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Journal articleMaples HA, Robinson P, Bismarck A, 2012,
High performance carbon fibre reinforced polymer composites with controllable stiffness: Can it be done?
, Eccm 2012 Composites at Venice Proceedings of the 15th European Conference on Composite MaterialsMorphing wings have the potential to reduce drag, noise and vibration in aircraft. One of the main challenges associated with morphing wings is the development of a skin material that can be deformed with acceptable actuation forces and yet transfer aerodynamic loads. To achieve this, an interleaved carbon fibre reinforced polymer (CFRP) composite with controllable stiffness has been manufactured. The composite contain plies of polystyrene that when heated above their glass transition temperature result in a large reduction in flexural stiffness and so permits structural deformations with relatively low actuation forces. When heated to 120 °C this composite exhibited a 98% reduction in flexural stiffness from 65 GPa to 1 GPa. The process was found to be reversible as the composite could be returned to its original configuration and on cooling its flexural strength and stiffness returned to their full values with no damage observed.
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Journal articleWienrich M, Kalinka G, Greenhalgh ES, et al., 2012,
Impact of ionic liquid on the mechanical performance of matrix polymer for fibre reinforced materials for energy storage
, Eccm 2012 Composites at Venice Proceedings of the 15th European Conference on Composite MaterialsFor the concept of using structural materials such as carbon fibre reinforced plastics as energy storage devices, new matrix polymers are required. These polymers must provide ionic conductivity as well as adequate mechanical strength. In the EU-Project StorAGE this requirements are fulfilled by adding ionic liquid to commercial polymers. The mechanical properties of these mixtures materials were characterized by using a 3-point-bending device. In addition, single fibre pull test were performed in order to get information on the interfacial shear strength. Adding of ionic liquid has an impact on the mechanical performance of the materials. A decrease of the flexural strength and modulus of less than 10% of the value of the reference materials took part. The interfacial shear strength decreased to a value of around one third compare to the reference material.
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Journal articleQian H, Diao HL, Houllé M, et al., 2012,
Carbon fibre modifications for composite structural power devices
, Eccm 2012 Composites at Venice Proceedings of the 15th European Conference on Composite MaterialsThis research project focuses on the development of new multifunctional composite materials, which allow energy storage functionality to be imbued upon low weight structural components. A crucial requirement for efficient structural energy storage composites is the development of structural carbon fibre electrode materials that possess high electrochemical surface area and stability whilst supporting high mechanical loads. In the present work, a variety of carbon fibre modifications were investigated, including chemical activation, carbon nanotube (CNT) sizing and CNT-grafting. The effects of these different modification methods on the fibre surface microstructure, electrochemical, and mechanical performance were studied and compared. In the most promising cases, up to a hundred-fold improvement in electrical storage capacity was achieved. Furthermore, single fibre tensile tests demonstrated that the intrinsically excellent mechanical properties of the carbon fibre were retained after the modifications.
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Journal articleShamsuddin SR, Hodgkinson J, Asp L, et al., 2012,
Carbon fibre reinforced PVDF composites
, Eccm 2012 Composites at Venice Proceedings of the 15th European Conference on Composite MaterialsUnidirectional (UD) carbon fibre reinforced polyvinylidene fluoride (PVDF) was manufactured using a laboratory scale composite line with in-line atmospheric plasma fluorination of carbon fibre surface. The resulting continuous UD carbon fibre reinforced PVDF prepregs were used to fabricate reinforced thermoplastic pipes (RTPs) via filament winding method. Winding angle of ±55° was employed as a preliminary study. The impact of APF treatment of carbon fibres on the hoop tensile strength as well as stiffness of the RTP is presented. Improvements in the mechanical properties of the RTP indicates the ability of stress transfer between the fibres and the matrix through the interface is enhanced and this is due to the improved adhesion between the fibres and the matrix by incorporating APF on the fibre surface.
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Journal articleBai S, Ho KKC, Knox G, et al., 2012,
Impact of continuous atmospheric pressure plasma polymerisation of acrylic acid on the interfacial propterties of carbon fibre -RFL elastomer composites
, Eccm 2012 Composites at Venice Proceedings of the 15th European Conference on Composite MaterialsAn atmospheric pressure plasma polymerisation (APP) route to enhance the adhesion properties between carbon fibres and elastomeric matrix was developed. The surface chemistry and physical properties of the modified carbon fibres were characterised to examine the impact of APP treatment on carbon fibres in regards to different treatment times. The wettability of treated carbon fibres was significantly improved as result of the introduction of chemical functionalities to the fibre surface, which was indicated by XPS measurements. Micromechanical characterisation of adhesion behaviour between carbon fibres and elastomeric matrix showed significant improvement by around 60% with the longest treatment time.
