11 documents found, page 1 of 2
Comparative thermoelectric properties of polypropylene composites melt-processe...
Paleo, Antonio J.; Krause, Beate; Mendes, Ana R.; Tavares, C. J.; Cerqueira, M. F.; Muñoz, Enrique; Pötschke, PetraThe electrical conductivity (σ) and Seebeck coefficient (S) at temperatures from 40 ◦C to 100 ◦C of melt-processed polypropylene (PP) composites filled with 5 wt.% of industrial-grade carbon nanofibers (CNFs) is investigated. Transmission Electron Microscopy (TEM) of the two Pyrograf® III CNFs (PR 19 LHT XT and PR 24 LHT XT), used in the fabrication of the PP/CNF composites (PP/CNF 19 and PP/CNF 24), reveals th...
Thermoelectric properties of cotton fabrics dip-coated in pyrolytically strippe...
Paleo, Antonio J.; Krause, Beate; Cerqueira, Maria F.; González-Domínguez, Jose M.; Muñoz, Enrique; Pötschke, Petra; Rocha, A. M.The transport properties of commercial carbon nanofibers (CNFs) produced by chemical vapor deposition (CVD) depend on the various conditions used during their growth and post-growth synthesis, which also affect their derivate CNF-based textile fabrics. Here, the production and thermoelectric (TE) properties of cotton woven fabrics (CWFs) functionalized with aqueous inks made from different amounts of pyrolytica...
Electronic features of cotton fabric e-textiles prepared with aqueous carbon na...
Paleo, Antonio J.; Krause, Beate; Cerqueira, M. F.; Muñoz, Enrique; Pötschke, Petra; Rocha, A. M.Cotton woven fabrics functionalized with aqueous inks made with carbon nanofibers (CNFs) and anionic surfactant are prepared via dip-coating followed by heat treatment, and their electronic properties are discussed. The e-textiles prepared with the inks made with the highest amount of CNFs (6.4 mg mL−1 ) show electrical conductivities (σ) of ∼35 S m−1 and a negative Seebeck (S) of −6 μV K−1 at 30 °C, which mean...
Carbon nanotube-polyurethane composite sheets for flexible thermoelectric mater...
Paleo, Antonio J.; Martinez-Rubi, Yadienka; Krause, Beate; Pötschke, Petra; Jakubinek, Michael B.; Ashrafi, Behnam; Kingston, ChristopherIntegration of single-wall carbon nanotubes (SWCNTs) in the form of fabriclike sheets or other preformed assemblies (films, fibers, etc.) simplifies their handling and allows for composites with higher nanotube contents, which is needed to better exploit their outstanding properties and achieve multifunctional materials with improved performance. Here, we show the development of p-type SWCNT-thermoplastic polyu...
Nonlinear thermopower behaviour of n-type carbon nanofibres and their melt mixe...
Vieito, António Jose Paleo; Krause, Beate; Cerqueira, M. F.; Muñoz, Enrique; Pötschke, Petra; Rocha, A. M.The temperature dependent electrical conductivity <i>σ</i> (<i>T</i>) and thermopower (Seebeck coefficient) <i>S</i> (<i>T</i>) from 303.15 K (30 °C) to 373.15 K (100 °C) of an as-received commercial n-type vapour grown carbon nanofibre (CNF) powder and its melt-mixed polypropylene (PP) composite with 5 wt.% of CNFs have been analysed. At 30 °C, the <i>σ</i> and <i>S</i> of the CNF powder are ~136 S m<sup>−1</s...
Thermoelectric properties of n-type poly (ether ether ketone)/carbon nanofiber ...
Paleo, Antonio J.; Krause, Beate; Soares, Delfim; Melle-Franco, Manuel; Muñoz, Enrique; Pötschke, Petra; Rocha, A. M.The thermoelectric properties, at temperatures from 30 °C to 100 °C, of melt-processed poly(ether ether ketone) (PEEK) composites prepared with 10 wt.% of carbon nanofibers (CNFs) are discussed in this work. At 30 °C, the PEEK/CNF composites show an electrical conductivity (σ) of ~27 S m<sup>−1</sup> and a Seebeck coefficient (S) of −3.4 μV K<sup>−1</sup>, which means that their majority charge carriers are ele...
Thermoelectric properties of polypropylene carbon nanofiber melt-mixed composit...
Paleo, Antonio J.; Krause, Beate; Cerqueira, M. F.; Melle-Franco, Manuel; Pötschke, Petra; Rocha, A. M.The effect of polypropylene (PP) on the Seebeck coefficient (S) of carbon nanofibers (CNFs) in melt-extruded PP composites filled with up to 5 wt. % of CNFs was analyzed in this study. The as-received CNFs present an electrical conductivity of ~320 S m−1 and an interesting phenomenon of showing negative S-values of −5.5 μVK−1, with 10−2 µW/mK2 as the power factor (PF). In contrast, the PP/CNF composites with 5 ...
Polylactic acid/carbon nanoparticle composite filaments for sensing
Silva, Mariana M.; Lopes, Paulo Estevão Caldeira; Li, Yilong; Pötschke, Petra; Ferreira, Fernando; Paiva, M. C.Polylactic acid (PLA) is a bio-based, biodegradable polymer that presents high potential for biomedical and sensing applications. Ongoing works reported in the literature concern mainly applications based on 3D printing, while textile applications are hindered by the limited flexibility of PLA and its composite filaments. In the present work, PLA/multiwall carbon nanotube (MWCNT) composite filaments were produc...
Bio-inspired deposition of electrochemically exfoliated graphene layers for ele...
Utech, Toni; Pötschke, Petra; Simon, Frank; Janke, Andreas; Kettner, Hannes; Paiva, M. C.; Zimmerer, CordeliaElectrochemically exfoliated graphene (eeG)layers possess a variety of potential applications, e.g. as susceptor material for contactless induction heating in dynamic electro-magnetic fields, and as flexible and transparent electrode or resistivity heating elements. Spray coating of eeG dispersions was investigated in detail as a simple and fast method to deposit both, thin conducting layers and ring structures...
Mixed carbon nanomaterial/epoxy resin for electrically conductive adhesives
Lopes, Paulo Estevão Caldeira; Moura, Duarte; Hilliou, L.; Krause, Beate; Pötschke, Petra; Figueiredo, Hugo; Alves, Ricardo; Lepleux, EmmanuelThe increasing complexity of printed circuit boards (PCBs) due to miniaturization, increased the density of electronic components, and demanding thermal management during the assembly triggered the research of innovative solder pastes and electrically conductive adhesives (ECAs). Current commercial ECAs are typically based on epoxy matrices with a high load (>60%) of silver particles, generally in the form of m...