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Projeto de investigação
PrintIL: Printable ionic liquid based multifunctional materials and devices for sensors and actuators
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Multifunctional Magnetoelectric Sensing and Bending Actuator Response of Polymer-Based Hybrid Materials with Magnetic Ionic Liquids
Publication . Fernandes, Liliana C.; Correia, Daniela M.; Tariq, Mohammad; Esperança, José M. S. S.; Martins, Pedro; Lanceros-Méndez, Senentxu; DQ - Departamento de Química; LAQV@REQUIMTE; MDPI AG
With the evolution of the digital society, the demand for miniaturized multifunctional devices has been increasing, particularly for sensors and actuators. These technological translators allow successful interaction between the physical and digital worlds. In particular, the development of smart materials with magnetoelectric (ME) properties, capable of wirelessly generating electrical signals in response to external magnetic fields, represents a suitable approach for the development of magnetic field sensors and actuators due to their ME coupling, flexibility, robustness and easy fabrication, compatible with additive manufacturing technologies. This work demonstrates the suitability of magnetoelectric (ME) responsive materials based on the magnetic ionic liquid (MIL) 1-butyl-3-methylimidazolium tetrachloroferrate ([Bmim][FeCl4]) and the polymer poly(vinylidene fluoride-co-trifluoroethylene) (P(VDF-TrFE) for magnetic sensing and actuation device development. The developed sensor works in the AC magnetic field and has frequency-dependent sensitivity. The materials show voltage responses in the mV range, suitable for the development of magnetic field sensors with a highest sensitivity (s) of 76 mV·Oe−1. The high ME response (maximum ME voltage coefficient of 15 V·cm−1·Oe−1) and magnetic bending actuation (2.1 mm) capability are explained by the magnetoionic (MI) interaction and the morphology of the composites.
Thermochromic poly(L-lactic acid) based materials and their printability on different substrates
Publication . Cruz, B. D. D.; Silva, I. R.; Pereira, N.; Fernandes, L. C.; Tubio, C. R.; Tariq, M.; Esperança, J. M. S. S.; Botelho, G.; Lanceros-Méndez, S.; Correia, D. M.; LAQV@REQUIMTE; DQ - Departamento de Química; Elsevier Science Publisher B.V.
Ionic liquids (ILs) have been combined with different polymer matrixes to develop smart and functional materials. Due to their versatility, hybrid materials with specific tailor made properties can be obtained, including printable thermochromic materials, with a strong potential for sensing applications. In this context, the thermochromic IL bis(1-butyl-3-methylimidazolium) tetrachloronickelate ([Bmim]2[NiCl4]) was incorporated into a biopolymer derived matrix, poly(L-lactic acid) (PLLA) in distinct concentrations up to 40% wt. aiming to develop environmentally friendly screen-printable printable thermochromic materials. The addition of IL does not induce changes on the thermal properties of the material. On the other hand, the incorporation of the IL leads to the development of a porous structure in the films, a mechanical plasticizing effect in the polymer matrix, revealed by the decrease of the Young's Modulus from 1110 ± 66 MPa to 572 ± 41 MPa and a increase in the electrical conductivity from 2.89x10-14 S·cm−1 to 2.66x10-8 S·cm−1, for PLLA and the samples with 40 % wt. of IL, respectively. Finally, the thermochromic material was screen-printed on various substrates, including paper, polyethylene terephthalate (PET), textile and wood, opening the way for a wide range of applications.
Printable ionic liquid modified cellulose acetate for sustainable chromic and resistive temperature sensing
Publication . Cruz, B. D. D.; Castro, A. S.; Fernandes, L. C.; Pereira, N.; Mendes-Felipe, C.; Tariq, M.; Esperança, J. M. S. S.; Martins, P. M.; Lanceros-Méndez, S.; Correia, D. M.; LAQV@REQUIMTE; DQ - Departamento de Química; Elsevier
Sustainable technologies and the circular economy paradigms require a reduction of waste, and therefore, research is focusing on the development of sustainable materials and devices capable of being reused, refurbished or recycled. In the present work, printable ionic liquid (IL)-based polymer composites with thermochromic properties have been developed through a more sustainable approach to mitigate the negative impact of advanced functional materials and processes. For this purpose, composite films based on a natural polymer, cellulose acetate (CA), and different contents of the thermochromic IL, bis(1-butyl-3-methylimidazolium) tetrachloronickelate ([Bmim]2[NiCl4]), have been processed by a solvent casting method for the development of sustainable temperature sensors. The composites are transparent at room temperature, but when exposed to a temperature of 50 °C, the colour changes to blue. Incorporating the thermochromic IL led to the appearance of pores in the material's structure, which increased with increasing IL concentration. Additionally, the Young Modulus decreases with increasing IL concentration, reaching a value of 840 ± 158 MPa) for the sample with 40 % wt. Contrarily, the electrical conductivity strongly increases with the highest DC electrical conductivity, with a maximum conductivity of 1.1 × 10–5 ± 1.5 × 10–6 S.cm-1 obtained for the sample with 40 % wt. of [Bmim]2[NiCl4]. As a proof of concept, the potential applicability of the developed natural-based nanoparticle-free materials was demonstrated with a CA/40[Bmim]2[NiCl4] sample by the development of printable thermochromic temperature sensors for thermotherapy applications in the temperature range from 33 °C to 50 °C.
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Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
CEEC IND 3ed
Número da atribuição
2020.02915.CEECIND/CP1600/CT0029