Paula Ferreira

University of Aveiro | UA · CICECO - Aveiro Institute of Material

Ultraviolet (UV) radiation is known to promote health concerns that can manifest over both short and long terms. Aging, sunburn, skin cancer, and other conditions are related to UV radiation. Medication can also be negatively affected by this radiation. Moreover, UV radiation modifies the taste, colour, and texture of food, and may compromise its s...

Non-invasive routes for insulin delivery are emerging as alternatives to currently painful subcutaneous injections. For pulmonary delivery, formulations may be in powdered particle form, using carriers such as polysaccharides to stabilise the active principle. Roasted coffee beans and spent coffee grounds (SCG) are rich in polysaccharides, namely g...

Starch is a biodegradable and biocompatible carbohydrate that, when combined with bioactive molecules, can be processed as biomimetic platforms with enhanced performance, allowing its use as active wound dressing materials. Porphyrinoid photosensitizers can tune the physicochemical/functional profile of biomacromolecules, allowing their use in anti...

Natural polymers such as cellulose have interesting tribo- and piezoelectric properties for paper-based energy harvesters, but their low performance in providing sufficient output power is still an impediment to a wider deployment for IoT and other low-power applications. In this study, different types of celluloses were combined with nanosized car...

The implementation of efficient treatments to remove antibiotics from wastewater is necessary to avoid their discharge in the aquatic environment and the associated negative effects. In order to address this challenge, the adsorptive performance of an optimized brewery waste-derived activated carbon (AC-SBG), produced by one-step microwave pyrolysi...

Coccolithophore microalgae, such as Emiliania huxleyi (EHUX) and Chrysotila pseudoroscoffensis (CP), are composed of calcium carbonate (CaCO3) and contain bioactive compounds that can be explored to produce sustainable food packaging. In this study, for the first time, these microalgae were incorporated as fillers in starch-based films, envisioning...

Calcium carbonate (CaCO3) is used as a filler to improve the stiffness and processability of plastics at low cost. However, its high density limits the quantity to be used. In this work, the feasibility of using starch consolidation of eggshells-derived CaCO3 (ES) to develop lightweight fillers for low density polyethylene (LDPE)-based materials wa...

Chlorococcum amblystomatis is a novel microalga with a high content of omega-3 fatty acids (FAs), with applications for food, feed, nutraceuticals, and biotechnology. These applications require the use of food-grade green solvents such as ethanol (EtOH) for lipid extraction, which can be associated with lower lipid recovery yields if not assisted w...

Carbonaceous materials derived from biomass have been used as sustainable platforms for the growth of ZnO particles aiming the production of functional composite fillers. Kidney-bean pods were pyrolyzed by applying an experimental design that demonstrates that the specific surface area (SBET) of biochar is improved with increasing pyrolysis tempera...

Bioplastics have emerged to minimize the ecological footprint of non-degradable plastics. However, the effect of their degradation in aquatic systems, including the interaction with toxic metals, is still unexplored. In this work, the influence of UV-aging on structure, chemistry, wettability, rigidity, and Hg-sorption of commercially available bio...

Underexploited sources of bio-based wall materials for bioactive compounds (such as β-carotene) encapsulation have gained increasing interest within the scientific community. In this study, the potential of amaranth (Amaranthus cruentus) grain starch and protein rich fractions as microcapsules’ wall materials to carrier β-carotene was evaluated. Mi...

Magnetite nanoparticles were synthesized by the co-precipitation method with and without the assistance of an additive, namely, gelatin, agar-agar or pectin, using eco-friendly conditions and materials embodying a green synthesis process. X-ray diffraction and transmission electron microscopy were used to analyze the structure and morphology of the...

Interest in producing films from renewable and biodegradable polymers, such as polysaccharides, has increased in recent years with the aim of reducing the environmental pollution caused by petroleum-based plastics. Additionally, combining the thermoplastic property of starch with the antioxidant and antimicrobial activities of chitosan is of great...

Background: Non-value agrifood byproducts are rich in biomolecules such as proteins and polysaccharides, and possess film-forming ability, motivating their use in the development of biodegradable plastics. This work studied the feasibility of using locust bean milling-derived dust (LBMD) as a source of biomolecules suitable for developing biodegra...

