Development of biocompatible and ���smart��� porous structures using CO2-assisted processes

Disserta����o apresentada para a obten����o do grau de Doutor em Engenharia Qu��mica, especialidade Engenharia da Reac����o Qu��mica, pela Universidade Nova de Lisboa, Faculdade de Ci��ncias e Tecnologia

The solvation and electrochemical behaviour of Copper acetylacetonate complexes in ionic liquids

The behavior of copper(II) complexes of pentane-2,4-dione and 1,1,1,5,5,5-hexafluoro-2,4-pentanedione, [Cu(acac)(2) (1) and [Cu(HFacac)(2)(H2O)] (2), in ionic liquids and molecular organic solvents, was studied by spectroscopic and electrochemical techniques. The electron paramagnetic resonance characterization (EPR) showed well-resolved spectra in most solvents. In general the EPR spectra of [Cu(acac)(2)] show higher g(z) values and lower hyperfine coupling constants, A(z), in ionic liquids than in organic solvents, in agreement with longer Cu-O bond lengths and higher electron charge in the copper ion in the ionic liquids, suggesting coordination of the ionic liquid anions. For [Cu(HFacac)(2)(H2O)] the opposite was observed suggesting that in ionic liquids there is no coordination of the anions and that the complex is tetrahedrically distorted. The redox properties of the Cu(II) complexes were investigated by cyclic voltammetry (CV) at a Pt electrode (d = 1 mm), in bmimBF(4) and bmimNTf(2) ionic liquids and, for comparative purposes, in neat organic solvents. The neutral copper(II) complexes undergo irreversible reductions to Cu(I) and Cu(0) species in both ILs and common organic solvents (CH2Cl2 or acetonitrile), but, in ILs, they are usually more easier to reduce (less cathodic reduction potential) than in the organic solvents. Moreover, 1 and 2 are easier to reduce in bmimNTf(2) than in bmimBF(4) ionic liquid. (C) 2013 Elsevier B.V. All rights reserved.

The solvation and redox behaviour of mixed ligand COPPER(II) complexes of acetylacetonate and aromatic dimines in ionic liquids

The behavior of two cationic copper complexes of acetylacetonate and 2,2'-bipyridine or 1,10-phenanthroline, [Cu(acac)(bipy)]Cl (1) and [Cu(acac)(phen)]Cl (2), in organic solvents and ionic liquids, was studied by spectroscopic and electrochemical techniques. Both complexes showed solvatochromism in ionic liquids although no correlation with solvent parameters could be obtained. By EPR spectroscopy rhombic spectra with well-resolved superhyperfine structure were obtained in most ionic liquids. The spin Hamiltonian parameters suggest a square pyramidal geometry with coordination of the ionic liquid anion. The redox properties of the complexes were investigated by cyclic voltammetry at a Pt electrode (d = 1 mm) in bmimBF(4) and bmimNTf(2) ionic liquids. Both complexes 1 and 2 are electrochemically reduced in these ionic media at more negative potentials than when using organic solvents. This is in agreement with the EPR characterization, which shows lower A(z) and higher g(z) values for the complexes dissolved in ionic liquids, than in organic solvents, due to higher electron density at the copper center. The anion basicity order obtained by EPR is NTf2-, N(CN)(2)(-), MeSO4- and Me2PO4-, which agrees with previous determinations. (C) 2013 Elsevier B.V. All rights reserved.

