Article
Materials Science, Multidisciplinary
Cindy Le Hel, Pierre Alcouffe, Antoine Lucas, Philippe Cassagnau, Veronique Bounor-Legare
Summary: The localization of carbon black filler in PP/EPDM thermoplastic vulcanizate was found to be dependent on the type of crosslinking chemistry, with phenolic resin leading to rubber phase localization and dicumyl peroxide leading to interface localization.
MATERIALS CHEMISTRY AND PHYSICS
(2022)
Article
Polymer Science
Hyungu Im, Sunkyoung Jeoung
Summary: Ethylene-propylene-diene monomer (EPDM) rubber is a promising material for fuel cell gaskets, but faces challenges in terms of molding processability and recycling ability. To overcome these challenges, thermoplastic vulcanizate (TPV) with vulcanized EPDM in a polypropylene matrix was investigated. TPV showed better long-term stability and mechanical properties compared to EPDM, indicating its potential as a gasket material.
Article
Chemistry, Analytical
Kathleen E. Berg, Yann R. Leroux, Philippe Hapiot, Charles S. Henry
Summary: Thermoplastic electrodes (TPEs) are carbon composite electrodes made of graphite and a thermoplastic polymer binder, offering excellent electrochemical performance and high conductivity. Scanning electrochemical microscopy (SECM) serves as an effective screening tool for characterizing TPEs, allowing for rapid comparison of numerous images and preparation optimization.
ANALYTICAL CHEMISTRY
(2021)
Article
Polymer Science
Krishnan A. Iyer, Antonios Doufas, Dinara R. Sunagatullina
Summary: This study investigates the use of PP and PMP as a thermoplastic phase in the production of TPVs with EPDM as the elastomer phase. The replacement of PP with PMP results in a fine dispersion of rubber particles and high temperature TPVs with superior properties. The unique microstructure of PMP provides exceptional breathability and low thermal conductivity. By using ester oil, the microstructure and dispersion of rubber particles can be further enhanced, leading to improved mechanical, permeability, and thermal properties.
Article
Nanoscience & Nanotechnology
Yunyun Huang, Zhi Liu, Hongyan Xu, Ruoyu Hong
Summary: Conductive elastomer materials using carbon black-filled TPV were prepared by two-step and one-step methods, with the two-step method showing better dispersion of CB and higher EMI shielding performance.
REVIEWS ON ADVANCED MATERIALS SCIENCE
(2021)
Article
Engineering, Electrical & Electronic
Kristel Fobelets, Ghena Hammour, Kris Thielemans
Summary: This study explores the use of statistical methods and various signal quality indices (SQIs) to optimize knitted textile electrodes for electrocardiogram (ECG) recordings. The best SQIs were achieved with dry electrodes made of conductive yarn, compact knit structure, and medium roughness. Sewing electrodes at their edges into the knitted garment outperformed other methods, reducing motion artifacts and allowing for independent movement of the garment. Tests on a healthy volunteer showed excellent system performance during gentle ambulation. The advantage of using SQIs in optimizing dry textile ECG electrodes is the availability of a quantitative benchmark for comparison.
IEEE SENSORS JOURNAL
(2023)
Article
Physics, Applied
Congchao Liu, Lifeng Ma, Chengyuan He, Xinhu Xu
Summary: In the field of thermoplastic vulcanizate (TPV), experimental methods cannot quantify the relationship between the internal structure and performance of TPV, which hinders the accurate design of TPV structure and performance. In this study, a two-dimensional micromechanical model based on the real microstructure of TPV was established, and the mechanical properties of TPV with different EPDM mass fractions were investigated. The results showed that the EPDM content affects the stress distribution, elastic modulus, and resilience of TPV.
MODERN PHYSICS LETTERS B
(2023)
Article
Materials Science, Multidisciplinary
Bani Gandhi, N. S. Raghava
Summary: Highly conductive electrodes were fabricated using MWCNT-COOH and PDMS, with a two-step dispersion method used to create thirteen electrodes with varying CNT concentrations and a low percolation threshold. These electrodes were able to be monitored in real-time and remotely through an IoT system.
