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1Latest Papers from Table of Contents or Articles in PressP. K. Joshi ; T. Esko ; H. Mattsson ; N. Eklund ; I. Gandin ; T. Nutile ; A. U. Jackson ; C. Schurmann ; A. V. Smith ; W. Zhang ; Y. Okada ; A. Stancakova ; J. D. Faul ; W. Zhao ; T. M. Bartz ; M. P. Concas ; N. Franceschini ; S. Enroth ; V. Vitart ; S. Trompet ; X. Guo ; D. I. Chasman ; J. R. O'Connel ; T. Corre ; S. S. Nongmaithem ; Y. Chen ; M. Mangino ; D. Ruggiero ; M. Traglia ; A. E. Farmaki ; T. Kacprowski ; A. Bjonnes ; A. van der Spek ; Y. Wu ; A. K. Giri ; L. R. Yanek ; L. Wang ; E. Hofer ; C. A. Rietveld ; O. McLeod ; M. C. Cornelis ; C. Pattaro ; N. Verweij ; C. Baumbach ; A. Abdellaoui ; H. R. Warren ; D. Vuckovic ; H. Mei ; C. Bouchard ; J. R. Perry ; S. Cappellani ; S. S. Mirza ; M. C. Benton ; U. Broeckel ; S. E. Medland ; P. A. Lind ; G. Malerba ; A. Drong ; L. Yengo ; L. F. Bielak ; D. Zhi ; P. J. van der Most ; D. Shriner ; R. Magi ; G. Hemani ; T. Karaderi ; Z. Wang ; T. Liu ; I. Demuth ; J. H. Zhao ; W. Meng ; L. Lataniotis ; S. W. van der Laan ; J. P. Bradfield ; A. R. Wood ; A. Bonnefond ; T. S. Ahluwalia ; L. M. Hall ; E. Salvi ; S. Yazar ; L. Carstensen ; H. G. de Haan ; M. Abney ; U. Afzal ; M. A. Allison ; N. Amin ; F. W. Asselbergs ; S. J. Bakker ; R. G. Barr ; S. E. Baumeister ; D. J. Benjamin ; S. Bergmann ; E. Boerwinkle ; E. P. Bottinger ; A. Campbell ; A. Chakravarti ; Y. Chan ; S. J. Chanock ; C. Chen ; Y. D. Chen ; F. S. Collins ; J. Connell ; A. Correa ; L. A. Cupples ; G. D. Smith ; G. Davies ; M. Dorr ; G. Ehret ; S. B. Ellis ; B. Feenstra ; M. F. Feitosa ; I. Ford ; C. S. Fox ; T. M. Frayling ; N. Friedrich ; F. Geller ; G. Scotland ; I. Gillham-Nasenya ; O. Gottesman ; M. Graff ; F. Grodstein ; C. Gu ; C. Haley ; C. J. Hammond ; S. E. Harris ; T. B. Harris ; N. D. Hastie ; N. L. Heard-Costa ; K. Heikkila ; L. J. Hocking ; G. Homuth ; J. J. Hottenga ; J. Huang ; J. E. Huffman ; P. G. Hysi ; M. A. Ikram ; E. Ingelsson ; A. Joensuu ; A. Johansson ; P. Jousilahti ; J. W. Jukema ; M. Kahonen ; Y. Kamatani ; S. Kanoni ; S. M. Kerr ; N. M. Khan ; P. Koellinger ; H. A. Koistinen ; M. K. Kooner ; M. Kubo ; J. Kuusisto ; J. Lahti ; L. J. Launer ; R. A. Lea ; B. Lehne ; T. Lehtimaki ; D. C. Liewald ; L. Lind ; M. Loh ; M. L. Lokki ; S. J. London ; S. J. Loomis ; A. Loukola ; Y. Lu ; T. Lumley ; A. Lundqvist ; S. Mannisto ; P. Marques-Vidal ; C. Masciullo ; A. Matchan ; R. A. Mathias ; K. Matsuda ; J. B. Meigs ; C. Meisinger ; T. Meitinger ; C. Menni ; F. D. Mentch ; E. Mihailov ; L. Milani ; M. E. Montasser ; G. W. Montgomery ; A. Morrison ; R. H. Myers ; R. Nadukuru ; P. Navarro ; M. Nelis ; M. S. Nieminen ; I. M. Nolte ; G. T. O'Connor ; A. Ogunniyi ; S. Padmanabhan ; W. R. Palmas ; J. S. Pankow ; I. Patarcic ; F. Pavani ; P. A. Peyser ; K. Pietilainen ; N. Poulter ; I. Prokopenko ; S. Ralhan ; P. Redmond ; S. S. Rich ; H. Rissanen ; A. Robino ; L. M. Rose ; R. Rose ; C. Sala ; B. Salako ; V. Salomaa ; A. P. Sarin ; R. Saxena ; H. Schmidt ; L. J. Scott ; W. R. Scott ; B. Sennblad ; S. Seshadri ; P. Sever ; S. Shrestha ; B. H. Smith ; J. A. Smith ; N. Soranzo ; N. Sotoodehnia ; L. Southam ; A. V. Stanton ; M. G. Stathopoulou ; K. Strauch ; R. J. Strawbridge ; M. J. Suderman ; N. Tandon ; S. T. Tang ; K. D. Taylor ; B. O. Tayo ; A. M. Toglhofer ; M. Tomaszewski ; N. Tsernikova ; J. Tuomilehto ; A. G. Uitterlinden ; D. Vaidya ; A. van Hylckama Vlieg ; J. van Setten ; T. Vasankari ; S. Vedantam ; E. Vlachopoulou ; D. Vozzi ; E. Vuoksimaa ; M. Waldenberger ; E. B. Ware ; W. Wentworth-Shields ; J. B. Whitfield ; S. Wild ; G. Willemsen ; C. S. Yajnik ; J. Yao ; G. Zaza ; X. Zhu ; R. M. Salem ; M. Melbye ; H. Bisgaard ; N. J. Samani ; D. Cusi ; D. A. Mackey ; R. S. Cooper ; P. Froguel ; G. Pasterkamp ; S. F. Grant ; H. Hakonarson ; L. Ferrucci ; R. A. Scott ; A. D. Morris ; C. N. Palmer ; G. Dedoussis ; P. Deloukas ; L. Bertram ; U. Lindenberger ; S. I. Berndt ; C. M. Lindgren ; N. J. Timpson ; A. Tonjes ; P. B. Munroe ; T. I. Sorensen ; C. N. Rotimi ; D. K. Arnett ; A. J. Oldehinkel ; S. L. Kardia ; B. Balkau ; G. Gambaro ; A. P. Morris ; J. G. Eriksson ; M. J. Wright ; N. G. Martin ; S. C. Hunt ; J. M. Starr ; I. J. Deary ; L. R. Griffiths ; H. Tiemeier ; N. Pirastu ; J. Kaprio ; N. J. Wareham ; L. Perusse ; J. G. Wilson ; G. Girotto ; M. J. Caulfield ; O. Raitakari ; D. I. Boomsma ; C. Gieger ; P. van der Harst ; A. A. Hicks ; P. Kraft ; J. Sinisalo ; P. Knekt ; M. Johannesson ; P. K. Magnusson ; A. Hamsten ; R. Schmidt ; I. B. Borecki ; E. Vartiainen ; D. M. Becker ; D. Bharadwaj ; K. L. Mohlke ; M. Boehnke ; C. M. van Duijn ; D. K. Sanghera ; A. Teumer ; E. Zeggini ; A. Metspalu ; P. Gasparini ; S. Ulivi ; C. Ober ; D. Toniolo ; I. Rudan ; D. J. Porteous ; M. Ciullo ; T. D. Spector ; C. Hayward ; J. Dupuis ; R. J. Loos ; A. F. Wright ; G. R. Chandak ; P. Vollenweider ; A. R. Shuldiner ; P. M. Ridker ; J. I. Rotter ; N. Sattar ; U. Gyllensten ; K. E. North ; M. Pirastu ; B. M. Psaty ; D. R. Weir ; M. Laakso ; V. Gudnason ; A. Takahashi ; J. C. Chambers ; J. S. Kooner ; D. P. Strachan ; H. Campbell ; J. N. Hirschhorn ; M. Perola ; O. Polasek ; J. F. Wilson
Nature Publishing Group (NPG)
Published 2015Staff ViewPublication Date: 2015-07-02Publisher: Nature Publishing Group (NPG)Print ISSN: 0028-0836Electronic ISSN: 1476-4687Topics: BiologyChemistry and PharmacologyMedicineNatural Sciences in GeneralPhysicsKeywords: Biological Evolution ; Blood Pressure/genetics ; Body Height/*genetics ; Cholesterol, LDL/genetics ; *Cognition ; Cohort Studies ; Educational Status ; Female ; Forced Expiratory Volume/genetics ; Genome, Human/genetics ; *Homozygote ; Humans ; Lung Volume Measurements ; Male ; PhenotypePublished by: -
2Articles: DFG German National LicensesBLUMENTHAL, M. N. ; BANKS-SCHLEGEL, S. ; BLEECKER, E. R. ; MARSH, D. G. ; OBER, C.
Oxford, UK : Blackwell Publishing Ltd
Published 1995Staff ViewISSN: 1365-2222Source: Blackwell Publishing Journal Backfiles 1879-2005Topics: MedicineType of Medium: Electronic ResourceURL: -
3Articles: DFG German National LicensesStaff View
ISSN: 1436-2449Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: Summary A series of model liquid crystalline (LC) polyesters have been prepared by low temperature solution polycondensation using staged addition methods. The model thermotropic polyesters were composed of aliphatic spacers and mesogenic groups made from substituted terephthalic acid and methyl hydroquinone. Both the mesogenic groups and the spacers were placed in the main chain. Attractive properties of these polymers