@phdthesis{Andersen2005, author = {Andersen, Audr{\´e}e}, title = {Surfactant dynamics at interfaces : a series of second harmonic generation experiments}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus-6553}, school = {Universit{\"a}t Potsdam}, year = {2005}, abstract = {Adsorption layers of soluble surfactants enable and govern a variety of phenomena in surface and colloidal sciences, such as foams. The ability of a surfactant solution to form wet foam lamellae is governed by the surface dilatational rheology. Only systems having a non-vanishing imaginary part in their surface dilatational modulus, E, are able to form wet foams. The aim of this thesis is to illuminate the dissipative processes that give rise to the imaginary part of the modulus. There are two controversial models discussed in the literature. The reorientation model assumes that the surfactants adsorb in two distinct states, differing in their orientation. This model is able to describe the frequency dependence of the modulus E. However, it assumes reorientation dynamics in the millisecond time regime. In order to assess this model, we designed a SHG pump-probe experiment that addresses the orientation dynamics. Results obtained reveal that the orientation dynamics occur in the picosecond time regime, being in strong contradiction with the two states model. The second model regards the interface as an interphase. The adsorption layer consists of a topmost monolayer and an adjacent sublayer. The dissipative process is due to the molecular exchange between both layers. The assessment of this model required the design of an experiment that discriminates between the surface compositional term and the sublayer contribution. Such an experiment has been successfully designed and results on elastic and viscoelastic surfactant provided evidence for the correctness of the model. Because of its inherent surface specificity, surface SHG is a powerful analytical tool that can be used to gain information on molecular dynamics and reorganization of soluble surfactants. They are central elements of both experiments. However, they impose several structural elements of the model system. During the course of this thesis, a proper model system has been identified and characterized. The combination of several linear and nonlinear optical techniques, allowed for a detailed picture of the interfacial architecture of these surfactants.}, subject = {Tensid}, language = {en} } @article{AndersenPeterRoepstorff1996, author = {Andersen, S. O. and Peter, Martin G. and Roepstorff, Peter}, title = {Cuticular sclerotization in insects}, year = {1996}, language = {en} } @article{AndrewsFergusonRangaswamyetal.2017, author = {Andrews, N. L. P. and Ferguson, T. and Rangaswamy, A. M. M. and Bernicky, A. R. and Henning, N. and Dudelzak, A. and Reich, Oliver and Barnes, Jack A. and Loock, Hans-Peter}, title = {Hadamard-Transform Fluorescence Excitation-Emission-Matrix Spectroscopy}, series = {Analytical chemistry}, volume = {89}, journal = {Analytical chemistry}, publisher = {American Chemical Society}, address = {Washington}, issn = {0003-2700}, doi = {10.1021/acs.analchem.7b02400}, pages = {8554 -- 8564}, year = {2017}, abstract = {We present a fluorescence excitation-emission-matrix spectrometer with superior data acquisition rates over previous instruments. Light from a white light emitting diode (LED) source is dispersed onto a digital micromirror array (DMA) and encoded using binary n-size Walsh functions ("barcodes"). The encoded excitation light is used to irradiate the liquid sample and its fluorescence is dispersed and detected using a conventional array spectrometer. After exposure to excitation light encoded in n different ways, the 2-dimensional excitation-emission-matrix (EEM) spectrum is obtained by inverse Hadamard transformation. Using this technique we examined the kinetics of the fluorescence of rhodamine B as a function of temperature and the acid-driven demetalation of chlorophyll into pheophytin-a. For these experiments, EEM spectra with 31 excitation channels and 2048 emission channels were recorded every 15 s. In total, data from over 3000 EEM spectra were included in this report. It is shown that the increase in data acquisition rate can be as high as [{n(n + 1)}/2]-fold over conventional EEM spectrometers. Spectral acquisition rates of more than two spectra per second were demonstrated.