TY  - JOUR
A1  - Jetzschmann, Katharina J.
A1  - Jagerszki, Gyula
A1  - Dechtrirat, Decha
A1  - Yarman, Aysu
A1  - Gajovic-Eichelmann, Nenad
A1  - Gilsing, Hans-Detlev
A1  - Schulz, Burkhard
A1  - Gyurcsanyi, Robert E.
A1  - Scheller, Frieder W.
T1  - Vectorially Imprinted Hybrid Nanofilm for Acetylcholinesterase Recognition
JF  - Advanced functional materials
N2  - Effective recognition of enzymatically active tetrameric acetylcholinesterase (AChE) is accomplished by a hybrid nanofilm composed of a propidium-terminated self-assembled monolayer (Prop-SAM) which binds AChE via its peripheral anionic site (PAS) and an ultrathin electrosynthesized molecularly imprinted polymer (MIP) cover layer of a novel carboxylate-modified derivative of 3,4-propylenedioxythiophene. The rebinding of the AChE to the MIP/Prop-SAM nanofilm covered electrode is detected by measuring in situ the enzymatic activity. The oxidative current of the released thiocholine is dependent on the AChE concentration from approximate to 0.04 x 10(-6) to 0.4 x 10(-6)m. An imprinting factor of 9.9 is obtained for the hybrid MIP, which is among the best values reported for protein imprinting. The dissociation constant characterizing the strength of the MIP-AChE binding is 4.2 x 10(-7)m indicating the dominant role of the PAS-Prop-SAM interaction, while the benefit of the MIP nanofilm covering the Prop-SAM layer is the effective suppression of the cross-reactivity toward competing proteins as compared with the Prop-SAM. The threefold selectivity gain provided by i) the shape-specific MIP filter, ii) the propidium-SAM, iii) signal generation only by the AChE bound to the nanofilm shows promise for assessing AChE activity levels in cerebrospinal fluid.
KW  - acetylcholinesterase
KW  - biomimetic sensors
KW  - molecularly imprinted electropolymers
KW  - peripheral anionic site
KW  - propidium
Y1  - 2015
U6  - https://doi.org/10.1002/adfm.201501900
SN  - 1616-301X
SN  - 1616-3028
VL  - 25
IS  - 32
SP  - 5178
EP  - 5183
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Reiche, Jürgen
A1  - Freydank, Anke-Christine
A1  - Helms, Andreas
A1  - Geue, Thomas
A1  - Schulz, Burkhard
A1  - Brehmer, Ludwig
A1  - Stiller, Burkhard
A1  - Knochenhauer, Gerald
T1  - Vacuum deposition films of oxadiazole compounds : formation and structure investigation
N2  - The search for alternative routes of organic thin film formation is stimulated by the outstanding properties of these films in such fields as nonlinear optics, photonic data processing and molecular electronics. The formation of highly ordered multilayer structures by thermal vacuum deposition (VD) of organic compounds is an essential step toward the application of supramolecular organic architectures in technical systems. The VD of an amphiphilic substituted 2,5- diphenylene-1,3,4-oxadiazole 1 onto silicon substrates at defined temperature was used for the formation of ultrathin films. The structural data obtained for the VD-films of oxadiazole 1 by means of X-ray reflectivity, X-ray grazing incidence diffraction and atomic force microscopy (AFM) investigations indicate the formation of well ordered oxadiazole multilayers. The structure of the VD-multilayers is compared with that of Langmuir-Blodgett (LB) films and thermally treated LB-multilayers prepared from the same compound.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Diez, Isabel
A1  - Tauer, Klaus
A1  - Schulz, Burkhard
T1  - Unusual polymer dispersions-polypyrrole suspensions made of rings, frames, and platelets
JF  - Colloid and polymer science : official journal of the Kolloid-Gesellschaft
N2  - Experimental results show that the polymerization of pyrrole in the presence of beta-naphthalenesulfonic acid and different fluorosurfactants like perfluorooctanesulfonic acid, perfluorooctyldiethanolamide, and ammonium perfluorooctanoate leads to polypyrrole with special morphologies, such as rings or disks and rectangular frames or plates. The formation of these unusually shaped particles of polymer dispersions is explained by the chemical and colloidal peculiarities of the oxidative pyrrole polymerization with ammonium peroxodisulfate in aqueous medium.
KW  - polypyrrole
KW  - chemical oxidative polymerization
KW  - particle morphology
Y1  - 2006
U6  - https://doi.org/10.1007/s00396-006-1521-8
SN  - 0303-402X
VL  - 284
SP  - 1431
EP  - 1442
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Schürmann, H.
A1  - Koch, Norbert
A1  - Imperia, Paolo
A1  - Schrader, Sigurd
A1  - Jandke, M.
A1  - Strohriegl, P.
A1  - Schulz, Burkhard
A1  - Leising, G.
A1  - Brehmer, Ludwig
T1  - Ultraviolet photoelectron spectroscopic study of heterocyclic model compounds for electroluminescent devices
Y1  - 1999
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  - 
TY  - JOUR
A1  - Okatova, Olga V.
A1  - Andreeva, Katharina A.
A1  - Schulz, Burkhard
T1  - Thermal hydrolytic degradation of polyoxadiazole derivatives
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Banks, Jo Ann
A1  - Nishiyama, Tomoaki
A1  - Hasebe, Mitsuyasu
A1  - Bowman, John L.
A1  - Gribskov, Michael
A1  - dePamphilis, Claude
A1  - Albert, Victor A.
A1  - Aono, Naoki
A1  - Aoyama, Tsuyoshi
A1  - Ambrose, Barbara A.
