The research activities of the Group on Particles, Polymers and Biomaterials Technology address a wide variety of topics ranging from pulp and paper, sustainable processes, polymers and biomaterials, particle technology, biorefineries and forest products, fully in-line with the four thematic lines that constitute CIEPQPF’s strategy for the next 6 years.
The main areas of current research can be organized as follows, even if it must be stressed that there are many interactions between the five main areas:
PULP & PAPER
PPB has been involved since its beginning in this domain and has recognized expertise in this area. It has been involved in several projects focussing either on industrial problems or fundamental research. A close collaboration with the national paper mills, through RAIZ- Forest and Paper Research Institute, should be highlighted. Issues like fibre characterization, flocculation processes (mechanisms and optimization), flow dynamics of pulp fibre suspensions, paper surface characterization and modification, flocculation of fillers and fillers modification, paper-ink interactions (inkjet and offset), dimensional stability and cooking as well as bleaching conditions have been subjects of investigation.
NATURAL PRODUCTS AND SUSTAINABLE PROCESSES
This is another domain where the group has also been gathering critical mass and recognition. Members of the group have been developing work on the extraction/separation of high added-value compounds from agro-industrial wastes as well as from other natural renewable products and their residues. The use of "green", sustainable, biomimetic and environmental-friendly processes for the development of high-value materials, products and applications, including the use of supercritical carbon dioxide, ionic liquids, biomimetic catalysts, aqueous- and ethanolic-based solventes are research lines pursued by the group. These compounds will be employed as additives or as raw materials in food, cosmetic, pharmaceutical, environmental and other industrial applications (such as lipids and oils, phytopharmaceuticals, essential oils, anti-oxidants, polyphenolics, natural colorants, tanning agents, bioadhesives, etc.).
POLYMERS AND BIOMATERIALS
Regarding Polymeric Materials, special emphasis has been given to the synthesis and characterization of new polymeric materials using new polymerization techniques; synthesis of biodegradable polymers (e. g. poly(lactic acid)) and development of new polymers. Micro and nanotechnologies have been implemented for application in paints and coatings, in new composites and in textiles. Synthesis of nanoparticles via self-assembly with controlled amphiphilic block copolymers with stimuli-responsive segments are also being synthesized.
In the area of biomaterials, special attention has been devoted to the development and characterization of hydrogels, adhesives, biosensors, drug delivery systems and nanotechnology, namely using supercritical fluid and molecular imprinting technologies. These biomaterials have been tested for medical applications, namely in orthopaedic implants, as bone substitutes, in ophthalmology, as contact lenses, in dentistry, and in biological adhesives. Drug carriers include micro- and nanoparticles, hydrogels, films, adhesives as well as some finished biomedical devices such as contact and intraocular lenses. New unsaturated biodegradable polyesters are also being developed with tailored/improved thermomechanical properties for micro-thermo-stereo-litography in order to allow the preparation of 3D scaffolds for tissue engineering. Polymer/ceramic and bone surface modification for biomedical applications; scaffold biofabrication for bone regeneration; new biodegradable/bioerodible materials for medical applications are other lines under development within the group.
BIOREFINERIES AND FOREST PRODUCTS
The group is developing work concerning the fermentation of wood and pulp sludge liquid hydrolysates to produce bioethanol, as well as the extraction of proteins and/or carbohydrates from defatted oilseed meals and also the extraction of hemicelluloses and their conversion into added-value products (e.g. bioethanol) and pulp sludge valorization.
The main strategy is an integrated biorefinery approach to produce sustainable biofuels from forest and industrial residues within the concept of wood biorefinery, namely their valorization to obtain bioproducts and/or renewable energy, using biocatalysis and fermentation as transformation tools. Ionic liquids have been used as powerful solvents for forest residues to separate lignin from carbohydrates.
More recently the group got involved on the tailored modification of cellulose or tannin polymers (namely residues) to produce specific polelectrolytes for added value applications such as in cosmetics, food and biomedical applications, but also in environmental applications.
PARTICLE TECHNOLOGY AND MULTIPHASE PROCESSES
Another active area of research is Particle Characterization and Multiphase Processes, which, again, was one of the initial areas of development of the group when it was created. The group has a long tradition in the field of particle sizing (micro and nano particles) as well as on the determination of porosity and pore size distribution, surface area and density (bulk and real density) of granulate materials. Recently, members of the group are very much involved in the study of aggregation mechanisms, namely aggregation induced by polyelectrolytes, including the modelling of these processes based on population balances. A new area of development is the application of CFD and Tomographic Techniques to monitor multiphase processes (solid/liquid, includig fibres, as well as emulsions). Also rheological studies of different types of suspensions, including fibre suspensions, is another field of activity of the group. Production of micro/nanoparticles by emulsion/microemulsion methods is another area of activity of the group in this subdomain. Lately, the group got also strongly involved in the field of Nanotoxicology, mainly in the area of the interaction of NPs with the aquatic environment.