}, language = {en} } @article{AndrewsRossMunzkeetal.2016, author = {Andrews, Nicholas L. P. and Ross, Rachel and Munzke, Dorit and van Hoorn, Camiel and Brzezinski, Andrew and Barnes, Jack A. and Reich, Oliver and Loock, Hans-Peter}, title = {In-fiber Mach-Zehnder interferometer for gas refractive index measurements based on a hollow-core photonic crystal fiber}, series = {Optics express : the international electronic journal of optics}, volume = {24}, journal = {Optics express : the international electronic journal of optics}, publisher = {Optical Society of America}, address = {Washington}, issn = {1094-4087}, doi = {10.1364/OE.24.014086}, pages = {14086 -- 14099}, year = {2016}, abstract = {We describe an in-fiber interferometer based on a gas-filled hollow-core photonic crystal fiber. Expressions for the sensitivity, figure of merit and refractive index resolution are derived, and values are experimentally measured and theoretically validated using mode field calculations. The refractive indices of nine monoatomic and molecular gases are measured with a resolution of delta(ns) < 10(-6). (C)2016 Optical Society of America}, language = {en} } @article{AndrianovSaalfrank2006, author = {Andrianov, Ivan and Saalfrank, Peter}, title = {Free vibrational relaxation of H adsorbed on a Si(100) surface investigated with the multi-configurational time-dependent Hartree method}, series = {Chemical physics letters}, volume = {433}, journal = {Chemical physics letters}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0009-2614}, doi = {10.1016/j.cplett.2006.11.067}, pages = {91 -- 96}, year = {2006}, abstract = {The results of a quantum-mechanical study of vibrational relaxation of hydrogen adsorbed on a Si(100) surface with the multi-configurational time-dependent Hartree (MCTDH) method are presented. A two-dimensional subsystem is coupled non-linearly to a bath of harmonic oscillators (phonons of the Si bulk), and the relaxation of subsystem vibrations proceeds primarily via a two-phonon process. Characteristic times of the system evolution agree well with our previous perturbation theory study. The vibrational population decay is non-exponential, exhibiting pronounced recurrences due to finite bath size. The dependence of the lifetimes of the vibrational levels on the bath size and on the coupling details is investigated.}, language = {en} } @article{AnklamBehlerDingermannetal.2013, author = {Anklam, Elke and Behler, J{\"o}rg and Dingermann, Theodor and Elsinghorst, Paul and Fischer, Jochen and Esselen, Melanie and Foerster, Christian and Fr{\"o}hlich, Daniel and Goedel, Werner Andreas and Gregory, Peter and Grimme, Stefan and Hackenberger, Christian and Hansmann, Max and Heppekausen, Johannes and Hasenstab-Riedel, Sebastian and Kirchhoff, Erhard and Kratz, Karl-Ludwig and Krausz, Ferenc and Linker, Torsten and List, Benjamin and Ray, Kallol and Salzer, Reiner and Schubert, Ulrich and Schueth, Ferdi and Schwarz, Helmut and Schwietzke, Uta and Strey, Reinhard and Stumpf, Thorsten and Vaagt, Franziska and Volodkin, Dmitry and Wilke, Guenther and Zass, Engelbert and Zemb, Thomas}, title = {Awards}, series = {Nachrichten aus der Chemie : Zeitschrift der Gesellschaft Deutscher Chemiker}, volume = {61}, journal = {Nachrichten aus der Chemie : Zeitschrift der Gesellschaft Deutscher Chemiker}, number = {11}, publisher = {Ges. Dt. Chemiker}, address = {Frankfurt, Main}, issn = {1439-9598}, doi = {10.1002/nadc.201390372}, pages = {1145 -- 1148}, year = {2013}, language = {de} } @phdthesis{Antipov2003, author = {Antipov, Alexei}, title = {Polyelectrolyte multilayer capsules as controlled permeability vehicles and catalyst carriers}, pages = {100 S.