26 documents found, page 1 of 3
Novel benzothiazole Boc-Phe-Phe-Bz derivative dipeptide forming fluorescent and...
Baptista, Rosa Maria Ferreira; Santos, Daniela; Cunha, N. F.; Castro, Maria Cidália Rodrigues; Rodrigues, Pedro António Veiga; Machado, A. V.This work explores the self-assembly and optical properties of a novel chiral, aromatic-rich Boc-Phe-Phe dipeptide derivative functionalized with a benzothiazole bicyclic ring that forms supramolecular structures. Leveraging the well-known self-assembling capabilities of diphenylalanine dipeptides, this modified derivative introduces a heterocyclic benzothiazole unit that significantly enhances the fluorescence...
Development of a polyethylene breathable packaging film with modified microcrys...
Rodrigues, Pedro António Veiga; Castro, Maria Cidália Rodrigues; Soares, Ana M. S.; Melro, Liliana; Machado, A. V.In this study, a material based on polyethylene (PE) and microcrystalline cellulose (MC) was developed as a breathable packaging film. Surface functionalization of MC with 3-aminopropyltriethoxysilane (APTES) has been shown to be an efficient option to tailor their properties and increase opportunities for the application of MC on the reinforcement of polymers such as polyethylene (PE). The functionalization of...
A new approach in PLS/TPS compatibilization using garlic oil: effect on morphol...
Castro, Maria Cidália Rodrigues; Rodrigues, Pedro António Veiga; Cruz, Vasco; Machado, A. V.The packaging industry has made efforts to reduce food waste and improve the resilience of food systems worldwide. Active food packaging, which incorporates active agents, represents a dynamic area where industry and academia have developed new strategies to produce innovative and sustainable packaging solutions that are more compatible with conventional options. Due to health and environmental concerns, indust...
Blown film of PLA for packaging with green tea and fish industrial residues: an...
Rodrigues, Pedro António Veiga; Cunha, Ana B.; Andrade, Mariana A.; Vilarinho, Fernanda; Machado, Ana Vera; Castro, Maria Cidália RodriguesThe use of food waste on the production of packaging can be seen as a promising strategy to cost reduction and new properties. Moreover, packaging, besides food physical protection, should establish a barrier to light and oxygen together with antioxidant and antibacterial activity, to extend the shelf-life of perishable products. In this study, PLA films with the incorporation of natural additives (cold fish pr...
Compatibilizer efficiency in enhancing marine plastic waste valorization throug...
Piedade Cestari, Sibele; Rodrigues, Pedro António Veiga; Ribeiro, Ana Cristina; Castro, Maria Cidália Rodrigues; Cruz, Vasco; Torres, Ana Rita OliveiraThis study investigated the optimal combination of compatibilizers and stabilizers to enhance the value of marine environment plastic (MEP). The composition of the plastics was analysed, and a simulated recycled plastic blend (sMEP) was prepared based on a simplified composition of actual MEP. Different concentrations of three commercial compatibilizers (C1, C2 and C3) were tested to improve tensile strength. T...
Investigation of toughening mechanisms in elastomeric polycarbonate blends thro...
Rodrigues, Pedro António Veiga; Ramoa, Bruno; Castro, Maria Cidália Rodrigues; Machado, A. V.Despite polycarbonate (PC) being a widely used engineering plastic, its notch and crack sensitivity pose challenges in critical applications. To address this, PC was blended with elastomeric polymers to explore the improvement in toughness. This study systematically investigates the toughening mechanisms of PC blended with acrylonitrile–butadiene–styrene (ABS), copolyether ester elastomer (COPE), and ABS and st...
Piezoelectric and pyroelectric properties of organic MDABCO-NH4Cl3 perovskite f...
Baptista, Rosa M. F.; Silva, Bruna Machado; Oliveira, João; Almeida, B. G.; Castro, Maria Cidália Rodrigues; Rodrigues, Pedro António VeigaThis study describes the synthesis and characterization of the lead-free organic ferroelectric perovskite N-methyl-N’-diazabicyclo [2.2.2]octonium)-ammonium trichloride (MDABCO-NH4Cl3). The electrospinning technique was employed to obtain nanofibers embedded with this perovskite in a PVC polymer for hybrid fiber production. The dielectric, piezoelectric, and pyroelectric properties of these fibers were carefull...
Enhancing the interface behavior on polycarbonate/elastomeric blends: morpholog...
Rodrigues, Pedro António Veiga; Ramôa, Bruno Manuel Oliveira; Torres, Ana Rita Oliveira; Castro, Maria Cidália Rodrigues; Machado, A. V.A systematic study was performed to provide better understanding of the effect of elas tomeric materials on the behavior of polycarbonate blends (PC). Thus, blends of PC with different amounts of elastomers, such as copolyether ester elastomer (COPE), acrylonitrile–butadiene–styrene (ABS), maleic anhydride-grafted ABS (ABS-g-MA), and styrene–ethylene–butylene–styrene (SEBS g-MA) were prepared in a co-rotating t...
Evaluation of active LDPE films for packaging of fresh orange juice
Rodrigues, Pedro V.; Vieira, Dalila Assunção Maia; Martins, Paola Chaves; Martins, Vilásia Guimarães; Castro, Maria Cidália Rodrigues; Machado, A. V.Microbial development, enzymatic action, and chemical reactions influence the quality of untreated natural orange juice, compromising its organoleptic characteristics and causing nutritional value loss. Active low-density polyethylene (LDPE) films containing green tea extract (GTE) were previously prepared by a blown film extrusion process. Small bags were prepared from the produced films, which were then fille...
Enhancing the longevity and functionality of Ti-Ag dry electrodes for remote bi...
Carvalho, Daniel; Marques, Sandra Mariana Silva; Siqueira, Giorgia; Ferreira, Armando José Barros; Santos, João; Geraldo, DulceThis study aims to evaluate the lifespan of Ti-Ag dry electrodes prepared using flexible polytetrafluoroethylene (PTFE) substrates. Following previous studies, the electrodes were designed to be integrated into wearables for remote electromyography (EMG) monitoring and electrical stimulation (FES) therapy. Four types of Ti-Ag electrodes were prepared by DC magnetron sputtering, using a pure-Ti target doped with...