Calix[4]arene-carbazole-containing polymers: synthesis and properties

New highly fluorescent calix[4]arene-containing phenylene-alt-ethynylene-3,6- and 2,7-carbazolylene polymers (CALIX-PPE-CBZs) have been synthesized for the first time and their photophysical properties evaluated. Both polymers were obtained in good isolated yields (70-84%), having M-w ranging from 7660-26,700 g mol(-1). It was found that the diethynyl substitution (3,6- or 2,7-) pattern on the carbazole monomers markedly influences the degree of polymerization. The amorphous yellow polymers are freely soluble in several nonprotic organic solvents and have excellent film forming abilities. TG/DSC analysis evidences similar thermal behaviors for both polymers despite their quite different molecular weight distributions and main-chain connectivities (T-g, in the range 83-95 degrees C and decomposition onsets around 270 degrees C). The different conjugation lengths attained by the two polymers dictates much of their photophysical properties. Thus, whereas the fully conjugated CALIX-PPE-2,7-CBZ has its emission maximum at 430 nm (E-g = 2.84 eV; Phi(F) = 0.62, CHCl3), the 3,6-linked counterpart (CALIX-PPE-3,6-CBZ) fluoresces at 403 nm with a significant lower quantum yield (E-g = 3.06 eV; Phi(F) = 0.31, CHCl3). The optical properties of both polymers are predominantly governed by the intrachain electronic properties of the conjugated backbones owing to the presence of calix[4]arenes along the polymer chain which disfavor significant interchain interactions, either in fluid- or solid-state.

Is it possible to remove polymeric nanoparticles from aqueous paints during the activated sludge treatment?

The market for emulsion polymers (latexes) is large and growing at the expense of other manufacturing processes that emit higher amounts of volatile organic solvents. The paint industry is not an exception and solvent-borne paints have been gradually substituted by aqueous paints. In their life-cycle, much of the aqueous paint used for architectural or decorative purposes will eventually be discharged into wastewater treatment facilities, where its polymeric nanoparticles (mainly acrylic and styrene-acrylic) can work as xenobiotics to the microbial communities present in activated sludge. It is well established that these materials are biocompatible at macroscopic scale. But is their behaviour the same at nanoscale? What happens to the polymeric nanoparticles during the activated sludge process? Do nanoparticles agregate and are discharged together with the sludge or remain in emulsion? How do microorganisms interact with these nanoparticles? Are nanoparticles degradated by them? Are they adsorbed? Are these nanoparticles toxic to the microbial community? To study the influence of these xenobiotics in the activated sludge process, an emulsion of cross-linked poly(butyl methacrylate) nanoparticles of ca. 50 nm diameter was produced and used as model compound. Activated sludge from a wastewater treatment plant was tested by the OCDE���s respiration inhibition test using several concentrations of PBMA nanoparticles. Particle aggregation was followed by Dynamic Light Scattering and microorganism surfaces were observed by Atomic Force Microscopy. Using sequential batch reactors (SBRs) and continuous reactors, both inoculated with activated sludge, the consumption of carbon, ammonia, nitrite and nitrate was monitored and compared, in the presence and absence of nanoparticles. No particles were detected in all treated waters by Dynamic Light Scattering. This can either mean that microorganisms can efficiently remove all polymer nanoparticles or that nanoparticles tend to aggregate and be naturally removed by precipitation. Nevertheless respiration inhibition tests demonstrated that microorganisms consume more oxygen in the presence of nanoparticles, which suggests a stress situation. It was also observed a slight decrease in the efficiency of nitrification in the presence of nanoparticles. AFM images showed that while the morphology of some organisms remained the same both in the presence and absence of nanoparticles, others assumed a rough surface with hilly like shapes of ca. 50 nm when exposed to nanoparticles. Nanoparticles are thus likely to be either incorporated or adsorbed at the surface of some organisms, increasing the overall respiration rate and decreasing nitrification efficiency. Thus, despite its biocompatibility at macroscopic scale, PBMA is likely to be no longer innocuous at nanoscale.

Solution enthalpies of hydroxylic compounds

Solution enthalpies of adamantan-1-ol, 2-methyl- butan-2-ol, and 3-methylbutan-1-ol have been measured at 298.15 K, in a set of 16 protogenic and non-protogenic solvents. The identification and quantification of solvent effects on the solution processes under study were performed using quantitative-structure property relationships. The results are discussed in terms of solute-solvent-solvent interactions and also in terms of the influence of compound's size and position of its hydroxyl group.

