Browsing by Author "Gomes, Catarina P."
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- Carbon-based hydrogelsPublication . Bzainia, Amir; Gomes, Catarina P.; Dias, Rolando; Costa, Mário RuiThis chapter intends to give insight into the use of carbon-based hydrogels for energy storage and/or conversion, which are becoming critical, given the ongoing need for decarbonization and growing renewable energy production. The ability to use sustainable materials and the added advantage to incorporate tailor-made, nontoxic, cheap, and electrochemically active functional moieties during their synthesis make them frontrunner materials in the field of green chemistry and energy applications. Here, after a brief introduction of graphene-, synthetic polymer-, and natural polymer-based hydrogels and many possibilities for their hybrid combination, a particular emphasis is given to their application to energy storage, energy conversion, and energy efficiency enhancement systems. Application examples concerning metal-air batteries, fuel cells, water electrolyzers, microbial fuel cells, photoelectrochemical water splitting, supercapacitors, lithium-ion batteries, and other metal-ion batteries, desalination, and water purification through solar vapor generation are highlighted.
- Fractionation of flavonols and anthocyanins in winemaking residues using molecularly imprinted cellulose‐synthetic hybrid particles with pyridyl active surfacePublication . Gomes, Catarina P.; Dias, Rolando; Costa, Mário RuiHybrid cellulose-synthetic particles with surface active pyridyl moieties and molecularly imprinted cavities for quercetin were prepared via atom transfer radical polymerization. The functionalization of the materials with pyridyl groups was confirmed by FTIR and the SEM micrographs of the hybrid particles demonstrate a clear surface modification compared with the pristine cellulose. Competitive sorption/desorption testing of the imprinted and non-imprinted particles with standard polyphenols show the achievement of an imprinting factor IF similar to 8. Moreover, it was also confirmed the high retention capability of the hybrid materials for polyphenols, due to their strong binding with the surface pyridyl moieties, even when using hydroalcoholic solvents of high ethanol content (e.g., ethanol/water 80/20 v/v). The sorption capabilities of the synthesized materials for polyphenols were explored with the fractionation of flavonols and anthocyanins in winemaking residues. High concentration and enrichment factors were achieved for high-added value compounds, namely five times for quercetin and 12 for quercetin-3-O-glucuronide with a diatomaceous earth extract and up to 4 for flavonols in a grape pomace (e.g. myricetin and quercetin glucosides). This research demonstrates de feasibility for the combination between the development of engineered materials addressing sustainability with their application to the valorization of agro-industrial wastes.
- Molecular imprinting and surface grafting of glycoprotein fragments in polymeric nanosystems: from cancer diagnosis to virus targetingPublication . Bzainia, Amir; Gomes, Catarina P.; Dias, Rolando; Costa, Mário RuiGlycoproteins and glycans are widely found in eukaryotes, prokaryotes, archaea, and viruses. Many fundamental biological mechanisms, such as molecular recognition, signal transduction, cell adhesion, and immune response are regulated with the intervention of glycoproteins, glycans, and monosaccharides. Several diseases are a result of anomalous changes affecting the structure of these molecules or their abnormal expression. Therefore, glycoproteins, glycans, and monosaccharides are often considered biomarkers for diagnosis purposes and therapeutic agents in cancer treatment. The development of vaccines and antibodies for infection diseases also relies on these kinds of molecular structures. The mimic of glycoproteins or their molecular recognition with tailored synthetic polymers can be used to develop tools aiding in the diagnosis and treatment of different kinds of diseases, through sensing, imaging, controlled drug delivery, virus inhibition, and so on. This chapter describes the use of molecular imprinting techniques and grafting mechanisms with glycoproteins, glycans, and saccharides aiming at the development of such kinds of synthetic polymers. Due to their practical relevance, a special emphasis is given to systems involving sialic acid or derivatives, boronic acid-based polymers (e.g., with surface-oriented molecular imprinting of glycoproteins) and glycopolymers synthesis through grafting of saccharide moieties in polymer backbones or nano-surfaces (e.g., for the generation of macromolecules/surfaces with polyvalent interactions). Along the text, the use of “controlled” (or rather reversibly deactivated) radical polymerization is highlighted to show new opportunities arising in this field with these synthetic routes. Improved precision in the design of special molecular architectures, functionalization, hybridization, surface modification, and size control of macromolecular-based devices (e.g., nanofabrication) are some important goals in the development of tailored synthetic materials that can be achieved with controlled radical polymerization. Specific examples involving these special kinds of synthetic polymers with their application in cancer and virus targeting are provided.