include solubility in many organic solvents such as THF and DMSO with softening temperatures below 150°C. Some of these polymers show no melting transitions, and depending on the terephthalate group substituent, either smectic or nematic phases are formed. Results from GPC analysis show good solubility of polymers in THF with Mw lower than 10,000 compared to polystyrene standards. The synthesis and characterization of these LC polyesters are reported here.Type of Medium: Electronic ResourceURL: -
4Articles: DFG German National LicensesStaff View
ISSN: 1434-6036Keywords: PACS. 63.20.Dj Phonon states and bands, normal modes, and phonon dispersion - 76.80.+y Mössbauer effect; other -ray spectroscopy - 39.30.+w Spectroscopic techniquesSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Abstract: Mössbauer studies were performed on single crystals of guanidinium nitroprusside with different orientations of their principal crystallographic axes (a, b, c) with respect to the incident radiation. The markedly anisotropic Lamb-Mössbauer factor f LM , i.e. f LM (a) = 0.118(8), f LM (b) = 0.174(8), f LM (c) = 0.202(8) is in contrast to that of nitroprussides with inorganic anions. The observed anisotropy is ascribed to the anisotropic vibrational mean-square displacement of the nitroprusside anions as a whole which is due to the specific packing of both, anions and cations, as well as the very weak chemical bonding between the ions, typical only for guanidinium nitroprusside. The vibrational anisotropy of iron atoms in barium nitroprusside that has been observed by X-ray structural investigations has a different origin and therefore does not result in an anisotropic Lamb-Mössbauer factor. We have also investigated metastable states in guanidinium nitroprusside that have been populated by means of incoherent irradiation from light-emitting diodes. With a specific orientation of the guanidinium nitroprusside single crystal a population of the metastable states up to 26% could be achieved. Populations of comparable size on lithium, sodium and potassium nitroprussides have only been reached using coherent laser irradiation.Type of Medium: Electronic ResourceURL: -
5Articles: DFG German National LicensesStaff View
ISSN: 1432-1211Keywords: Key words HLA ; Ancestral haplotypes ; Recombinant haplotypes ; HutteritesSource: Springer Online Journal Archives 1860-2000Topics: BiologyMedicineNotes: Abstract Prior studies in the Schmiedeleut Hutterites of South Dakota have demonstrated associations between human leukocyte antigen (HLA) haplotype matching and fetal loss (Ober et al. 1992) and mate preferences (Ober et al. 1997), as well as deficiencies of homozygotes for HLA haplotypes (Kostyu et al. 1993). These studies were based on the serologically-defined five-locus HLA-A, -C, -B, -DR, -DQ haplotype. To further elucidate the effects of specific major histocompatibility (MHC) loci or regions on fetal loss and mate choice, we genotyped a sample of Hutterites for 14 MHC loci by DNA or biochemical methods. Typing for additional loci in the HLA-A to HLA-DPB1 region increased the number of recognized Hutterite MHC haplotypes to 67, and further localized the site of cross-over in 9 of 15 recombinant haplotypes. Hutterite MHC haplotype sequences are similar to those observed in outbred Caucasians, suggesting that the influence of HLA haplotypes on fetal loss and mating structure may be general.Type of Medium: Electronic ResourceURL: -
