Optically anisotropic and photoconducting Langmuir-Blodgett films of neat poly(3-hexylthiophene)

Among the several types of conjugated polymers used in recent investigations, polythiophene and its derivatives have attracted considerable attention over the past 20 years due to their high mobility and other remarkable solid-state properties. They have potential applications in many fields, such as microelectronic devices, catalysts, organic field-effect transistors, chemical sensors and biosensors. There are two critical parameters that determine the polymer-based device performance: chemical structure and nanostructure of the conjugated polymer in solid state. Langmuir–Blodgett (LB) films may be an interesting alternative for producing the films used in the devices since they can be obtained with high degree of thickness control, low number of defects, and some degree of organization at the molecular scale. However, most of the polythiophene derivatives have poor film forming properties by LB method and need the use of film form aiding materials. In this work, we report on the fabrication and characterization of Langmuir and Langmuir–Blodgett films of neat poly(3-hexylthiophene). Although the LB technique is not suitable to obtain LB films with a great number of layers, good quality films, with thicknesses suitable for fabrication of opto-eletronic devices could be easily built by using the proper deposition conditions.CNPqFAPESPINEO/CNPqLNL

Polymeric coatings for photostability enhancement of poly(p-phenylene vinylene) derivative films

Poly(p-phenylene vinylene) (PPV) derivatives are an important class of conjugated polymers, known for their applications as electroluminescent materials for light-emitting devices and sensors. These derivatives are highly susceptible to photodegradation by the combined action of oxygen and light. Here, the use of various commercial polymers as protective coatings against the photodegradation of PPV derivatives was explored. Cast films of two similar PPV derivatives, poly[(2-methoxy-5-n-hexyloxy)-p-phenylene vinylene] and poly[2-methoxy-5-(2-ethylhexyloxy)-p-phenylene vinylene], were submitted to photodegradation by exposure to white light under atmospheric conditions in order to verify if the type of side chain (linear or branched) had an effect on the photodegradation. No significant differences in the photodegradation behaviour between the two polymers were noticed. The following commercial polymers were tested as protective coatings for the PPV derivative cast films: 99 and 80% hydrolysed poly(vinyl alcohol) (PVA) and starch. The best results were achieved using coatings of 99% hydrolysed PVA, which increased about 700 times the time necessary for complete degradation of the PPV derivative films. The results show the effectiveness of this coating in minimizing and, possibly, controlling the effects of the photodegradation of PPV derivative films, which can be useful in many applications, e.g. oxygen sensors.FAPESPCNPqInstituto Multidisciplinar de Materiais Poliméricos (IMMP)/MCT

Dor no idoso: satisfação com o tratamento

Conscientes de que a dor é um flagelo a nível mundial, um fenómeno complexo e multifactorial presente na vida de qualquer ser humano, numa determinada fase da vida, e porque efectivamente nos preocupa o sofrimento dos idosos, a forma como eles vivenciam a dor, as repercussões que esta acarreta para as suas vidas, bem como se os tratamentos e as estratégias implementadas são eficazes, decidimos desenvolver este trabalho, cujo objectivo principal é o de “Identificar o grau de satisfação dos Idosos face ao tratamento da dor”. Sabe-se que a satisfação é hoje um indicador de qualidade dos cuidados de saúde, que permite responder às expectativas dos idosos e também identificar estratégias e implementar acções de melhoria, que visem obter ganhos em saúde. Trata-se de um estudo transversal, de natureza quantitativa (questionário sociodemográfico e a Escala de Satisfação com o Tratamento da Dor), seguindo uma via decritivo-correlacional. Utilizou-se uma amostra não probabilística por conveniência, constituída por 89 idosos do Concelho da Covilhã. A amostra estudada apresenta uma média de idades de 77 anos, casados, reformados, a residir no meio rural e detendo baixos níveis de instrução, apresentam na sua maioria dor crónica de origem músculo esquelética, de duração superior a 1 ano com predomínio na região dorso lombar. Grande parte da nossa amostra refere estar satisfeita com o tratamento para a sua dor, contudo as análises exploratórias revelaram que as variáveis como a idade, local de residência, rendimento mensal e religião têm um impacto na satisfação do tratamento com a dor. Palavras Chave: dor, idoso, satisfação com o tratamento da dor.ABSTRACT Conscious that pain is a worldwide scourge, a complex and multidimensional phenomena, present in a certain phase of life of any human being and deeply worried with older adults suffering, the way as they feel pain, its impact on their lives, as well as with efficacy of the treatment and of the implemented strategies, we decided to develop this work, which main purpose is “Evaluating the Older Adults satisfaction degree regarding pain treatment”. Today, it’s known that older adults satisfaction is an indicator of health care quality, allowing answering to their expectations as well as planning strategies and implementing actions to improve health of an increasing number of people in this stage of life. Therefore, the question is: in which way social, demographic and clinical conditions of the older adults are related with their pain treatment satisfaction. It is a transversal and quantitative (questionnaire social demographic and the Pain Treatment Satisfaction Scale) study in a descriptive and correlative way. We used a non probabilistic sample of 89 older adults, living in Covilhã Municipality. The studied sample states an average of 77 years old, married and retired old people, living in rural area, having low level of instruction, most of them suffering from musculoskeletal chronic pain, especially low back pain, lasting for more than one year. Most of them report satisfaction with their pain treatment; however deeper analyses showed that conditions such as age, place of living, monthly income and religion affect treatment pain satisfaction. This knowledge about old adults pain treatment satisfaction is relevant to the health care professionals in order to provide a greater autonomy and independence to those individuals, and consequently improving their quality of life. Keywords: pain, old adults, pain treatment satisfaction