Carbon nanostructures are widely used as fillers to tailor the mechanical, thermal, barrier, and electrical properties of polymeric matrices employed for a wide range of applications. Reduced graphene oxide (rGO), a carbon nanostructure from the graphene derivatives family, has been incorporated in composite materials due to its remarkable electric...

This study aimed at optimizing the one-step chemical activation and microwave pyrolysis of an agro-industrial waste to obtain a microporous activated carbon (AC) with superior textural and adsorptive properties by a fast, low-reagent and low-energy process. Spent brewery grains were used as precursor, and the antibiotics sulfamethoxazole (SMX), tri...

Magnetic nanoparticles (NP), such as magnetite, have been the subject of research for application in the biomedical field, especially in Magnetic Hyperthermia Therapy (MHT), a promising technique for cancer therapy. NP are often coated with different compounds such as natural or synthetic polymers to protect them from oxidation and enhance their co...

Glycolipids and phospholipids are the main reservoirs of omega polyunsaturated fatty acids in microalgae. Their extraction for the food industry requires food grade solvents, however, the use of these solvents is generally associated with low extraction yields. In this study, we evaluated the lipid extraction efficiency of food-grade ethanol, ultra...

Bionanocomposite materials have been designed as a promising route to enhance biopolymer properties, especially for food packaging application. The present study reports the preparation of bionanocomposite films of alginate with different loadings of pure reduced graphene oxide (rGO) or of mixed zinc oxide-rGO (ZnO-rGO) fillers by solvent casting....

The diversity of zinc oxide (ZnO) particles and derived composites applications is highly dependent on their structure, size, morphology, defect amounts, and/or presence of dopant molecules. In this work, ZnO nanostructures are grown in situ on graphene oxide (GO) sheets by an easily implementable solvothermal method with simultaneous reduction of...

The incorporation of carbon-based nanomaterials into biopolymer matrix, to provide mechanical reinforcement and to obtain electrically conductive bionanocomposites, requires the homogeneous dispersion of the fillers. Herein it is investigated the influence of surfactant structures on the dispersibility of multiwalled carbon nanotubes (MWNT) within...

Starch, due to its thermoplastic capacity, is being explored for developing food packaging bioplastics. Nevertheless, it gives rise to brittle and hydrophilic materials. To overcome these drawbacks, in this work, the influence of potato peel phenolic extracts (PhE) on physicochemical and mechanical properties of starch-based films was studied. PhE...

The coffee industry generates a wide variety of by-products derived from green coffee processing (pulp, mucilage, parchment, and husk) and roasting (silverskin and spent coffee grounds). All these fractions are simply discarded, despite their high potential value. Given their polysaccharide-rich composition, along with a significant number of other...

Reduced graphene oxide (rGO) is a promising graphene-based material, with transversal applicability to a wide range of technological fields. Nevertheless, the common use of efficient—but hazardous to environment and toxic—reducing agents prevents its application in biological and other fields. Consequently, the development of green reducing strateg...

There is currently a demand for flexible biomedical sensors. Characteristics as soft, thin, elastic, flexible and comfortable to the contact with skin should be matched with performance and ultimately made of sustainable, and biocompatible materials. In this work, chitosan as a flexible biodegradable polymeric matrix was combined with ferroelectric...

The Front Cover shows a flexible functional biocomposite film composed of chitosan biopolymer and BaTiO3 particles, which was prepared by environmentally benign methodologies. This film is flexible, and its elasticity can be tailored by the addition of BaTiO3 particles. The dielectric permittivity increases with the barium titanate content. The evi...

Periodic mesoporous organosilicas (PMO) were proposed as potential adsorbents for CO2/CH4 adsorption-separation due to their strong interactions with CO2 and low affinity for CH4. Herewith, we present a comprehensive density functional theory (DFT) study about the binding properties of CO2 and CH4 with the pore walls of different PMO materials. The...