A1  - Ashton, Neil W.
A1  - Axtell, Michael J.
A1  - Barker, Elizabeth
A1  - Barker, Michael S.
A1  - Bennetzen, Jeffrey L.
A1  - Bonawitz, Nicholas D.
A1  - Chapple, Clint
A1  - Cheng, Chaoyang
A1  - Correa, Luiz Gustavo Guedes
A1  - Dacre, Michael
A1  - DeBarry, Jeremy
A1  - Dreyer, Ingo
A1  - Elias, Marek
A1  - Engstrom, Eric M.
A1  - Estelle, Mark
A1  - Feng, Liang
A1  - Finet, Cedric
A1  - Floyd, Sandra K.
A1  - Frommer, Wolf B.
A1  - Fujita, Tomomichi
A1  - Gramzow, Lydia
A1  - Gutensohn, Michael
A1  - Harholt, Jesper
A1  - Hattori, Mitsuru
A1  - Heyl, Alexander
A1  - Hirai, Tadayoshi
A1  - Hiwatashi, Yuji
A1  - Ishikawa, Masaki
A1  - Iwata, Mineko
A1  - Karol, Kenneth G.
A1  - Koehler, Barbara
A1  - Kolukisaoglu, Uener
A1  - Kubo, Minoru
A1  - Kurata, Tetsuya
A1  - Lalonde, Sylvie
A1  - Li, Kejie
A1  - Li, Ying
A1  - Litt, Amy
A1  - Lyons, Eric
A1  - Manning, Gerard
A1  - Maruyama, Takeshi
A1  - Michael, Todd P.
A1  - Mikami, Koji
A1  - Miyazaki, Saori
A1  - Morinaga, Shin-ichi
A1  - Murata, Takashi
A1  - Müller-Röber, Bernd
A1  - Nelson, David R.
A1  - Obara, Mari
A1  - Oguri, Yasuko
A1  - Olmstead, Richard G.
A1  - Onodera, Naoko
A1  - Petersen, Bent Larsen
A1  - Pils, Birgit
A1  - Prigge, Michael
A1  - Rensing, Stefan A.
A1  - Mauricio Riano-Pachon, Diego
A1  - Roberts, Alison W.
A1  - Sato, Yoshikatsu
A1  - Scheller, Henrik Vibe
A1  - Schulz, Burkhard
A1  - Schulz, Christian
A1  - Shakirov, Eugene V.
A1  - Shibagaki, Nakako
A1  - Shinohara, Naoki
A1  - Shippen, Dorothy E.
A1  - Sorensen, Iben
A1  - Sotooka, Ryo
A1  - Sugimoto, Nagisa
A1  - Sugita, Mamoru
A1  - Sumikawa, Naomi
A1  - Tanurdzic, Milos
A1  - Theissen, Guenter
A1  - Ulvskov, Peter
A1  - Wakazuki, Sachiko
A1  - Weng, Jing-Ke
A1  - Willats, William W. G. T.
A1  - Wipf, Daniel
A1  - Wolf, Paul G.
A1  - Yang, Lixing
A1  - Zimmer, Andreas D.
A1  - Zhu, Qihui
A1  - Mitros, Therese
A1  - Hellsten, Uffe
A1  - Loque, Dominique
A1  - Otillar, Robert
A1  - Salamov, Asaf
A1  - Schmutz, Jeremy
A1  - Shapiro, Harris
A1  - Lindquist, Erika
A1  - Lucas, Susan
A1  - Rokhsar, Daniel
A1  - Grigoriev, Igor V.
T1  - The selaginella genome identifies genetic changes associated with the evolution of vascular plants
JF  - Science
N2  - Vascular plants appeared similar to 410 million years ago, then diverged into several lineages of which only two survive: the euphyllophytes (ferns and seed plants) and the lycophytes. We report here the genome sequence of the lycophyte Selaginella moellendorffii (Selaginella), the first nonseed vascular plant genome reported. By comparing gene content in evolutionarily diverse taxa, we found that the transition from a gametophyte- to a sporophyte-dominated life cycle required far fewer new genes than the transition from a nonseed vascular to a flowering plant, whereas secondary metabolic genes expanded extensively and in parallel in the lycophyte and angiosperm lineages. Selaginella differs in posttranscriptional gene regulation, including small RNA regulation of repetitive elements, an absence of the trans-acting small interfering RNA pathway, and extensive RNA editing of organellar genes.
Y1  - 2011
U6  - https://doi.org/10.1126/science.1203810
SN  - 0036-8075
VL  - 332
IS  - 6032
SP  - 960
EP  - 963
PB  - American Assoc. for the Advancement of Science
CY  - Washington
ER  - 
TY  - JOUR
A1  - Schöne, Anne-Christin
A1  - Kratz, Karl
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - The relevance of hydrophobic segments in multiblock copolyesterurethanes for their enzymatic degradation at the air-water interface
JF  - Polymer : the international journal for the science and technology of polymers
N2  - The interplay of an enzyme with a multiblock copolymer PDLCL containing two segments of different hydrophilicity and degradability is explored in thin films at the air-water interface. The enzymatic degradation was studied in homogenous Langmuir monolayers, which are formed when containing more than 40 wt% oligo(epsilon-caprolactone) (OCL). Enzymatic degradation rates were significantly reduced with increasing content of hydrophobic oligo(omega-pentadecalactone) (OPDL). The apparent deceleration of the enzymatic process is caused by smaller portion of water-soluble degradation fragments formed from degradable OCL fragments. Beside the film degradation, a second competing process occurs after adding lipase from Pseudomonas cepacia into the subphase, namely the enrichment of the lipase molecules in the polymeric monolayer. The incorporation of the lipase into the Langmuir film is experimentally revealed by concurrent surface area enlargement and by Brewster angle microscopy (BAM). Aside from the ability to provide information about the degradation behavior of polymers, the Langmuir monolayer degradation (LMD) approach enables to investigate polymer-enzyme interactions for non-degradable polymers. (C) 2016 Elsevier Ltd. All rights reserved.