Synthesis and characterization of copolymers of alkyl- and azo-thiophenes: chromic properties and photoinduced birefringence

Polyazothiophene is a type of polythiophene derivative that combines the electrical and luminescent properties of polythiophenes with the photoisomerization property of azopolymers. Extensive efforts have been made to improve the properties of polyazothiophenes, such as solubility, optical, and chromic properties. We report the preparation of copolymers of an alkylthiophene (3-octylthiophene, 3-OT) and an azothiophene (2-[N-ethyl-N-[4-[(4-(4-nitrophenyl)azo]phenyl]amino]ethyl 3-thienylacetate, 3-AzoT) in different ratios as an alternative route to improve these properties. The azosubstituted monomer contents in these copolymers were 6, 9, 12, and 51% (in mol), as evaluated by elemental analysis. Their chemical structures were confirmed by FTIR and 1H-NMR. HPSEC and thermal analysis were used to characterize the polymers. The presence of thermochromic and solvatochromic properties was demonstrated by UV-Vis spectroscopy. Optically induced birefringence was detected only in polymers with 12 and 51 mol % of azo-units. The introduction of different ratios of the azothiophene in the copolymer alters the polymer solubility and emissive properties. The results indicate that the polyazothiophene copolymers presented are promising active layers for optical devices and sensor

Hydrophobic methacrylic copolymers containing azobenzene moieties

The functionalization of polymer materials to produce hydrophobic surfaces is an important goal for a number of applications, especially those associated with self-cleaning and anti-adherent surfaces. Azopolymers are known for photoisomerization property that can lead to photoinduced anisotropy, photomechanical effect and surface modification with surface-relief gratings. In this study, we combine the low surface energy property of perfluoroalkyl methacrylates with the photoinduced characteristics of azopolymers, by fabricating cast films of copolymers of 2,2,2 trifluorethyl methacrylate (TFEMA) or 2,2,3,3,4,4,5,5 octafluoropentyl methacrylate (OFPMA) and 4′-[N-ethyl-N-(2methacryloxy-ethyl)]amine-4-nitro-azobenzene (DR13MA). The intended structures of the copolymers synthesized using radicalar polymerization was confirmed with Fourier transform infrared (FTIR) spectroscopy and nuclear magnetic resonance (NMR). The polymers had much higher thermal stability than conventional azopolymers, and formed hydrophobic surfaces with a water contact angle of ca. 96°. These hydrophobic azopolymers were amenable to the formation of surface-relief gratings at room temperature resulting from an all-photonic mass transport process, which opens the way for a number of new applications to be designed.CAPESCNPqFAPESPINCT-INE

Molecular-level interactions of an azopolymer and poly(dodecylmethacrylate) in mixed Langmuir and Langmuir-Blodgett films for optical storage

