Polymeric Dye Research Articles

Self-Sensitized Carbon Nitride Microspheres for Long-Lasting Visible-Light-Driven Hydrogen Generation.

A new type of metal-free photocatalyst is reported having a microsphere core of oxygen-containing carbon nitride and self-sensitized surfaces by covalently linked polymeric triazine dyes. These self-sensitized carbon nitride microspheres exhibit high visible-light activities in photocatalytic H2 generation with excellent stability for more than 100 h reaction. Comparing to the traditional g-C3 N4 with activities terminated at 450 nm, the polymeric triazine dyes on the carbon nitride microsphere surface allow for effective wide-range visible-light harvesting and extend the H2 generation activities up to 600 nm. It is believed that this new type of highly stable self-sensitized metal-free structure opens a new direction of future development of low-cost photocatalysts for efficient and long-term solar fuels production.

Voltammetric detection of Cu2+ using poly(azure A) modified glassy carbon electrode based on mimic peroxidase behavior of copper

Poly(azure A) (PAA) modified glassy carbon electrode was prepared by cyclic voltammetry and it was characterized by scanning electron microscopy and electrochemical analysis. The organic dye polymer on an electrode surface exhibited a limited catalytic ability for the reduction of H2O2. As a mimic peroxidase, copper ion induced the decomposition of H2O2 due to Fenton-type reaction. The generated hydroxyl radical could effectively oxidize PAA and lead to the great increase of the reduction current of the dye polymer in the cyclic voltammetric scan. An indirect and sensitive method for the trace Cu2+ detection was developed. Under the optimized conditions, the fabricated sensor displayed a linear response in the Cu2+ concentration range from 50nM to 10μM and that from 10μM to 100μM with a detection limit of 8.4nM estimated at a signal-to-noise ratio of 3. The interference experiments show that some common metal cations had little influence on the electrochemical measurement. The proposed method was successfully applied to the determination of copper ions in water samples by standard addition method and the recovery values were found to vary from 95.4% to 108%.

Solvation effects on spectral and photophysical properties of phenalenone dyes in polyurethane polymers

Spectral and photophysical properties of several phenalenone dyes were investigated in the dependence on a type of the polyurethane polymer matrix. The increase in polarity of the solid-state medium was shown to shift absorption and luminescence spectra to the low energy side. Effects of the substituents in the phenalenone chromophore on a Stokes shift value were studied. Photophysical properties of phenalenones were found out to be significantly dependent on the polymerization method of polymer matrices. Considerable growth in photostability of organic dyes was observed when the dyes were bonded covalently with a polymer chain.

Synthesis and characterization of colored EUDRAGIT® as enteric coating material

The synthesis of novel polymeric dyes by directly attaching toluidine blue O and MPPD via EDC and CDI coupling is described for polymers with enteric properties [poly(methacrylic acid-co-ethyl acrylate)]. The polymeric dyes are analyzed by SEC and UV/Vis measurements as well as investigated regarding their dissolution and permeation characteristics. Almost no changes between the modified and nonmodified polymer could be observed by conventional drug studies and a self-established method for dissolution rates. Also no influence on the film formation properties was observed by SEM measurements. In vitro toxicity studies showed no increase of toxicity compared to the non modified polymer. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016, 54, 2386–2393

Electrochemical detection of nitrite on poly(pyronin Y)/graphene nanocomposites modified ITO substrate

The present study reports on an easy preparation of poly(pyronin Y)/graphene (poly(PyY)/graphene) nanocomposites thin films on indium tin oxide coated glass substrates (ITO). The thin films of poly(PyY)/graphene nanocomposites are prepared by a novel method consisting of three steps; (i) preparation of graphene oxide (GO) thin films on ITO by spin-coating method, (ii) self-assembly of PyY molecules from aqueous solution onto the GO thin film, (iii) surface-confined electropolymerization (SCEP) of the adsorbed PyY molecules on the GO thin film. The as-prepared poly(PyY)/graphene nanocomposites thin films are characterized by using electroanalytical and spectroscopic techniques. Afterwards, the graphene-based polymeric dye thin film on ITO is used as an electrode in an electrochemical cell. Its performance is tested for electrochemical detection of nitrite. Under optimized conditions, the electrocatalytical effect of the nanocomposites thin film through electrochemical oxidation of nitrite is better than that of GO coated ITO.

