- Email: [email protected]
Polyfluorenes with dendron side chains for polymer LEDs
~ESEARCH TREND c. optimised to an 'average' person but that 'one size adapted to all'. The 'smart' design approach can also contribute strongly here. For example, handles that adapt uniquely to their immediate user and which also uniquely adapt to all subsequent users. These could be applied to products ranging from kitchen goods and consumer healthcare to the automotive sector. Here again highly conformable elastic materials such as elastomers and polymer gels can play a central role. Such products offer significantly enhanced usability for the old, handicapped, young, left/right-handed, with the design concept being sufficiently generic to be applied in a wide range of products. The 'smart' structures concept is attractive and entirely transferable to the consumer goods
ResearchTrends Smart performance garments The difficulties facing manufacturers of survival clothing is considered, including the need to define worst case conditions in which garments may need to afford protection. Decathlon, with a turnover of £2bn has worked closely with Leeds University to define the most important performance parameters for survival clothing. Key factors in comfort are ambient humidity and moisture management, not temperature. The design and patenting of an ultra-low spacer fabric claimed to be superior to current fleece fabrics is outlined. Detailed design of performance clothing is as important as materials used, as is subsequent testing to confirm design goals have been reached. High technology (or smart textiles in both passive form (achieved by textile design), or active form (where energy input is needed) are detailed. I Holme: Textile Horizons May/June 7-8 (2002) Survival 2002.
Shape change from AgnOxHy silver cluster on graphite induced by their chemical composition The deposition of AgnOxHy clusters onto a graphite surface, maintained at room temperature, as a function of the cluster chemical composition has been investigated. The incident clusters were produced by a gasaggregation silver cluster source when adding 0 2 and H 2 0 molecules in the carrier gas, and monitored by a time of flight mass spectrometer. Samples were imaged by electron microscopy.
Smart Materials Bulletin
market, providing that simpler technological solutions are sought which best match the requirements of the sector. The adaptivity of 'smart' products offers a new design paradigm enhancing user/product interaction through much greater emotional engagement and the use of dynamic visual and physical affordances.
Breakthrough products We have only just begun to explore the potential of 'smart' consumer products, which offer the potential of breakthrough products in a wide range of consumer goods markets. Successful development of 'smart' consumer products depends on a clear understanding of product design, user/object interaction and deep knowledge of appropriate adaptive technologies.
Results show that cluster diffusion and agglomeration on the surface as well as the resulting island morphology strongly depend on the cluster chemical composition. If the deposition of pure silver clusters leads to nano-fractal islands, a few of oxide/hydroxide molecules incorporated as impurities into the incident clusters prior to their deposition induce a post fractal island fragmentation, keeping constant the fractal dimension.Deposition of totally oxidised/hydroxided clusters induces drastic change in island morphology with a decrease of the cluster diffusion on graphite. In this case a dense nano-phase material with narrow size particle distribution in chain-like structure is obtained. C. Brdchignac, Ph. Cahuzac, E Carlier, N. Kdba'ili, J. Le Roux, A. Masson: Surface Science 518 (3) 192-200 (20 October, 2002).
Photoemission effects from Au nano clusters on TiO2 Valence level and shallow core states of Au nanoclusters on TiO2(1 1 0) have been studied by synchrotron excited photoemission. The shift to high binding energy and broadening of the Au 4f peaks with decreasing Au surface coverage can be understood in terms of decreasing cluster size and the associated effects of charge on the cluster in the final state. Shifts in the photo emission onset are more pronounced than the core level shifts and show strong dependence on the degree of reduction of the TiO2(1 1 0) substrate. This suggests that photoemission onset is influenced by initial state effect involving charge transfer from defect into cluster states. A. Howard, D. N. S. Clark, C. E. J. Mitchell, R. G. Egdell, V. R. Dhanakb: SurfaceScience518 (3) 210-224 (20 October 2002).
References 1. D.A. Norman: 'Psychology of everyday things' (Basic Books, New York, 1998). 2. J.J. Gibson: 'Ecological approach to visual perception' (Houghton-Mifflin, Boston, 1979). 3. C. Thorpe and C.M. Friend: 'Modelling intelligent electronic consumer products', J. of Intelligent Mat. Syst. & Struct. 10(7) 552-557. 4. C. Thorpe: 'Smart consumer products - An approach to their design and evaluation'. PhD thesis, Cranfield University, UK, 2000. For more information contact: Clifford M. Friend, Humanware Group, Cranfleld University,Shrivenham, SwindonSN6 8LA, UK.TeI:+44 1793 785327. Email:
[email protected] Thispaper was presentedat the EuropeanWorkshop on Applications for Smart Structures in Engineering and Technologyin May 2002.
Radar absorbing materials for X- and Ku-band frequencies Samples consisting of an elastomeric matrix containing different kinds of active materials in particulate form were prepared for reflectivity measurements. The materials individually used in weight contents of 80% in polychloroprene matrix were: carbonyl-iron (CI) and doped ferrite powders. The microwave reflectivity levels were determined from the magnetic and dielectric properties of the elastomeric composites obtained from scattering data, by fitting the samples in a waveguide, for measurements in the frequency range from 8 to 16GHz. Better microwave absorption for X-band was obtained for CI while doped ferrite absorbed at higher frequencies (Ku-band). M.S Pinho, M.L. Gregori, R.C.R Nunes, B.G. Soares: European PolymerJournal38, (11) 23212327 (2002).