}, year = {2003}, language = {en} } @article{AntoniouPashalidisGessneretal.2011, author = {Antoniou, Stella and Pashalidis, I. and Gessner, Andre and Kumke, Michael Uwe}, title = {The effect of humic acid on the formation and solubility of secondary solid phases (Nd(OH)CO3 and Sm(OH)CO3)}, series = {Radiochimica acta : international journal for chemical aspects of nuclear science and technology}, volume = {99}, journal = {Radiochimica acta : international journal for chemical aspects of nuclear science and technology}, number = {4}, publisher = {De Gruyter}, address = {Berlin}, issn = {0033-8230}, doi = {10.1524/ract.2011.1812}, pages = {217 -- 223}, year = {2011}, abstract = {The formation of secondary Ln(III) solid phases (e.g. Nd(OH)CO3 and Sm(OH)CO3) has been studied as a function of the humic acid (HA) concentration in 0.1 M NaClO4 aqueous solution and their solubility has been investigated in the neutral pH range (6.5-8) under normal atmospheric conditions. Nd(III) and Sm(III) were selected as analogues for trivalent lanthanide and actinide ions. The solid phases under investigation have been prepared by alkaline precipitation and characterized by TGA, ATR-FTIR, XRD, TRLFS, DR-UV-Vis and Raman spectroscopy, and solubility measurements. The spectroscopic data obtained indicate that Nd(OH)CO3 and Sm(OH)CO3 are stable and remain the solubility limiting solid phases even in the presence of increased HA concentration (0.5 g/L) in solution. Upon base addition in the Ln(III)-HA system decomplexation of the previously formed Ln(III)-humate complexes and precipitation of two distinct phases occurs, the inorganic (Ln(OH)CO3) and the organic phase (HA), which is adsorbed on the particle surface of the former. Nevertheless, HA affects the particle size of the solid phases. Increasing HA concentration results in decreasing crystallite size of the Nd(OH)CO3 and increasing crystallite size of the Sm(OH)CO3 solid phase, and affects inversely the solubility of the solid phases. However, this impact on the solid phase properties is expected to be of minor relevance regarding the chemical behavior and migration of trivalent lanthanides and actinides in the geosphere.}, language = {en} } @article{AntoniouPashalidisGessneretal.2011, author = {Antoniou, Stella and Pashalidis, Ioannis and Gessner, Andre and Kumke, Michael Uwe}, title = {Spectroscopic investigations on the effect of humic acid on the formation and solubility of secondary solid phases of Ln(2)(CO3)(3)}, series = {Journal of rare earths}, volume = {29}, journal = {Journal of rare earths}, number = {6}, publisher = {Elsevier}, address = {Amsterdam}, issn = {1002-0721}, doi = {10.1016/S1002-0721(10)60490-5}, pages = {516 -- 521}, year = {2011}, abstract = {The formation of secondary Ln(III) solid phases (e.g., Nd-2(CO3)(3) and Sm-2(CO3)(3)) was studied as a function of the humic acid concentration in 0.1 mol/L NaClO4 aqueous solution in the neutral pH range (5-6.5). The solid phases under investigation were prepared by alkaline precipitation under 100\% CO2 atmosphere and characterized by attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray diffraction (XRD), time-resolved laser fluorescence spectroscopy (TRLFS), diffuse reflectance ultraviolet-visible (DR-UV-Vis), Raman spectroscopy, and solubility measurements. The spectroscopic data obtained indicated that Nd-2(CO3)(3) and Sm-2(CO3)(3) were stable and remained the solubility limiting solid phases even in the presence of increased humic acid concentration (0.5 g/L) in solution. Upon base addition in the Ln(III)-HA system, decomplexation of the previously formed Ln(III)-humate complexes and precipitation of two distinct phases occurred, the inorganic (Ln(2)(CO3)(3)) and the organic phase (HA), which was adsorbed on the particle surface of the former. Nevertheless, humic acid affected the particle size of the solid phases. Increasing humic acid concentration resulted in decreasing crystallite size of the Nd-2(CO3)(3) and increasing crystallite size of the Sm-2(CO3)(3) solid phase, and affected inversely the solubility of the solid phases. However, this impact on the solid phase properties was expected to be of minor relevance regarding the chemical behavior and migration of trivalent lanthanides and actinides in the geosphere.