Synthesis and characterization of stable main-chain polymeric metal complex dyes based on phenothiazine or carbazole units for dye-sensitized solar cells

Novel polymeric metal complex dyes with phenothiazine or carbazole derivative as donor and Zn(II) or Co(II) complexes as acceptors were synthesized for dye-sensitized solar cells. The dyes based on carbazole derivatives exhibited wider absorption spectra, and after replacement of the Co(II) coordinated ion with Zn(II), a bathochromic shift in the absorption spectrum was observed. The device sensitized by P3 exhibited the best photocurrent conversion efficiency (2.06%). Moreover, these dyes all exhibited excellent chemical and thermal stability.

Thermoresponsive Polymer and Fluorescent Dye Hybrids for Tunable Multicolor Emission.

Fully reversible emission color change is achieved by blending a thermoresponsive polymer with dye hybrids. The emission color can be tuned by changing the mixing ratio of each polymer-dye hybrid.

Cleaner production applied to urea-free printing of cotton fabrics using polyethylene glycol polymers as alternative additives

Urea plays an important role in the cotton fabric printing process as a dye solubilization and disaggregating agent. However, the using of urea can cause a series of environmental problems because of the high ammonia–nitrogen content in the printing effluent. Polyethylene glycol is a nonionic soluble polymer without nitrogen element. The printability of cotton fabric using polyethylene glycol with different molecular weight, PEG-400, PEG-800, PEG-1000, PEG-2000, as additives instead of urea in the reactive dye print paste was investigated. The intermolecular interaction between the polymer and reactive dye were discussed by the absorbance spectra. The color yield, dye fixation, building up, colorimetric data and fastness of the printed fabrics with polyethylene glycols as additives were evaluated. The results showed that PEG-400, PEG-800, PEG-1000 had better effect on increasing the solubility of the reactive dye. PEG-400 as an additive instead of urea could be applied in urea-free printing for cotton fabric. The printed fabrics can obtain high color yield and fixation, and good fastness properties. PEG-400 and PEG-800 instead of urea have potential application in the cleaner production of the cotton fabric printing. Nowadays, it is urgent to reduce the environmental impacts of textile wet processing.

Synthesis of blocked waterborne polyurethane polymeric dyes with tailored molecular weight: thermal, rheological and printing properties

The structure–property relationship of the polymeric dyes with tailored molecular weight including rheological, thermal, and printing properties are mainly investigated.

Selective uptake of organic dyes in a silver-based coordination polymer

Coordination polymer [Ag4(dpe)4]·(butca)·13H2O was used to efficiently conduct selective uptake of organic dyes and achieve the rapid separation of a MO and MB mixture.

Chitosan Modified by Polymeric Reactive Dyes Containing Quanternary Ammonium Groups as a Novel Anion Exchange Membrane for Alkaline Fuel Cells

Chitosan Modified by Polymeric Reactive Dyes Containing Quanternary Ammonium Groups as a Novel Anion Exchange Membrane for Alkaline Fuel Cells

Comparison of metal free polymer–dye conjugation strategies in protic solvents

Introducing the TAD chemistry to the field of polymer–dye conjugations to broaden the toolbox of metal- and additive-free linking methods.

Thienyl Difluoroboron β-Diketonates in Solution and Polylactide Media.

Difluoroboron β-diketonates have impressive optical properties in both solution and the solid state. In particular, both fluorescence and room-temperature phosphorescence are present when the dyes are confined to a rigid matrix, such as poly(lactic acid) (PLA). To expand current knowledge and color range capabilities of this unique type of multi-emitting chromophore, a series of thienyl-substituted BF2bdk complexes have been synthesized. The photophysical properties were investigated in methylene chloride solution and in the solid state as dye/PLA blends. By varying donor ability, i.e. methyl, phenyl, methoxyl, and thienyl substituents, and by changing the dye loading in the PLA media (0.1-10% dye loading) red-shifted emission was achieved, important for biological imaging applications. In dilute CH2Cl2 solution, complexes exhibited absorptions ranging from 350 - 420 nm, solid-state fluorescence in PLA ranging from 390 - 500 nm, and oxygen sensitive phosphorescence ranging from 540 - 585 nm in PLA blends. Promising candidates as dye/PLA blends serve as models for dyepolymer conjugates for application as biological oxygen nanoprobes.