6Articles: DFG German National LicensesStaff View
ISSN: 0047-2484Keywords: gene flow ; rhesus macaques ; stochastic migrationSource: Elsevier Journal Backfiles on ScienceDirect 1907 - 2002Topics: BiologyType of Medium: Electronic ResourceURL: -
7Articles: DFG German National LicensesStaff View
ISSN: 0392-6737Keywords: Mössbauer spectra ; Spectra ; photodissociation and photoionization of biomolecules ; bioluminescence ; Measurement of rate constants ; reaction cross-sections and activation energy ; Conference proceedingsSource: Springer Online Journal Archives 1860-2000Topics: PhysicsNotes: Summary Partial photodissociation of two carbonmonoxy-porphyrin complexes, a bridged and a fenced one, has been achieved. The results from monitoring the recombination point to an important influence of the solvent matrix on the recombination rates.Type of Medium: Electronic ResourceURL: -
8Articles: DFG German National LicensesOber, C. ; Burkardt, M. ; Winkler, H. ; Trautwein, A. X. ; Zharikov, A. A. ; Fischer, S. F. ; Parak, F.
Springer
Published 1997Staff ViewISSN: 1432-1017Keywords: Key words Carbonmonoxy-Myoglobin ; Recombination kinetics ; Mössbauer spectroscopy ; Scaling law ; Activated tunnelingSource: Springer Online Journal Archives 1860-2000Topics: BiologyPhysicsNotes: Abstract We have studied the recombination kinetics of carboxymyoglobin (after photodissociation of the CO ligand) by Mössbauer spectroscopy for temperatures in the range 4.2 – 60 K. The observed kinetics display non-exponential behaviour which was monitored over periods of a few days. It is shown that the time dependence of the kinetics can be reduced to a single universal function of the temperature-dependent variable (t/τ 1/2(T)) β(T) . The half-decay time τ 1/2(T) and the scaling parameter β(T) are analysed for the presence of tunneling effects. The non-Arrhenius temperature dependence of the half-decay time below 60 K is interpreted as activated tunneling in models with an Eckart barrier or a fluctuating barrier.Type of Medium: Electronic ResourceURL: -
9Articles: DFG German National LicensesStaff View
ISSN: 1432-0711Source: Springer Online Journal Archives 1860-2000Topics: MedicineNotes: Zusammenfassung 46 chromosomal normale Abortfrüchte von Paaren mit zuvor mindestens 3 spontanen Aborten ungeklärter Ätiologie wurden typisiert für 8 HLA-DQA1 und 16 HLA-DQB1 Allele. Die beobachteten Häfigkeiten an homozygoten und mit der Mutter kompatiblen Feten unterschieden sich nicht signifikant von den erwarteten Häufigkeiten bei einer rein zufälligen Verteilung der elterlichen Allele. Diese Daten widersprechen der These, daß HLA-kompatible Feten in der Schwangerschaft einem Selektionsanteil unterlägen und bevorzugt abortiert würden.Type of Medium: Electronic ResourceURL: -
10Articles: DFG German National LicensesStaff View
ISSN: 1435-1528Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyPhysicsType of Medium: Electronic ResourceURL: -
11Articles: DFG German National LicensesStaff View