Article
Electrochemistry
Tugba Ozer, Cynthia McCord, Brian J. Geiss, David Dandy, Charles S. Henry
Summary: A new amine functionalized electrochemical immunosensor for label-free detection of Escherichia coli using modified thermoplastic electrodes was reported, with successful application in urine samples for selective and sensitive detection of the bacteria. The sensor showed high specificity and sensitivity, making it suitable for accurate detection of different pathogenic bacteria.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2021)
Article
Chemistry, Physical
Shipeng Zhang, Md. Sharifuzzamn, S. M. Sohel Rana, Md Abu Zahed, Sudeep Sharma, Youngdo Shin, Hyesoo Song, Jae Yeong Park
Summary: In this study, a novel dry electrode was proposed for long-term bioelectric potential recording. By transferring laser-induced graphene (LIG) to flexible substrates, the electrode achieved stretchability and flexibility. A simple and reliable transfer technique was used to embed LIG onto a new elastomer substrate and deposit a polymer conductive coating, resulting in a dry electrode with high conductivity, stretchability, and low impedance.
Article
Materials Science, Paper & Wood
Yanping Wang, Xing Zhong, Wei Wang, Dan Yu
Summary: The study introduces a flexible, low-cost conductive electrode by using cellulose and polyvinyl alcohol as a substrate, assembling with conductive polymer polythiophene. The composite electrode shows good flexibility and stability, capable of clearly monitoring ECG signals.
Article
Electrochemistry
Cynthia P. McCord, Bali Summers, Charles S. Henry
Summary: Carbon composite electrodes consisting of thermoplastics mixed with graphite demonstrate enhanced electrochemical performance compared to traditional electrodes. The addition of polystyrene (PS) to polycaprolactone (PCL) electrodes significantly lowers capacitance and increases conductivity. The use of PS as a binder in composite electrodes shows similar redox behavior to nanomaterial-modified electrodes.
ELECTROCHIMICA ACTA
(2021)
Article
Electrochemistry
Catherine J. Mcmahon, Brandaise Martinez, Charles S. Henry
Summary: Thermoplastic carbon electrodes (TPEs) are a type of alternative carbon composite electrodes that have shown promising electrochemical performance in biological sensing. However, their application in environmental sensing, particularly heavy metal analysis, has been limited. In this study, TPEs were investigated for lead analysis and were expected to outperform other carbon composite materials based on their electrochemical properties. However, experimental results showed inferior performance. Detailed electrode characterization revealed that the presence of acidic and alkaline functional groups as well as the binder and graphite influenced the lead sensing behavior of TPEs.
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Shoujun Wu, Bing Zhang, Guo Fu, Yue Chen, Wei He, Bo Zhang
Summary: The fracture strength of titanium nitride coatings prepared by PIRAC on Ti6Al4V at 700 degrees Celsius increased with longer processing times, mainly due to the variation in composition, especially the higher content of TiN and Ti2N with superior mechanical properties.
Article
Engineering, Electrical & Electronic
Mst Moriom Rojy Momota, Bashir I. Morshed, Tamanna Ferdous, Tomoko Fujiwara
Summary: In this study, flexible dry ECG electrodes of different shapes and sizes were developed using inkjet printing technology. Compared to commercial gel electrodes, inkjet printing electrodes have a longer lifetime and lower noise. Inkjet printing allows for personalized shape and size customization of the electrodes through additive manufacturing.
IEEE SENSORS JOURNAL
(2023)
Review
Materials Science, Coatings & Films
Carolina Barros, Sonia Miranda, Olga Castro, O. S. Carneiro, A. Machado
Summary: This study focuses on developing low-density polyethylene nanocomposite films for food packaging, aiming to improve oxygen barrier properties while maintaining other relevant characteristics. The nanocomposites, prepared with 1 and 2.5 wt.% nanoclay and compatibilized with 5 wt.% PE-g-MA, showed good dispersion and decreased oxygen permeability. Overall, the film properties were improved with added nanoclay and PE-g-MA, making them potentially suitable for food packaging.
JOURNAL OF PLASTIC FILM & SHEETING
(2023)
Article
Polymer Science
Pedro V. Rodrigues, Dalila M. Vieira, Paola Chaves Martins, Vilasia Guimaraes Martins, M. Cidalia R. Castro, Ana V. Machado
Summary: By adding 3% GTE to LDPE films, the shelf-life of fresh orange juice can be extended, reducing nutrient loss and maintaining the microbial load within acceptable limits.
Article
Computer Science, Information Systems
Julio Barros, Francisco Cunha, Candido Martins, Paulo Pedrosa, Paulo Cortez
Summary: The emergence of Industry 4.0 and digital transformation have significantly improved supply chain performance and competitive advantage. This study focuses on enhancing the order fulfilment process and specifically the cement loading process by using machine learning to predict weighing deviations. The random forest model provides the best predictive performance, and the Shapley additive explanations method helps understand the influence of input data attributes.
