| 1. |
- Andersson, Mats R., et al.
(author)
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Regioselective polymerization of 3-(4-octylphenyl)thiophene with FeCl3
- 1994
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In: Macromolecules. - : American Chemical Society. - 0024-9297 .- 1520-5835. ; 27:22, s. 6503-6506
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Journal article (peer-reviewed)abstract
- We have shown that it is possible to regioselectively polymerize 3-(4-octylphenyl) thiophene with FeCl3. Adding FeCl3 slowly to the monomer leads to a soft and therefore regioselective polymerization. The head-to-tail content was determined by H-1 NMR to be 94 +/- 2%. Thin films of the polymer treated with chloroform vapor have an absorption maximum at 602 nm (2.06 eV) with clear vibronic fine structure. Free standing films have a conductivity of 4 S/cm, which is 100 times higher than for earlier prepared poly(3-(4-octylphenyl)thiophene). A mechanism for the regioregular polymerization is also proposed.
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| 2. |
- Berggren, Magnus, et al.
(author)
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Light-emitting diodes with variable colours from polymer blends
- 1994
-
In: Nature. - : Nature Publishing Group. - 0028-0836 .- 1476-4687. ; 372:6505, s. 444-446
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Journal article (peer-reviewed)abstract
- THE range of materials now available for polymer-based light-emitting diodes (LEDs) is such that electroluminescence can be obtained throughout the visible spectrum(1-12). Here we show that, by blending polymers with different emission and charge-transport characteristics, LEDs can be fabricated in which the emission colour varies as a function of the operating voltage. This phenomenon arises from the self-organizing properties of the blends, in which entropy drives phase separation of the constituent polymers and gives rise to submicrometre-sized domains having a range of compositions and emission characteristics. Emission from domains of different composition is controlled by the ease with which charge is injected, which in turn depends on the applied voltage.
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| 3. |
- Berggren, Magnus, et al.
(author)
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White light from an electroluminescent diode made from poly[3(4‐octylphenyl)‐2,2′‐bithiophene] and an oxadiazole derivative
- 1994
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In: Journal of Applied Physics. - : American Institute of Physics (AIP). - 0021-8979 .- 1089-7550. ; 76:11, s. 7530-7534
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Journal article (peer-reviewed)abstract
- We report on an electroluminescent diode emitting red, green, and blue light simultaneously. The device is based on a thin polymer layer, poly[3‐(4‐octylphenyl)‐2,2′‐bithiophene] and a thick molecular layer, 2‐(4‐biphenylyl)‐5‐(4‐tertbutyl‐phenyl)1,3,5‐oxadiazole. The quantum efficiency for light conversion is 0.3% and the turn‐on voltage for light emission is 7 V. In this article we present electric and spectroscopic characterizations. A mechanism for the light emission, based on electron and hole recombination between the two organic layers, is proposed
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| 4. |
- Moore, R, et al.
(author)
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Generalization of effects of dental fear treatment in a self-referred population of odontophobics.
- 1991
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In: Journal of behavior therapy and experimental psychiatry. - 0005-7916. ; 22:4, s. 243-53
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Journal article (peer-reviewed)abstract
- Effects of dental fear treatment on general anxiety and mood in 60 dental phobics with high and low general anxiety were compared with "attention" effects in 75 dental phobics on a waiting list using the Dental Anxiety Scale, a State-Trait Anxiety Inventory and a modified Fear Survey Schedule. Positive effects of the treatment were apparent in reduced dental and general fearfulness as well as elevated mood on numerous measures that paralleled dentist ratings of patient behavior. Ss had less fear of going to the next dentist after the program than before, according to a visual analogue measure. Ninety-three percent of Ss started dental treatment with private dentists within 1 year.
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| 5. |
- Moore, R, et al.
(author)
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Reliability and clinical usefulness of psychometric measures in a self-referred population of odontophobics.
- 1992
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In: Community dentistry and oral epidemiology. - 0301-5661. ; 19:6, s. 347-51
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Journal article (peer-reviewed)abstract
- Questionnaire responses of 155 self-referred subjects with extreme dental fear were used to evaluate the reliability and clinical usefulness of some psychometric tests used in diagnosis and treatment. The Corah Dental Anxiety Scale (DAS), State-Trait Anxiety Inventory (STAI), and a general Geer Fear Scale (GFS) were filled out by all subjects, while 80 patients with highest dental fear scores were also tested before and after dental fear treatment with the following scales; a Getz Dental Belief Survey (DBS), Dental Fear Survey (DFS), and a Mood Adjective Checklist (MACL). Cronbach's alpha measured internal consistency reliability. SPSS data analyses calculated item-remainder and test-retest correlations. Clinical usefulness of scales was judged by Spearman correlations of initial scores and test score changes after dental fear treatment. All total test scores showed high internal consistency and test-retest reliability. DFS was judged the preferred clinical measure of threatening perceptions of pain or unpleasantness specific to dental procedures. DBS and STAI-State measured confidence in relating with the dentist and situational fear associated with that relationship. GFS, STAI-Trait, and MACL discriminated levels of general fearfulness, anxiety and mood fluctuations that can impact on dental fear.
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