TY - JOUR A1 - Pommet, M. A1 - Juntaro, J. A1 - Heng, J.Y.Y. A1 - Mantalaris, A. A1 - Lee, A.F. A1 - Wilson, K. A1 - Kalinka, Gerhard A1 - Shaffer, M.S.P. A1 - Bismarck, A. T1 - Surface modification of natural fibers using bacteria: depositing bacterial cellulose onto natural fibers to create hierarchical fiber reinforced nanocomposites N2 - Triggered biodegradable composites made entirely from renewable resources are urgently sought after to improve material recyclability or be able to divert materials from waste streams. Many biobased polymers and natural fibers usually display poor interfacial adhesion when combined in a composite material. Here we propose a way to modify the surfaces of natural fibers by utilizing bacteria (Acetobacter xylinum) to deposit nanosized bacterial cellulose around natural fibers, which enhances their adhesion to renewable polymers. This paper describes the process of modifying large quantities of natural fibers with bacterial cellulose through their use as substrates for bacteria during fermentation. The modified fibers were characterized by scanning electron microscopy, single fiber tensile tests, X-ray photoelectron spectroscopy, and inverse gas chromatography to determine their surface and mechanical properties. The practical adhesion between the modified fibers and the renewable polymers cellulose acetate butyrate and poly(l-lactic acid) was quantified using the single fiber pullout test. KW - Composires KW - Bacteria KW - Surface KW - Cellulose natural fibers PY - 2008 U6 - https://doi.org/10.1021/bm800169g SN - 1525-7797 VL - 9 IS - 6 SP - 1643 EP - 1651 PB - ACS Publ. CY - Washington, DC, USA AN - OPUS4-23162 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bismarck, A. A1 - Carreyette, S. A1 - Fontana, Q.P.V. A1 - Greenhalgh, E.S. A1 - Jacobsson, P. A1 - Johansson, P. A1 - Marczewski, M.J. A1 - Kalinka, Gerhard A1 - Kucernak, A. A1 - Shaffer, M.S. A1 - Shirshova, N. A1 - Steinke, J.H.G. A1 - Wienrich, Malte T1 - Multifunctional epoxy resin for structural supercapacitors N2 - Polymer-based electrolytes based on commercially available epoxy resins were prepared through the addition of a liquid electrolyte, a solution of a lithium salt in an ionic liquid. The polymer monoliths were characterized using impedance spectroscopy, 3-point bending test, scanning electron microscopy (SEM) and nitrogen adsorption (BET). The balance of ionic conductivity and flexural modulus is crucially dependent on the relative proportions of epoxy resin to electrolyte. Also the effect of the liquid electrolyte on curing kinetics and processing was assessed by complex viscosity measurements and differential scanning calorimetry (DSC). Only one out of the three resins investigated exhibited a significant acceleration effect. T2 - ECCM15 - 15th European conference on composite materials CY - Venice, Italy DA - 2012-06-24 KW - Multifunctional epoxy KW - Polymer electrolyte KW - Morphology KW - Ionic liquid PY - 2012 SN - 978-88-88785-33-2 SP - 1 EP - 8(?) AN - OPUS4-28694 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Juntaro, J. A1 - Pommet, M. A1 - Kalinka, Gerhard A1 - Mantalaris, A. A1 - Shaffer, M.S.P. A1 - Bismarck, A. T1 - Creating Hierarchical Structures in Renewable Composites by Attaching Bacterial Cellulose onto Sisal Fibers KW - Nanotubes KW - Cellulose KW - Polymer KW - Interface KW - Hierarchical Structures PY - 2008 U6 - https://doi.org/10.1002/adma.200703176 SN - 0935-9648 SN - 1521-4095 VL - 20 IS - 16 SP - 3122 EP - 3126 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-18258 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Greenhalgh, E.S. A1 - Ankersen, J. A1 - Asp, L. E. A1 - Bismarck, A. A1 - Fontana, Q.P.V. A1 - Houlle, M. A1 - Kalinka, Gerhard A1 - Kucernak, A. A1 - Mistry, M. A1 - Nguyen, S. A1 - Qian, H. A1 - Shaffer, M.S.P. A1 - Shirshova, N. A1 - Steinke, J.H.G. A1 - Wienrich, Malte T1 - Mechanical and microstructural characterisation of multifunctional structural power composites N2 - Although the inherent anisotropy of polymer composites has presented daunting technical challenges, these materials now offer engineers considerable opportunities for efficient structural design. More recently, the advent of multifunctional composites which can fulfill more than one role within a system has attracted considerable interest, providing designers with exciting opportunities to innovate. Of particular interest here are structural power composites, which simultaneously carry mechanical load whilst storing/delivering electrical energy. Although the development of these composites is highly challenging, often with conflicting constituent requirements, the STORAGE consortium has had considerable success in the development of these materials for automotive applications. The focus of this paper is structural supercapacitors, the basic architecture of a single cell of which is shown in Fig. 1. This entails two carbon fibre woven lamina (electrodes) which sandwich a glass fibre woven lamina (separator), all