Aiming to evaluate how the release profile of naproxen (nap) is influenced by its physical state, molecular mobility, and distribution in the host, this pharmaceutical drug was loaded in three different mesoporous silicas differing in their architecture and surface composition. Unmodified and partially silylated MCM-41 matrices, respectively MCM-41...

Food processing wastes together with the perishable foodstuff loss promote environmental and societal concerns. Food byproducts can have value as a source of functional molecules for developing active packaging without food waste, under a circular economy. Nevertheless, the often-associated extraction/chemical processes compromise the sustainabilit...

An activated carbon was produced from paper mill sludge (AC-P) and functionalized with thiol groups (AC-MPTMS) for the adsorptive removal of the antibiotic sulfamethoxazole (SMX) from buffered solutions prepared in ultrapure water (pH 8) and real wastewater samples. The physicochemical properties of the two materials (AC-P and AC-MPTMS) showed diff...

In the present study, two photocatalytic graphene oxide (GO) and carbon nanotubes (CNT) modified TiO 2 materials thermally treated at 300 • C (T300_GO and T300_CNT, respectively) were tested and revealed their conversion efficiency of nitrogen oxides (NO x) under simulated solar light, showing slightly better results when compared with the commerci...

This review aims to showcase the current use of graphene derivatives, graphene-based nanomaterials in particular, in biopolymer-based composites for food packaging applications. A brief introduction regarding the valuable attributes of available and emergent bioplastic materials is made so that their contributions to the packaging field can be unde...

The small amount of proteins in starch-rich food industry byproducts can be an advantage to crosslink with genipin and tailor the performance of biobased films. In this work, genipin was combined with non- purified starch recovered from industrial potato washing slurries and used for films production. Starch recovered from potato washing slurries c...

Agrofood byproducts may be exploited as a source of biomolecules suitable for developing bioplastic materials. In this work, the feasibility of using starch, oil, and waxes recovered from potato chips byproducts for films production was studied. The recovered potato starch-rich fraction (RPS) contained an amylopectin/amylose ratio of 2.3, gelatiniz...

Titanium oxide-based materials with different physical and chemical features were synthetized aiming at removing organic pollutants from both water and air media. The materials were produced employing two different heating methodologies (thermal, T and hydrothermal, H) at distinct temperatures resulting in porous materials. These materials were als...

Genipin crosslinking increases the acidic stability of chitosan-based materials, opening an opportunity to explore new applications. In this work, the viability of using chitosan-genipin solutions on cellulose-based materials coating was studied. Non-calendered paper and cardboard were used as raw materials. Different number of chitosan-genipin coa...

Climate change is leading to a gradual increase in the ocean temperature, which can cause physiological and biochemical impairments in aquatic organisms. Along with the environmental changes, the presence of emerging pollutants such as titanium oxide (TiO2) in marine coastal systems has also been a topic of concern, especially considering the inter...

Chitosan-genipin (Ch-Ge) films have been proposed as wine preservative due to their capacity to uptake iron ions. The wine is an aqueous acidic solution of water and ethanol, whose acidity derives from tartaric acid. This acid has been shown to form negatively charged iron-tartrate complexes able to interact with the positively charged amine groups...

Sustainably made, flexible and biocompatible composites, having environmentally friendly compositions and multifunctional capabilities, are promising materials for several emerging biomedical applications. Here, the development of flexible and multifunctional chitosan-based bionanocomposites with a mixed reduced graphene oxide-iron oxide (rGO-Fe3-x...

The functionalization of a paper mill sludge-based activated carbon (AC) was addressed in this work for the first time. Four different procedures have been accomplished in order to introduce amine functional groups (AC-NH2 and AC-APTES), thiol functional groups (AC-MPTMS), and a covalent organic polymer (AC-COP) onto the AC surface. The materials w...

Titanium dioxide (TiO2) particles have been widely used in various industrial applications and consumer products. Due to their large production and use, they will eventually enter into aquatic environments. Once in the aquatic environment TiO2 particles may interact with the organisms and induce toxic effects. Since the most common crystallographic...