KW  - Multiblock copolymer
KW  - Enzymatic polymer degradation
KW  - Oligo(omega-pentadecalactone)
KW  - Oligo(epsilon-caprolactone)
KW  - Langmuir monolayer degradation technique
Y1  - 2016
U6  - https://doi.org/10.1016/j.polymer.2016.09.001
SN  - 0032-3861
SN  - 1873-2291
VL  - 102
SP  - 92
EP  - 98
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Machatschek, Rainhard Gabriel
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - The influence of pH on the molecular degradation mechanism of PLGA
JF  - MRS Advances
N2  - Poly[(rac-lactide)-co-glycolide] (PLGA) is used in medicine to provide mechanical support for healing tissue or as matrix for controlled drug release. The properties of this copolymer depend on the evolution of the molecular weight of the material during degradation. which is determined by the kinetics of the cleavage of hydrolysable bonds. The generally accepted description of the degradation of PLGA is a random fragmentation that is autocatalyzed by the accumulation of acidic fragments inside the bulk material. Since mechanistic studies with lactide oligomers have concluded a chain-end scission mechanism and monolayer degradation experiments with polylactide found no accelerated degradation at lower pH, we hypothesize that the impact of acidic fragments on the molecular degradation kinetics of PLGA is overestimated By means of the Langmuir monolayer degradation technique. the molecular degradation kinetics of PLGA at different pH could be determined. Protons did not catalyze the degradation of PLGA. The molecular mechanism at neutral pH and low pH is a combination of random and chainend-cut events, while the degradation under strongly alkaline conditions is determined by rapid chainend cuts. We suggest that the degradation of bulk PLGA is not catalyzed by the acidic degradation products. Instead. increased concentration of small fragments leads to accelerated mass loss via fast chain-end cut events. In the future, we aim to substantiate the proposed molecular degradation mechanism of PLGA with interfacial rheology.
Y1  - 2018
U6  - https://doi.org/10.1557/adv.2018.602
SN  - 2059-8521
VL  - 3
IS  - 63
SP  - 3883
EP  - 3889
PB  - Cambridge Univ. Press
CY  - New York
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Orgzall, Ingo
A1  - Diez, Isabel
A1  - Dietzel, Birgit
A1  - Tauer, Klaus
T1  - Template mediated formation of shaped polypyrrole particles
N2  - The formation of different micro- and nanostructures during the chemical synthesis of polypyrrole is reviewed shortly based on the conceptions of hard- and soft-templating models. Contrary to other models that emphasize the role of micelles it is found here that during the oxidative polymerization of pyrole using sulfonic acid dopants a crystalline hard template is found in the first steps of the reaction before the addition of the oxidant. This template is formed by a complex consisting of 2,5-bis(pyrrole-2-yl)pyrrolidine and the sulfonic acid anion. The acid catalyzed formation of this specific tripyrrole is discussed. (C) 2009 Elsevier B.V. All rights reserved.
Y1  - 2010
U6  - https://doi.org/10.1016/j.colsurfa.2009.11.034
SN  - 0927-7757
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Hamciuc, Elena
A1  - Schulz, Burkhard
A1  - Köpnick, Thomas
A1  - Stiller, Burkhard
A1  - Mercer, Frank W.
T1  - Synthesis of fluorinated poly(phenylquinoxaline-amide)s and study of thin films made therefrom
N2  - A series of five fluorinated poly(phenylquinoxaline-amide)s were synthesized by a polycondensation reaction of a diacid chloride containing the hexafluoroisopropylidene (6F) group, namely 2,2-bis(p-chlorocarbonylphenyl)- hexafluoropropane, with various aromatic diamines incorporating two phenyl-substituted quinoxaline rings. These polymers were easily soluble in polar aprotic solvents such as N-methylpyrrolione (NMP), dimethylformamide (DMF), and tetrahydrofurane (THF), and showed a high thermal stability with decomposition temperatures above 400 °C and glass transition temperatures in the range of 260-290 Tg. Polymer solutions in NMP were processed into free-standing films that showed low dielectric constant values, in the range of 3.4-3.9, and good mechanical properties, with tensile strength in the range of 40-80 MPa and elongation to break in the range of 22-55%. Very thin films, in the range of tens of nanometer, which were deposited onto silicon wafers exhibited very smooth surfaces, free of pinholes when studied by atomic force microscopy (AFM).
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Hamaciuc, E.
A1  - Bruma, Maria
A1  - Köpnick, Thomas
A1  - Kaminorz, Yvette
A1  - Schulz, Burkhard
T1  - Synthesis and Study of New Silicon-containing Polyoxadiazoles
N2  - A series of new poly-1,3,4-oxadiazoles has been synthesized by polycondensation reaction of hydrazine sulfate with a mixture of a dicarboxylic acid containing unsaturated bonds and a dicarboxylic acid containing silicon, by using methanesulfonic acid/phosphorus pentoxide as a reaction medium. These polymers were highly thermostable but they were only soluble in strong inorganic acids such as sulfuric or methanesulfonic ones. An alternative way was followed by using the corresponding dihydrazides containing unsaturated bonds and the corresponding diacid chloride containing silicon that reacted in N-methylpyrrolidinone (NMP) to give soluble silicon-containing unsaturated polyhydrazides, which were cyclodehydrated either by thermal or chemical treatment to give the corresponding polyoxadiazoles. Very thin coatings of polyhydrazides and polyoxadiazoles were deposited onto silicon wafers and they showed a very smooth surface, free of pinholes, when studied by atomic force microscopy (AFM). Some polyoxadiazole films showed strong blue photoluminescence.