}, language = {en} } @article{ApitzBellDamgaardetal.2005, author = {Apitz, Sabine E. and Bell, Elanor M. and Damgaard, Lars and Gilbert, Franck and Glud, R and Hall, P. O. J. and Kershaw, P. J. and Nickel, L and Parker, R and Rabouille, Christophe and Shimmield, Grahamm and Solan, Martin and Soltwedel, Thomas and Spagnoli, Federico and Witte, Ursula}, title = {Coastal Ocean Benthic Observatories (COBO) : integrated tools for the in situ observation and study of benthic ecosystem biogeochemical processes}, year = {2005}, language = {en} } @phdthesis{Appajaiah2004, author = {Appajaiah, Anilkumar}, title = {Climatic stability of polymer optical fibers (POF)}, url = {http://nbn-resolving.de/urn:nbn:de:kobv:517-0001661}, school = {Universit{\"a}t Potsdam}, year = {2004}, abstract = {Optische Polymerfasern stellen ein relativ neues Medium zur Hochgeschwindigkeitsdaten{\"u}bertragung mittels moduliertem Licht dar. Sie gestatten die Verbreitung großer Datenmengen {\"u}ber Entfernungen bis zu ca. 100 m, ohne eine Beeinflussung durch externe elektromagnetischen Feldern. Jedoch reagieren die Fasern und somit auch ihre optischen Eigenschaften aufgrund des organischchemischen Faseraufbaus empfindlich auf das Klima ihrer Umgebung. Die Ursachen f{\"u}r die Abnahme der optischen Transmission aufgrund von klimatischen Einfl{\"u}ssen (Alterung, Degradation) werden mittels chemisch analytischer Verfahren wie Chemilumineszenz (CL) und Fourier Transform Infrarot (FTIR) Spektroskopie untersucht. Dabei kommen f{\"u}nf, von verschiedenen Herstellern bezogene, Multimode- POFs aus PMMA in sieben verschiedenen Klimaten zum Einsatz. Drei dieser f{\"u}nf POFs werden genauer untersucht, um den Einfluss einzelner Parameter festzustellen und optische Langzeitstabilit{\"a}t aufgrund von Kurzzeittests vorherzusagen. Als erstes erfolgt eine Kennzeichnung unbeanspruchter POF Komponenten (Kern, Mantel und nackte POF als Kombination von Kern und Mantel) {\"u}ber ihre physikalischen und chemischen Eigenschaften. Die Glas- und die Schmelztemperaturen liegen im Bereich von 120 °C bis 140 °C, das Molekulargewicht des Kerns bei gr{\"o}ßenordnungsm{\"a}ßig 105 g mol-1 ;. FTIR-Messungen zeigen zwar Unterschiede in der chemischen Zusammensetzung der M{\"a}ntel aber keine Unterschiede bei den Kernen. Bei zwei der POF Proben , die als Kabel (Kern, Mantel und Schutzh{\"u}lle) f{\"u}r 3300 Stunden einem Klima aus 92 °C und 95 \% relativer Feuchte (r.F.) ausgesetzt waren, verringern sich daraufhin die optische Transmissionen in unterschiedlicher Weise. Die Untersuchung der zugeh{\"o}rigen nackten POFs mittels CL, FTIR, Thermogravimetrie (TG), UV/VIS und Gel Permeation Chromatographie (GPC) l{\"a}sst eine st{\"a}rkere Sch{\"a}digung der M{\"a}ntel als der Kerne vermuten. Wahrscheinlich f{\"u}hrt eine starke Manteldegradation zu einer erh{\"o}hten Absorption und Fehlstellen im Mantel und damit zu einer Transmissionsabnahme. Daher scheint die optische Stabilit{\"a}t der POF st{\"a}rker durch die thermo-oxidative Stabilit{\"a}t des Mantels bestimmt zu sein als durch die des Kernes. Drei nackte POFs (Kern und Mantel) sind unterschiedlich lang (30 Stunden bis 3000 Stunden) folgenden Klimaten ausgesetzt: 92 °C / 95 \% r.F., 92 °C / 50 \% r.F., 50 °C / 95 \% r.F., 90 °C / geringe Feuchte, 100 °C / geringe Feuchte, 110 °C / geringe Feuchte and 120 °C / geringe Feuchte. Auch in diesen Klimaten ergaben sich probenbedingte unterschiedliche Transmissions{\"a}nderungen. Die Ergebnisse deuten stark darauf hin, dass bei gleichzeitig hoher Temperatur und hoher Feuchte physikalische {\"A}nderungen wie die Volumenausdehnung die Hauptursachen f{\"u}r die Abnahme der optischen Transmission bilden. Ein weiterer Einflussfaktor ist die chemische Zusammensetzung der M{\"a}ntel. Bei Kombination von hoher Temperatur und geringer Feuchte erzeugen in den Anfangsstadien der Alterung physikalische {\"A}nderungen Transmissionsabnahmen, vermutlich entstehen Fehlstellen in der Kern-Mantel-Grenzschicht. Hinzukommen in den sp{\"a}teren Stadien wahrscheinlich zunehmende Lichtabsorption in Kern und Mantel. L. Jankowski (Doktorand in der BAM) best{\"a}tigt diese Annahme durch parallel ausgef{\"u}hrte optische Simulationsrechnungen. Auch f{\"u}r nackte POFs scheint also die thermo-oxidative Stabilit{\"a}t die optische Stabilit{\"a}t zu