of which is embedded within a multifunctional matrix (electrolyte). This architecture has been the focus of the research to date, leading to components such as that shown in Fig.1 having been fabricated. This paper reports on the mechanical properties and microstructures of the different reinforcement and matrix combinations for structural supercapacitors. T2 - ICCM19 - 19th International conference on composite materials CY - Montreal, Canada DA - 28.07.2013 KW - Structural electrolyte KW - Multifunctional supercapacitor KW - Fractography KW - Ionic conductivity KW - Mechanical properties PY - 2013 SP - 2228 EP - 2237 AN - OPUS4-29272 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Greenhalgh, E.S. A1 - Ankersen, J. A1 - Asp, L. E. A1 - Bismarck, A. A1 - Fontana, Q.P.V. A1 - Houlle, M. A1 - Kalinka, Gerhard A1 - Kucernak, A. A1 - Mistry, M. A1 - Nguyen, S. A1 - Qian, H. A1 - Shaffer, M.S.P. A1 - Shirshova, N. A1 - Steinke, J.H.G. A1 - Wienrich, Malte T1 - Mechanical, electrical and microstructural characterisation of multifunctional structural power composites N2 - Multifunctional composites which can fulfil more than one role within a system have attracted considerable interest. This work focusses on structural supercapacitors which simultaneously carry mechanical load whilst storing/delivering electrical energy. Critical mechanical properties (in-plane shear and in-plane compression performance) of two monofunctional and four multifunctional materials were characterised, which gave an insight into the relationships between these properties, the microstructures and fracture processes. The reinforcements included baseline T300 fabric, which was then either grafted or sized with carbon nanotubes, whilst the baseline matrix was MTM57, which was blended with ionic liquid and lithium salt (two concentrations) to imbue multifunctionality. The resulting composites exhibited a high degree of matrix heterogeneity, with the ionic liquid phase preferentially forming at the fibres, resulting in poor matrix-dominated properties. However, fibre-dominated properties were not depressed. Thus, it was demonstrated that these materials can now offer weight savings over conventional monofunctional systems when under modest loading. KW - Carbon fibres KW - Functional composites KW - Mechanical properties KW - Elastic properties KW - Fractography PY - 2014 U6 - https://doi.org/10.1177/0021998314554125 SN - 0021-9983 SN - 1530-793X SP - 1 EP - 12 PB - Sage CY - London AN - OPUS4-34567 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Shirshova, N. A1 - Bismarck, A. A1 - Carreyette, S. A1 - Fontana, Q.P.V. A1 - Greenhalgh, E.S. A1 - Jacobsson, P. A1 - Johansson, P. A1 - Marczewski, M.J. A1 - Kalinka, Gerhard A1 - Kucernak, A.R.J. A1 - Scheers, J. A1 - Shaffer, M.S.P. A1 - Steinke, J.H.G. A1 - Wienrich, Malte T1 - Structural supercapacitor electrolytes based on bicontinuous ionic liquid-epoxy resin systems N2 - 'Structural electrolytes' retain the desirable mechanical characteristics of structural (epoxy) resins whilst introducing sufficient ionic conductivity to operate as electrolytes in electrochemical devices. Here, a series of ionic liquid–epoxy resin composites were prepared to identify the optimum system microstructure required to achieve a high level of multifunctionality. The ionic conductivity, mechanical properties, thermal stability and morphology of the cured epoxy based structural electrolytes were studied as a function of phase composition for three fully formulated high performance structural epoxy systems. At only 30 wt% of structural resin and 70 wt% of ionic liquid based electrolyte, stiff monolithic plaques with thicknesses of 2–3 mm were obtained with a room temperature ionic conductivity of 0.8 mS cm-1 and a Young's modulus of 0.2 GPa. This promising performance can be attributed to a long characteristic length scale spinodal microstructure, suggesting routes to further optimisation in the future. KW - Epoxy KW - Ionic liquid KW - Supercapacitor PY - 2013 U6 - https://doi.org/10.1039/c3ta13163g SN - 2050-7496 SN - 2050-7488 VL - 1 IS - 48 SP - 15300 EP - 15309 PB - RSC CY - London [u.a.] AN - OPUS4-29735 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Qian, H. A1 - Kalinka, Gerhard A1 - Chan, K.L.A. A1 - Kazarian, S.G. A1 - Greenhalgh, E.S. A1 - Bismarck, A. A1 - Shaffer, M.S.P. T1 - Mapping local microstructure and mechanical performance around carbon nanotube grafted silica fibres: Methodologies for hierarchical composites N2 - The introduction of carbon nanotubes (CNTs) modifies bulk polymer properties, depending on intrinsic quality, dispersion, alignment, interfacial chemistry and mechanical properties of the nanofiller. These effects can be exploited to enhance the matrices of conventional microscale fibre-reinforced polymer composites, by using primary reinforcing fibres grafted with CNTs. This paper presents a methodology that combines atomic force microscopy, polarised Raman spectroscopy, and nanoindentation techniques, to