Polyfluorenes with dendron side chains for polymer LEDs The synthesis of a polyfuorene with polyphenylene dendrons as side chains was reported. It was shown that polymer light-emitting devices (PLEDs)from these materials possess very promising properties. In addition, it was also shown that the chemical stability and the shape persistence of Mullen-type dendrimers allows an effective shielding of the polyfluorene backbone at lower dendron generation numbers compared to Frechet-type ones. Alexander Pogantsch, Franz P Wenzl, Emil J.W. List, Gunther Leising, Andrew C. Grimsdale, Klaus Mullen, Advanced Materials 14 (15) 10611064 (5 August, 2002).
November 2002
ResearchTrends Smart performance garments The difficulties facing manufacturers of survival clothing is considered, including the need to define worst case conditions in which garments may need to afford protection. Decathlon, with a turnover of £2bn has worked closely with Leeds University to define the most important performance parameters for survival clothing. Key factors in comfort are ambient humidity and moisture management, not temperature. The design and patenting of an ultra-low spacer fabric claimed to be superior to current fleece fabrics is outlined. Detailed design of performance clothing is as important as materials used, as is subsequent testing to confirm design goals have been reached. High technology (or smart textiles in both passive form (achieved by textile design), or active form (where energy input is needed) are detailed. I Holme: Textile Horizons May/June 7-8 (2002) Survival 2002.
Shape change from AgnOxHy silver cluster on graphite induced by their chemical composition The deposition of AgnOxHy clusters onto a graphite surface, maintained at room temperature, as a function of the cluster chemical composition has been investigated. The incident clusters were produced by a gasaggregation silver cluster source when adding 0 2 and H 2 0 molecules in the carrier gas, and monitored by a time of flight mass spectrometer. Samples were imaged by electron microscopy.
Smart Materials Bulletin
market, providing that simpler technological solutions are sought which best match the requirements of the sector. The adaptivity of 'smart' products offers a new design paradigm enhancing user/product interaction through much greater emotional engagement and the use of dynamic visual and physical affordances.
Breakthrough products We have only just begun to explore the potential of 'smart' consumer products, which offer the potential of breakthrough products in a wide range of consumer goods markets. Successful development of 'smart' consumer products depends on a clear understanding of product design, user/object interaction and deep knowledge of appropriate adaptive technologies.
Results show that cluster diffusion and agglomeration on the surface as well as the resulting island morphology strongly depend on the cluster chemical composition. If the deposition of pure silver clusters leads to nano-fractal islands, a few of oxide/hydroxide molecules incorporated as impurities into the incident clusters prior to their deposition induce a post fractal island fragmentation, keeping constant the fractal dimension.Deposition of totally oxidised/hydroxided clusters induces drastic change in island morphology with a decrease of the cluster diffusion on graphite. In this case a dense nano-phase material with narrow size particle distribution in chain-like structure is obtained. C. Brdchignac, Ph. Cahuzac, E Carlier, N. Kdba'ili, J. Le Roux, A. Masson: Surface Science 518 (3) 192-200 (20 October, 2002).
Photoemission effects from Au nano clusters on TiO2 Valence level and shallow core states of Au nanoclusters on TiO2(1 1 0) have been studied by synchrotron excited photoemission. The shift to high binding energy and broadening of the Au 4f peaks with decreasing Au surface coverage can be understood in terms of decreasing cluster size and the associated effects of charge on the cluster in the final state. Shifts in the photo emission onset are more pronounced than the core level shifts and show strong dependence on the degree of reduction of the TiO2(1 1 0) substrate. This suggests that photoemission onset is influenced by initial state effect involving charge transfer from defect into cluster states. A. Howard, D. N. S. Clark, C. E. J. Mitchell, R. G. Egdell, V. R. Dhanakb: SurfaceScience518 (3) 210-224 (20 October 2002).
References 1. D.A. Norman: 'Psychology of everyday things' (Basic Books, New York, 1998). 2. J.J. Gibson: 'Ecological approach to visual perception' (Houghton-Mifflin, Boston, 1979). 3. C. Thorpe and C.M. Friend: 'Modelling intelligent electronic consumer products', J. of Intelligent Mat. Syst. & Struct. 10(7) 552-557. 4. C. Thorpe: 'Smart consumer products - An approach to their design and evaluation'. PhD thesis, Cranfield University, UK, 2000. For more information contact: Clifford M. Friend, Humanware Group, Cranfleld University,Shrivenham, SwindonSN6 8LA, UK.TeI:+44 1793 785327. Email:
[email protected] Thispaper was presentedat the EuropeanWorkshop on Applications for Smart Structures in Engineering and Technologyin May 2002.
Radar absorbing materials for X- and Ku-band frequencies Samples consisting of an elastomeric matrix containing different kinds of active materials in particulate form were prepared for reflectivity measurements. The materials individually used in weight contents of 80% in polychloroprene matrix were: carbonyl-iron (CI) and doped ferrite powders. The microwave reflectivity levels were determined from the magnetic and dielectric properties of the elastomeric composites obtained from scattering data, by fitting the samples in a waveguide, for measurements in the frequency range from 8 to 16GHz. Better microwave absorption for X-band was obtained for CI while doped ferrite absorbed at higher frequencies (Ku-band). M.S Pinho, M.L. Gregori, R.C.R Nunes, B.G. Soares: European PolymerJournal38, (11) 23212327 (2002).
Polyfluorenes with dendron side chains for polymer LEDs The synthesis of a polyfuorene with polyphenylene dendrons as side chains was reported. It was shown that polymer light-emitting devices (PLEDs)from these materials possess very promising properties. In addition, it was also shown that the chemical stability and the shape persistence of Mullen-type dendrimers allows an effective shielding of the polyfluorene backbone at lower dendron generation numbers compared to Frechet-type ones. Alexander Pogantsch, Franz P Wenzl, Emil J.W. List, Gunther Leising, Andrew C. Grimsdale, Klaus Mullen, Advanced Materials 14 (15) 10611064 (5 August, 2002).
November 2002