Y1  - 2001
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Schulz, Burkhard
A1  - Köpnick, Thomas
A1  - Stiller, Burkhard
A1  - Belomoina, Nataliya
A1  - Mercer, Frank W.
T1  - Synthesis and study of aromatic polyamides containing silicon and phenylquinoxaline rings in the main chain
N2  - New poly(phenylquinoxaline-amide)s with silicon in the main chain have been prepared by polycondensation reaction of a diacid chloride, namely bis(p-chlorocarbonyl-phenyl)-diphenylsilane, with aromatic diamines containing one or two phenylquinoxaline rings separated by a flexible bridge such as ether or methylene. These polymers were easily soluble in polar aprotic solvents such as N-methylpyrrolidinone (NMP) and dimethylformamide (DMF) and showed high thermal stability with decomposition temperature being above 450°C and glass transition temperature in the range of 260- 304°C. Polymer solutions in NMP were processed into thin flexible films which exhibited very smooth surfaces, free of pinholes when studied by atomic force microscopy. The free-standing films showed a dielectric constant in the range of 3.6-3.7.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Sava, Ion
A1  - Bruma, Maria
A1  - Schulz, Burkhard
A1  - Mercer, Frank W.
A1  - Belomoina, Nataliya
T1  - Synthesis and Properties of Silicon-containing Polyamides
N2  - A series of aromatic polyamides incorporating silicon together with phenylquinoxaline or with hexafluoroisopropylidene groups has been synthesized by solution polycondensation of a silicon-containing diacid chloride with aromatic diamines having phenylquinoxaline rings or hexafluoroisopropylidene groups. These polymers are easily soluble in polar aprotic solvents, such as N-methylpyrrolidinone and dimethylformamide, and in tetrahydrofurane, and can be solution-cast into thin, transparent films having low dielectric constant, in the range of 3.26 to 3.68. These polymers show high thermal stability with decomposition temperature being above 400 °C and glass transition temperature in the range of 236 °C to 275 °C.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Mercer, Frank W.
A1  - McKenzie, M.
A1  - Bruma, Maria
A1  - Schulz, Burkhard
T1  - Synthesis and properties of fluorinated polyimides and fluorinated poly(imide-amide)s containing pendent cyano groups
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Schulz, Burkhard
A1  - Strelina, Irina A.
A1  - Okatova, Olga V.
T1  - Synthesis and molecular properties of new poly(naphthalene-1,3,4-oxadiazole)s
N2  - Poly[(1,4-naphthalene)-2,5-diyl-1,3,4-oxadiazole] and poly[(2,6-naphthalene)-2,5-diyl-1,3,4-oxadiazole] have been synthesized and investigated in conc. H2S04, by the flow birefringence method in comparison with poly(1,4- phenylene)-2,5-diyl-1,3,4-oxadiazole]. Changes in conformation parameters and optical anisotropy of a chain unit induced by incorporation of the naphthalene groups into the macromolecule backbone have been evaluated.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Freydank, Anke-Christine
A1  - Janietz, Silvia
A1  - Schulz, Burkhard
T1  - Synthesis and electrochemical characterization of new amphiphilic 1,3,4-oxadiazoles
N2  - The electrochemical behaviour of new amphiphilic 1,3,4-oxadiazoles were studied by cyclic voltammetry. The influence of the supra- molecular structure on the redox behaviour in liquid or solid solutions, in Langmuir-Blodgett multilayers, and in amorphous films is investigated in detail. The reversible reduction of amphiphilic 2,5-diarylene- 1,3,4-oxadiazoles is significantly influenced by substituents in the para position of the phenylene ring. In the solid states the reduction peak potentials are shifted to more negative values compared to data measured in solution. This shift increases as the film thickness is increased. An influence of the supramolecular order in the solid films was not found. In-situ UV-vis spectroelectrochemistry of LB-multilayers deposited onto indium tin oxide (ITO) glass give evidence for the formation of radical anions in the highly ordered layer.
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Freydank, Anke-Christine
A1  - Janietz, Silvia
A1  - Schulz, Burkhard
T1  - Synthesis and electrochemical behaviour of Amphiphilic 1,3,4-Oxadiazole derivatives
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Sava, Ion
A1  - Schulz, Burkhard
A1  - Zhu, Shigen
A1  - Bruma, Maria
T1  - Synthesis and characterization of new silicon-containing poly(arylene-1,3,4-oxadiazole)s
Y1  - 1995
UR  - http://hip.sagepub.com/
U6  - https://doi.org/10.1088/0954-0083/7/4/011
SN  - 0954-0083
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Schulz, Burkhard
A1  - Mercer, Frank W.
