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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.
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.
Piezoelectric biomaterials with embedded ionic liquids for improved orthopedic interfaces through osseointegration and antibacterial dual characteristics
Publication . Carvalho, E. O.; Marques-Almeida, T.; Cruz, B. D. D.; Correia, D. M.; Esperança, J. M. S. S.; Irastorza, I.; Silvan, U.; Fernandes, M. M.; Lanceros-Mendez, S.; Ribeiro, C.; LAQV@REQUIMTE; DQ - Departamento de Química; Elsevier
Orthopedic implant failures, primarily attributed to aseptic loosening and implant site infections, pose significant challenges to patient recovery and lead to revision surgeries. Combining piezoelectric materials with ionic liquids as interfaces for orthopedic implants presents an innovative approach to addressing both issues simultaneously. In this study, films of poly(vinylidene fluoride-trifluoroethylene) (P(VDF-TrFE)) incorporated with 1-ethyl-3-methylimidazolium hydrogen sulfate ([Emim][HSO4]) ionic liquid were developed. These films exhibited strong antibacterial properties, effectively reducing biofilm formation, thereby addressing implant-related infections. Furthermore, stem cell-based differentiation assays exposed the potential of the composite materials to induce osteogenesis. Interestingly, our findings also revealed the upregulation of calcium channel expression as a result of electromechanical stimulation, pointing to a mechanistic basis for the observed biological effects. This work highlights the potential of piezoelectric materials with ionic liquids to improve the longevity and biocompatibility of orthopedic implants. Offering dual-functionality for infection prevention and bone integration, these advancements hold significant potential for advancing orthopedic implant technologies and improving patient outcomes.
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Fundação para a Ciência e a Tecnologia
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POR_NORTE
Número da atribuição
2022.13287.BD