M. L. Vueba, L. A. E. Batista de Carvalho, F. Veiga, J. J. Sousa, M. E. Pina,” Influence of cellulose ether polymers on ketoprofen release from hydrophilic matrix tablets “, European Journal of Pharmaceutics and Biopharmaceutics, 58 (1), 51-59, 2004.
J.F. Almeida, P. Ferreira, P. Alves, A. Lopes, M. H. Gil, “Synthesis of a thermo-sensitive drug delivery system by gamma irradiation”, International Journal of Biological Macromolecules, 61:150–155, 2013.
P. Alves, A. A. Hugo, E. E. Tymczyszyn, A. F. Ferreira, R. Fausto, P. F. Pérez, J. F. J. Coelho, P. N Simões, A. Gómez-Zavaglia, “Effect of cholesterol-poly(N,N-dimethylaminoethyl methacrylate) on the properties of stimuli-responsive polymer liposome complexes”, Colloids Surfaces B, 104: 254–261, 2013.
A. M. A. Dias, A. Rey-Rico, R. A. Oliveira, S. Marceneiro, C. Alvarez-Lorenzo, A. Concheiro, R. N. C. Júnior, M. E. M. Braga, H. C. de Sousa, “Wound dressings loaded with an anti-inflammatory juca (Libidibia ferrea) extract using supercritical carbon dioxide technology”, Journal of Supercritical Fluids, 74, 34-45, 2013.
A. M. A. Dias, A. R. Cortez, M. Barsan, J. B. Santos, C. M. A. Brett, H. C. de Sousa, “Development of greener multi-responsive chitosan biomaterials doped with biocompatible ammonium ionic liquids, ACS Sustain”, Chemical Engineering, 1, 1480-1492, 2013.
A. Figueiredo, P. Coimbra, A. Cabrita, F. Guerra, M. Figueiredo, “Comparison of a xenogeneic and an alloplastic material used in dental implants in terms of physico-chemical characteristics and in vivo inflammatory response”, Materials Science and Engineering: C, 33(6), 3506-3513, 2013.
P. Ferreira, A. Carvalho, T. R. Correia, B. P. Antunes, I. J. Correia, P. Alves, “Functionalization of polydimethylsiloxane membranes to be used in the production of voice prosthesis”, Science and Technology of Advanced Materials, 14: 1–8, 2013.
J. A. F. Gamelas, “The surface properties of cellulose and lignocellulosic materials assessed by inverse gas chromatography: A review”, Cellulose, 20 (6), 2675-2693, 2013.
A. F. Lourenço, J. A. F. Gamelas, C. Zscherneck, P. J. Ferreira, “Evaluation of Silica-Coated PCC as New Modified Filler for Papermaking”, Industrial & Engineering Chemistry Research, 52(14), 5095−5099, 2013
M. B. C. de Matos, A. P. Piedade, C. Alvarez-Lorenzo, A. Concheiro, M. E. M. Braga, H. C. de Sousa, “Dexamethasone-loaded poly(E-caprolactone)/silica nanoparticles composites prepared by supercritical CO2 foaming/mixing and deposition”, International Journal of Pharmaceutics, 456, 269-281, 2013
M.J. Moura, M. H. Gil, M.M. Figueiredo, “Delivery of cisplatin from thermosensitive co-cross-linked chitosan hydrogels”, European Polymer Journal, Volume 49, Issue 9, 2504–2510, 2013.
I. Pinheiro, P. J. Ferreira, F. A. Garcia, M. S. Reis, A. C. Pereira, C. Wandrey, H. Ahmadloo, J. L. Amaral, D. Hunkeler, M. G. Rasteiro, “An Experimental design methodology to evaluate the importance of different parameters on flocculation by polyelectrolytes”, Powder Technology, 238, 2-13, 2013.
P. C. Pinheiro, C. T. Sousa, J. P. Araújo, A. J. Guiomar, T. Trindade, “Functionalization of nickel nanowires with a fluorophore aiming at new probes for multimodal bioanalysis”, Journal of Colloid and Interface Science, 410, 21−26, 2013.