T1  - Synthesis and characterization of fluorinated poly(imide-pyridazine- amide)s
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Brehmer, Ludwig
A1  - Knochenhauer, Gerald
T1  - Supramolecular structures of aromatic 1,3,4-oxadiazole solids
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Reiche, Jürgen
A1  - Schulz, Burkhard
A1  - Knochenhauer, Gerald
A1  - Dietzel, Birgit
A1  - Freydank, Anke-Christine
A1  - Zetzsche, Thomas
A1  - Brehmer, Ludwig
T1  - Supramolecular structures formed from heterocyclic aromatic molecules
N2  - This paper describes the formation and structure investigation of Langmuir monolayers and Langmuir-Blodgett multilayers formed from amphiphilic derivatives of 2,5-diphenyl-1,3,4-oxadiazole. The 2,5-diphenyl-1,3,4-oxadiazole group as a functional unit with interesting physical and chemical properties is maintained, while the head group, the length of the alkyl chain and the structure of the coupling unit between aromatic and aliphatic part of these linear short-chain amphiphiles is systematically varied in order to explore the influence of this change on the film forming properties and the stability of Langmuir and Langmuir-Blodgett films. Molecular mechanics simulations are shown by these systematic variations to be suitable for the prediction of optimal chemical structures allowing for a stable stratified molecular packing. The combination of a detailed structure investigation of the multilayers based on scanning force microscopy and X-ray data with molecular mechanics simulations yields an insight into the packing of the molecules and the intermolecular interactions.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Schulz, Burkhard
A1  - Köpnick, Thomas
A1  - Stiller, Burkhard
A1  - Mercer, Frank W.
T1  - Study of thin films made from aromatic polyamides with silicon and phenylquinoxaline rings in the main chain
N2  - Aromatic polyamides containing silicon and phenylquinoxaline rings in the main chain have been prepared by polycondensation reaction of a silicon-containing diacid chloride, namely bis(p-chlorocarbonylphenyl) -diphenylsilane, with various aromatic diamines having preformed phenylquinoxaline units. These polymers were easily soluble in polar aprotic solvents, such as N-methylpyrrolidinone (NMP) and dimethylformamide (DMF), and in tetrahydrofurane. They showed high thermal stability with decomposition temperature being above 450°C and glass transition temperature in the range of 253-304°C. Polymer solutions in NMP were processed into thin films having the thickness of tens of nanometer to 10 mm, by spin-coating onto glass plates or silicon wafers. The films had strong adhesion to substrates and exhibited very smooth surfaces, free of pinholes, in atomic force microscopy (AFM) studies. The free-standing films had dielectric constant in the range of 3.48-3.69. Thermal treatment of the films up to 350°C rendered them completely insoluble in organic solvents, while maintaining their smoothness and strong adhesion to the silicon substrate, and with no Tg in DSC experiments. Their FTIR spectra did not show any changes compared to the untreated films, meaning that polymers maintain their structural integrity at high temperature. Ó 1999 Elsevier Science S.A. All rights reserved.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Mercer, Frank W.
A1  - Schulz, Burkhard
A1  - Dietel, Reinhard
A1  - Fitch, J.
A1  - Cassidy, Peter
T1  - Study of crosslinking process in fluorinated poly(imide-amide)s containing pendant cyano groups
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Mercer, Frank W.
A1  - Schulz, Burkhard
A1  - Dietel, Reinhard
A1  - Fitch, J.
A1  - Cassidy, Peter
T1  - Study of crosslinking process in fluorinated poly(imide-amide)s containing pendant cyano groups
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Knochenhauer, Gerald
A1  - Brehmer, Ludwig
A1  - Janietz, Silvia
T1  - Stuctures and properties of aromatic poly(1,3,4-oxadiazole)s
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Knochenhauer, Gerald
A1  - Brehmer, Ludwig
A1  - Janietz, Silvia
T1  - Stuctures and properties of aromatic poly(1,3,4-oxadiazole)s
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
T1  - Struktur und Eigenschaften dünner Schichten aus aromatischen Poly(1,3,4- oxadiazol)en
Y1  - 1994
ER  - 
TY  - JOUR
A1  - Emmerling, Franziska
A1  - Orgzall, Ingo
A1  - Reck, Günter
A1  - Schulz, Burkhard W.
A1  - Stockhause, Sabine
A1  - Schulz, Burkhard
T1  - Structures of substituted di-aryl-1, 3,4-oxadiazole derivatives: 2,5-bis(pyridyl)- and 2,5-bis(aminophenyl)-substitution
JF  - Journal of molecular structure
N2  - Crystal structures of four different di-aryl-1,3,4-oxadiazole compounds (aryl = 2-pyridyl-, 3-pyridyl-, 2-aminophenyl-, 3-aminophenyl-) are determined. Crystallization of di(2-pyridyl)-1,3,4-oxadiazole yielded monoclinic and triclinic polymorphs. The structures are characterized by the occurrence of pi-pi interactions. Additionally, in case of the aminophenyl compounds intra- as well as intermolecular hydrogen bonds are found that influence the packing motif as well. Since these molecules are often used as ligands in metal-organic complexes similarities and differences of the molecular conformation between the molecules in the pure crystals and that of the ligands in the complexes are discussed. (c) 2006 Elsevier B.V. All rights reserved.
