16 documents found, page 1 of 2
The aqueous processing of carbon nanofibers via cellulose nanocrystals as a gre...
Calvo, V.; Paleo, Antonio J.; González-Domínguez, J. M.; Muñoz, E.; Krause, B.; Pötschke, P.; Maser, W. K.; Benito, A. M.Cellulose nanocrystals (CNCs) are a nanostructured biopolymer with unique properties, such as high strength and water stability. These properties make CNCs ideal for diverse applications, including dispersing agents for hydrophobic carbon nanomaterials in water. Specifically, carbon nanomaterials can be integrated into textiles to produce flexible electronic wearables with excellent performance. However, the ne...
Carbon nanomaterials-Based Inks and Electrodes Using Chitin Nanocrystals
Calvo, Víctor; Martínez-Barón, Carlos; Vázquez-Conejo, Benjamín; Dominguez-Alfaro, Antonio; Paleo, Antonio J.; Villacampa, BelénDispersing 1D carbon nanomaterials (CNMs) for film processing traditionally relies on surfactants or organic solvents. These methods, however, raise environmental concerns and can negatively impact the final properties of the CNMs. In this work we demonstrate that chitin nanocrystals (ChNCs) synthesized via acid hydrolysis provide a greener pathway for the development of waterborne CNMs-based inks, including si...
Doping effect of poly(vinylidene fluoride) on carbon nanofibers deduced by ther...
Paleo, Antonio J.; Serrato, V. M.; Mánuel, J. M.; Toledano, O.; Muñoz, E.; Melle-Franco, M.; Krause, B.; Pötschke, P.; Lozano, K.The effect of temperature on the electrical conductivity (σ) and Seebeck coefficient (S) of n-type vapor grown carbon nanofibers (CNFs) and poly(vinylidene fluoride) (PVDF) melt-mixed with 15 wt% of those CNFs is analyzed. At 40 °C, the CNFs show stable n-type character (S=−4.8 µV·K−1) with an σ of ca.165 S·m−1, while the PVDF/CNF composite film shows an σ of ca. 9 S·m−1 and near-zero S (S=−0.5 µV·K−1). This ex...
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...
Electrical properties of polypropylene-based composites melt-processed with as-...
Paleo, Antonio J.; Samir, Zineb; Aribou, Najoia; Nioua, Yassine; Moreira, Joaquim Agostinho; Achour, Mohammed EssaidElectrical conductivity, dielectric permittivity, electrical modulus, and electrical impedance of polypropylene (PP) composites melt-processed with different contents of as-grown carbon nanofibers (CNFs) are studied. As expected, the electrical conductivity of PP/CNF composites increased as the incorporation of CNFs is raised in the polymer, yielding a maximum of ∼ 6 ×10−6 S m−1 for PP/CNF 3 wt. % composites. T...
Electrical properties of melt-mixed polypropylene and as-grown carbon nanofiber...
Paleo, Antonio J.; Aribou, Najoia; Nioua, Yassine; Samir, Zineb; Fernandes, Lisete; Moreira, J. Agostinho; Achour, Mohammed E.The morphology, crystallinity, and electrical conductivity (σ′ and σ″) as a function of frequency of polypropylene (PP) melt-extruded with different amounts of as-grown carbon nanofibers (CNFs) from 0 to 1.4 vol. % are examined. The PP/CNF composites present CNF aggregates randomly distributed within the PP and an insulator–conductor transition at CNF contents near 0.9 vol. %. The degree of crystallinity of PP/...
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...