M. L. Vueba, A. Rodrigues, P. Lourenço, L. A. E. Batista de Carvalho, F. Veiga, J. J. Sousa, M. E. Pina, “Gamma scintigraphy in the analysis of ketoprofen behaviour from matrix tablets”, International Journal of Pharmaceutics, 448 (1), 298 – 304, 2013
A. M.A. Dias, S. Marceneiro, M. E.M. Braga, J. F.J. Coelho, A. G.M. Ferreira, P. N. Simões, I. M. Veiga, L. C. Tomé, I. M. Marrucho, J. M. S. S. Esperança, A. Matias, C. M. M. Duarte, L. P. N. Rebelo, H. C. de Sousa, “Phosphonium-based ionic liquids as modifiers for biomedical grade poly(vinyl chloride)”, Acta Biomaterialia, 8, 1366-1379, 2012.
A. P. Duarte, J. F. Coelho, J. C. Bordado, M. T. Cidade, M. H. Gil, “Surgical adhesives: Systematic review of the main types and development forecast”, Progress in Polymer Science, Volume 37, Issue 8, 1031–1050, 2012.
I. Lopes, R. Ribeiro, F. E. Antunes, T. A. P. Rocha-Santos, M. G. Rasteiro, A. M. V. M. Soares, F. Gonçalves, R. pereira, “Toxivity and Genotoxicity of Organic and Inorganic Nanoparticles to the Bacteria Vibrio Fischeri and Salmonella Typhimurium”, Ecotoxicology, 21 (3), 637-648, 2012.
P. E. G. Loureiro, M. R. M. Domingues, A. J. S. Fernandes, M. G. V. S. Carvalho, D. V. Evtuguin, “Discriminating the brightness stability of cellulosic pulp in relation to the final bleaching stage”, Carbohydrate Polymers, 88(2):726-733, 2012.
C. M. N. Maleita, R. Curtis, I. Abrantes, “Thermal requirements for the embryonic development and life cycle of Meloidogyne hispânica”, Plant Pathology, 61, 1002–1010, 2012.
C. M. N. Maleita, R. H. C. Curtis, S. J. Powers, I. Abrantes, “Host status of cultivated plants to Meloidogyne hispânica”, European Journal of Plant Pathology, 133, 449–460, 2012
P. Coimbra, P. Alves, T. A. M. Valente, R. Santos, I. J. Correia, P. Ferreira, “Sodium hyalunorate/chitosan polyelectrolyte complex scaffolds for dental pulp regeneration: Synthesis and characterization”, International Journal of Biological Macromolecules, 49(4), 573-579, 2011.
E. Forján, I. Garbayo, M. Henriques, J. Rocha, J. M. Veja, C. Vílchez, “UV-A Mediated Modulation of Photosynthetic Efficiency, Xanthophyll Cycle and Fatty Acid Production of Nannochloropsis”, Marine Biotechnology, 13:366-375, 2011.
M. J. Moura, H. Faneca, M. P. Lima, M. H Gil, M. M. Figueiredo, “In Situ Forming Chitosan Hydrogels Prepared via Ionic/Covalent Co-Cross-Linking”, Biomacromolecules 12, 3275–3284, 2011.
C. A. F. Ventura, F. A. P. Garcia, P. J. Ferreira, M. G. Rasteiro, “Modelling the turbulent flow of pulp suspensions”, Industrial & Engineering Chemistry Research, 50 (16), 9735-9742, 2011.
F. Yañez, L. Martikainen, M. E. M. Braga, C. Alvarez-Lorenzo, A. Concheiro, C. M. M. Duarte, M. H. Gil, H. C. de Sousa, “Supercritical fluid-assisted preparation of imprinted contact lenses for drug delivery”, Acta Biomaterialia, 7, 1019-1030, 2011.
E. Antunes, F. A. P. Garcia, P. F erreira, A. Blanco, C. Negro, M. G. Rasteiro, “Modelling PCC flocculation by bridging mechanism using population balances: effect of polymer characteristics on flocculation”, Chemical Engineering Science, 65 (12), 3798-3807, 2010.
M. Figueiredo, J. C. Henriques, G. Martins, F. A. Guerra, F. Judas, H. Figueiredo, “Physicochemical characterization of biomaterials commonly used in dentistry as bone substitutes- comparison with human bone”, Journal of Biomedical Materials Research Part B: Applied Biomaterials, 92 (2), 409-419, 2010.
M. S. Saraiva, J. A. F. Gamelas, A. P. M. de Sousa, B. M. Reis, J. L. Amaral, P. J. Ferreira, “A new approach for the modification of paper surface properties using polyoxometalates”, Materials, 3(1), 201 – 215, 2010.