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  - Rottke, Falko O.
A1  - Schulz, Burkhard
A1  - Richau, Klaus
A1  - Kratz, Karl
A1  - Lendlein, Andreas
T1  - An ellipsometric approach towards the description of inhomogeneous polymer-based Langmuir layers
JF  - Beilstein journal of nanotechnology
N2  - The applicability of nulling-based ellipsometric mapping as a complementary method next to Brewster angle microscopy (BAM) and imaging ellipsometry (IE) is presented for the characterization of ultrathin films at the air-water interface. First, the methodology is demonstrated for a vertically nonmoving Langmuir layer of star-shaped, 4-arm poly(omega-pentadecalactone) (PPDL-D4). Using nulling-based ellipsometric mapping, PPDL-D4-based inhomogeneously structured morphologies with a vertical dimension in the lower nm range could be mapped. In addition to the identification of these structures, the differentiation between a monolayer and bare water was possible. Second, the potential and limitations of this method were verified by applying it to more versatile Langmuir layers of telechelic poly[(rac-lactide)-co-glycolide]-diol (PLGA). All ellipsometric maps were converted into thickness maps by introduction of the refractive index that was derived from independent ellipsometric experiments, and the result was additionally evaluated in terms of the root mean square roughness, R-q. Thereby, a three-dimensional view into the layers was enabled and morphological inhomogeneity could be quantified.
KW  - ellipsometric mapping
KW  - Langmuir monolayer
KW  - polyester
KW  - root mean square roughness
KW  - spectroscopic ellipsometry
Y1  - 2016
U6  - https://doi.org/10.3762/bjnano.7.107
SN  - 2190-4286
VL  - 7
SP  - 1156
EP  - 1165
PB  - Beilstein-Institut zur Förderung der Chemischen Wissenschaften
CY  - Frankfurt, Main
ER  - 
TY  - JOUR
A1  - Rossberg, Joana
A1  - Rottke, Falko O.
A1  - Schulz, Burkhard
A1  - Lendlein, Andreas
T1  - Enzymatic Degradation of Oligo(epsilon-caprolactone)s End-Capped with Phenylboronic Acid Derivatives at the Air-Water Interface
JF  - Macromolecular rapid communications
N2  - The influence of terminal functionalization of oligo(epsilon-caprolactone)s (OCL) with phenylboronic acid pinacol ester or phenylboronic acid on the enzymatic degradation behavior at the air-water interface is investigated by the Langmuir monolayer degradation technique. While the unsubstituted OCL immediately degrades after injection of the enzyme lipase from Pseudomonas cepacia, enzyme molecules are incorporated into the films based on end-capped OCL before degradation. This incorporation of enzymes does not inhibit or suppress the film degradation, but retards it significantly. A specific binding of lipase to the polymer monolayer allows studying the enzymatic activity of bound proteins and the influence on the degradation process. The functionalization of a macromolecule with phenyl boronic acid groups is an approach to investigate their interactions with diol-containing biomolecules like sugars and to monitor their specified impact on the enzymatic degradation behavior at the air-water interface.
Y1  - 2016
U6  - https://doi.org/10.1002/marc.201600471
SN  - 1022-1336
SN  - 1521-3927
VL  - 37
SP  - 1966
EP  - 1971
PB  - Wiley-VCH
CY  - Weinheim
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  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Hamciuc, Corneliu
A1  - Hamciuc, Elena
A1  - Mercer, Frank W.
A1  - Belomoina, Nataliya
A1  - Schulz, Burkhard
T1  - Heterocyclic polyamides containing hexafluoroisopropylidene groups
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Bruma, Maria
A1  - Hamciuc, Corneliu
A1  - Sava, Ion
A1  - Hamciuc, Elena
A1  - Mercer, Frank W.
A1  - Fritzsche, P.