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Journal articleDiao H, Bismarck A, Robinson P, et al., 2012,
Pseudo-ductile behavior of unidirectional fibre reinforced polyamide-12 composite by intra-tow hybridization
, Eccm 2012 Composites at Venice Proceedings of the 15th European Conference on Composite MaterialsConventional carbon fibre reinforced plastics (CFRP) possess high specific strength and stiffness, can provide good chemical resistance and achieve long fatigue lives. However these materials are relatively brittle and have a low strain to failure and so structural failure can be catastrophic with little warning. In order to enhance the ductility of CFRP and change its catastrophic failure mode into a progressive one, carbon fibre tows with different failure strains were carefully selected and combined together into intra-tow hybrid reinforcement by using a gas-flow-assisted commingling process. This hybrid reinforcement was used to manufacture a polyamide-12 matrix composite using a polymer powder suspension impregnation method. By controlling the manufacturing parameters (speed and air flow rate in commingling process), a hybrid composite with significantly improved failure characteristics was obtained. Compared with corresponding single-fibre type composites, this hybrid composite has an improved tensile failure strain and still retains good tensile strength and stiffness properties.
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Conference paperLee KY, Ho KCC, Schlufter K, et al., 2012,
Bacterial cellulose as the binder for natural fibre preforms to produce green nanocomposites
A novel robust non-woven sisal fibre preform was manufactured using a papermaking process utilising nanosized bacterial cellulose (BC) as binder for the sisal fibres. It was found that BC provides significant mechanical strength to the sisal fibre preforms. This can be attributed to the high stiffness and strength of the BC network. Truly green non-woven fibre preform reinforced hierarchical composites were prepared by infusing the fibre preforms with acrylated epoxidised soybean oil (AESO) using vacuum assisted resin infusion, followed by thermal curing. Both the tensile and flexural properties of the hierarchical composites showed significant improvements over polyAESO and neat sisal fibre preform reinforced polyAESO. These results were corroborated by the thermo-mechanical behaviour of the (hierarchical) composites, which showed an increased storage modulus and enhanced fibrematrix stress transfer. By using BC as binder for short sisal fibres, added benefits such as the high Young's modulus of BC, enhanced fibre-fibre and fibre-matrix stress transfer can be utilised in the resulting hierarchical composites.
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Journal articleEge D, Lee K, Bismarck A, et al., 2012,
Evaluation of the degradation properties of carbonate substituted hydroxyapatite-poly(ε-caprolactone) composites
, Key Engineering Materials, Vol: 493-494, Pages: 120-125, ISSN: 1013-9826The aim of this work is to produce and characterise carbonate substituted hydroxyapatite (CHA) reinforced polycaprolactone (PCL) nanocomposites with a controlled degradation rate in order to match the rate of bone in-growth. The ideal degradation time for this purpose is estimated to be around 5-6 months however, in vivo, PCL degrades over a period of 2 to 3 years. It has been reported that NaOH surface treatment can accelerate the degradation of PCL [1-3]. In order to further modify the degradation rate of PCL, the effects of the incorporation of different volume fractions of CHA in samples surface treated with NaOH was investigated. CHA was produced by wet chemical synthesis. Samples comprising 8, 19, 25 wt% uncalcined CHA-PCL composites were produced by twin screw extrusion which were then injection moulded into cylinders. In order to accelerate the degradation rate of PCL, it was surface treated with 5 M NaOH for 3 days prior to PBS studies. The degradation profile was examined by % weight loss and % water uptake measurements. NaOH treatment was observed to erode the polymer surface and the polymer-filler interface. On subsequently degrading the pre-treated samples in PBS, it was observed that with increasing fraction of CHA, the degradation rate in PBS of the sample increased. Up to 8 wt % CHA filler there appeared to be little change in the degradation properties of the NaOH treated samples with the onset occurring after 60 days. However there was a marked acceleration of degradation for samples containing 19 wt% when degradation appeared to occur immediately. In conclusion, the addition of CHA significantly affects the behaviour of PCL. © (2012) Trans Tech Publications.
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Journal articleSinganayagam A, Singanayagam A, Elder DHJ, et al., 2012,
Is community-acquired pneumonia an independent risk factor for cardiovascular disease?
, EUROPEAN RESPIRATORY JOURNAL, Vol: 39, Pages: 187-196, ISSN: 0903-1936- Author Web Link
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Conference paperFreidin M, Nicholson A, Popat S, et al., 2012,
Distribution profile of baseline gene expression to standardise tumour expression: a pilot study of cisplatin resistant genes in lung cancer
, Publisher: ELSEVIER IRELAND LTD, Pages: S2-S3, ISSN: 0169-5002
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