Optimization process of polyester polymer mortars modified with recycled GFRP waste aggregates ��� application of factorial experiment design-

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both: cross-linked nature of thermoset resins, which cannot be remolded, and complex composition of the composite itself, which includes glass fibres, matrix and different types of inorganic fillers. Presently, most of the GFRP waste is landfilled leading to negative environmental impacts and supplementary added costs. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. There are several methods to recycle GFR thermostable materials: (a) incineration, with partial energy recovery due to the heat generated during organic part combustion; (b) thermal and/or chemical recycling, such as solvolysis, pyrolisis and similar thermal decomposition processes, with glass fibre recovering; and (c) mechanical recycling or size reduction, in which the material is subjected to a milling process in order to obtain a specific grain size that makes the material suitable as reinforcement in new formulations. This last method has important advantages over the previous ones: there is no atmospheric pollution by gas emission, a much simpler equipment is required as compared with ovens necessary for thermal recycling processes, and does not require the use of chemical solvents with subsequent environmental impacts. In this study the effect of incorporation of recycled GFRP waste materials, obtained by means of milling processes, on mechanical behavior of polyester polymer mortars was assessed. For this purpose, different contents of recycled GFRP waste materials, with distinct size gradings, were incorporated into polyester polymer mortars as sand aggregates and filler replacements. The effect of GFRP waste treatment with silane coupling agent was also assessed. Design of experiments and data treatment were accomplish by means of factorial design and analysis of variance ANOVA. The use of factorial experiment design, instead of the one factor at-a-time method is efficient at allowing the evaluation of the effects and possible interactions of the different material factors involved. Experimental results were promising toward the recyclability of GFRP waste materials as polymer mortar aggregates, without significant loss of mechanical properties with regard to non-modified polymer mortars.

New end-use application for GFRP recyclates as reinforcement for concrete-polymer materials���

Glass fibre-reinforced plastics (GFRP), nowadays commonly used in the construction, transportation and automobile sectors, have been considered inherently difficult to recycle due to both: cross-linked nature of thermoset resins, which cannot be remolded, and complex composition of the composite itself, which includes glass fibres, matrix and different types of inorganic fillers. Presently, most of the GFRP waste is landfilled leading to negative environmental impacts and supplementary added costs. With an increasing awareness of environmental matters and the subsequent desire to save resources, recycling would convert an expensive waste disposal into a profitable reusable material. There are several methods to recycle GFR thermostable materials: (a) incineration, with partial energy recovery due to the heat generated during organic part combustion; (b) thermal and/or chemical recycling, such as solvolysis, pyrolisis and similar thermal decomposition processes, with glass fibre recovering; and (c) mechanical recycling or size reduction, in which the material is subjected to a milling process in order to obtain a specific grain size that makes the material suitable as reinforcement in new formulations. This last method has important advantages over the previous ones: there is no atmospheric pollution by gas emission, a much simpler equipment is required as compared with ovens necessary for thermal recycling processes, and does not require the use of chemical solvents with subsequent environmental impacts. In this study the effect of incorporation of recycled GFRP waste materials, obtained by means of milling processes, on mechanical behavior of polyester polymer mortars was assessed. For this purpose, different contents of recycled GFRP waste materials, with distinct size gradings, were incorporated into polyester polymer mortars as sand aggregates and filler replacements. The effect of GFRP waste treatment with silane coupling agent was also assessed. Design of experiments and data treatment were accomplish by means of factorial design and analysis of variance ANOVA. The use of factorial experiment design, instead of the one-factor-at-a-time method is efficient at allowing the evaluation of the effects and possible interactions of the different material factors involved. Experimental results were promising toward the recyclability of GFRP waste materials as aggregates and filler replacements for polymer mortar, with significant gain of mechanical properties with regard to non-modified polymer mortars.

