Carbon nanotube 'webs' prevent ice build-up on planes
Queen's University Belfast researchers have developed a new system to prevent ice from building up on aircraft. The conventional anti-icing system on most passenger aircraft is based on hot air which is 'bled' from the engines and piped to the inner surface of the wing. The heat is then transferred to the outer surface by thermal conduction, which stops the ice from building. This system adds weight and maintenance requirements, and is not energy efficient, particularly on the new generation of composite aircraft. A team of experts at Queen's have developed a more efficient alternative - an ultra-light weight heater, based on 'webs' made from carbon nanotubes (CNT) - which can also be used for de-icing. Professor Brian Falzon, from the School of Mechanical and Aerospace Engineering led the Queen's team to the discovery and the research has been published in the journal Carbon. He explains: "This research is funded by the Engineering and Physical Sciences Research Council (EPSRC) and forms part of a larger research programme aimed at developing the aircraft structures of tomorrow. We started by creating a 'CNT web', where individual CNTs are aligned in the draw direction, and horizontally stacking 10-40 layers of the webs, at different orientations, to achieve the desired heating characteristics. Each layer of CNT web can be as thin as 1/2000 the thickness of a human hair and the weight of a web large enough to cover a football field would be less than 30 sheets of A4 photocopy paper. These CNT webs were cured within a thin glass fibre laminate to provide structural support, and connected to a power supply. When we carried out testing, we discovered that the newly developed CNT heaters achieved rapid heating which shows that the CNT heaters could quickly de-ice aircraft and provide effective ice protection in flight." The team is developing further research on the system and it is hoped that it will be in use within a few years.
DPA, 3rd December, 2018
Turning plastic bottle waste into ultralight super material
A team led by researchers from the National University of Singapore has found a way to turn plastic bottle waste into ultralight polyethylene terephthalate (PET) aerogels. Plastic bottles are commonly made from polyethylene terephthalate (PET), which is the most recycled plastic in the world. The PET aerogels developed by the NUS-led research team using plastic bottle waste - a world's first - are soft, flexible, durable, extremely light and easy to handle. They also demonstrate superior thermal insulation and strong absorption capacity. These properties make them attractive for a wide range of applications, such as for heat and sound insulation in buildings, oil spill cleaning, and also as a lightweight lining for firefighter coats and carbon dioxide absorption masks that could be used during fire rescue operations and fire escape. This pioneering work was achieved by a research team led by Associate Professor Hai Minh Duong and Professor Nhan Phan-Thien from the Department of Mechanical Engineering at NUS Faculty of Engineering. The technology to produce PET aerogels was developed in collaboration with Dr Xiwen Zhang from the Singapore Institute of Manufacturing Technology (SIMTech) under the Agency for Science, Technology and Research (A*STAR).
DPA, 3rd December, 2018
Green and edible cling film and food packaging made from plants
Researchers developed 100% biodegradable and edible food packaging made from plant carbohydrates and proteins to replace polluting plastic materials. The Sino-UK project is led by Professor Saffa Riffat, from the Faculty of Engineering, University of Nottingham, whose research group is world-renown for innovations in sustainable materials, energy and building technologies. This includes their investigations into the structure and functionality of sustainable natural materials such as plant polysaccharides (carbohydrates) and proteins to develop advanced materials for applications in buildings, energy technologies, packaging and beyond. Using a special technical approach, the team is working on plastic films derived from konjac flour and starch, cellulose or proteins that are fully edible and harmless if accidentally eaten by people or animals - unlike health issues associated with microplastics and other plastic waste that make their way into the food chain. The researchers have found that plant carbohydrate and protein macromolecules bond together into a special network structure during the film-forming process. The network structure provides the film with a required mechanical strength and transparent appearance for the film to be used as packaging materials. The project is jointly investigated by Marie Curie Research Fellow, Professor Fatang Jiang, an expert in biodegradable polysaccharide materials for moisture control, thermal insulation and infiltration. He recently joined the University of Nottingham from Hubei University of Technology in China, where part of the study is being worked on. Fully-biodegradable bags could not only solve the safety and pollution issues of food packaging materials, but also efficiently lengthen the shelf life of fruit and vegetables and other fresh produce. "In addition to being edible, degradable, strong and transparent, the packaging materials we are working on have low gas permeability, making them more air tight. This feature cuts moisture loss, which slows down spoilage, and seals in the flavour. This is of great importance for the quality, preservation, storage and safety of foods," Professor Riffat adds. The project, currently supported by the £220K Horizon 2020 Marie Curie fellowship, will last two years with the potential to extend for another three to five years if further funding is secured.