Synthesis and properties of tetra-(4-tert-butyl-5-nitro)phthalocyanines

The interaction of 4-tert-butyl-5-nitrophthalonitrile with a series of metal acetates has yielded the corresponding metal phthalocyaninates. The treatment of magnesium tetra(4-tert-butyl-5-nitro)phthalocyaninate with hydrochloric acid has afforded tetra(4-tert-butyl-5-nitro)phthalocyanine. Spectral properties of the prepared macrocycles have been studied. The nature of the organic solvent and the complex forming metal marginally affect the position of the Q band in the electron absorption spectra of the studied compounds. It has been demonstrated that the prepared phthalocyanines can dye polymer materials and are catalytically active towards oxidation of a model sulfur-containing compound.

Synthesis and photovoltaic performance of novel polymeric metal complex sensitizer with benzodithiophene or carbazole derivative as donor in dye-sensitized solar cell

Four donor-acceptor (D-A) types of novel conjugated polymeric metal complex dyes (P1–P4) with Zn (II) or Cd (II) complexes as the electron acceptors and benzodithiophene or carbazole derivative as the electron donors were designed and prepared, as promising sensitizers for dye-sensitized solar cells (DSSCs). Diaminomaleonitrile acted as ancillary ligand. The structures of the polymers were confirmed, and their thermal, optical, electrochemical, and photovoltaic properties were investigated. All conjugated polymers exhibit good thermal stability with onset decomposition temperatures with 5% weight loss over 315 °C, broad absorption with the onset of absorption at 588 nm in the visible region, and relatively lower HOMO energy levels from −5.54 to −5.71 eV. The DSSC device based on P2 which containing Cd(II) as coordination metal ion and benzodithiophene derivative as donor exhibited the highest power conversion efficiency of 2.18% under the AM 1.5 G (100 mW cm−2) sunlight illumination with an open-circuit voltage of Voc = 0.68 V, a short current density of Jsc = 4.85 mA cm−2, and a fill factor of FF = 66.2%, respectively. Therefore, these results provide a new way to design dye sensitizers for DSSCs.

Vesicular Nanostructure Formation by Self-Assembly of Anisotropic Penta-phenol-Substituted Fullerene in Water.

A study on self-assembly of anisotropically substituted penta-aryl fullerenes in water has been reported. The penta-phenol-substituted amphiphilic fullerene derivative [C60Ph5(OH)5] exhibited self-assembled vesicular nanostructures in water under the experimental conditions. The size of the vesicles was observed to depend upon the kinetics of self-assembly and could be varied from ∼300 to ∼70 nm. Our mechanistic study indicated that the self-assembly of C60Ph5(OH)5 is driven by extensive intermolecular as well as water-mediated hydrogen bonding along with fullerene-fullerene hydrophobic interaction in water. The cumulative effect of these interactions is responsible for the stability of vesicular structures even on the removal of solvent. The substitution of phenol with anisole resulted in different packing and interaction of the fullerene derivative, as indicated in the molecular dynamics studies, thus resulting in different self-assembled nanostructures. The hollow vesicles were further encapsulated with a hydrophobic conjugated polymer and water-soluble dye as guest molecules. Such confinement of π-conjugated polymers in fullerene has significance in bulk heterojunction devices for efficient exciton diffusion.

Hybrids formed between polyvinylpyrrolidone and an A3B porphyrin dye: behaviour in aqueous solutions and chemical response to CO2 presence

AbstractThis study reports the incorporation of an A3B mixed functionalized porphyrin, namely 5‐(4‐pyridyl)‐10,15,20‐tris(4‐phenoxyphenyl)porphyrin (PyTPOPP), into polyvinylpyrrolidone (PVP), a biocompatible polymer, with the purpose of preparing water‐soluble polymer–dye (PVP‐PyTPOPP) hybrids. The hybrids were obtained in two variants, differing by molar ratios, and their molecular characteristics and aggregation in dilute aqueous solutions were investigated using static and dynamic light scattering and analytical ultracentrifugation methods. The hybrids were characterized using 1H NMR, UV‐visible and Fourier transform infrared spectroscopies, atomic force microscopy (AFM) and transmission electron microscopy (TEM). A study of the influence of acidic media on the electronic spectra was carried out, evidencing the similar behaviour of the hybrids and the bare porphyrin. The interaction between CO2 and the PVP‐PyTPOPP hybrids was studied using UV‐visible spectroscopy and a continuous hypochromic response of the Soret band in direct relationship with increased CO2 concentration was noticed. Based on the UV‐visible spectral differences between the PVP‐PyTPOPP hybrids in acidic media and during CO2 exposure, we can presume that the mechanism of CO2 detection is not based on pH changes of the solution but on chemisorption phenomena which modify the surface properties as confirmed by TEM and AFM. These porphyrin–PVP hybrid nanomaterials offer the possibility for achieving optical and colorimetric sensors for monitoring CO2 and are also promising for biomedical applications. © 2015 Society of Chemical Industry