bestimmen. Kurzzeitalterungstests sollen Aufschluss {\"u}ber den Einfluss individueller Klimaparameter auf die POF Eigenschaften geben. Es zeigt sich bei dauerhaft hoher Temperatur und variabler Feuchte aufgrund des physikalisch absorbierten Wassers bis zu einem gewissen Grad ein reversibles Verhalten des Transmissionsverlustes. Dieses Verhalten tritt aber nur kaum merkbar auf, wenn bei konstanter hoher Feuchte die Temperatur variiert wird. Bei Raumtemperatur und variabler Feuchte stellt sich jedoch ein voll reversibles Verhalten des Transmissionsverlustes ein. Die hier beschriebenen Untersuchungen sind als Ausgangspunkt f{\"u}r weitergehende Forschungen zu verstehen. Die begrenzte Zurverf{\"u}gungstellung von POF Basisdaten durch die Hersteller und der zeitaufwendige klimabedingte Alterungsprozess beschr{\"a}nken die Ergebnisse mehr oder weniger auf die untersuchten Proben. Signifikante allgemeine Aussagen erfordern aber beispielsweise zus{\"a}tzliche statistische Daten der Produktionsschwankungen von POF Eigenschaften. Dennoch besitzen die hier beschriebenen Tests das Potential f{\"u}r eine Ann{\"a}herung an die optische Langzeitstabilit{\"a}t und deren Vorhersage.}, language = {en} } @article{AravopoulouKyriakosMiasnikovaetal.2018, author = {Aravopoulou, Dionysia and Kyriakos, Konstantinos and Miasnikova, Anna and Laschewsky, Andre and Papadakis, Christine M. and Kyritsis, Apostolos}, title = {Comparative Investigation of the Thermoresponsive Behavior of Two Diblock Copolymers Comprising PNIPAM and PMDEGA Blocks}, series = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, volume = {122}, journal = {The journal of physical chemistry : B, Condensed matter, materials, surfaces, interfaces \& biophysical chemistry}, number = {9}, publisher = {American Chemical Society}, address = {Washington}, issn = {1520-6106}, doi = {10.1021/acs.jpcb.7b09647}, pages = {2655 -- 2668}, year = {2018}, abstract = {The thermoresponsive behavior of two diblock copolymers PS-b-PNIPAM and PS-b-PMDEGA, which both comprise a hydrophobic polystyrene (PS) block but different thermoresponsive blocks, also differing in length, poly(N-isopropylacrylamide) (PNIPAM) and poly(methoxy diethylene glycol acrylate) (PMDEGA), respectively, was comparatively investigated in a wide temperature range. Concentrated aqueous solutions containing 25 wt \% polymer were studied by small-angle X-ray scattering (SAXS), differential scanning calorimetry (DSC), and broadband dielectric spectroscopy (BDS). DSC measurements show that, during the demixing phase transition, the hydration number per oligo(ethylene glycol) side chain in the PS-b-PMDEGA solution decreases rather gradually, even up to 20 °C above the onset of the transition, i.e., the cloud point (CP). In contrast, the PS-b-PNIPAM solution exhibits an abrupt, stepwise dehydration behavior at its CP, indicated by the sharp, narrow endothermic peak. BDS measurements suggest that the organization of the expelled water during the phase transition and the subsequent evolution of the micellar aggregates are different for the two copolymers. In the PS-b-PMDEGA solution, the long-range charge transport process changes significantly at its CP and strong interfacial polarization processes appear, probably due to charge accumulation at the interfaces between the micellar aggregates and the aqueous medium. On the contrary, in the PS-b-PNIPAM solution, the phase transition has only a marginal effect on the long-range conduction process and is accompanied by a reduction in the high-frequency (1 MHz) dielectric permittivity, ε′. The latter effect is attributed to the reduced polarization strength of local chain modes due to an enhancement of intra- and interchain hydrogen bonds (HBs) in the polymer-rich phase during the water detaching process. Surprisingly, our BDS measurements indicate that prior to both the demixing and remixing processes the local chain mobility increases temporally. Our dielectric studies suggest that for PS-b-PNIPAM the water detaching process initiates a few degrees below CP and that the local chain mobility and intra- and/or interchain HBs of the PNIPAM blocks may control its thermoresponsive behavior. Dielectric "jump" experiments show that the kinetics of micellar aggregation in the PS-b-PMDEGA solution is slower than that in the PS-b-PNIPAM solution and is independent of the target temperature within the two-phase region. From the experimental point of view, it is shown that the dielectric susceptibility, especially, the dielectric permittivity, ε′, is a well-suited probe for monitoring both the reversible changes in the molecular dipolar bond polarizability and the long-range interfacial polarization at the phase transition.