Catalytic oxidation of cyclohexane with hydrogen peroxide and a tetracopper(II) complex in an ionic liquid

The catalytic peroxidative oxidation (with H2O2) of cyclohexane in an ionic liquid (IL) using the tetracopper(II) complex [(CuL)2(��4-O,O���,O������,O���������-CDC)]2��2H2O [HL = 2-(2-pyridylmethyleneamino)benzenesulfonic acid, CDC = cyclohexane-1,4-dicarboxylate] as a catalyst is reported. Significant improvements on the catalytic performance, in terms of product yield (up to 36%), TON (up to 529), reaction time, selectivity towards cyclohexanone and easy recycling (negligible loss in activity after three consecutive runs), are observed using 1-butyl-3-methylimidazolium hexafluorophosphate as the chosen IL instead of a molecular organic solvent including the commonly used acetonitrile. The catalytic behaviors in the IL and in different molecular solvents are discussed.

Choosing amine-based absorbents for CO2 capture

CO2 capture from gaseous effluents is one of the great challenges faced by chemical and environmental engineers, as the increase in CO2 levels in the Earth atmosphere might be responsible for dramatic climate changes. From the existing capture technologies, the only proven and mature technology is chemical absorption using aqueous amine solutions. However, bearing in mind that this process is somewhat expensive, it is important to choose the most efficient and, at the same time, the least expensive solvents. For this purpose, a pilot test facility was assembled and includes an absorption column, as well as a stripping column, a heat exchanger between the two columns, a reboiler for the stripping column, pumping systems, surge tanks and all necessary instrumentation and control systems. Some different aquous amine solutions were tested on this facility and it was found that, from a set of six tested amines, diethanol amine is the one that turned out to be the most economical choice, as it showed a higher CO2 loading capacity (0.982 mol of CO2 per mol of amine) and the lowest price per litre (25.70 ��/L), even when compared with monoethanolamine, the benchmark solvent, exhibiting a price per litre of 30.50 ��/L.

Use of quantitative structure-property relationships to study the solvation process of 18-crown-6

Solution enthalpies of 18-crown-6 have been obtained for a set of 14 protic and aprotic solvents at 298.15 K. The complementary use of Solomonov's methodology and a QSPR-based approach allowed the identification of the most significant solvent descriptors that model the interaction enthalpy contribution of the solution process (Delta H-int(A/S)). Results were compared with data previously obtained for 1,4-dioxane. Although the interaction enthalpies of 18-crown-6 correlate well with those of 1,4-dioxane, the magnitude of the most relevant parameters, pi* and beta, is almost three times higher for 18-crown-6. This is rationalized in terms of the impact of the solute's volume in the solution processes of both compounds. (C) 2015 Elsevier B.V. All rights reserved.

Spent coffee grounds for biodiesel production and other applications

This work evaluates the possibility of using spent coffee grounds (SCG) for biodiesel production and other applications. An experimental study was conducted with different solvents showing that lipid content up to 6 wt% can be obtained from SCG. Results also show that besides biodiesel production, SCG can be used as fertilizer as it is rich in nitrogen, and as solid fuel with higher heating value (HHV) equivalent to some agriculture and wood residues. The extracted lipids were characterized for their properties of acid value, density at 15 ��C, viscosity at 40 ��C, iodine number, and HHV, which are negatively influenced by water content and solvents used in lipid extraction. Results suggest that for lipids with high free fatty acids (FFA), the best procedure for conversion to biodiesel would be a two-step process of acid esterification followed by alkaline transesterification, instead of a sole step of direct transesterification with acid catalyst. Biodiesel was characterized for its properties of iodine number, acid value, and ester content. Although these quality parameters were not within the limits of NP EN 14214:2009 standard, SCG lipids can be used for biodiesel, blended with higher-quality vegetable oils before transesterification, or the biodiesel produced from SCG can be blended with higher-quality biodiesel or even with fossil diesel, in order to meet the standard requirements.