KW  - crystal structure
KW  - 1,3,4-oxadiazole
KW  - molecular conformation
KW  - hydrogen bonds
Y1  - 2006
U6  - https://doi.org/10.1016/j.molstruc.2006.03.076
SN  - 0022-2860
VL  - 800
IS  - 1-3
SP  - 74
EP  - 84
PB  - Elsevier
CY  - Amsterdam
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
T1  - Structure and properties of thin polyoxadiazole films
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Franco, Olga
A1  - Orgzall, Ingo
A1  - Reck, Günter
A1  - Stockhause, Sabine
A1  - Schulz, Burkhard
T1  - Structure and high-pressure behavior of 2,5-di-(4-aminophenyl)-1,3,4-oxadiazole
N2  - The crystalline structures of two modifications of a compound containing the oxadiazole ring, 2,5-di-(4- aminophenyl)-1,3,4-oxadiazole (DAPO) were determined. One of these modifications contains water molecules in the crystal structure, which is observed for the first time for an oxadiazole crystal. Both crystals show an orthorhombic structure. The water free modification, DAPO L belongs to the space group Pbca (61) and has the lattice parameters: a = 13.461(5), b = 7.937(3) and c = 22.816(8) angstrom (CCDC 246608). The water containing pseudo-polymorph, DAPO 11, has the space group Cmcm (63) and the lattice parameters: a = 16.330(5), b = 12.307(2) and c = 6.9978(14) angstrom (CCDC 246609). To gain information on the inter molecular interactions within the crystals, X-ray experiments under compression at ambient temperature and under heating at vacuum conditions were performed. Neither DAPO I nor DAPO II undergo phase transitions in the ressure range up to 5 GPa, as could be concluded from X-ray and Raman experiments. X-ray and calorimetric studies indicate that DAPO II dehydrates into DAPO I under increasing temperature. Structural considerations suggest a two-stage process. The compression behavior of both substances is well described by the Murnaghan equation of state (MEOS) and the values of the bulk modulus and its pressure derivative are determined for these crystals. Additionally, in the case of DAPO I, also the thermal expansion coefficient an was measured. (c) 2005 Elsevier Ltd. All rights reserved
Y1  - 2005
SN  - 0022-3697
ER  - 
TY  - JOUR
A1  - Franco, Olga
A1  - Orgzall, Ingo
A1  - Regenstein, Wolfgang
A1  - Schulz, Burkhard
T1  - Structural and spectroscopical study of a 2,5-diphenyl-1,3,4-oxadiazole polymorph under compression
N2  - The x-ray pattern and the Raman and luminescence spectra of crystalline 2,5-diphenyl-1,3,4-oxadiazole in one of its polymorphic forms (DPO II) have been investigated under pressure up to 5 GPa. The behaviour of the lattice parameters under compression was determined and it was found that the Murnaghan equation of state provides a good description of the volume-pressure relationship of DPO II. The values for the bulk modulus and its pressure derivative are K-0 = 8.6 GPa and K-0' = 7.2. The analysis of the Raman spectrum under compression clearly shows the pressure- induced shift of the Raman modes to higher frequencies. The mode Gruneisen parameters for the lattice modes were determined. Additionally, it was found that the emission spectrum of DPO II moves to lower energies and that the luminescence intensity decreases when pressure is applied
Y1  - 2006
UR  - http://iopscience.iop.org/0953-8984
U6  - https://doi.org/10.1088/0953-8984/18/4/029
SN  - 0953-8984
ER  - 
TY  - JOUR
A1  - Schöne, Anne-Christin
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Stimuli Responsive and Multifunctional Polymers: Progress in Materials and Applications
JF  - Macromolecular rapid communications
Y1  - 2016
U6  - https://doi.org/10.1002/marc.201600650
SN  - 1022-1336
SN  - 1521-3927
VL  - 37
SP  - 1856
EP  - 1859
PB  - Wiley-VCH
CY  - Weinheim
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Okatova, Olga V.
A1  - Schulz, Burkhard
T1  - Stability and degradation of poly(p-pheneylene-1,3,4-oxadiazole) molecules in sulphuric acid
N2  - The translational diffusion coefficient and intrinsic viscosity of poly(1,4-phenylene-1,3,4-oxadiazole) molecules in 96% H2S04 have been determined at different stages of degradation of the molecules in acid solution at temperature ranging from 82 to 105 °C. The degradation rate constant, k, has been obtained from the change in the molecular weight, M, of the product degraded in solution with time at high temperature. The activation energy of the hydrolysis process was 103 ± 7 kJmol-1, which is smaller than that of aromatic polyamides in the same solvent. According to our hydrodynamic data, the degree of coiling of the molecules of degraded products does not differ from that of undegraded samples, and our conclusion was that the degradation is not accompanied with a noticeable change in the short- range interactions in the molecular chain and may be understood as a random chain scission.
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Sava, Ion
A1  - Mercer, Frank W.
A1  - Reddy, Victor N.
A1  - Köpnick, Thomas
A1  - Stiller, Burkhard
A1  - Schulz, Burkhard
T1  - Silicon-containing poly(amide-ether)s
N2  - New aromatic poly(amide-ether)s (II) have been synthesized by solution polycondensation of various aromatic diamines having two ether bridges (I) with a diacid chloride containing silicon, namely bis(chlorocarbonylphenyl)- diphenyIsilane. These polymers are easy soluble in polar amidic solvents such as N-methylpyrrolidinone or dimethylformamide and can be cast into thin flexible films or coatings from such solutions. They show high thermal stability with initial decomposition temperature being above 400 °C. Their glass transition temperatures lie in the range of 220-250 °C, except for polymer He which did not show a clear Tg when heated in a differential scanning calorimetry experiment up to 300 °C. The large interval between the glass transition and decomposition temperatures of pnlymers Ia-Id could be advantageous for their processing via compression molding. The polymer coatings deposited by the spincoating, technique onto silicon wafers showed a very smooth, pinhole-free surface in atomic force microscopy investigations. The free-standing films of 20-30 mm thickness show low dielectric constant, in the range of 3.65-3.78, which is promising for future application as high performance dielectrics.