Nanopatterned porous thin films of bismuth ferrite (BiFeO3) with porosity perpendicular to the plane are prepared by an evaporation-induced self-assembly methodology using nitrate metal salts and a commercial block copolymer as a structure-directing agent. The sol–gel based method is successfully used to achieve crystalline nanopatterned porous BiF...

Chitosan is a biopolymer obtained by deacetylation of chitin extracted from sub-products of the food industry and it is rich in nitrogen content. Pyrolyzed chitosan– and chitosan-periodic mesoporous organosilica (PMO)– based porous materials with different pore structures and chemical features are prepared using different dry methods and ensuing py...

Periodic mesoporous organosilicas (PMOs) were suggested as potential adsorbents for CO2/CH4 separation because of their large affinities towards CO2 and low interaction with CH4. Herewith, we present a comprehensive computational study on the binding properties of flue gas species with the pore walls of periodic mesoporous phenylene-silica (Ph-PMO)...

Chitosan-based functional materials are emerging for food applications. The covalent bonding of molecular entities demonstrates to enhance resistance to the typical acidity of food assigning mechanical and moisture/gas barrier properties. Moreover, the grafting to chitosan of some functional molecules, like phenolic compounds or essential oils, giv...

This chapter presents a general view of the different aspects involved in the research on nanoparticles for magnetic hyperthermia therapeutic. After a short review of the most important requirements for magnetic nanoparticles to be used as local heaters for cancer therapy, the experimental parameters influencing the nanoparticles heating efficiency...

The world energy demands have been increasing in the last decades driven by strong economic growth and expanding populations. Alternative energy resources have been proposed to satisfy part of the energy needs. Biogas is an alternative energy source produced through the anaerobic digestion process of organic matter. Conventional and commercial proc...

Biobased materials arise has potential solution to minimize the environmental impact caused by the disposal of synthetic polymers into landfills. Starch is an abundant thermoplastic biopolymer that allows the production of bioplastics with notable renewability and biodegradability. However, starch-based materials are hygroscopic and have poor mecha...

This research describes the synthesis and characterization of a periodic mesoporous organosilica (PMO) with low thiol density, and its efficiency to trap Hg(II) from waters under realistic environmental conditions. Despite the low density of SH groups grafted to the silanol groups of the pristine PMO, the functionalized material displays effective...

Chitosan-genipin films present a bluish-green color due to the conjugated double bonds formed when monomeric or dimeric genipin residues bridge chitosan. This phenomenon limits their use when colorless materials are required. In this work, a two-step oxidation strategy was developed aiming to remove color from chitosan-genipin films while preservin...

N,N-dialkylation reaction of mesoporous aniline-silica is successfully achieved with nearly total conversion of the amine-phenylene periodic mesoporous organosilica (NH2-PMO) to the N,N-dialkylated amine material. Microwave-assisted dialkylation was optimized. Two cycles are required to promote the reaction of 2-bromopropane with the NH2-PMO and ob...

Pristine, amino monofunctionalized and amino and thiol bifunctionalized phenylene-bridged periodic mesoporous organosilicas (Ph-PMO) were synthetized by a simple methodology without any protection/deprotection steps. The Ph-PMO materials were characterized and their potential as new sorbents for Hg(II) was investigated for low-contamination scenari...

Periodic mesoporous organosilicas (PMO), with phenylene or biphenylene organic linkers, were thermally treated in flowing nitrogen atmosphere upon different conditions aiming the enhancement of their CO2 adsorption/separation properties. As-synthesized and template-extracted phenylene- and biphenylene-PMO were pyrolysed at 800 and 1200 °C. The effe...

Efficient separation of CO2/CH4 is critical in biogas upgrading, requiring highly selective adsorbents. Based on the adsorption energies of -0.30 and -0.14 eV, previously calculated by dispersion corrected density functional theory for adsorption/desorption of CO2 and CH4 on the functionalized periodic mesoporous phenylene-silica material APTMS@Ph-...

Non-porous bridged silsesquioxanes (BSs) were produced by sol-gel reactions and self-directed assembly, in the presence of an acid catalyst and a large excess of water, from bridged organosilane precursors (BOPs) synthesized by click chemistry. The rational design of the compounds, comprising an amine group and alkyl chains with variable length (n)...