}, language = {en} } @article{AriasFeuerbachSchmidtetal.2018, author = {Arias, Hugo R. and Feuerbach, Dominik and Schmidt, Bernd and Heydenreich, Matthias and Paz, Cristian and Ortells, Marcelo O.}, title = {Drimane Sesquiterpenoids Noncompetitively Inhibit Human alpha 4 beta 2 Nicotinic Acetylcholine Receptors with Higher Potency Compared to Human alpha 3 beta 4 and alpha 7 Subtypes}, series = {Journal of natural products}, volume = {81}, journal = {Journal of natural products}, number = {4}, publisher = {American Chemical Society}, address = {Washington}, issn = {0163-3864}, doi = {10.1021/acs.jnatprod.7b00893}, pages = {811 -- 817}, year = {2018}, abstract = {The drimane sesquiterpenoids drimenin, cinnamolide, dendocarbin A, and polygodial were purified from the Canelo tree (Drimys winteri) and chemically characterized by spectroscopic methods. The pharmacological activity of these natural compounds were determined on hα4β2, hα3β4, and hα7 nicotinic acetylcholine receptors (AChRs) by Ca2+ influx measurements. The results established that drimane sesquiterpenoids inhibit AChRs with the following selectivity: hα4β2 > hα3β4 > hα7. In the case of hα4β2 AChRs, the following potency rank order was determined (IC50's in μM): drimenin (0.97 ± 0.35) > cinnamolide (1.57 ± 0.36) > polygodial (62.5 ± 19.9) ≫ dendocarbin A (no activity). To determine putative structural features underlying the differences in inhibitory potency at hα4β2 AChRs, additional structure-activity relationship and molecular docking experiments were performed. The Ca2+ influx and structural results supported a noncompetitive mechanism of inhibition, where drimenin interacted with luminal and nonluminal (TMD-β2 intrasubunit) sites. The structure-activity relationship results, i.e., the lower the ligand polarity, the higher the inhibitory potency, supported the nonluminal interaction. Ligand binding to both sites might inhibit the hα4β2 AChR by a cooperative mechanism, as shown experimentally (nH > 1). Drimenin could be used as a molecular scaffold for the development of more potent inhibitors with higher selectivity for the hα4β2 AChR.}, language = {en} } @inproceedings{ArltSchwiebsPfarretal.2014, author = {Arlt, Olga and Schwiebs, Anja and Pfarr, Kathrin and Ranglack, Annika and Bouzas, Ferreiros Nerea and Schreiber, Yannick and Neuber, Corinna and Kleuser, Burkhard and Pfeilschifter, Josef M. and Radeke, Heinfried H.}, title = {Dynamic interaction between sphingolipid enzymes, S1P and inflammatory cytokine regulation in dendritic cells}, series = {NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY}, volume = {387}, booktitle = {NAUNYN-SCHMIEDEBERGS ARCHIVES OF PHARMACOLOGY}, publisher = {Springer}, address = {New York}, issn = {0028-1298}, pages = {S91 -- S91}, year = {2014}, language = {en} } @article{ArminDurrantShoaee2017, author = {Armin, Ardalan and Durrant, James R. and Shoaee, Safa}, title = {Interplay Between Triplet-, Singlet-Charge Transfer States and Free Charge Carriers Defining Bimolecular Recombination Rate Constant of Organic Solar Cells}, series = {The journal of physical chemistry : C, Nanomaterials and interfaces}, volume = {121}, journal = {The journal of physical chemistry : C, Nanomaterials and interfaces}, publisher = {American Chemical Society}, address = {Washington}, issn = {1932-7447}, doi = {10.1021/acs.jpcc.7b04825}, pages = {13969 -- 13976}, year = {2017}, abstract = {Despite the myriad of organic donor:acceptor materials, only few systems have emerged in the life of organic solar cells to, exhibit considerable reduced bimolecular recombination, with respect to the random encounter rate