A1  - Schulz, Burkhard
T1  - High temperature polyamides containing pendant imide groups
Y1  - 1996
ER  - 
TY  - JOUR
A1  - Zhu, Shigen
A1  - Schulz, Burkhard
A1  - Bruma, Maria
A1  - Brehmer, Ludwig
T1  - Comparative study of the thermal properties of related aromatic polyhydrazides and poly(1,3,4-oxadiazole)s
Y1  - 1996
UR  - http://www3.interscience.wiley.com/journal/5401/home?CRETRY=1&SRETRY=0
U6  - https://doi.org/10.1002/(SICI)1099-1581(199612)7:12<879::AID-PAT600>3.0.CO;2-X
SN  - 1042-7147
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  - 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  - 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  - Stiller, Burkhard
A1  - Zetzsche, Thomas
A1  - Knochenhauer, Gerald
A1  - Brehmer, Ludwig
T1  - Characterization of crystals based on 1,3,4-oxadiazoles by atomic force microscopy
N2  - The surface structures of crystals based on aromatic oxadiazoles were investigated by AFM. The crystal structure for 2,5-di(p-tolyl)-1,3,4-oxadiazole (DTO) differs from that of 2,5-di (4-methoxycarbonyl-phenyl)-1,3,4- oxadiazole (DMPO). In DMPO all molecules show parallel orientation to the surface in such a way that the surface is formed as well as by the nitrogen atoms of the heterocyclic rings and the methyl groups of the ester substituents. By contrast, the oxadiazole molecules in DTO crystals are oriented perpendicular to the crystal surface. The experimental data are interpreted by molecular modelling. It is shown that there is a difference between molecular structure of the surface, as detected by AFM, and the bulk structure determined by X-ray diffraction.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Reiche, Jürgen
A1  - Zetzsche, Thomas
A1  - Helms, Andreas
A1  - Freydank, Anke-Christine
A1  - Knochenhauer, Gerald
A1  - Schulz, Burkhard
A1  - Brehmer, Ludwig
T1  - Organized molecular films of oxadiazole compounds formed by vacuum deposition
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Reiche, Jürgen
A1  - Freydank, A.
A1  - Dietzel, Birgit
A1  - Katholy, Stefan
A1  - Knochenhauer, Gerald
A1  - Zetzsche, Thomas
A1  - Schulz, Burkhard
A1  - Brehmer, Ludwig
T1  - Komplexe Strukturanalytik von Oxadiazol-Mono- und Multischichten
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Brehmer, Ludwig
A1  - Dietzel, Birgit
A1  - Freydank, Anke-Christine
A1  - Katholy, Stefan
A1  - Knochenhauer, Gerald
A1  - Reiche, Jürgen
A1  - Schulz, Burkhard
A1  - Zetzsche, Thomas
T1  - Langmuir- und Langmuir-Blodgett-Filme amphiphiler Oxadiazole
Y1  - 1995
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Bruma, Maria
A1  - Brehmer, Ludwig
T1  - Aromatic poly(1,3,4-oxadiazole)s as advanced materials
N2  - Poly(1,3,4-oxadiazole)s have been the focus of considerable interest with regard to the- production of high- performance materials, particularly owing to their high thermal stability in oxidative atmosphere and specific properties determined by the structure of 1,3,4-oxadiazole ring, which, from the spectral and electronic points of view, is similar to a p-phenylene structure.[1] Besides their excellent resistance to high temperature, polyoxadiazoles have many desirable characteristics, such as good hydrolytic stability, high glass transition temperatures, low dielectric constants, and tough mechanical properties. Some polyoxadiazoles have semiconductive properties, other structures can be electrochemically doped and thus made conductive, and other have liquid-crystalline properties, which make them very attractive for a wide range of high-performance applications. They exhibit excellent fiber- and film-forming capabilities, thus being considered for use as heat-resistant reinforcing fibers for advanced composite materials, highly resistant fabrics for the filtration of hot gases, special membranes for gas separation or reverse osmosis, precursors for highly oriented graphite fibers, films, and blocks to be used in the construction of electronic instruments based on X-rays, neutron beams, or a-particles, or in the construction of nuclear reactor walls. Since they were first reported in 1961,[2] a wide variety of polymers containing 1,3,4-oxadiazole rings have been synthesized, and their preparation, characterization, and physico-mechanical properties have been periodically reviewed .[3-8] This article will present a general overview of this class of polymers and will refer to the work carried out by different researchers in the last ten years with the emphasis on the potential uses of such polymers as advanced materials.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Sava, Ion
A1  - Szesztay, Marta
A1  - Bruma, Maria
A1  - Mercer, Frank W.
