Effect of Oxidants on Properties of Electroactive Ultrathin Polyazulene Films Synthesized by Vapor Phase Polymerization at Atmospheric Pressure

A non-benzenoid aromatic hydrocarbon azulene, naturally found in plants and mushrooms, is known for its derivatives applications in medicines. However, the processability of its chemically synthesized high-capacitance polymer is constrained by the sparingly soluble nature of its polymeric form. Oxidative chemical synthesis on a desirable substrate overcomes this difficulty. In this report, polyazulene (PAz) thin films are synthesized by vapor phase polymerization at atmospheric pressure using oxidants, such as CuCl2, CuBr2, FeCl3, and FeTOS. The effect of oxidants on morphologies of PAz films is studied using atomic force microscopy and microscope imaging. Each oxidant produced distinct microstructures in the films. The films synthesized using Cu(II) salts showed organized and knitted structures, whereas Fe(III) salts formed casted sheet-like disordered arrangements. The films synthesized using CuCl2 created uniform porous film assemblies. The pre-peak formations and their splitting observed in the cyclic voltammograms revealed phase segregations in the films. Oxidant-dependent structural and chemical differences such as charge carrier formation, doping levels, and polymer chain length in the PAz films are studied by using UV-Vis and FTIR spectroscopy. The results indicated that 240 and 180 mM are the optimum concentration of CuCl2 to produce high capacitance and well-organized single-and triple-layered PAz films, respectively.</p

Highly controllable ambient atmosphere spray deposition of water dispersible poly(benzimidazobenzophenanthroline) films

Thin films of water dispersible poly(ethylene oxide) (PEO) functionalized poly(benzimidazobenzophenanthroline) (BBL) polymers have been prepared by a pulse spray technique on a spinning substrate in ambient atmosphere. The deposition method is advantageous for generating ultra-thin films of nanometer thicknesses. A single spray pulse was found in a reproducible manner to generate a layer of ca. 2 nm thickness. The PEO-chain length in the BBL functionalization had an essential influence on the building mechanism of the films. The polymers functionalized by short PEO chains induced the formation of very smooth films while longer PEO chains induced rough films and notable nanostructuration. The BBL-PEO film deposited using spray pulse deposition was found to be electro- and photoactive. The electron transfer processes observed are slightly different from earlier reported results for similar polymers, which is probably due to the very thin film. The films exhibited photocurrent generation when transformed into conducting form.Peer reviewe

Improved long term cycling of polyazulene/reduced graphene oxide composites fabricated in a choline based ionic liquid

To improve the energy density of supercapacitors, novel electronically conducting polymers should be introduced to the research field. Polyazulene is a well-suitable candidate as it exhibits good capacitive behavior both in organic solvents as well as in various ionic liquids, but especially its long term cycling stability should be improved. Previously, enhanced properties have been obtained by combining conducting polymers with carbon nanomaterials to fabricate composites. This work presents an ionic liquid assisted electrochemical polymerization and characterization of polyazulene-reduced graphene oxide composites. The ionic liquid of our choice is choline-based liquid salt. We prepared stable dispersions of graphene oxide in this ionic liquid and performed potentiodynamic electropolymerization of azulene in the mixture. Changing the concentration of graphene oxide between 0.1 and 2 mg mL(-1) had no remarkable effect on the polymerization or electrochemical behavior of the composite materials. The composites exhibit higher capacitances compared to neat polymer films determined by cyclic voltammetry and electrochemical impedance spectroscopy. The obtained films also exhibit excellent cycling stabilities retaining over 90% of their initial capacitance with tendency towards improved cycling stability when combined with reduced graphene oxide. The successful incorporation and reduction of graphene oxide was determined by several spectroscopic techniques

Fabrication of electroactive multi-layered polyazulene thin films by atmospheric pressure-vapor phase polymerization