DPA, 3rd December, 2018
Victrex launches PEEK polymer for cryogenics
Victrex has announced that it has designed a new high-performance PEEK polymer to offer the cryogenics industry a sealing solution with a broader range of usage temperature. The company's new VICTREX CT 200 is designed for dynamic sealing applications where gases such as liquefied natural gas (LNG) are stored and transported at cryogenic temperatures (-150°C / -238°F to -200°C / -328°F). According to Victrex, its 200 grade series polymers exhibit improved sealing over a wider range of temperatures, compared to commonly used materials such as PCTFE. The product does so at low temperatures because of its good ductility, and at high temperatures due to its good creep resistance. VICTREX CT polymers have also reportedly been shown to maintain better dimensional stability, with a lower coefficient of thermal expansion than incumbent material. The higher thermal conductivity of these polymers is said to enable a fast response to temperature changes and ensure the material is engaged with the counter-surface at all times. According to Victrex, laboratory testing indicates that the polymers also may require less torque to actuate since they have a lower static and dynamic coefficient of friction compared to PCTFE, resulting in less wear and higher performance. VICTREX CT 200 has successfully completed stringent TAT test as per the Shell Mesc 77/300 and holds promise for injection molding, compression molding and extrusion processing advantages. The product is scheduled for commercial availability beginning in December 2018.
CW Today, 30th November, 2018
Daimler uses organo panels in new SUV
Daimler's Mercedes-Benz is using organo panels in the main front end member of the redesigned, US-built GLE SUV, noting it's the first time it has used this innovative material for such a large and visible component. Organo panelling provides an alternative to sheet metal panels and consists of fibre-reinforced plastic panels. After heating in a press, these panels are formed into three-dimensional components via a process which involves very short cycle times. The fibre reinforcement endows organo panels with very good mechanical properties, such as rigidity and strength, combined with only a fraction of the weight of their sheet metal counterparts. The thermoplastic plastic matrix offers another advantage. An injection moulding process follows in a second, integrated production step, in the course of which ribs, mountings, and any other required items are added. This takes place in the same tool in which the organo panel was formed. The organo panelling of the GLE can be permanently fused to adjacent parts made of polypropylene. Only butt-welding was possible previously, with the risk of fractures. Use of the sandwich construction principle means that fewer components are needed overall, as air ducts and sleeves for bolt-on components are directly integrated. As organo panels do not corrode, they do not need to be painted. The front end member made of organo panels is around 30% lighter than a conventional design.
Bombardier builds Airbus wing hopes
Bombardier will pitch to play a key role in a future Airbus composite wing programme, believing that its expertise in designing and building the carbon fibre wing for the A220 gives it the edge over Airbus's own factories. The Belfast facility has been pioneering composite technologies since it was Shorts Aerospace in the 1980s. Airbus took control of the former CSeries in July, renaming it the A220, and effectively allowing Bombardier to exit from a loss-making commitment. However, Bombardier retains the intellectual property rights on the wing, which BAES in Belfast continues to build for Airbus as a supplier. The Belfast operation, together with Airbus's own wing operations in Broughton and Filton, remain crucial to government efforts to keep wing production in the UK following Brexit.
Flight International, 4-10 Dec. 2018. p.4.
Graphene-based spine in seaweed gel offers industrial applications
Brown University researchers have created a hybrid material out of seaweed-derived alginate and the nanomaterial graphene oxide. They have developed a way of reinforcing alginate by incorporating the atomically-thick layered material graphene oxide into its structure. This produces a material that can be 3D printed into structures that are stiffer and more fracture resistant than alginate alone. Furthermore, changes in the chemical environment can make the composite even stiffer or softer, allowing the structures to respond their surroundings in real time. Despite this change in behaviour, the composite retains some of the useful properties of alginate. The team believes that reinforcing alginate with graphene strengthens the material because it changes the way that cracks propagate through its structure.