ISSN: 1436-2449Source: Springer Online Journal Archives 1860-2000Topics: Chemistry and PharmacologyMechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsPhysicsNotes: Summary Liquid crystalline copolyethers were prepared from monomer pairs selected from biphenol (BP), dihydroxy-α-methylstilbene (DHMS), and 2,2′-dimethyl-4,4′-dihydroxyazoxybenzene (DMAz) which were copolymerized with either dibromononane or dibromodecane spacers by phase transfer catalysis. Nematic LC mesophases were observed for most copolymers, but some exhibited dual mesophases. Smectic to nematic transitions were found in polymers with intermediate ratios of DMAz and DHMS with the nonamethylene spacer. These polymers showed excellent solubility in THF and CHCl3. The longest mesophase range which consisted of two mesophases was found in a polymer composed of a 4:1 ratio of DHMS to BP and a nonane spacer.Type of Medium: Electronic ResourceURL: -
12Articles: DFG German National LicensesStaff View
ISSN: 1573-4803Source: Springer Online Journal Archives 1860-2000Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsNotes: Abstract The microdeformation and fracture mechanisms of a densely crosslinked, polydomain, smectic liquid crystalline thermoset (LCT) were investigated in order to gain some insight into its interesting mechanical properties (e.g. improved fracture toughness). A difunctional LC epoxy monomer, diglycidyl ether of 4,4′-dihydroxy-α-methylstilbene (DGDHMS), was crosslinked with the tetrafunctional, aromatic crosslinker, 4,4′-methylene dianiline (MDA) to produce the LCT. Thermoset films (30 μm in thickness) were bonded to copper grids, strained in tension, and observed under the polarizing optical microscope. A new type of microdeformation and fracture mechanism was observed for the smectic LCT. At small strains, numerous microcracks formed which were oriented at various angles to the straining direction. Many smaller isolated and interconnected defects (of the order of a single LC domain, ∼1 μm in size) surrounded and emanated from the crack tips. At larger strains, the microcracks propagated slowly and stably until reaching a critical size of ∼250 μm, at which time they began to widen and change direction, indicative of plastic deformation which extended over many LC domains. Film failure occurred through microcrack interconnection. A fracture mechanism for the LCT is proposed based on microscopic voiding near the crack tip through the failure of individual LC domains.Type of Medium: Electronic ResourceURL: -
13Articles: DFG German National LicensesHall, E. E. ; Robinson, A. A. ; Mcnamee, S. G. ; Ober, C. K. ; Freidzon, Y. S.
Springer
Published 1995Staff ViewISSN: 1573-4803Source: Springer Online Journal Archives 1860-2000Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision MechanicsNotes: Abstract Shear alignment studies of a semirigid, main-chain liquid crystalline polymer found very different behaviour within a low temperature, birefringent phase than within the higher temperature, nematic phase. Using X-ray scattering techniques and thermal analysis, the low temperature “intermediate” phase was identified as a nematic phase with approximately 5–10 vol% smectic cophase. Unique thermal characteristics of the intermediate phase are described.Type of Medium: Electronic ResourceURL: -
14Articles: DFG German National LicensesBarclay, G. G. ; McNamee, S. G. ; Ober, C. K. ; Papathomas, K. I. ; Wang, D. W.