Thin films of polyazulene (PAz) are produced by using an optimized atmospheric pressure–vapor phase polymerization (AP-VPP) method. Method optimization is carried out by studying the effect of cell temperature, substrate temperature, polymerization time, and washing-solvent on film properties like optical bandgap, sheet resistance, surface roughness, and % transmittance (%T). Multi-layered PAz films were produced by layer-by-layer engineering. The effects of thin, electroactive multiple layers on film properties are investigated. UV–Vis, IR, and Raman analysis are utilized to understand the extended conjugation length and nature of the charge carriers. The spectroscopic data revealed the anomalous behaviour of PAz at a high level of doping. The proportion and amount of quinoid conformation is discussed. The addition of layers changes the transport of ions across the electroactive PAz films, which is studied using cyclic voltammetry at various scan rates. AFM and SEM images reveal a change in structural properties which is further correlated with a deviation of capacitance values at elevated scan rate. Comparison with earlier reported literature on electrochemically and chemically synthesized PAz is also provided. The conductivity, transparency and high capacitance show a promising application of AP-VPP PAz in various fields.</p

Exploring amide linkage in a polyviologen derivative towards simultaneous voltammetric determination of Pb(II), Cu(II) and Hg(II) ions

In this study, we report reductive electrosynthesis of a polyviologen derivative bearing amide linkage in its side chain, derived from a cyanopyridinium based monomer with amide functionality. The as grown film was characterized by cyclic voltammetry which displays a well-defined and reversible two step redox response characteristic of viologen. FTIR analysis show evidence of amide linkage and successful reduction of cyanopyridinium moieties to polyviologen. In situ multi ESR/UV-Vis-NIR spectroelectrochemistry show a single line in ESR signal, thereby suggesting polarons as the only charge carrier involved during charging/discharging process. Furthermore, a characteristic UV&ndash;Vis absorption spectra confirms viologen formation. Finally, the polyviologen film is subjected to simultaneous voltammetric determination of heavy metal ions, Pb(II), Cu(II) and Hg(II). The amide linkage in the polyviologen derivative is supposedly complexing these divalent metal ions, enabling their sensitive and simultaneous determination with low detection limits.</div

Synthesis of Layered Double Hydroxides and TiO2 Supported Metal Nanoparticles for Electrocatalysis

In the present work, solution-phase synthesis was employed to prepare two sets of catalysts with different transition metals as active sites. One set contained Au or Pd supported on TiO2 (Au-TiO2, Pd-TiO2), whereas the other set contained layered double hydroxides (NiFe-LDH and CuFe-LDH). The electrocatalytic performance of these composite materials was investigated by cyclic voltammetry (CV) using a model compound 4-nitrophenol (4-NP). Composite materials were characterized by various analytical techniques to gain insight into the catalysts active sites. The morphology and structure of the prepared samples were investigated by X-ray diffraction, attenuated total reflectance Fourier transform infrared, X-ray photoelectron spectroscopy, transmission scanning electron microscope, and field emission scanning electron microscope. Metal nanoparticles loading on TiO2 was measured by inductively coupled plasma - optical emission spectrometry. CV measurements were performed in acetonitrile solution containing 0.1 m tetrabutylammonium hexafluorophosphate (TBAPF(6)) and 1 mm 4-NP. Among all dioxides (Au-TiO2, Pd-TiO2) and hydroxides (NiFe-LDH and CuFe-LDH) studied, Pd-TiO2 shows the lowest onset potential (-0.32 V vs. Ag/AgCl) for the electrocatalytic reduction of 4-NP. This is the first comparative study of such materials for 4-NP electrocatalysis in aprotic solvent, thus demonstrating the suitability of dioxide and hydroxide based materials as electrocatalysts

J-like aggregation of a cationic polythiophene with hydrogen-bonding capabilities due to 1,4-dioxane: Solution excitation spectra and fluorescence, morphology and surface free energy of films