Article
Chemistry, Physical
Rosa M. F. Baptista, Clara S. B. Gomes, Bruna Silva, Joao Oliveira, Bernardo Almeida, Cidalia Castro, Pedro V. Rodrigues, Ana Machado, Ruben B. Freitas, Manuel J. L. F. Rodrigues, Etelvina de Matos Gomes, Michael Belsley
Summary: A polymorph of glycyl-L-alanine HI.H2O is synthesized from chiral cyclo-glycyl-L-alanine dipeptide, which exhibits polar space group and shows pyroelectricity, optical second harmonic generation, thermal memory effect, and piezoelectric properties. It has a high pyroelectric coefficient and a nonlinear optical effective coefficient, making it suitable for energy harvesting applications.
Article
Chemistry, Physical
Daniela Santos, Rosa M. F. Baptista, Adelino Handa, Bernardo Almeida, Pedro V. Rodrigues, Ana R. Torres, Ana Machado, Michael Belsley, Etelvina de Matos Gomes
Summary: This work presents the fabrication of hybrid systems based on chiral cyclic dipeptide L-Tryptophan-L-Tryptophan incorporated into biopolymer electrospun fibers. The micro/nanofibers contain self-assembled nano-spheres embedded into the polymer matrix, exhibiting wide-band gap semiconductors with a 4.0 eV band gap energy, blue photoluminescence, and significant piezoelectric and pyroelectric properties. These hybrid mats have potential applications in thermal sensing and energy harvesting.
Article
Polymer Science
Pedro Veiga Rodrigues, Bruno Ramoa, Ana Rita Torres, Maria Cidalia R. Castro, Ana Vera Machado
Summary: A systematic study was conducted to investigate the influence of elastomeric materials on the behavior of polycarbonate blends. Different elastomers were blended with polycarbonate and characterized using various techniques. The incorporation of elastomer was observed through changes in FTIR bands, and a transesterification reaction was identified in COPE. The addition of modified ABS had no effect on the glass transition temperature of PC, while 1% SEBS-g-MA slightly increased it. SEM analysis revealed three main toughening mechanisms depending on the type of elastomer.
Article
Food Science & Technology
Mariana A. Andrade, Cassia H. Barbosa, Miguel A. Cerqueira, Ana Gabriela Azevedo, Carolina Barros, Ana Vera Machado, Anabela Coelho, Rosalia Furtado, Cristina Belo Correia, Margarida Saraiva, Fernanda Vilarinho, Ana Sanches Silva, Fernando Ramos
Summary: In this study, it was found that Rosmarinus officinalis extract (RE) had higher antioxidant capacity and total phenolic content compared to Green tea extract (GTE). The main phenolic compounds in RE were carnosic acid, carnosol, and rosmarinic acid, while catechins, rutin, and gallic acid were the main compounds identified in GTE. PLA active films incorporated with these extracts were evaluated for their properties. The results showed that the films with RE were most effective in reducing oxidation in almonds and beef with high fat content.
FOOD PACKAGING AND SHELF LIFE
(2023)
Article
Nanoscience & Nanotechnology
Claiudia Lopes, Armando Ferreira, Marcio Correa, Andre Machado Rodrigues, Paulo Mendes, Filipe Vaz
Summary: This study investigates the potential of thin-film technology in the development of new electromagnetic interference shielding and conductive materials for textiles and wearables. The study used three different thin films (pure Ti, pure Cu, and Ti-doped Cu) to enhance textile knits made of cotton and lyocell fibers. The films exhibited varying structures, morphologies, and topographies based on their chemical compositions. The effectiveness of these functionalized knits in shielding against EMI was evaluated, as well as their electrical response under stress.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Ceramics
S. A. N. Franca Junior, W. Acchar, S. L. A. Dantas, P. H. Chiberio, H. P. A. Alves, M. R. D. Bomio, F. V. Motta, F. Bohn, A. Ferreira, F. Vaz, M. A. Correa
Summary: We conducted a comprehensive investigation on the high-frequency dielectric properties of (ZrO2)100-x(BaTiO3)x heterostructures. By adjusting the content of BaTiO3, we could modify the dielectric constant of the resulting ceramic sheets. Our results demonstrated successful fabrication of heterostructured ceramic sheets and the ability to tailor the electric, structural, and dielectric properties of both ZrO2 and BaTiO3 materials. Furthermore, the evolution of the dielectric constant could be manipulated according to specific technological applications.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Armando Ferreira, Carlos M. Costa, Marcio A. Correa, Rafael S. Pinto, Renato Gonsalves, Luana C. Benetti, Senentxu Lanceros-Mendez, Filipe Vaz