given by the Langevin equation. Monte Carlo simulations have revealed that the rate constant of the formation of electron-hole bound states depends on the random encounter of opposite charges and is nearly given by the Langevin equation for the domain sizes relevant to efficient bulk heterojunction systems. Recently, three studies :suggested that charge transfer states dissociating much faster than their decay rate to the ground state, can result in reduced bimolecular recombination by lowering the recombination rate to the ground state as a loss pathway. A separate study identified another loss pathway and suggested that forbidden back electron transfer from triplet charge transfer states to triplet excitons is a key to achieving reduced recombination. Herein we further explain the reduced bimolecular recombination by investigating the limitations of these two proposals. By solving kinetic rate equations for a BHJ system with realistic rates, we show that both of these previously presented conditions must only be held at the same time fora system to exhibit non-Langevin behavior. We demonstrate that suppression of both of the parallel loss channels of singlet and triplet states can be achieved through increasing the dissociation rate of the charge transfer states; a crucial requirement to achieve a high charge carrier extraction efficiency.}, language = {en} } @book{ArndtArnoldBelter2000, author = {Arndt, Barbara and Arnold, Karin and Belter, Heinz}, title = {Chemie : Stoffe, Reaktionen, Umwelt ; Ausgabe Sachsen-Anhalt, Sekundarschule, 7/8, Lehrbuch}, editor = {Meyendorf, Gerhard}, publisher = {Volk und Wissen}, address = {Berlin}, year = {2000}, language = {de} } @book{ArndtArnoldBelter2000, author = {Arndt, Barbara and Arnold, Karin and Belter, Heinz}, title = {Chemie : Stoffe, Reaktionen, Umwelt ; Ausgabe Mecklenburg-Vorpommern, Realschule, 10, Lehrbuch}, editor = {Meyendorf, Gerhard}, publisher = {Volk und Wissen}, address = {Berlin}, pages = {116 S.}, year = {2000}, language = {de} } @article{ArotcarenaHeiseIshayaetal.2002, author = {Arotcarena, Michel and Heise, Bettina and Ishaya, Sultana and Laschewsky, Andr{\´e}}, title = {Switching the inside and the outside of aggregates of water-soluble block copolymers with double thermoresponsivity}, year = {2002}, abstract = {Water-soluble block copolymers were prepared from the non-ionic monomer N-isopropylacrylamide (NIPA) and the zwitterionic monomer 3-[N-(3-methacrylamidopropyl)-N,N-dimethyl]-ammonio propane sulfonate (SPP) by sequential free radical polymerization via the RAFT process. Such block copolymers with two hydrophilic blocks exhibit double thermo- responsive behavior in water: the poly-NIPA block shows a lower critical solution temperature, whereas the poly-SPP block exhibits an upper critical solution temperature. Appropriate design of the block lengths leads to block copolymers which stay in solution in the full temperature range between 0°C and 100°C. Both blocks of these polymers dissolve in water at intermediate temperatures, whereas at high temperatures, the poly-NIPA block forms colloidal hydrophobic associates that are kept in solution by the poly-SPP block, and at low temperatures, the poly-SPP block forms colloidal polar aggregates that are kept in solution by the poly-NIPA block. In this way, colloidal aggregates can be prepared in water which switch reversibly, and without any additive, their "inside" to the "outside", and vice versa. The aggregates provide microdomains and surfaces of different character, which can be controlled by a simple thermal stimulus.}, language = {en} } @article{ArrietaBeyerLehmannetal.1992, author = {Arrieta, A. and Beyer, L. and Lehmann, J. and Dargatz, M. and Kleinpeter, Erich}, title = {Synthese und 1H-NMR-spektroskopische Untersuchungen neuer Curcuminanaloga}, year = {1992}, language = {de} } @article{ArysFischerJonasetal.2003, author = {Arys, Xavier and Fischer, Peter and Jonas, Alain M. and Koetse, Marc M. and Legras, Roger and Laschewsky, Andr{\´e} and Wischerhoff, Erik}, title = {Ordered polyelectrolyte multilayers : rules governing layering in organic binary multilayers}, year = {2003}, language = {en} }