TY - JOUR A1 - Turhan, Metehan C. A1 - Sarac, A. Sezai A1 - Gencturk, Asli A1 - Gilsing, Hans-Detlev A1 - Faltz, Heike A1 - Schulz, Burkhard T1 - Electrochemical impedance characterization and potential dependence of poly[3,4-(2,2-dibutylpropylenedioxy)thiophene] nanostructures on single carbon fiber microelectrode JF - Synthetic metals : the journal of electronic polymers and electronic molecular materials N2 - The electropolymerization of 3,4-(2,2-dibutylpropylenedioxy)thiophene (ProDOT-Bu-2) onto single carbon fiber microelectrode (SCFME) was conducted in acetonitrile (ACN) containing sodium perchlorate (NaClO4) as electrolyte and investigated by cyclic voltammetry (CV). The nanostructured films of poly[3,4-(2,2-dibutyl-propyleneclioxy)thiophene] (PProDOT-Bu-2) which were depositing showed complete reversible redox behavior in monomer-free electrolyte solution. The capacitive behavior of the films was investigated by electrochemical impedance spectroscopy (EIS) at applied potentials from 0.1 V to 1.3 V. The analysis by equivalent circuit modeling revealed an applied potential around 0.4V to be most suitable for the system PProDOT-Bu-2/SCFME as a double layer supercapacitor component inducing a double layer capacitance C-d, value of 62 mFcm(-2). KW - Nanostructure KW - Electrochemical impedance spectroscopy KW - Conjugated polymeric thin film KW - Carbon fiber Y1 - 2012 U6 - https://doi.org/10.1016/j.synthmet.2012.01.012 SN - 0379-6779 VL - 162 IS - 5-6 SP - 511 EP - 515 PB - Elsevier CY - Lausanne ER - TY - JOUR A1 - Guler, Fatma G. A1 - Gilsing, Hans-Detlev A1 - Schulz, Burkhard A1 - Sarac, A. Sezai T1 - Impedance and morphology of hydroxy- and chloro-functionalized poly(3,4-propylenedioxythiophene) nanostructures JF - Journal of nanoscience and nanotechnolog N2 - The new 3,4-propylenedioxythiophenes (ProDOT) bearing hydroxy- or chloro-functionalized side chains of varying length and polarity were synthesized and electropolymerized on single carbon fiber microelectrode (SCFME) using cyclo-voltammetry. Electrochemical impedance spectroscopy (EIS) revealed highest capacitance values for the hydroxy-functionalized Poly 5 carrying a side chain of medium length. The EIS data were fitted with an equivalent electrical circuit giving a good correlation. AFM analysis of the topography showed higher roughness values for Poly 5 than for the two other polymers bearing longer side chains. Due to their reactive end groups the polymers should be useful for post-polymerization functionalization of the electrode surface. KW - 3,4-Propylenedioxythiophene KW - Electroactive Conjugated Polymer KW - EIS KW - AFM Y1 - 2012 U6 - https://doi.org/10.1166/jnn.2012.6594 SN - 1533-4880 VL - 12 IS - 10 SP - 7869 EP - 7878 PB - American Scientific Publ. CY - Valencia ER - TY - JOUR A1 - Emmerling, Franziska A1 - Orgzall, Ingo A1 - Dietzel, Birgit A1 - Schulz, Burkhard A1 - Larrucea, Julen T1 - Ordering the amorphous - Structures in PBD LED materials JF - Journal of molecular structure N2 - The class of 2,5 disubstituted-1,3,4-oxadiazoles containing a biphenyl unit on one side is intensively used as electron transport materials to enhance the performance of organic light emitting diodes (OLEDs). In contrast to the ongoing research on these materials insights in their structure-property relationships are still incomplete. To overcome the structural tentativeness and ambiguities the crystal structures of 2-(4-biphenylyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole, that of the related compound 2-(4-biphenylyl)-5-phenyl-1,3,4-oxadiazole and of 2-(4-biphenylyl)-5-(2,6-dimethylphenyl)-1,3,4-oxadiazole are determined. A comparison with the results of GAUSSIAN03 calculations and similar compounds in the Cambridge Structural Database leads to a profound characterization. KW - OLED KW - PBD KW - Diphenyl-1,3,4-oxadiazole KW - Crystallization Y1 - 2012 U6 - https://doi.org/10.1016/j.molstruc.2012.04.040 SN - 0022-2860 VL - 1030 IS - 23 SP - 209 EP - 215 PB - Elsevier CY - Amsterdam ER - TY - JOUR A1 - Sarauli, David A1 - Xu, Chenggang A1 - Dietzel, Birgit A1 - Stiba, Konstanze A1 - Leimkühler, Silke A1 - Schulz, Burkhard A1 - Lisdat, Fred T1 - Thin films of substituted polyanilines interactions with biomolecular systems JF - Soft matter N2 - We use substituted polyanilines for the construction of new polymer electrodes for interaction studies with the redox protein cytochrome c (cyt c) and the enzyme sulfite oxidase (SO). For these purposes four different polyaniline copolymers are chemically synthesized. Three of them are copolymers, containing 2-methoxyaniline-5-sulfonic acid with variable ratios of aniline; the fourth copolymer consists of 3-amino-benzoic acid and aniline. The results show that all polymers are suitable for being immobilized as thin stable films on gold wire and indium tin oxide (ITO) electrode surfaces from DMSO solution. This can be demonstrated by cyclic voltammetry and UV-Vis spectroscopy measurements. Moreover, cyt c can be electrochemically detected not only in solution, but also immobilized on top of the polymer films. Furthermore, the appearance of a significant catalytic current has been demonstrated for the sulfonated polyanilines, when the polymer-coated protein electrode is being measured upon addition of sulfite oxidase, confirming the establishment of a bioanalytical signal chain. Best results have been obtained for the polymer with highest sulfonation grade. The redox switching of the polymer by the enzymatic reaction can also be analyzed by following the spectral properties of the polymer electrode. Y1 - 2012 U6 - https://doi.org/10.1039/c2sm07261k SN - 1744-683X VL - 8 IS - 14 SP - 3848 EP - 3855 PB - Royal Society of Chemistry CY - Cambridge ER -