This work presents solution- and solid-state evidence of the enhancement of J-like aggregation of a cationic polythiophene (CPT) with isothiouronium functionalities (PT1), caused by a decrease in the polarity and hydrogen-bonding (H-bonding) capacity of the solvent, generated by using a 50:50 v/v 1,4-dioxane-water mixture (W-DI) instead of water. In solution, the presence of 1,4-dioxane (DI) seems to generate selective solvation, tuning the energy transfer within PT1 from inter-chain into intra-chain, enhancing J-like aggregation. On the other hand, during the casting process, the presence of DI directs the interaction with solid-substrates, generating an increase in the solid-state fluorescence, modifying the morphology from one similar to ballistic-aggregation (BA) into one similar to attachment limited aggregation (ALA), DI also modifies the SFE by increasing slightly its polar contribution (γSp) and decreasing the dispersive one (γSd). These results can be explained to be caused by a "coating" effect in presence of DI (as proposed before experimentally and computationally). Our results show a clear correlation between the solution- and solid-state properties of PT1 in each solvent, further validating the use of the fluorescence excitation spectra to trace J-like aggregation of water-soluble conjugated polymeric fluorophores in solution. This information could be useful for predicting and designing specific mesoscopic architectures of CPTs (and conjugated polyelectrolytes in general), which are molecules lacking of clear structure-function guidelines for designing high-performance polythiophene-based interlayer materials, especially for CPTs (and conjugated polyelectrolytes (CPEs) in general), particularly those with H-bonding capabilities. To the best of our knowledge the use of solution-state fluorescence excitation spectra to identify J-like aggregation of water-soluble conjugated polymers (CPs) has been scarcely used/discussed in literature and no correlation with solid-state properties was reported previously

Study of the sterile conk of Inonotus obliquus using 13C CPMAS NMR and FTIR spectroscopies coupled with multivariate analysis

The sterile conk caused by the infection of the basidiomycete Inonotus obliquus (Chaga) is an important source of bioactive compounds. However, its structure and biochemistry are only generally understood. Solid state 13C NMR and FTIR spectroscopy have been utilized for the first time to investigate the sterile conk with non-invasive methods. The application of multivariate data analysis techniques and spectral distance algorithm to the obtained datasets showed clear distinction between the outer and inner layers of the sterile conk. Moreover, the sterile conk bark, compared to the inner layers, was spectroscopically more similar to wood tissues. The fungal tissue was proven to be concentrated below the bark. The similarity of the sterile conk inner layers to both decayed wood and hyphae of I. obliquus was shown by the multivariate data analysis of both spectra datasets. The spectroscopic data indicated lack of lignin degradation in the heart rot, except for demethoxylation, and a slight preference for hemicellulose degradation. Therefore, the results obtained suggest that the classification of I. obliquus as preferential lignin degrader (white-rot fungus) should be revised and clarified by further studies.</p

Moniammatillisen lääkehoidon arviointimallin kehittäminen Järvenpään kotihoidossa

Apteekki- ja sairaalafarmasian erikoistumiskoulutus ProjektityöJohdanto: Tutkimuksessa kehitettiin toimintamalli Järvenpään kotihoidon asiakkaiden lääkitysten moni­ammatilliseen arviointiin. Aineisto ja menetelmät: Toimintamallin kehittämisen kannalta moniammatillisen tiimin palavereiden si­sältö oli aineistoa, joka ohjasi toimintamallin seuraavan version kehittämistä. Tutkimus tehtiin toimintatut­kimuksen menetelmin. Lääkehoidon arviointimallin kehittäminen tapahtui moniammatillisessa tiimissä, jo­hon kuuluivat kotihoidon lääkäri, kaksi sairaanhoitajaa ja proviisori. Tiimi kokoontui arvioimaan prosessin sujuvuutta ja toimintamallin kehityskohtia seitsemän kertaa seitsemän kuukauden aikana. Toimintamallia muutettiin aina arvioinnin perusteella ja seuraavat arvioinnit tehtiin uuden suunnitelman mukaan. Kehi­tystä jatkettiin sykleissä, kunnes oli saavutettu toimiva lääkehoidon arvioinninmalli. Arviointeja tehtiin yh­teensä 58 kappaletta. Tulokset: Kehitimme toimivan lääkehoidon prosessimallin kotihoidon kahteen tiimiin. Kuntoutustiimin asi­akkaat ovat kotihoidossa vain muutaman viikon, muissa tiimeissä jopa vuosia. Kuntoutustiimi eroaa tämän vuoksi toiminnaltaan niin paljon kotihoidon muista tiimeistä, että sille tehtiin oma malli. Kuntoutustiimissä proviisorin tekemät asiakkaan haastattelut olivat hyödyllisiä. Asiakas sai tietoa ja neuvoja lääkitykseensä, ja samalla asiakkaan käyttämä lääkitys selkiytyi ja mahdolliset ongelmat paljastuivat. Toisessa tiimissä todet­tiin, että jos lääkitys on täysin hoitajien vastuulla, ei proviisorin kannata haastatella asiakasta. Lääkityksen arviointi onnistuu tällöin sairaanhoitajan kirjausten perusteella, kun hoitajaa on ohjeistettu huomioimaan arvioinnin kannalta oleelliset asiat. Lääkehoidon seuranta parani molemmissa tiimeissä mallin kehityksen aikana. Tämä johtui siitä, että lääkärit alkoivat kirjoittaa hoitajille seurantaan tarkat ohjeet ja hoitajat rupe­sivat kirjaamaan seurannan kuvailevasti. Johtopäätökset: Tutkimuksessa kehitetty moniammatillinen lääkehoidon arvioinnin toimintamalli selkeyt­ti eri toimijoiden vastuualueita ja paransi lääkehoidon seurantaa. Lääkehoidon arvioinnin mallia joudutaan usein muokkaamaan saman organisaation sisälläkin eri yksiköiden ja tiimien toimintaan sopivaksi. Farmasisti tuo oman ammatillisen näkökulmansa asiakkaan hoitoon, mikä täydentää hoitokokonaisuutta