Summary: The necessity for energy conversion solutions has increased in recent years, particularly for powering small and flexible IoT devices. This study explores the use of thermoelectric effects, specifically the anomalous Nernst effect, by producing Co2FeAl/P(VDF-TrFE-CFE) heterostructures on flexible poly (vinylidene fluoride-trifluoroethylene-chlorofluoroethylene) (P(VDF-TrFE-CFE)) substrates. The results demonstrate that the flexible polymer substrate does not affect the thermomagnetic effect, opening new possibilities for integrating flexible high-dielectric polymers with thermomagnetic phenomena for energy harvesting applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Daniela Santos, Rosa M. F. Baptista, Adelino Handa, Bernardo Almeida, Pedro V. Rodrigues, Cidalia Castro, Ana Machado, Manuel J. L. F. Rodrigues, Michael Belsley, Etelvina de Matos Gomes
Summary: In this study, a hybrid system comprising biopolymer electrospun fibers incorporated with the chiral cyclo-dipeptide L-Tryptophan-L-Tyrosine was developed. The resulting nanofibers are wide-bandgap semiconductors consisting of self-assembled nanotubes embedded within a polymer matrix, exhibiting intense blue photoluminescence. Moreover, the cyclodipeptide L-Tryptophan-L-Tyrosine incorporated into polycaprolactone nanofibers displays strong second harmonic generation and notable piezoelectric properties. These hybrid systems hold great promise for applications in the field of nanoenergy harvesting and nanophotonics.
Proceedings Paper
Computer Science, Artificial Intelligence
R. Conselheiro, C. Lopes, N. Azevedo, P. Leitao, C. Agulhari, H. Veloso, F. Vaz, J. Goncalves, T. Franco, L. Sestrem
Summary: Wet electrodes, which rely on conductive electrolyte gel, have issues such as long setup time, disposability or time-consuming cleaning, skin irritation, and signal quality deterioration. To overcome these drawbacks, 3D printed bases with polymers and functionalized with thin films of titanium and titanium-nitride, doped with copper, were developed. The results show that these dry electrodes have similar performance to wet AgCl/Ag electrodes for data acquisition, but improvements are needed for muscle stimulation and the durability and adhesion of the thin films.
19TH INTERNATIONAL SYMPOSIUM ON DISTRIBUTED COMPUTING AND ARTIFICIAL INTELLIGENCE
(2023)
Article
Chemistry, Physical
Diogo Costa, Marco S. Rodrigues, Eduardo Alves, Nuno P. Barradas, Joel Borges, Filipe Vaz
Summary: This work describes the development of nanoplasmonic thin films with Au, Ag, or Au-Ag nanoparticles dispersed in a TiO2 matrix, and the optimization of deposition parameters to adjust their optical response. The study found that using Au-Ag nanoparticles can increase the refractive index sensitivity of the thin films and reduce the cost of fabrication.
Article
Chemistry, Analytical
Diana I. Meira, Marco S. Rodrigues, Joel Borges, Filipe Vaz
Summary: The extinction efficiency of noble metal nanoparticles, such as gold and silver, depends on their size and the dielectric surrounding them. By exploiting the Localized Surface Plasmon Resonance (LSPR) phenomenon, the composition and structure of these nanoparticles can be tailored to optimize their sensitivity to environmental changes. Incorporating these nanoparticles into solid support in the form of nanocomposite thin films enhances the robustness of LSPR sensing. In this study, bimetallic films composed of gold, silver, and their mixture in a titanium dioxide matrix were grown using reactive DC magnetron sputtering. The LSPR response and sensitivity of the films were tunable by thermal treatment at different temperatures. The bimetallic film with an Au/Ag atomic ratio of 1 exhibited the highest refractive index sensitivity, showcasing the potential of bimetallic film systems in enhancing LSPR sensing.
Article
Engineering, Electrical & Electronic
Giorgia Siqueira, David Baptista, Claudia Lopes, Marcio A. Correa, Filipe Vaz, Armando Ferreira
Summary: This study explores the influence of non-magnetic cap layer thickness on the thermoelectric properties of Co2FeAl/NM heterostructures and analyzes their potential applications in the Anomalous Nernst Effect and Longitudinal Spin Seebeck Effect. The experimental results demonstrate that Co2FeAl/W and Co2FeAl/Ti heterostructures exhibit enhanced ANE voltages, providing valuable insights into Co2FeAl-based materials and spintronic devices.
SENSORS AND ACTUATORS A-PHYSICAL
(2023)
