TY - JOUR A1 - Weber, Nancy A1 - Tiersch, Brigitte A1 - Unterlass, Miriam M. A1 - Heilig, Anneliese A1 - Tauer, Klaus T1 - "Schizomorphic" Emulsion Copolymerization Particles JF - Macromolecular rapid communications N2 - Cryo-electron microscopy, atomic force microscopy, and light microscopy investigations provide experimental evidence that amphiphilic emulsion copolymerization particles change their morphology in dependence on concentration. The shape of the particles is spherical at solids content above 1%, but it changes to rod-like, ring-like, and web-like structures at lower concentrations. In addition, the shape and morphology of these particles at low concentrations are not fixed but very flexible and vary with time between spheres, flexible pearlnecklace structures, and stretched rods. KW - amphiphilic particles KW - emulsion polymerization KW - morphology Y1 - 2011 U6 - https://doi.org/10.1002/marc.201100491 SN - 1022-1336 VL - 32 IS - 23 SP - 1925 EP - 1929 PB - Wiley-Blackwell CY - Malden ER - TY - JOUR A1 - Ott, Susan A1 - Höhle, Barbara T1 - Verb inflection in German-learning children with typical and atypical language acquisition BT - the impact of subsyllabic frequencies JF - Journal of child language N2 - Previous research has shown that high phonotactic frequencies facilitate the production of regularly inflected verbs in English-learning children with specific language impairment (SLI) but not with typical development (TD). We asked whether this finding can be replicated for German, a language with a much more complex inflectional verb paradigm than English. Using an elicitation task, the production of inflected nonce verb forms (3rd person singular with - t suffix) with either high-or low-frequency subsyllables was tested in sixteen German-learning children with SLI (ages 4;1-5;1), sixteen TD-children matched for chronological age (CA) and fourteen TD-children matched for verbal age (VA) (ages 3;0-3;11). The findings revealed that children with SLI, but not CA-or VA-children, showed differential performance between the two types of verbs, producing more inflectional errors when the verb forms resulted in low-frequency subsyllables than when they resulted in high-frequency subsyllables, replicating the results from English-learning children. KW - english past tense KW - sentence repetition KW - nonword repetition KW - speaking children KW - impairment KW - morphology KW - infants KW - speech KW - words Y1 - 2012 U6 - https://doi.org/10.1017/S030500091200027X SN - 0305-0009 VL - 40 IS - 1 SP - 169 EP - 192 PB - Cambridge University Press CY - New York ER - TY - JOUR A1 - Turner, Sarah T. A1 - Pingel, Patrick A1 - Steyrleuthner, Robert A1 - Crossland, Edward J. W. A1 - Ludwigs, Sabine A1 - Neher, Dieter T1 - Quantitative analysis of bulk heterojunction films using linear absorption spectroscopy and solar cell performance JF - Advanced functional materials N2 - A fundamental understanding of the relationship between the bulk morphology and device performance is required for the further development of bulk heterojunction organic solar cells. Here, non-optimized (chloroform cast) and nearly optimized (solvent-annealed o-dichlorobenzene cast) P3HT:PCBM blend films treated over a range of annealing temperatures are studied via optical and photovoltaic device measurements. Parameters related to the P3HT aggregate morphology in the blend are obtained through a recently established analytical model developed by F. C. Spano for the absorption of weakly interacting H-aggregates. Thermally induced changes are related to the glass transition range of the blend. In the chloroform prepared devices, the improvement in device efficiency upon annealing within the glass transition range can be attributed to the growth of P3HT aggregates, an overall increase in the percentage of chain crystallinity, and a concurrent increase in the hole mobilities. Films treated above the glass transition range show an increase in efficiency and fill factor not only associated with the change in chain crystallinity, but also with a decrease in the energetic disorder. On the other hand, the properties of the P3HT phase in the solvent-annealed o-dichlorobenzene cast blends are almost indistinguishable from those of the corresponding pristine P3HT layer and are only weakly affected by thermal annealing. Apparently, slow drying of the blend allows the P3HT chains to crystallize into large domains with low degrees of intra- and interchain disorder. This