Bognor Regis [u.a.] : Wiley-Blackwell
Published 1992Staff ViewISSN: 0887-624XKeywords: liquid crystalline ; networks ; epoxy ; thermotropic ; thermoset ; smectic ; nematic ; Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: The processing of a new series of liquid crystalline (LC) epoxy networks was evaluated. Above the glass transition temperature, the low crosslink density networks could be mechanically aligned. The mechanically oriented networks readily lost orientation upon heating. Highly anisotropic liquid crystalline (LC) epoxy networks were also prepared by aligning the mesophase of the prepolymer during the curing process under the influence of a magnetic field. Orientation parameters (f) of 0.13 to 0.57 were achieved by these processes as determined by x-ray diffraction analysis. The ability of the magnetically aligned networks to retain their orientation above the glass transition temperature was determined by time-resolved x-ray diffraction. The stability of the alignment of these networks was found to depend on crosslink density. The effect of the anisotropy of these networks was investigated by measuring the coefficient of thermal expansion (CTE). In the aligned networks, there was a substantial reduction in CTE parallel to the direction of the applied field compared to the randomly oriented networks. © 1992 John Wiley & Sons, Inc.Additional Material: 7 Ill.Type of Medium: Electronic ResourceURL: -
15Articles: DFG German National LicensesStaff View
ISSN: 0887-624XKeywords: nonlinear optics ; liquid crystal ; polymers ; photocrosslinking ; Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: New liquid-crystalline (LC) polymers and small molecules have been synthesized based on the 1,4-diphenylbutadiene mesogen, a chromophore with χ(3) nonlinear optical properties. Polyethers were formed by phase-transfer reaction, and polyesters were prepared by Schotten-Bauman polymerization from these 4,4'-bisphenolic mesogenic structures. Liquid crystallinity was examined using differential scanning calorimetry (DSC) and optical microscopy. Most of the model compounds were found to be nematic. All mesomorphic polymers were nematic and displayed LC ranges of up to 50°C as well as a wide diversity of melting points. The melting points varied with the flexible (methylene) spacer length and were strongly dependent upon the presence of substituents in the mesogenic core. Crosslinking and cis-trans isomerization were observed under the influence of heat and ultraviolet radiation. © 1992 John Wiley & Sons, Inc.Additional Material: 3 Ill.Type of Medium: Electronic ResourceURL: -
16Articles: DFG German National LicensesLiquid crystalline epoxy thermosets based on dihydroxymethylstilbene: Synthesis and characterizationBarclay, G. G. ; Ober, C. K. ; Papathomas, K. I. ; Wang, D. W.
