroscopic identification of electroactive and electroinactive polyaniline films prepared by the electrochemical polymerization of aniline
J. Electroanal. Chem. (Lausanne)
The genesis of polyaniline nanotubes
Polymer
FTIR spectroscopic and conductivity study of the thermal degradation of polyaniline films
Polym. Degrad. Stab.
The carbonization of granular polyaniline to produce nitrogen-containing carbon
Synth. Met.
The concept of secondary doping as applied to polyaniline
Synth. Met.
Complete doping in solid-state by silica-supported perchloric acid as dopant solid acid: synthesis and characterization of the novel chiral composite of poly [(±)-2-(sec-butyl) aniline]
J. Solid State Chem.
Measurement of the lowest unoccupied molecular orbital energies of molecular organic semiconductors
Org. Electron.
The molecular weight of polyaniline by light scattering and gel permeation chromatography
Synth. Met.
Peroxidase-mediated synthesis of water-soluble fully sulfonated polyaniline
Synth. Met.
Self-assembled aggregates of amphiphilic perylene diimide–based semiconductor molecules: effect of morphology on conductivity
J. Colloid Interface Sci.
Structural, morphological and sensing properties of layered polyaniline nanosheets towards hazardous phenol chemical
Talanta
Facile preparation of polyaniline nanosheets via chemical oxidative polymerization in saturated NaCl aqueous solution for supercapacitors
Int. J. Elec. Sci.
Theories of polyaniline nanostructure self-assembly: towards an expanded, comprehensive Multi-Layer Theory (MLT)
Prog. Polym. Sci.
Voltammetric and in situ FTIRS study of the electrochemical oxidation of aniline from aqueous solutions buffered at pH 5
J. Electroanal. Chem. (Lausanne)
Infrared spectra of soluble polyaniline
Synth. Met.
Polyaniline/TiO2 solar cells
Synth. Met.
Synthesis and application in solar cell of poly (3-octylthiophene)/titania nanotubes composite
Org. Electron.
Photovoltaic study of chemically engineered nano-titanium oxide loaded polyaniline matrix of architecture ITO/titanium oxide-polyaniline/aluminum
Synth. Met.
Efficient benzodithiophene and thienopyrroledione containing random polymers as components for organic solar cells
Polymer
Graphene-modified polyaniline as the catalyst material for the counter electrode of a dye-sensitized solar cell
J. Power. Source
Temperature variation of the photoinduced birefringence of an azo dye doped polymer
Polym. Eng. Sci.
Thermally assisted recording of holographic gratings in semicrystalline azobenzene-containing polymers
Appl. Opt.
Organic glasses: a new class of photorefractive materials
Science
Oxidative polymerization of 4-aminoazobenzene under the action of iodine
Russ. J. Gen. Chem.
Electrochemical studies on photoactively conducting poly (4-aminoazobenzene) coating: electrochromic property
Adv. Mater. Res.
Control over molecular motion using the cis-trans photoisomerization of the azo group
Beilstein J. Org. Chem.
Stimuli-responsive polymers: fundamental considerations and applications
Macromol. Res.
Shape‐shifting azo dye polymers: towards sunlight‐ molecular devices
Macromol. Rapid Commun.
Photodeformable polymer gels and crosslinked liquid-crystalline polymers
Soft Matter
Recent developments in aromatic azo polymers research
Chem. Mater.
Photoresponsive polymers
Light-Associated Reactions of Synthetic Polymers
Photochemistry of azobenzene-containing polymers
Chem. Rev.
Photoresponsive polymers. 2. Reversible solution viscosity change of polyamides having azobenzene residues in the main chain
Macromolecules
Chiral methacrylic polymers containing permanent dipole azobenzene chromophores. 13C NMR spectra and photochromic properties
Macromol. Chem. Phys.
Synthesis of photoresponsive organic− inorganic polymer hybrids from azobenzene-modified poly (2-methyl-2-oxazoline)
Macromolecules
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Poly(p-aminoazobenzene)