morphology appears to be most favorable for the efficient generation and extraction of charges. KW - Organic electronics KW - morphology KW - solar cells KW - mobility KW - absorption spectroscopy Y1 - 2011 U6 - https://doi.org/10.1002/adfm.201101583 SN - 1616-301X VL - 21 IS - 24 SP - 4640 EP - 4652 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Schubert, Marcel A1 - Dolfen, Daniel A1 - Frisch, Johannes A1 - Roland, Steffen A1 - Steyrleuthner, Robert A1 - Stiller, Burkhard A1 - Chen, Zhihua A1 - Scherf, Ullrich A1 - Koch, Norbert A1 - Facchetti, Antonio A1 - Neher, Dieter T1 - Influence of aggregation on the performance of All-Polymer Solar Cells containing Low-Bandgap Naphthalenediimide Copolymers JF - dvanced energy materials N2 - The authors present efficient all-polymer solar cells comprising two different low-bandgap naphthalenediimide (NDI)-based copolymers as acceptors and regioregular P3HT as the donor. It is shown that these naphthalene copolymers have a strong tendency to preaggregate in specific organic solvents, and that preaggregation can be completely suppressed when using suitable solvents with large and highly polarizable aromatic cores. Organic solar cells prepared from such nonaggregated polymer solutions show dramatically increased power conversion efficiencies of up to 1.4%, which is mainly due to a large increase of the short circuit current. In addition, optimized solar cells show remarkable high fill factors of up to 70%. The analysis of the blend absorbance spectra reveals a surprising anticorrelation between the degree of polymer aggregation in the solid P3HT:NDI copolymer blends and their photovoltaic performance. Scanning near-field optical microscopy (SNOM) and atomic force microscopy (AFM) measurements reveal important information on the blend morphology. It is shown that films with high degree of aggregation and low photocurrents exhibit large-scale phase-separation into rather pure donor and acceptor domains. It is proposed that, by suppressing the aggregation of NDI copolymers at the early stage of film formation, the intermixing of the donor and acceptor component is improved, thereby allowing efficient harvesting of photogenerated excitons at the donoracceptor heterojunction. KW - aggregation KW - morphology KW - naphthalenediimide KW - organic semiconductors KW - organic photovoltaics Y1 - 2012 U6 - https://doi.org/10.1002/aenm.201100601 SN - 1614-6832 VL - 2 IS - 3 SP - 369 EP - 380 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Sauter, Tilman A1 - Kratz, Karl A1 - Lendlein, Andreas T1 - Pore-size distribution controls shape-memory properties on the macro- and microscale of polymeric foams JF - Macromolecular chemistry and physics N2 - Open porous foams with identical foam density but different pore-size distributions (bimodal or monomodal) are prepared from a shape-memory polyetherurethane (PEU) by thermally induced phase separation. The shape-memory effect of the two PEU foams is explored by cyclic thermomechanical compression tests and microstructural analysis. The obtained results reveal that the PEU foam with a bimodal pore-size distribution exhibits an increased shape-recovery under stress-free conditions, both on the macro- (foam level) as well as the microscale (pore level). While bimodal pore-size distributions induce microscale bending during compression, buckling occurs in foams with monomodal pore-size distributions, leading to both a reduced and delayed shape recovery. KW - microstructure KW - morphology KW - polymer foams KW - pore-size distribution KW - shape-memory polymers Y1 - 2013 U6 - https://doi.org/10.1002/macp.201300062 SN - 1022-1352 VL - 214 IS - 11 SP - 1184 EP - 1188 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Gardiner, Lauren M. A1 - Kocyan, Alexander A1 - Motes, Martin A1 - Roberts, David L. A1 - Emerson, Brent C. T1 - Molecular phylogenetics of Vanda and related genera (Orchidaceae) JF - Botanical journal of the Linnean Society N2 - The genus Vanda and its affiliated taxa are a diverse group of horticulturally important species of orchids occurring mainly in South-East Asia, for which generic limits are poorly defined. Here, we present a molecular study using sequence data from three plastid DNA regions. It is shown that Vanda s.l. forms a clade containing approximately 73 species, including the previously accepted genera Ascocentrum, Euanthe, Christensonia, Neofinetia and Trudelia, and the species Aerides flabellata. Resolution of the phylogenetic relationships of species in Vanda s.l. is relatively poor, but existing morphological classifications for Vanda are incongruent with the results produced. Some novel species relationships are revealed, and a new morphological sectional classification is proposed based on support for these groupings and corresponding morphological characters shared by taxa and their geographical distributions. The putative occurrence of multiple pollination syndromes in this group of taxa, combined with complex biogeographical history of the South-East Asian region, is discussed in the context of these results.