Y1  - 1998
ER  - 
TY  - BOOK
A1  - Schulz, Burkhard
A1  - Orgzall, Ingo
A1  - Freydank, Anke-Christine
A1  - Chenggang, Xü
T1  - Self-organization of substituted 1,3,4-oxadizazoles in the solid state and at surfaces
N2  - Different aspects of the structure formation for a class of molecules containing the diphenyl-1,3,4-oxadiazole fragment are discussed. Starting from the bulk state with the ideal crystal lattice and the derivation of some common packing motifs the formation of liquid-crystalline states are described. This leads to the consideration of structures found in Langmuir-Blodgett films and those obtained by organic molecular beam deposition. These structures may again be compared to those for the bulk crystalline state. Common features as well as characteristic differences due to peculiarities of the individual molecular structures are discussed. (c) 2005 Elsevier B.V. All rights reserved
Y1  - 2005
ER  - 
TY  - JOUR
A1  - Saretia, Shivam
A1  - Machatschek, Rainhard Gabriel
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Reversible 2D networks of oligo(epsilon-caprolactone) at the air-water interface
JF  - Biomedical Materials
N2  - Hydroxyl terminated oligo(epsilon-caprolactone) (OCL) monolayers were reversibly cross-linked forming two dimensional networks (2D) at the air-water interface. The equilibrium reaction with glyoxal as the cross-linker is pH-sensitive. Pronounced contraction in the area of the prepared 2DOCL films in dependence of surface pressure and time revealed the process of the reaction. Cross-linking inhibited crystallization and retarded enzymatic degradation of the OCLfilm. Altering the subphase pH led to a cleavage of the covalent acetal cross-links. The reversibility of the covalent acetal cross-links was proved by observing an identical isotherm as non-cross-linked sample. Besides as model systems, these customizable reversible OCL2D networks are intended for use as pHresponsive drug delivery systems or functionalized cell culture substrates.
KW  - poly(epsilon-caprolactone)
KW  - langmuir monolayer
KW  - two dimensional network
KW  - crystallization
KW  - cross-linking
Y1  - 2019
U6  - https://doi.org/10.1088/1748-605X/ab0cef
SN  - 1748-6041
SN  - 1748-605X
VL  - 14
IS  - 3
PB  - IOP Publ. Ltd.
CY  - Bristol
ER  - 
TY  - JOUR
A1  - Orgzall, Ingo
A1  - Lorenz, Bernd
A1  - Mikat, Jürgen E. R.
A1  - Dietel, Reinhard
A1  - Knochenhauer, Gerald
A1  - Schulz, Burkhard
T1  - Raman and IR spectroscopic investigation of aromatic 1,3,4-oxadiazole polymers and oligomers
N2  - The molecular structure of poly(p-phenylene-1,3,4-oxadiazole) (POD) is investigated using i.r. and Raman spectroscopy. Both methods reveal characteristic differences for the a- and b-POD forms that are most obvious in the spectral region between 1500 and 1650 cm-1. The spectra for dimer and tetramer compounds already show the same features as found for longer chains. Based on molecular modelling calculations these differences are assigned to cis and trans conformations of the main chain segments. High pressure measurements show a linear shift of the Raman lines and support the result of the thermodynamic stability of the trans conformation.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Janietz, Silvia
T1  - Preparation and characterization of thin films containing aromatic poly(1,3,4- oxadiazole)s
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Brehmer, Ludwig
A1  - Dietzel, Birgit
A1  - Zetzsche, Thomas
T1  - Preparation and characterization of ordered thin films based on aromatic poly(1,3,4-oxadiazole)s
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Brehmer, Ludwig
T1  - Preparation and characterization of ordered thin films based on aromatic poly(1,3,4-oxadiazole)s
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Lohwaßer, Roswitha
A1  - Haßler, Gerda
A1  - Behrmann, Günter C.
A1  - Schulz, Burkhard
A1  - Mieske, Silvio
T1  - Portal = Knappe Kassen: Was das akademische Jahr bringt
BT  - Die Potsdamer Universitätszeitung
N2  - Aus dem Inhalt:
- Knappe Kassen: Was das akademische Jahr bringt
- Sparkasse finanziert Stiftungsprofessur 
- Chipkarte ersetzt Studentenausweis aus Papier 
- Unikonzert im Potsdamer Nikolaisaal
T3  - Portal: Das Potsdamer Universitätsmagazin - 08-10/2003 
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-502262
SN  - 1618-6893
VL  - 2003
ER  - 
TY  - JOUR
A1  - Diez, Isabel
A1  - Tauer, Klaus
A1  - Schulz, Burkhard
T1  - Polypyrrole tubes via casting of pyrrole-beta-naphthalenesulfonic acid rods
N2  - A comprehensive study gives experimental evidence that a complex made from pyrrole and beta-naphthalenesulfonic acid in a molar composition of 3:1 acts as morphological precursor in the subsequent oxidative polymerization of pyrrole initiated with ammonium peroxodisulfate. The precursor complex itself is unable to polymerize but its outer parallelepipedal shape with a high aspect ratio is templated in the inner surface of the formed conducting polypyrrole tubes
Y1  - 2004
SN  - 0303-402X
ER  - 
TY  - JOUR
A1  - Schöne, Anne-Christin
A1  - Kratz, Karl
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Polymer architecture versus chemical structure as adjusting tools for the enzymatic degradation of oligo(epsilon-caprolactone) based films at the air-water interface
JF  - Polymer Degradation and Stability
N2  - The enzymatic degradation of oligo(epsilon-caprolactone) (OCL) based films at the air-water interface is investigated by Langmuir monolayer degradation (LMD) experiments to elucidate the influence of the molecular architecture and of the chemical structure on the chain scission process. For that purpose, the interactions of 2D monolayers of two star-shaped poly(epsilon-caprolactone)s (PCLs) and three linear OCL based copolyesterurethanes (P(OCL-U)) with the lipase from Pseudomonas cepacia are evaluated in comparison to linear OCL. While the architecture of star-shaped PCL Langmuir layers slightly influences their degradability compared to OCL films, significantly retarded degradations are observed for P(OCL-U) films containing urethane junction units derived from 2, 2 (4), 4-trimethyl hexamethylene diisocyanate (TMDI), hexamethylene diisocyanate (HDI) or lysine ethyl ester diisocyanate (LDI). The enzymatic degradation of the OCL based 2D structures is related to the presence of hydrophilic groups within the macromolecules rather than to the packing density of the film or to the molecular weight. The results reveal that the LMD technique allows the parallel analysis of both the film/enzyme interactions and the degradation process on the molecular level. (C) 2016 Elsevier Ltd. All rights reserved.