The applicability of azopolymers in optical storage can be extended through the use of nanostructured films produced with the Langmuir–Blodgett (LB) technique, but the film properties need to be optimized since these polymers generally do not form stable Langmuir films to be transferred onto solid substrates. Here, photoinduced birefringence was investigated for mixed Langmuir–Blodgett films from the homopolymers 4-[N-ethyl-N-(2-methacryloxyethyl)]-4′-nitroazobenzene (HPDR1-MA) and poly(dodecylmethacrylate) (HPDod-MA). The interactions between these polymers were studied in Langmuir and LB films. Surface pressure–area isotherms pointed to molecular-level interactions for proportions of 51 mf%, 41 mf% and 31 mf% of HPDR1-MA. Phase segregation was not apparent in the BAM images, in which the morphology of the blend film was clearly different from that of the Langmuir films of neat homopolymers. Through PM-IRRAS, we noted that the interaction between the azopolymer and HPDod-MA affected the orientation of carbonyl groups. Strong interactions for the mixture with 41 mf% of poly(dodecylmethacrylate) led to stable Langmuir films that were transferred onto solid supports as LB films. The photoinduced birefringence of 101-layer mixed LB films show features that make these films useful for optical storage, with the advantage of short writing times in comparison to other azopolymer films.CAPESFAPESPCNP

Exploring Utility-based Optimization and Management for Wireless Sensor Networks and Machine-to-Machine Communications

The control of molecular architecture provided by the Langmuir–Blodgett (LB) method allows one to obtain enhanced luminescence properties in polymer films, which can be exploited in polymer light emitting diodes (PLEDs). In this study, we show that incorporating a liquid crystal (LC) (PCH302/304) into poly-(2-methoxy-5-hexyloxy-p-phenylene-vinylene) (OC1OC6-PPV) in LB films leads to a 4-fold increase in photoluminescence and 2-fold increase in electroluminescence for (ITO/OC1OC6-PPV(LC5%)/Al) devices for emission at 585 nm, with the current vs. voltage (I vs. V) characteristics exhibiting a typical behavior of rectifying diode. The enhanced luminescence was attributed to an efficient separation of emitting OC1OC6-PPV units induced by the LC in the LB film, which were less ordered than LB films from neat OC1OC6-PPV.FAPESPCNPqMMP/MC

New records and observations on Macrolepidoptera (Insecta: Lepidoptera) from the Azores.

This paper presents a summary of butterflies and moths from Santa Maria, Faial, Pico and S. Miguel islands. Collections and/or observations were made mostly during short visits in the years 1997, 1998 and 2001. The list of records includes 40 Macrolepidoptera species, belonging to the families Pieridae, Nymphalidae, Lycaenidae, Geometridae, Sphingidae and Noctuidae. Some species are new confirmed records, for Faial (Vanessa virginiensis (Drury), Hippotion celerio (Linnaeus), Ophiusa tirhaca (Cramer), Agrotis segetum (Denis & Schiffermüller)), for Pico (Vanessa cardui (Linnaeus)) and for Ilhéu de Vila Franca do Campo (Autographa gamma (Linnaeus))

Excited State Absorption of Doped and Undoped Polyanyline

Polyaniline is a conducting polymer with appealing electrical and optical properties, arising from the -conjugation along the polymer backbone. The understanding of its excited state absorption is of prime importance for designing and fabricating optical devices. Here, we report on the study of the excited state absorption of doped and undoped PANI by using femtosecond pulses in the spectral range from 450nm up to 850nm. For undoped PANI, we observed saturation of absorption as well as reverse saturable absorption, depending on the excitation wavelength. For doped PANI, however, only saturable absorption was observed.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESPCNPqConselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)CAPES from BrazilU.S. Air Force Office of Scientific Research (AFOSR)AFOSR from USA[FA9550-07-1-0374

Laser microstructuring for fabricating superhydrophobic polymeric surfaces

In this paper we show the fabrication of hydrophobic polymeric surfaces through laser microstructuring. By using 70-ps pulses from a Q-switched and mode-locked Nd:YAG laser at 532 nm, we were able to produce grooves with different width and separation, resulting in square-shaped pillar patterns. We investigate the dependence of the morphology on the surface static contact angle for water, showing that it is in agreement with the Cassie-Baxter model. We demonstrate the fabrication of a superhydrophobic polymeric surface, presenting a water contact angle of 157 degrees. The surface structuring method presented here seems to be an interesting option to control the wetting properties of polymeric surfaces. (C) 2010 Elsevier B.V. All rights reserved.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP (Fundacao de Amparo a Pesquisa do Estado de Sao Paulo)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)CNPQ (Conselho Nacional de Desenvolvimento Cientifico e Tecnologico)U.S. Air Force Office of Scientific Research (AFOSR)Air Force Office of Scientific Research (AFOSR) [FA9550-07-1-0374