A1  - Schulz, Burkhard
T1  - Compared properties of aromatic polyamides containing silicon in the chain
N2  - Two series of aromatic polyamides incorporating silicon together with phenylquinoxaline or with hexafluoroisopropylidene groups have been synthesized and their properties have been characterized and compared with those of related polymers. These polymers are easily soluble in polar amidic solvents such as N-rnethyl-2-pyrrolidinone and dimethylformamide, and in tetrahydrofuran, and can be cast into thin, transparent films from solution. The polyamides have weight- and number-average molecular weights in the range of 10000-40000 and 3000-6000, respectively, and polydispersities in the range of 3-10. They show glass transition temperatures in the range of 236 °C-275 °C and decomposition temperatures above 400 °C. The polymer films have low dielectric constants in the range of 3.26-3.68, and good mechanical properties (tensile strength 74-100 MPa, tensile modulus 180-386 MPa), thus being comparable with other high performance dielectrics.
Y1  - 1997
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  - Bruma, Maria
A1  - Hamciuc, Corneliu
A1  - Hamciuc, Elena
A1  - Mercer, Frank W.
A1  - Belomoina, Nataliya
A1  - Schulz, Burkhard
T1  - Heterocyclic polyamides containing hexafluoroisopropylidene groups
N2  - New heterocyclic polyamides have been synthesized by solution polycondensation of aromatic diamines containing phenyl- quinoxaline units with diacid chlorides having both imide and hexafluoroisopropylidene (6F) groups. These polymers are soluble in polar aprotic solvents, such as N-methylpyrrolidone (NMP) or N,N-dimethylformamide (DMF), and can be cast into flexible thin films from solutions. They show high thermooxidative stability with decomposition temperatures above 400°C and glass transition temperatures in the range of 225 - 300°C. The polymer films exhibit good chemical resistance towards deluted acids and good electrical insulating properties with dielectric constants in the range of 3.2 - 3.7.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Lavrenko, Peter N.
A1  - Strelina, Irina A.
A1  - Schulz, Burkhard
T1  - Dynamo-optical properties of poly(naphthylene oxadiazole)s in sulfuric acid
N2  - Flow birefringence induced in dilute solutions of poly[(1,4-naphthylene)-2,5-diyl-1,3,4-oxadiazole] and poly[2,6-naphthylene)-2,5-diyl-1,3,4-oxadiazole] in conc. sulphuric acid has been investigated. The shear optical coefficient was found for these polymers to be approximately double the value of that obtained in the same solvent for poly[(para-phenylene) -2,5-diyl-1,3,4-oxadiazole]. Rigid-chain behaviour of the polymers was characterized by hydrodynamic and dynamo-optical parameters evaluated with application of the worm-like chain model and the "method of similar structures". Change in optical anisotropy of a chain unit induced by incorporation of naphthylene groups into the main chain has been evaluated.
Y1  - 1997
ER  - 
TY  - JOUR
A1  - Schulz, Burkhard
A1  - Kaminorz, Yvette
A1  - Brehmer, Ludwig
T1  - New aromatic poly(1,3,4-oxadiazole)s for light emitting diodes
N2  - New aromatic poly(1,3,4-oxadiazole)s were synthesized having excellent film forming properties due to their solubility in common organic solvents. The investigated new polyoxadiazoles can be used as emission material in single layer LED. The poly- oxadiazoles show an emission in the range of blue to yellow light. The external quantum efficiency as well as the turn-on voltage of the devices are influenced when blends of the polyoxadiazole with hole transport materials are used.
Y1  - 1997
ER  -