17 documents found, page 1 of 2
CdWO4-on-MEH-PPV:PS as a candidate for real-time dosimeters.
Silva, M. M.; Novais, S. M. V.; Silva, E. S. S.; Schimitberger, Thiago; Macedo, Z. S.; Bianchi, Rodrigo FernandoWe report on the investigations about the modification of optical properties induced by X-rays onto film detectors of cadmium tungstate (CdWO4), poly[2-methoxy-5(20 -ethylhexyloxy)-p-phenylenevinylene] (MEH-PPV) and polystyrene (PS) This device takes advantage of reduction of spectral overlap between the radioluminescence (RL) of CdWO4 and the absorption of MEH-PPV as it is exposed to radiation, forming the bas...
Fabricação de sensor orgânico flexível para aplicação em terapia com luz azul.
Silva, Mariana de Melo; Ferreira, Giovana Ribeiro; Schimitberger, Thiago; Bianchi, Rodrigo FernandoA fototerapia com luz azul (460 nm - 490 nm) é o procedimento mais utilizado para o tratamento da icterícia em recém-nascidos. Contudo, dois fatores alteraram drasticamente a eficiência desse tratamento: (1) o espectro da fonte luminosa e (2) a dose de radiação absorvida pelos neonatos. Este trabalho apresenta o desenvolvimento de detectores de radiação orgânicos e flexíveis, de baixo custo, de bom desempenho e...
Spin coater based on brushless dc motor of hard disk drivers.
Bianchi, Rodrigo Fernando; Panssiera, M. F.; Lima, J. P. H.; Yagura, L.; Andrade, Adnei M. de; Faria, Roberto MendonçaWe have developed a novel programmable, low cost, spin coater to be used for applications where flat substrates are coated with an uniform thin layer of a desirable material. The equipment is built with dc brushless motor present in most of the hard disk drivers (HDDs). The system offers manual control, wide speed range (from 0 to 10,000 rpm), spin speed stability and compact size. The paper also describes the ...
Electrical characterization of in situ polymerized polyaniline thin films.
Travain, Silmar Antonio; Ferreira, Guilherme Fontes Leal; Giacometti, José Alberto; Bianchi, Rodrigo FernandoThe alternating conductivity, σ*(f) = σ (f) + iσ(f), of in situ polymerized polyaniline thin films doped with hydrochloric acid, deposited on top of an interdigitated gold line array previously deposited on glass substrates, were measured in the frequency (f) range between 0.1 Hz to 10 MHz and in the temperature range from 100 to 430 K. The results for σ (f) are typical of a disordered solid material: for frequ...
X-rays sensing properties of MEH-PPV, Alq3 and additive components : a new orga...
Schimitberger, Thiago; Ferreira, Giovana Ribeiro; Akcelrud, L. C.; Saraiva, Marcelo Frota; Bianchi, Rodrigo FernandoIn this paper, we report our experimental design in searching a smart and easy-to-read dosimeter used to detect 6 MV X-rays for improving patient safety in radiation oncology. The device was based on an organic emissive solutions of poly(2-methoxy-5(2 -ethylhexyloxy)-p-phenylenevinylene) (MEHPPV), aluminum-tris-(8-hydroxyquinoline) (Alq3) and additive components which were characterized by UV–Vis absorption, ph...
Photogenerated carrier profile determination in polymeric light-emitting diodes...
Santos, L. F.; Bianchi, Rodrigo Fernando; Faria, Roberto Mendonça; Mergulhão, SergioPhotogenerated charge carrier profiles in poly(2-methoxy-5-(2_-ethyl-hexyloxy)-1,4-phenylene vinylene) (MEH-PPV) light-emitting diodes were determined from steady-state photocurrent spectra and transient photocurrent decay measurements. The observation that the photocurrent spectra behavior is strongly dependent on the bias polarity and amplitude suggests the existence of an intrinsic electric field, determined...
Controlling photo-oxidation processes of a polyfluorene derivative : the effect...
Ferreira, Giovana Ribeiro; Nowacki, B.; Magalhães, A.; Azevedo, E. R. de; Sá, E. L. de; Akcelrud, L. C.; Bianchi, Rodrigo FernandoThe control of the photo degradation of a fluoreneevinyleneephenylene based-polymer, poly(9,9-dihexylfluorenediylvinylene-alt-1,4-phenylenevinylene) (LaPPS16) was achieved by addition of a radical scavenger (RS) (enhancing photo resistance) or a radical initiator (RI) (reducing photo resistance). Photoluminescence, UVeVis absorption, 1 H NMR spectroscopies and gel permeation chromatography (GPC) revealed that t...
Impressora de baixo custo desenvolvida a partir de sistema automotivo de injeçã...
Barbosa, Adriana Diniz; Silva, Sávio Augusto Lopes da; Col, Robson Nunes Dal; Bianchi, Rodrigo FernandoNeste trabalho, é apresentado o desenvolvimento de um novo equipamento para fabricação de filmes finos orgânicos, baseado na tecnologia automotiva de injeção eletrônica. Tal sistema apresenta, dentre as vantagens de disponibilidade comercial e baixo custo, baixas taxas de corrosão química e de problemas de entupimento dos bicos injetores, bem como o controle de taxas de temperatura de deposição. Portanto, apres...
Detector de radiação orgânico e inteligente para raios x de uso em radioterapia...
Schimitberger, Thiago; Ferreira, Giovana Ribeiro; Souza, Claudiano de Jesus de; Silva, Mariana de Melo; Saraiva, Marcelo FrotaNeste trabalho são apresentadas a fabricação e a caracterização óptica de um novo detector de raios X para monitoramento da dose nos processos de radioterapia empregando fótons de alta energia (6,0 MV). O dispositivo foi fabricado a partir de materiais orgânicos luminescentes consolidados como elemento ativo de displays eletroluminescentes nanoestrurados, mas que, até esse momento, têm sido pouco investigados c...
Spectroscopic ellipsometry as a complementary tool for studying luminescent pol...
Bianchi, Rodrigo Fernando; Gonçalves, DéboraA novel approach for studying the thermal conversion of poly-p-xylylidene tetrahydrothiophenium chloride (PTHT) into poly(p-phenylenevinylene) (PPV) films has been proposed on the basis of calculated optical parameters. Spin-cast PTHT films were thermally converted into partially conjugated PPV films over conversion temperatures ranging from 22 C to 200 C. A strong correlation between refractive index (n) and d...