study the distribution, alignment and orientation of CNTs in the vicinity of epoxy-embedded micrometre-scale silica fibres, as well as, the resulting local mechanical properties of the matrix. Raman maps of key features in the CNT spectra clearly show the CNT distribution and orientation, including a ‘parted’ morphology associated with long grafted CNTs. The hardness and indentation modulus of the epoxy matrix were improved locally by 28% and 24%, respectively, due to the reinforcing effects of CNTs. Moreover, a slower stress relaxation was observed in the epoxy region containing CNTs, which may be due to restricted molecular mobility of the matrix. The proposed methodology is likely to be relevant to further studies of nanocomposites and hierarchical composites. KW - Nanotubes KW - Silica fibres KW - Nano indentation KW - Mapping PY - 2011 U6 - https://doi.org/10.1039/c1nr10497g SN - 2040-3364 SN - 2040-3372 VL - 3 IS - 11 SP - 4759 EP - 4767 PB - RSC Publ. CY - Cambridge AN - OPUS4-34718 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Wienrich, Malte A1 - Kalinka, Gerhard A1 - Greenhalgh, E.S. A1 - Carreyette, S. A1 - Bistritz, Martina A1 - Shirshova, N. A1 - Houllé, M. A1 - Asp, L. E. A1 - Bismarck, A. A1 - Fontana, Q.P.V. T1 - Impact of ionic liquid on the mechanical performance of matrix polymer for fibre reinforced materials for energy storage N2 - For 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. T2 - ECCM15 - 15th European conference on composite materials CY - Venice, Italy DA - 2012-06-24 KW - Multifunctional epoxy resin KW - Fibre-matrix adhesion KW - Single fibre pull-out test KW - Ionic liquid PY - 2012 SN - 978-88-88785-33-2 SP - 1 EP - 4(?) AN - OPUS4-28695 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ho, K.K.C. A1 - Lamoriniere, S. A1 - Kalinka, Gerhard A1 - Schulz, Eckhard A1 - Bismarck, A. T1 - Interfacial behavior between atmospheric-plasma-fluorinated carbon fibers and poly(vinylidene fluoride) N2 - Atmospheric-plasma fluorination was used to introduce fluorine functionalities onto the surface of carbon fibers without affecting their bulk properties. The interfacial adhesion between atmospheric-plasma-fluorinated carbon fibers and poly(vinylidene fluoride) (PVDF) was studied by means of direct wetting measurements and single fiber pullout tests. Measured contact angles of PVDF melt droplets on modified carbon fibers show that short exposure times of carbon fibers to atmospheric-plasma fluorination (corresponding to a degree of surface fluorination of F/C = 0.01 (1.1%)) leads to improved wettability of the fibers by PVDF melts. The apparent interfacial shear strength as a measure of practical adhesion, determined by the single-fiber pullout test, increases by 65% under optimal treatment conditions. The improved practical adhesion is not due to the formation of transcrystalline regions around the fibers or a change of the bulk matrix crystallinity or to an increased surface roughness; it seems to be due to the compatibilization of the interface caused of the atmospheric-plasma fluorination of the carbon fibers. KW - Carbon fibers KW - Fluorination KW - Contact angle KW - Interface KW - Adhesion KW - Surface area KW - Fiber properties PY - 2007 U6 - https://doi.org/10.1016/j.jcis.2007.04.076 SN - 0021-9797 SN - 1095-7103 VL - 313 IS - 2 SP - 476 EP - 484 PB - Elsevier CY - Orlando, Fla. AN - OPUS4-16026 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Ho, K.K.C. A1 - Kalinka, Gerhard A1 - Tran, M.Q. A1 - Polyakova, N.V. A1 - Bismarck, A. T1 - Fluorinated carbon fibres and their suitability as reinforcement for fluoropolymers N2 - The interaction between direct fluorinated carbon fibres and various fluoropolymers (ethylene-chlorotrifluoroethylene, poly vinylidene fluoride, fluorinated ethylene propylene copolymer and tetrafluoroethylene-perfluoro alkoxy vinyl ether copolymer) was studied by means of direct wetting measurements between fibres and the polymer melts and single fibre pull-out tests. The results of both techniques allow the adhesion behaviour between the fibres and the matrices to be predicted. The results obtained show that a low degree of surface fluorination of carbon fibres leads to an improved wettability between the fibres and fluoropolymer melts and this is an indicator for an improved thermodynamic work of adhesion. The apparent interfacial shear strength as measure of practical adhesion, determined by the single fibre pull-out test, increases with increasing degree of surface fluorine content up to a maximum, which depends on the degree of fluorination of the matrix used. The improved interaction between the fibre and the matrix is due to an enhanced compatibility at the fibre/matrix interface. KW - Adhesion KW - A. Carbon fibres KW - B. Debonding KW - B. Interfacial strength PY - 2007 U6 - https://doi.org/10.1016/j.compscitech.2007.02.012 SN - 0266-3538 VL - 67 IS - 13 SP - 2699 EP - 2706 PB - Elsevier CY - Barking AN - OPUS4-15814 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -