[en] The structural investigation of thin films of two thiophene/fluorene based oligomers was performed using X-ray diffraction analysis, molecular modelling calculations including packing energy minimisation and fluorescence optical microscopy. Single molecule layers, double layers, and blended films of thickness ranging from 3 to 50 nm, of component ratio varying from 0.5 to 50%, were prepared by both ultra high vacuum (UHV) evaporation and co-evaporation, and were compared with spin-coated films of two components with comparable concentration and thickness. The growth develops by islands allowing for a complete phase micro-segregation both in spin coating and in UHV evaporated films. Average crystal size is compatible with a large number of micro-interfaces of two oligomers, thus yielding an efficient energy transfer from the high energy absorbing molecule to the low energy absorbing one
Journal
[en] Tapping mode atomic force microscopy (AFM) was employed to study the surface structure of spin-coated and solvent-cast films of the newly synthesized electroluminescent copolymer TT9 and its fractions A and B. Fraction A is well soluble in chloroform while fraction B forms aggregates of high molecular weight in the same solvent. TT9 and fraction A are photoluminescent; fraction B is not. TT9 spin-coated and solvent-cast films show similar morphologies characterized by wormlike structures. Solvent-cast films formed by fraction A have a large density of defects. Fraction B forms larger structures, giving rise to more corrugated surfaces. These structures are formed by grains of rather uniform size, likely to be related to the aggregates already present in solution. For all the examined films, the surface roughness scales in the same way with the linear dimension of the surface, suggesting similar growth mechanisms
Journal
Materials Science and Engineering. C, Biomimetic Materials, Sensors and Systems; ISSN 0928-4931; 
; v. 22(2); p. 313-317
; v. 22(2); p. 313-317
[en] The photoluminescence (PL) quantum yields (QYs) and lifetimes of the 1,6-diphenyl-1,3,5-hexatriene (DPH) blue emitter and of the acceptor-donor system, DPH and p-terphenyl (P3), are investigated embedded in the nanochannels of a perhydrotriphenylene (PHTP) matrix. In the co-inclusion system, light emission takes place from DPH, due to the efficient resonant energy transfer (RET) from the P3 donor molecules. The host matrix stabilizes the guest molecules against photooxidation degradation. The largest quantum yield, up to 100%, has been found in the co-inclusion compound (IC), where excitations are localized at the emissive acceptor sites
Journal
Materials Science and Engineering. C, Biomimetic Materials, Sensors and Systems; ISSN 0928-4931; ; v. 23(6-8); p. 909-912
; v. 23(6-8); p. 909-912
[en] The Ibrite reservoir in southeast Brazil is polluted with effluents from an oil refinery as well as domestic untreated sewage from cities in the region. In this study, calcium nitrate was used as a sediment remediation technology in order to reduce phosphorus availability. Experiments were conducted in microcosms incubated for up to 135 days. Ceriodaphnia silvestrii and Vibrio fisheri were used to conduct an acute toxicity assessment of the water column and pore water of the sediments. Chironomus xanthus was used to assess bulk sediments. Results of the chemical analyses showed that high values of acid volatile sulfide in the sediments decreased by 99 per cent after 135 days of incubation. Approximately 50 per cent of the soluble reactive phosphorus was removed from the water column. The toxicity of the tested organisms was attributed to high nitrate concentrations in pore water sediments. Results indicated that calcium nitrate is not suitable as a sediment remediation technology.
Source
Martel, L.; Triffault-Bouchet, G. (Centre d'expertise en analyse environnementale du Quebec, Quebec, PQ (Canada)); Fournier, M. (Inst. national de la recherche scientifique, Laval, PQ (Canada). Inst. Armand Frappier); Berryman, D.; Guay, I. (Ministere du Developpement durable, de l'Environnement et des Parcs, Quebec, PQ (Canada)); Campbell, P.G.C. (Quebec Univ., Quebec, PQ (Canada). Institut National de la Recherche Scientifique-Eau, Terre et Environnement); Lebeuf, M.; Couillard, C. (Fisheries and Oceans Canada, Mont-Joli, PQ (Canada). Inst. Maurice-Lamontagne); Parent, L. (Quebec Univ., Montreal, PQ (Canada)); Pellerin, J. (Quebec Univ., Rimouski, PQ (Canada). Institut des Sciences de la Mer de Rimouski); Benoit, P. (Ministere du Developpement durable, de l'Environnement et des Parcs du Quebec, Longueil, PQ (Canada)); Lacroix, E. (Environment Canada, Montreal, PQ (Canada)); Burridge, L.E. (Fisheries and Oceans Canada, St. Andrews, NB (Canada)) (eds.); Fisheries and Oceans Canada, St. Andrews, NB (Canada). Biological Station. Funding organisation: Ministere du Developpement durable, de l'Environnement et des Parcs, Quebec, PQ (Canada); Environment Canada, Gatineau, PQ (Canada); Quebec Univ., Rimouski, PQ (Canada). Centre interinstitutionnel de recherche en ecotoxicologie; Hydro-Quebec, Montreal, PQ (Canada); ExxonMobil, St. John's, NL (Canada); Rio Tinto, Canadian Exploration Ltd., Toronto, ON (Canada); Alcan International Ltd., Montreal, PQ (Canada); Vale Inco Ltd., Sudbury, ON (Canada); Quebec Univ., Montreal, PQ (Canada). Centre TOXEN; Institut national de sante publique du Quebec, Montreal, PQ (Canada); Degremont, Dorval, PQ (Canada); Paine, Ledge and Associates, North Vancouver, BC (Canada); Quebec Univ., Quebec, PQ (Canada). Institut National de la Recherche Scientifique-Eau, Terre et Environnement; Intrinsik, Ottawa, ON (Canada) (and others); 200 p; 2010; p. 133; 36. annual aquatic toxicity workshop; La Malbaie, PQ (Canada); 27-30 Sep 2009; ISSN 0706-6457; ; Available from the St. Andrews Biological Station, Fisheries and Oceans Canada, 531 Brandy Cove Road, St. Andrews, New Brunswick, E58 2L9
; Available from the St. Andrews Biological Station, Fisheries and Oceans Canada, 531 Brandy Cove Road, St. Andrews, New Brunswick, E58 2L9
No abstract available
Journal
Verhandlungen der Deutschen Physikalischen Gesellschaft; ISSN 0420-0195; ; CODEN VDPEAZ; v. 41(3); [1 p.]
; CODEN VDPEAZ; v. 41(3); [1 p.]
No abstract available
Journal
Verhandlungen der Deutschen Physikalischen Gesellschaft; ISSN 0420-0195; ; CODEN VDPEAZ; v. 41(3); [1 p.]
; CODEN VDPEAZ; v. 41(3); [1 p.]