Research Scientist, Textile coating and finishing, CENTEXBEL (BE)
Filip Govaert studied chemistry at the University of Ghent (BE) where he also accomplished his PhD on the development of an electrochemical sensor for the detection of dyes in textile processes. He worked at research departments in industry and agencies on the analysis and formulation of industrial coatings. Recently he has joined the research department of CENTEXBEL (BE) where he works on projects to introduce carbon nanotubes in textile materials and to develop electrically conductive textile coatings for smart materials. He is coordinating projects for textile companies on product and process improvement.
Carbon Nanotubes in Composites and Coatings for Smart Textile Applications
Centexbel is the Belgian Textile Research Centre, founded to reinforce the competitive position of the Belgian textile companies and nowadays offering an extensive range of activities and services to the textile industry worldwide, including testing, certification, consultancy and research & development. Centexbel assesses the usability of carbon nanotubes (CNTs) in various textile materials and applications by investigating CNTs as an additive in the extrusion of yarns and in coatings for textiles. Textile materials with integrated electrical conductivity make it possible to create intelligent articles with sensors, lighting, heating and solar cells without loosing the basic properties of a textile, i.e. light weight, stretchable and flexible, large contact area, comfortable and ease of use.
The idea behind using CNTs in conductive yarns is to replace the use of metal fibres for antistatic textile applications, resulting in lighter weight and better resistance to corrosion or to replace the conventional micron-size conducting fillers which require loadings as high as 15 wt.% for good antistatic properties. When using CNTs, a comparable conductivity is expected for much lower concentrations (<5%). The extent of property enhancement depends on many factors: (i) aspect, (ii) the degree of dispersion, (iii) the orientation of the CNTs in the matrix and (iv) the adhesion at the CNT-matrix interface.
The idea behind using CNTs in conductive coatings is not only to replace the use of metal fibres for antistatic textile applications, resulting in lighter weight and better resistance to corrosion. A new direction is that ofsmart textile or electronic textile, where the components are directly deposited onto the textile substrate instead of integrating the finished components or devices into the textile product as is done nowadays. At Centexbel conductive bottom electrodes are being developed for devices as photovoltaic (PV) cells or for resistive heating elements. In this work, a textile coating with variable amounts of carbon nanotubes was developed with high performance properties. Formulations of textile coatings were prepared with up to 15 wt % of CNT, based on the solid weight of the binder. The coatings can be regarded to be electrical conductive (sheet resistivity <104Ohm/sq) starting at 4 wt% CNT. The electrical conductivity of the coating was evaluated after subjecting the coated fabric to different processes and activities: washing cycles, UV-weathering and repeated flexing. This type of coating is suitable to introduce electrical conductivity in textile applications where high performance properties are needed.