Auditoria �� gest��o de res��duos industriais

A presente disserta����o foi realizada em colabora����o com o grupo empresarial Monteiro, Ribas, tendo como principal objectivo a realiza����o de uma auditoria �� gest��o dos res��duos industriais produzidos pelas suas f��bricas localizadas na Estrada da Circunvala����o, no Porto. Para cumprir este objectivo, inicialmente foi efectuado um levantamento das obriga����es legais relativas aos res��duos e foram procuradas pr��ticas aconselhadas para a gest��o interna. Para cada uma das f��bricas, verificaram-se, quais os res��duos produzidos e analisaram-se os seus percursos, considerando as suas origens, os locais e modos de acondicionamento na origem, os modos de transporte interno, os locais e modos de armazenagem preliminar, e ainda, as quantidades produzidas, os transportadores, os operadores finais e as opera����es finais de gest��o, sendo que estas quatro ��ltimas informa����es s��o relativas ao ano 2013. De seguida procedeu-se �� realiza����o da auditoria nas diferentes unidades, verificando o cumprimento dos requisitos legais e das boas pr��ticas em mat��ria de gest��o de res��duos. As principais n��o conformidades detectadas, comuns ��s v��rias unidades fabris foram a inexist��ncia de local/recipiente definido para acondicionamento de alguns res��duos, a falta ou insuficiente identifica����o de recipientes/zonas de acondicionamento, a inexist��ncia de bacias de reten����o para res��duos l��quidos perigosos, o facto de no transporte interno apenas os res��duos perigosos serem cobertos e, os res��duos l��quidos perigosos n��o serem transportados sobre bacias de reten����o m��veis nem com o material necess��rio para absorver derrames. Para cada res��duo e para cada unidade industrial foram propostas medidas correctivas e/ou de melhoria, quando aplic��vel. Relativamente �� armazenagem preliminar, a principal inconformidade detectada foi o facto de todos os parques (quatro) possu��rem res��duos perigosos no momento das auditorias, o que n��o �� adequado. Foram propostas medidas correctivas e/ou de melhoria para cada parque. Como proposta global, tendo em conta factores econ��micos e de seguran��a, sugeriu-se que apenas o parque de res��duos perigosos possa armazenar este tipo de res��duos, pelo que os procedimentos de transporte interno devem ser melhorados, fazendo com que estes res��duos sejam transportados directamente para o parque de res��duos perigosos. Desta forma dois dos parques devem sofrer algumas remodela����es, nomeadamente serem cobertos e fechados, ainda que n��o totalmente, e o parque de res��duos perigosos deve ser fechado, mantendo aberturas para ventila����o, deve ser equipado com kit��s de conten����o de derrames, fichas de seguran��a, procedimentos a realizar em caso de emerg��ncia, e ainda, devido ao facto do sistema de conten����o de derrames ser pequeno face ao total de armazenamento, aconselha-se o uso de bacias de reten����o para alguns dos recipientes de res��duos l��quidos perigosos. Ao longo deste processo e em consequ��ncia da realiza����o da auditoria, algumas situa����es consideradas n��o conformes foram sendo corrigidas. Tamb��m foram preparadas instru����es de trabalho adequadas que ser��o posteriormente disponibilizadas. Foi ainda elaborada uma metodologia de avalia����o de processos como base de trabalho para redu����o dos res��duos gerados. A etapa escolhida para a aplica����o da mesma foi uma etapa auxiliar do processo produtivo da Monteiro, Ribas - Revestimentos, S.A - a limpeza de cubas com solventes, por forma a tentar minimizar os res��duos de solventes produzidos nesta opera����o. Uma vez que a f��brica j�� realiza a opera����o tendo em considera����o medidas de preven����o e reutiliza����o, a reciclagem �� neste momento a ��nica forma de tentar minimizar os res��duos de solventes. Foram ent��o estudadas duas op����es, nomeadamente a aquisi����o de um equipamento de regenera����o de solventes e a contrata����o de uma operadora que proceda �� regenera����o dos res��duos de solventes e fa��a o retorno do solvente regenerado. A primeira op����o poder�� permitir uma redu����o de cerca de 95% na produ����o de res��duos de solventes e na aquisi����o de solvente puro, estimando-se uma poupan��a anual de cerca de **** ���, com um per��odo de recupera����o do capital de cerca de 16 meses e a segunda pode conduzir a uma redu����o significativa na aquisi����o de solvente puro, cerca de 65%, e a uma poupan��a anual de cerca de **** ���.