Moniammatillisen lääkehoidon arviointimallin kehittäminen Järvenpään kotihoidossa

Apteekki- ja sairaalafarmasian erikoistumiskoulutus ProjektityöJohdanto: Tutkimuksessa kehitettiin toimintamalli Järvenpään kotihoidon asiakkaiden lääkitysten moni­ammatilliseen arviointiin. Aineisto ja menetelmät: Toimintamallin kehittämisen kannalta moniammatillisen tiimin palavereiden si­sältö oli aineistoa, joka ohjasi toimintamallin seuraavan version kehittämistä. Tutkimus tehtiin toimintatut­kimuksen menetelmin. Lääkehoidon arviointimallin kehittäminen tapahtui moniammatillisessa tiimissä, jo­hon kuuluivat kotihoidon lääkäri, kaksi sairaanhoitajaa ja proviisori. Tiimi kokoontui arvioimaan prosessin sujuvuutta ja toimintamallin kehityskohtia seitsemän kertaa seitsemän kuukauden aikana. Toimintamallia muutettiin aina arvioinnin perusteella ja seuraavat arvioinnit tehtiin uuden suunnitelman mukaan. Kehi­tystä jatkettiin sykleissä, kunnes oli saavutettu toimiva lääkehoidon arvioinninmalli. Arviointeja tehtiin yh­teensä 58 kappaletta. Tulokset: Kehitimme toimivan lääkehoidon prosessimallin kotihoidon kahteen tiimiin. Kuntoutustiimin asi­akkaat ovat kotihoidossa vain muutaman viikon, muissa tiimeissä jopa vuosia. Kuntoutustiimi eroaa tämän vuoksi toiminnaltaan niin paljon kotihoidon muista tiimeistä, että sille tehtiin oma malli. Kuntoutustiimissä proviisorin tekemät asiakkaan haastattelut olivat hyödyllisiä. Asiakas sai tietoa ja neuvoja lääkitykseensä, ja samalla asiakkaan käyttämä lääkitys selkiytyi ja mahdolliset ongelmat paljastuivat. Toisessa tiimissä todet­tiin, että jos lääkitys on täysin hoitajien vastuulla, ei proviisorin kannata haastatella asiakasta. Lääkityksen arviointi onnistuu tällöin sairaanhoitajan kirjausten perusteella, kun hoitajaa on ohjeistettu huomioimaan arvioinnin kannalta oleelliset asiat. Lääkehoidon seuranta parani molemmissa tiimeissä mallin kehityksen aikana. Tämä johtui siitä, että lääkärit alkoivat kirjoittaa hoitajille seurantaan tarkat ohjeet ja hoitajat rupe­sivat kirjaamaan seurannan kuvailevasti. Johtopäätökset: Tutkimuksessa kehitetty moniammatillinen lääkehoidon arvioinnin toimintamalli selkeyt­ti eri toimijoiden vastuualueita ja paransi lääkehoidon seurantaa. Lääkehoidon arvioinnin mallia joudutaan usein muokkaamaan saman organisaation sisälläkin eri yksiköiden ja tiimien toimintaan sopivaksi. Farmasisti tuo oman ammatillisen näkökulmansa asiakkaan hoitoon, mikä täydentää hoitokokonaisuutta