KW  - Langmuir technique
KW  - Oligo(epsilon-caprolactone)
KW  - Enzymatic degradation
KW  - Polymer architecture
Y1  - 2016
U6  - https://doi.org/10.1016/j.polymdegradstab.2016.07.010
SN  - 0141-3910
SN  - 1873-2321
VL  - 131
SP  - 114
EP  - 121
PB  - Elsevier
CY  - Oxford
ER  - 
TY  - JOUR
A1  - Okatova, Olga V.
A1  - Lavrenko, Peter N.
A1  - Fedotov, Y. A.
A1  - Schulz, Burkhard
T1  - Polyelectrolyte behavior of some new polyheteroarylene derivatives in sulfuric acid
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Schulz, Burkhard
A1  - Mercer, Frank W.
T1  - Polyamide copolymers containing hexafluoroisopropylidene groups
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Hamciuc, Elena
A1  - Hamciuc, Corneliu
A1  - Bruma, Maria
A1  - Stoleriu, Andre
A1  - Schulz, Burkhard
T1  - Poly(hydrazide-ester)s and poly(1,3,4-oxadiazole-ester)s containing pendent phenoxy groups
N2  - A series of new arornatic poly(hydrazide-ester)s has been synthesized by solution polycondensation of two diacid dichlorides containing preformed ester groups with phenoxyterephthaloyl dihydrazide or with a mixture of phenoxyterephthaloyl dihydrazide with terephthaloyl- or isophthaloyl dihydrazide in N-methyl-2-pyrrolidinone. The thermal cyclization of the poly(hydrazide-ester)s gave the corresponding poly(1,3,4-oxadiazole-ester)s containing pendent phenoxy groups. The polymers were characterized by viscometry, solubility measurements, IR spectroscopy, differential scanning calorimetry and thermogravimetric analysis.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Orgzall, Ingo
A1  - Lorenz, Bernd
A1  - Mikat, Jürgen E. R.
A1  - Reck, Günter
A1  - Knochenhauer, Gerald
A1  - Schulz, Burkhard
T1  - Phase transition in 1,3,4-oxadiazole crystals under high pressure
Y1  - 1998
ER  - 
TY  - JOUR
A1  - Orgzall, Ingo
A1  - Lorenz, Bernd
A1  - Mikat, Jürgen E. R.
A1  - Reck, Günter
A1  - Knochenhauer, Gerald
A1  - Schulz, Burkhard
T1  - Phase transition in 1,3,4-oxadiazole crystals under high pressure
N2  - Crystalline 2,5-di(4-nitrophenyl)-1,3,4-oxadiazole (DNO) has been investigated at pressures up to 5 GPa using Raman and optical spectroscopy as well as energy dispersive X-ray techniques. At ambient pressure DNO shows an orthorhombic unit cell (a = 0.5448 nm, b = 1.2758 nm, c = 1.9720 nm, density 1.513 g cm-3) with an appropriate space group Pbcn. From Raman spectroscopic investigations three phase transitions have been detected at 0.88, 1.28, and 2.2 GPa, respectively. These transitions have also been confirmed by absorption spectroscopy and X-ray measurements. Molecular modeling simulations have considerably contributed to the interpretation of the X-ray diffractograms. In general, the nearly flat structure of the oxadiazole molecule is preserved during the transitions. All subsequent structures are characterized by a stack-like arrangement of the DNO molecules. Only the mutual position of these molecular stacks changes due to the transformations so that this process may be described as a topotactical reaction. Phases II and III show a monoclinic symmetry with space group P21/c with cell parameters a = 1.990 nm, b = 0.500 nm, c = 1.240 nm, ß = 91.7°, density 1.681 g cm-3 (phase II, determined at 1. 1 GPa) and a = 1.890 nm, b = 0.510 nm, C = 1.242 nm, ß = 89.0°, density 1.733 g cm-3 (phase 111, determined at 2.0 GPa), respectively. The high-pressure phase IV stable at least up to 5 GPa shows again an orthorhombic structure with space group Pccn with corresponding cell parameters at 2.9 GPa: a = 0.465 nm, b = 1.920 nm, c = 1.230 nm and density 1.857 g cm-3 . For the first phase a blue pressure shift of the onset of absorption by about 0.032 eV GPa has been observed that may be explained by pressure influences on the electronic conjugation of the molecule. In the intermediate and high-pressure phases II-IV the onset of absorption shifts to increased wavelengths due to larger intermolecular interactions and enhanced excitation delocalization with decreasing intermolecular spacing.
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Strelina, Irina A.
A1  - Okatova, Olga V.
A1  - Schulz, Burkhard
T1  - Orientation of naphthylene ring in the new poly(naphthylen-1,3,4-oxadiazole)s molecules
Y1  - 1996
ER  -