245 documents found, page 1 of 25
Toward mechanical recyclability of high barrier food packaging films through fi...
Barros, Carolina; Azevedo, Ana G.; Cerqueira, Miguel Ângelo Parente Ribeiro; Carneiro, O. S.; Machado, A. V.To preserve food from moisture and oxygen, polymers, such as ethylene vinyl alcohol (EVOH) are used in multilayer structures to provide oxygen barrier, while low-density polyethylene (LDPE) is used for a water vapor barrier. While this material combination is functionally ideal, it may not comply with the new packaging recycling guidelines. Some European markets have implemented rules that limit the weight perc...
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...
Active Low-Density Polyethylene-Based Films by Incorporating α-Tocopherol in th...
Azevedo, Ana G.; Barros, Carolina; Miranda, Sónia; Machado, A. V.; Carneiro, O. S.; Silva, Bruno; Andrade, Mariana A.; Vilarinho, FernandaIn this work, alpha-tocopherol (α-TOC) was encapsulated in poly(lactic acid) nanoparticles (PLA NPs) and added to low-density polyethylene (LDPE) films with the aim of producing an active film for food packaging applications. PLA NPs loaded with α-TOC were produced through nanoprecipitation and dried using two methods (freeze-dryer and oven). LDPE-based films with final polymeric matrix concentrations of 10 and...
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...
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...
Feasibility of incorporating recycled multilayer LDPE/EVOH films into flexible ...
Barros, Carolina Lemos; Carneiro, O. S.; Machado, A. V.Multilayer films are widely used in the food industry because they allow the combination of properties of different materials to increase product shelf life without sacrificing product value. Despite the associated benefits, these films are difficult to recycle due to material immiscibility and difficult layer separation. Thus, the purpose of this research is to investigate the feasibility of incorporating recy...
Nanoplasmonic Au:CuO thin films functionalized with APTES to enhance the sensit...
Proença, Manuela; Rodrigues, Marco S.; Moura, C.; Machado, A. V.; Borges, Joel; Vaz, FilipeCarbon monoxide (CO) is a highly flammable and toxic gas to humans and animals, that's why its detection and monitoring are crucial. A promising technique to develop a robust and cheap gas sensor, operating at room temperature, is Localized Surface Plasmon Resonance (LSPR) sensing. However, LSPR sensing of inorganic gas molecules, such as CO, is challenging due to their extremely small differences in refractive...
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...
From multilayer LDPE/EVOH flexible film scraps to new multilayer films
Barros, Carolina; Carneiro, O. S.; Machado, A. V.This study explores the mechanical and optical properties of multilayer films incorporating recycled materials, mimicking the structure of industrial films. Using a coextrusion blown film line with a three-layer ABC configuration extrusion head, films were produced using two different recycled multilayer films, from post-industrial scraps, in layers A and B and virgin low-density polyethylene (LDPE) in one of t...