(c) 2013 The Linnean Society of London, Botanical Journal of the Linnean Society, 2013, 173, 549-572. KW - Aeridinae KW - Ascocentrum KW - classification KW - Euanthe KW - matK KW - morphology KW - Neofinetia KW - psbA-trnH KW - trnL KW - trnL-F Y1 - 2013 U6 - https://doi.org/10.1111/boj.12102 SN - 0024-4074 SN - 1095-8339 VL - 173 IS - 4 SP - 549 EP - 572 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Lorenz, Antje A1 - Heide, Judith A1 - Burchert, Frank T1 - Compound naming in aphasia: effects of complexity, part of speech, and semantic transparency JF - Language, cognition and neuroscience KW - compound production KW - morphology KW - decomposition KW - lemma KW - part of speech KW - semantic transparency KW - aphasia KW - word-finding difficulties Y1 - 2014 U6 - https://doi.org/10.1080/01690965.2013.766357 SN - 2327-3798 SN - 2327-3801 VL - 29 IS - 1 SP - 88 EP - 106 PB - Routledge, Taylor & Francis Group CY - Abingdon ER - TY - JOUR A1 - Schöne, Anne-Christin A1 - Schulz, Burkhard A1 - Richau, Klaus A1 - Kratz, Karl A1 - Lendlein, Andreas T1 - Characterization of Langmuir films prepared from copolyesterurethanes based on oligo(omega-pentadecalactone) and oligo(epsilon-caprolactone)segments JF - Macromolecular chemistry and physics N2 - A series of multiblock copolymers (PDLCL) synthesized from oligo(omega-pentadecalactone) diol (OPDL) and oligo(epsilon-caprolactone) diol (OCL), which are linked by 2,2(4), 4-trimethyl-hexamethylene diisocyanate (TMDI), is investigated by the Langmuir monolayer technique at the air-water interface. Brewster angle microscopy (BAM) and spectroscopic ellipsometry are employed to characterize the polymer film morphologies in situ. PDLCL containing >= 40 wt% OCL segments form homogeneous Langmuir monofilms after spreading. The film elasticity modulus decreases with increasing amounts of OPDL segments in the copolymer. In contrast, the OCL-free polyesterurethane OPDL-TMDI cannot be spread to monomolecular films on the water surface properly, and movable slabs are observed by BAM even at low surface pressures. The results of the in situ morphological characterization clearly show that essential information concerning the reliability of Langmuir monolayer degradation (LMD) experiments cannot be obtained from the evaluation of the pi-A isotherms only. Consequently, in situ morphological characterization turns out to be indispensable for characterization of Langmuir layers before LMD experiments. KW - brewster angle microscopy KW - ellipsometry KW - Langmuir layers KW - morphology KW - polyesterurethanes Y1 - 2014 U6 - https://doi.org/10.1002/macp.201400377 SN - 1022-1352 SN - 1521-3935 VL - 215 IS - 24 SP - 2437 EP - 2445 PB - Wiley-VCH CY - Weinheim ER - TY - JOUR A1 - Clahsen, Harald A1 - Rothweiler, Monika A1 - Sterner, Franziska A1 - Chilla, Solveig T1 - Linguistic markers of specific language impairment in bilingual children: the case of verb morphology JF - Clinical linguistics & phonetics KW - Bilingualism KW - German KW - morphology KW - SLI KW - Turkish Y1 - 2014 U6 - https://doi.org/10.3109/02699206.2014.886726 SN - 0269-9206 SN - 1464-5076 VL - 28 IS - 9 SP - 709 EP - 721 PB - Taylor & Francis Group CY - London ER - TY - JOUR A1 - Albrecht, Steve A1 - Vandewal, Koen A1 - Tumbleston, John R. A1 - Fischer, Florian S. U. A1 - Douglas, Jessica D. A1 - Frechet, Jean M. J. A1 - Ludwigs, Sabine A1 - Ade, Harald W. A1 - Salleo, Alberto A1 - Neher, Dieter T1 - On the efficiency of charge transfer state splitting in polymer: Fullerene solar cells JF - Advanced materials KW - organic solar cells KW - charge generation KW - geminate recombination KW - charge transfer states KW - driving force KW - excess energy KW - morphology KW - spectroelectrochemistry Y1 - 2014 U6 - https://doi.org/10.1002/adma.201305283 SN - 0935-9648 SN - 1521-4095 VL - 26 IS - 16 SP - 2533 EP - 2539 PB - Wiley-VCH CY - Weinheim ER -