| 1. |
- Bjoerstroem, Cecilia M., et al.
(author)
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Influence of solvents and substrates on the morphology and the performance of low-bandgap polyfluorene: PCBM photovoltaic devices
- 2006
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In: Proceedings of SPIE-The International Society for Optical Engineering. ; 6192, s. 61921X/1-
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Conference paper (peer-reviewed)abstract
- Spin-coated thin films of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-5,5-(4',7'-di-2-thienyl-2',1',3'-benzothiadiazole)] (APFO-3) blended with [6,6]-phenyl-C61-butyric acid Me ester (PCBM) are used as the active material in polymer photovoltaic cells. Such blends are known for their tendency to phase sep. during film formation. Tuning the morphol. of the blend in a controlled way is one possible road towards higher efficiency. We studied the effect of adding chlorobenzene to chloroform-based blend solns. before spin-coating on the conversion efficiency of APFO-3:PCBM photodiodes, and related that to the lateral and vertical morphol. of thin films of the blend. The lateral morphol. is imaged by at. force microscopy (AFM) and the vertical compositional profile is obtained by dynamic secondary ion mass spectrometry (SIMS). The profiles reveal compositional variations consisting of multilayers of alternating polymer-rich and PCBM-rich domains in the blend film spin-coated from chloroform. The vertical compositional variations are caused by surface-directed spinodal waves and are frozen in during the rapid evapn. of a highly volatile solvent. With addn. of the low-vapor pressure solvent chlorobenzene, a more homogeneous vertical compn. is found. The conversion efficiency for solar cells of this blend was found to be optimal for chloroform:chlorobenzene mixts. with a vol.-ratio of 80:1. We have also investigated the role of the substrate on the morphol. We found that blend films spin-coated from chloroform solns. on PEDOT:PSS-coated ITO show a similar compositional structure as the films on silicon, and that changing the substrate from silicon to gold only affects the vertical phase sepn. in a region close to the substrate interface. [on SciFinder (R)]
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| 2. |
- Bjoerstroem, Cecilia M., et al.
(author)
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Multilayer formation in spin-coated thin films of low-bandgap polyfluorene: PCBM blends
- 2005
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In: Journal of Physics: Condensed Matter. ; 17:50, s. L529-L534
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Journal article (peer-reviewed)abstract
- Blends of the low-bandgap polymer poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-5,5-(4',7'-di-2-thienyl- 2',1',3'-benzothiadiazole)] (APFO-3) and the fullerene deriv. [6,6]-phenyl-C61-butyric acid Me ester (PCBM) were spin-coated from chloroform soln. into thin films, which were examd. with dynamic secondary ion mass spectrometry. For blends with high PCBM content, the depth profiles show compn. waves that were caused by surface-directed phase sepn. during spin-coating. The formation of such multilayer structures by spontaneous self-stratification probably has implications for optimization strategies for the performance of org. solar cells. [on SciFinder (R)]
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| 3. |
- Bjorstrom, Cecilia M., et al.
(author)
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Influence of solvents and substrates on the morphology and the performance of low-bandgap polyfluorene: PCBM photovoltaic devices - art. no. 61921X
- 2006
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In: Proceedings of SPIE, the International Society for Optical Engineering. - : International Society for Optical Engineering; 1999. - 0277-786X .- 1996-756X. ; 6192, s. X1921-X1921
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Journal article (peer-reviewed)abstract
- Spin-coated thin films of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-5,5-(4,7-di-2-thienyl-2,1,3-benzothiadiazole)] (APFO-3) blended with [6,6]-phenyl-C-61-butyric acid methyl ester (PCBM) are used as the active material in polymer photovoltaic cells. Such blends are known for their tendency to phase separate during film formation. Tuning the morphology of the blend in a controlled way is one possible road towards higher efficiency. We studied the effect of adding chlorobenzene to chloroform-based blend solutions before spin-coating on the conversion efficiency of APFO-3:PCBM photodiodes, and related that to the lateral and vertical morphology of thin films of the blend. The lateral morphology is imaged by atomic force microscopy (AFM) and the vertical compositional profile is obtained by dynamic secondary ion mass spectrometry (SIMS). The profiles reveal compositional variations consisting of multilayers of alternating polymer-rich and PCBM-rich domains in the blend film spin-coated from chloroform. The vertical compositional variations are caused by surface-directed spinodal waves and are frozen in during the rapid evaporation of a highly volatile solvent. With addition of the low-vapour pressure solvent chlorobenzene, a more homogeneous vertical composition is found. The conversion efficiency for solar cells of this blend was found to be optimal for chloroform: chlorobenzene mixtures with a volume-ratio of 80:1. We have also investigated the role of the substrate on the morphology. We found that blend films spin-coated from chloroform solutions on PEDOT:PSS-coated ITO show a similar compositional structure as the films on silicon, and that changing the substrate from silicon to gold only affects the vertical phase separation in a region close to the substrate interface.
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| 4. |
- Cardell, L O, et al.
(author)
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Genes regulating molecular and cellular functions in noninfectious nonallergic rhinitis.
- 2009
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In: Allergy. - : Wiley. - 1398-9995 .- 0105-4538. ; 64:9, s. 1301-8
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Journal article (peer-reviewed)abstract
- Chronic noninfectious, nonallergic rhinitis (NINAR) is a complex syndrome with a principally unknown pathophysiology. New technology has made it possible to examine differentially expressed genes and according to network theory, genes connected by their function that might have key roles in the disease.
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| 5. |
- Lindgren, Lars Johan, 1977, et al.
(author)
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Synthesis and properties of polyfluorenes with phenyl substituents
- 2005
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In: Synthetic Metals. ; 154:1-3, s. 97-100
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Conference paper (peer-reviewed)abstract
- Two new, alkoxyphenyl-substituted polyfluorenes, poly(9,9-bis(4'-hexyloxyphenyl)fluorene) and poly(9,9-bis(4'-hexyloxyphenyl)fluorene-alt-9,9-bis(4'-(2''-(2'''-methoxyethoxy)ethoxy)phenyl)fluorene), were synthesized using the Suzuki coupling reaction. The polymers were designed to obtain stable and efficient materials for light-emitting applications. Both polymers exhibit high PL-efficiencies and show PL- and EL-emission in the blue spectral region, with emission maxima in a narrow range around 427 nm. Annealing (200 DegC, 2 h) of polymer films exposed to normal indoor light in ambient atm., results in an addnl. emission band at higher wavelengths, indicating degrdn. by photo oxidn. [on SciFinder (R)]
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| 6. |
- Rockström, A., et al.
(author)
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Quest for next generation open testbed collaboration
- 2006
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In: 2nd International Conference on Testbeds and Research Infrastructures for the Development of Networks and Communities. TRIDENTCOM 2006. - 1424401062 - 9781424401062 ; , s. 479-486
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Conference paper (peer-reviewed)abstract
- In Sweden we have a long tradition of research collaboration using open testbeds. With that as background this paper discusses what factors make that type of collaboration successful, respectively what makes it fail (i.e. what are the ingredients to prepare successful testbed collaboration). Particularly in early life-cycle phases, looking for new and perhaps disruptive usages of technology factors as openness, informality and sharing are crucial. Focus itself is not an advantage if you do not know what you are looking for. Proposals for working methods and governance models are discussed. © 2006 IEEE.
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| 7. |
- Äbelö, Angela, et al.
(author)
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Application of a combined effect compartment and binding model for gastric acid inhibition of AR-HO47108 : a potassium competitive acid blocker, and its active metabolite AR-HO47116 in the dog
- 2006
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In: European Journal of Pharmaceutical Sciences. - : Elsevier BV. - 0928-0987 .- 1879-0720. ; 29:2, s. 91-101
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Journal article (peer-reviewed)abstract
- The effect of AR-HO47108, a potassium competitive acid blocker, and its active metabolite AR-HO47116 was studied in Heidenhain pouch dogs following administration of single oral and intravenous doses of the two compounds. The histamine-stimulated acid secretion was measured in different periods after dose up to 24 h. All data obtained in the different studies was pooled and analyzed by non-linear mixed effects modelling. It was found that there is a delay between the plasma concentration-time peak and the maximum inhibitory effect and that the effect persisted longer than anticipated from the plasma concentration half-lives of the compounds. in addition, it was found that the peak effect was reached earlier at higher doses. The effect data was well described by a combined effect compartment and binding model and both distribution to the biophase i.e. the canaliculus of the parietal cell and a rate limiting binding interaction between drug and enzyme appear to contribute to the observed delay. in addition, a secretion rate dependent washout from the biophase may contribute. Furthermore, because the parent compound and metabolite bind to the same enzyme, the effect is determined by competition between the two for the same enzyme. The metabolite was found to be less potent than the parent compound, with K-d values of the combined model of 125 and 11.2 nM for the metabolite and parent compound, respectively. However, the metabolite is generated in high concentrations that rapidly exceed the concentration of parent compound after oral administration of parent compound, and this together with its longer plasma half-life will make its contribution to -the overall effect increase with time and slightly prolong the duration of the effect.
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