Large deformations and fluorescence response of mechanochromic polyurethane sensors

A mechanochromic composite comprises an excimer-forming fluorescent dye dispersed in a compatible polymeric host. Upon large deformation of the polymeric structure, a shift of the fluorescence emission from the excimer band to the monomer band is observed, due to reorganization of dye aggregates. Mechanochromic elastomers can be tailored to produce a reversible optical response during cyclic deformation. Here, we study the optomechanical properties of mechanochromic elastomers undergoing large uniaxial and biaxial deformations. Through detailed experiments and constitutive modeling, we relate the optical response of the mechanochromic elastomer to the deformation of the polymer network. We confirm that optical response is largely reversible and is modulated by the initial dye concentration in the polymer. We adapt the classical Arruda–Boyce model to elucidate microstructural modifications of the polymer–dye blend. We propose a constitutive hypothesis for the optical behavior of the material, which relates variations of the emission spectrum to surface stretching. This knowledge can aid in the design of strain and stress sensors for applications in mechanics, biomechanics, and life sciences.

Non-enzymatic detection of hydrogen peroxide based on Fenton-type reaction on poly(azure A)-chitosan/Cu modified electrode

In this work, a sensitive electrochemical method for the detection of H2O2 was proposed based on Fenton-type reaction on the electrode surface. A glassy carbon electrode modified with poly(azure A) (PAA), chitosan (CS) and copper ions, displaying a good electrochemical activity, was fabricated by cyclic voltammetry and the adsorption of Cu2+. Scanning electron microscopy-Energy dispersive spectroscopy analysis, infrared and Raman spectral characterization and XPS measurement showed the stable complexation of Cu2+ with the PAA-CS film. Hydroxyl radicals derived from the Fenton-type reaction between Cu2+ and H2O2 could effectively oxidize poly(azure A), leading to the great reduction-current change of the dye polymer in the electrode process. Under the optimized conditions, the fabricated electrode displayed a linear response in the H2O2 concentration range from 0.002 to 0.5mM and that from 2.56 to 25.0mM with a detection limit of 0.7μM estimated at a signal-to-noise ratio of 3. The good analytical performance including low detection limit, fast response time, low cost, good anti-interference performance, satisfying stability, acceptable repeatability and reliable reproducibility were found from the proposed amperometric sensor, suggesting that the current work could provide a feasible approach for the non-enzymatic H2O2 detection.

Novel dye sensitizers of polymeric metal complexes with benzodithiophene derivatives as donor and their photovoltaic performance

Four novel donor–acceptor (D–A) type conjugated polymeric metal complexes (P1–P4) bearing benzodithiophene or carbazole derivative as donors were synthesized, characterized and applied as dye sensitizers in dye-sensitized solar cells (DSSCs). Salicylaldehyde derivative complexes acted as electron acceptors, Zn(II) or Cd(II) was chosen as the coordinated metal ion, and diaminomaleonitrile was ancillary ligand in these structures. The thermal, photophysical, electrochemical and photovoltaic properties of these polymeric metal complexes were investigated by FT-IR, GPC, TGA, DSC, UV-Vis absorption spectroscopy, elemental analysis, cyclic voltammetry (CV), J–V curves and IPCE plots. These polymer dyes exhibit good thermal stability for their application in DSSCs. The DSSC device based on P2 which contains benzodithiophene derivative as donor and Cd(II) as coordination ion, exhibited the highest power conversion efficiency of 2.43% (Jsc=4.95mA/cm2, Voc=0.71V, FF=69.3%) under AM 1.5G solar irradiation. It indicates a new way to design dye sensitizers for DSSCs.