Alternativas Processuais e Valoriza����o de Correntes da Refinaria de Matosinhos.

Evolu����o, ato ou efeito de evoluir, sequ��ncia de transforma����es, desenvolvimento progressivo. Se tudo �� nossa volta se transforma, a ind��stria tem de acompanhar esse sistema evolutivo, tornando assim imprescind��vel alterar ou melhorar processos de produ����o quando estes n��o se enquadram com a realidade, ou porque o mercado se altera, ou porque as necessidades mudam, ou por simplesmente ser mais rent��vel. Sendo a Galp Energia uma empresa que se encontra sempre na vanguarda da evolu����o tecnol��gica, encontra no Departamento de Engenharia Qu��mica do Instituto Superior de Engenharia do Porto um aliado na procura do melhor modo de valorizar os seus produtos. A Refinaria de Matosinhos tem atualmente duas correntes de gasolina leve e uma de refinado que apresentam grande potencialidade de valoriza����o. Parte destas correntes incorporam atualmente a pool de nafta qu��mica da refinaria que �� vendida �� Repsol Pol��meros. O desafio que �� proposto baseia-se em valorizar essas correntes atrav��s da sua isomeriza����o aumentando o seu RON podendo ent��o ter como fim a pool de gasolinas. Tirando partido da tecnologia dispon��vel para este efeito s��o apresentados quatro cen��rios de poss��veis solu����es. Sendo os dois primeiros exclu��dos por violarem restri����es impostas, o terceiro e quarto cen��rios foram analisados de um ponto de vista econ��mico. O terceiro cen��rio conduz a gasolina leve da F��brica de Arom��ticos para a pool de gasolinas sem qualquer tratamento e a gasolina leve da F��brica de Combust��veis continua a integrar a pool de nafta qu��mica. O refinado da F��brica de Arom��ticos ser�� enviado para um splitter, sendo a corrente de topo destinada �� pool de nafta qu��mica e a corrente de fundo enviada a um reator de isomeriza����o, Isomalk-4SM, passando previamente por uma torre de argila de forma a assegurar que a restri����o em teor de olefinas no reator n��o �� violada. O efluente, com RON maior, integrar�� igualmente a pool de gasolinas. No quarto cen��rio a corrente de refinado da F��brica de Arom��ticos n��o sofre qualquer tratamento, continuando a alimentar a unidade de solventes, a gasolina leve da F��brica de Arom��ticos ir�� diretamente para a pool de gasolinas e a gasolina leve da F��brica de Combust��veis passar�� pelo Isomalk-2SM para aumentar o ��ndice de octanos garantido assim ter condi����es de integrar a pool de gasolinas. Disserta����o de Mestrado em Engenharia Qu��mica Isomeriza����o de Gasolina Leve O terceiro cen��rio apresenta um aumento de 4 576 773 ��� anuais nas receitas e o quarto alcan��a 11 333 982 ��� anuais. O investimento inicial total do terceiro cen��rio �� de 28 821 608 ��� quando o quarto cen��rio carece de um investimento inicial de apenas 18 028 349 ���. Quanto aos custos associados �� implementa����o da unidade estes demonstram-se elevados, o terceiro cen��rio apresenta um custo de 23 133 429 ��� enquanto o do quarto cen��rio �� de 13 998 797 ���. O quarto cen��rio apresenta-se assim como a solu����o mais rent��vel para o objetivo desta disserta����o.

Development of 2-oxazoline-based hydrogels and porous polyester microparticles in scCO2

Thesis submitted to Faculdade de Ci��ncias e Tecnologia from Universidade Nova de Lisboa in partial fulfillment of the requirements for the obtention of the degree of Master of Science in Biotechnology