Bognor Regis [u.a.] : Wiley-Blackwell
Published 1992Staff ViewISSN: 0887-624XKeywords: liquid crystalline ; networks ; epoxy ; thermotropic ; thermoset ; smectic ; nematic ; Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: This article describes the synthesis and characterization of a new series of liquid crystalline thermosets. Nematic epoxy-terminated oligoethers based on dihydroxy-α-methylstilbene were synthesized for this study. These prepolymers were crosslinked within the nematic mesophase using methylenedianiline. Depending upon the molecular weight and polydispersity of the oligoether, the crosslinking reaction resulted in networks with either a smectic or nematic molecular organization in contrast to the simple nematic phase of the oligoether. The formation of a smectic-like structure on curing was found to be related to the breadth of the prepolymer molecular weight. In those networks with a low crosslink density a clearing transition could be observed, whereas in the more highly crosslinked networks the molecular organization was frozen in until decomposition. The glass transition temperature of these LC networks rose as the crosslink density was increased, ranging from 35 to 152°C. In agreement with theory, the clearing transition of the networks was found to be dependent on the phase state during curing © 1992 John Wiley & Sons, Inc.Additional Material: 11 Ill.Type of Medium: Electronic ResourceURL: -
17Articles: DFG German National LicensesStaff View
ISSN: 0887-6266Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyPhysicsNotes: Mesophase transitions in liquid-crystalline (LC) polyesters were studied by dynamic x-ray diffraction using a synchrotron radiation source. Powder and fiber samples were examined by continuous heating from 50°C to 270°C in a hot stage. The polymer systems consisted of two types of thermotropic polyesters with mesogenic cores composed of combinations of substituted terephthalate, oxybenzoate and hydroquinone units combined with aliphatic spacers placed in the main chain. One of these samples was a chemically homogeneous LC polyester (HTH12) while the other LC polyester possessed chemical heterogeneity (BP6). BP6 could also be processed to form fibers which showed thermal transition behavior by x-ray diffraction and no detectable melting or clearing transition by thermal measurements. LC textures were observed using polarized light microscopy. Results of the dynamic x-ray diffraction studies of these two LC polymers are described.Additional Material: 11 Ill.Type of Medium: Electronic ResourceURL: -
18Articles: DFG German National LicensesStaff View
ISSN: 0887-6266Keywords: liquid crystalline polymers ; isotropic-smectic transition ; kinetics ; x-ray dif-fraction ; synchrotron ; Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyPhysicsNotes: In this work we have used synchrotron x-radiation diffraction to follow in real-time the isotropic-smoetic phase transition of a side-chain liquid crystalline polymer. The analysis of the x-ray data indicated that the transition occurs within a very narrow biphasic region. As the transition takes place, the size of the smectic regions, as indicated by the width of the diffraction peaks, changed only very slightly before impingement, suggesting a two-dimensional growth pattern. A thermal investigation of the polymer paralleling the x-ray experiments was undertaken and a kinetic analysis applied to the resulting data. Qualitative agreement with a disk-like growth of the smectic regions was found. We have shown that the overall kinetics of the isotropic-smectic transition of a side-chain polymer can be studied by x-ray diffraction permitting the evaluation of several structural parameters. © 1993 John Wiley & Sons, Inc.Additional Material: 6 Ill.Type of Medium: Electronic ResourceURL: -
19Articles: DFG German National LicensesStaff View
ISSN: 0887-6258Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyNotes: New main-chain thermotropic liquid crystalline (lc) polymers based on four derivatives of 4,4′- (p-phenylenedi-1,2-ethenediyl)bisphenol have heen prepared by Schotten-Baumen polymerization. Fusibility and solubility were achieved through the incorporation of side groups and flexible methylene spacers. Both a model ester and polymers based on the unsubstituted bisphenol were thermotropic, but had melting points in the vicinity of decomposition. Methyl, methoxy, and ethoxy side groups were used to lower the melting transition. The liquid-crystallinity was investigated with polarized light microscopy, differential scanning calorimetry, and X-ray diffraction. Methyl substitution provided the model compound and polymers with the greatest number of mesophases. Chemical structure was analyzed by infrared and UV/visible spectroscopy, 1H NMR, and elemental analysis of monomers and model compounds. Intrinsic viscosities were measured in N-methylpyrrolidone (nmp) solution.Additional Material: 4 Ill.Type of Medium: Electronic ResourceURL: -
20Articles: DFG German National LicensesStaff View
ISSN: 0323-7648Keywords: Chemistry ; Polymer and Materials ScienceSource: Wiley InterScience Backfile Collection 1832-2000Topics: Chemistry and PharmacologyPhysicsNotes: The interest in block copolymers containing liquid crystalline (LC) segments is due to the resulting interplay between mesophase formation and the microphase structure which creates opportunities in tailoring their nanostructure. This review summarizes recent literature reporting LC-coil block copolymers with well controlled microphase morphologies produced using living methods. Developing applications are also described and include LC displays and low energy surfaces.Additional Material: 15 Ill.Type of Medium: Electronic ResourceURL: