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PERIODIC MESOPOROUS ORGANOSILICA: PREPARATION CHARACTERIZATION AND APPLICATIONS OF NOVEL MATERIALSDICKSON, STEVEN E 14 March 2011 (has links)
There is currently a great interest in the field of porous organosilica
materials because of the high surface areas (> 1000 m²/g) and narrow pore size
distributions which are beneficial for applications such as chromatography, chiral
catalysis, sensing or selective adsorption. Periodic mesoporous organosilicas
(PMOs) represent an interesting class of hybrid silica materials because of the
wide variety of bridging organic groups which can be incorporated within the
precursors [(OR)3Si-R-Si(OR)3] giving rise to materials with exceptional
properties.
We have synthesized and characterized various aromatic PMOs
composed of supporting structural monomers (phenylene- or biphenylenebridged)
and functional stilbene monomers (cis and trans) (1, 2). The effect of
the different synthetic procedures and varying amounts of functional stilbene
monomer on the properties of the materials was examined. The functional transstilbene
component was determined to be well distributed in a phenylene-bridged
PMO using P123 as a pore template from TEM techniques with Os staining. The
trans-stilbene linkers were completely transformed to aryl aldehydes through
ozonolysis with dimethylsulfide workup. Further transformation of the carbonyl
functionality to an aryl imine showed a moderate level of success.
Enantiomeric forms of a novel, chiral PMO precursor (CM) were
synthesized and incorporated into biphenylene-bridged PMOs. Under basic pH
conditions templated with C18TMACl, although very low levels of CM are incorporated, enantiomeric forms of chiral, porous materials are obtained as was
verified by distinct mirror-image circular dichroism spectra. Powder XRD patterns
suggest that a tightly packed asymmetric biphenylene arrangement may be
necessary for the optical activity. Preliminary results using these materials as a
chiral chromatographic phase are promising.
Finally, a thin film morphology of an ethane-bridged PMO incorporating a
thiol ligand, (3-mercaptopropyl)trimethoxysilane, was prepared on a fibre optic
cable and used as a component in a heavy-metal sensing application. / Thesis (Ph.D, Chemistry) -- Queen's University, 2011-03-11 17:24:48.997
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Electrically Controlled Formation and Release of Admicelles for Solid Phase ExtractionLee, Sukyeon 01 May 2014 (has links)
Solid phase extraction is one of the most widely used methods to concentrate diluted compounds in a solution. Substances can be extracted into admicelles and hemimicelles, which are surface adsorbed micelles and surfactant monolayers, respectively. Investigations of the electrical control of surfactants on surfaces for the purpose of analyte preconcentration prior to chromatographic analysis are presented. The surfactant layer serves as the “stationary phase” in a solid phase extraction sorbent scenario. Analytes are adsorbed on this layer, and then released from the solid phase via surfactant removal. The attachment and removal of the surfactant are controlled by means of an electric field. Because the surfactant-analyte association is released by electrical control, organic solvents, which are used in conventional solid phase extraction, are not required. Therefore, this procedure is advantageous for method development and environmental concerns. Presented is the preconcentration of a test probe, 2-naphthol, using electrical control of the formation and release of dodecyl sulfate on planar gold, gold coated stainless steel, and a porous stainless steel frit, using impedance spectroscopy to observe the layer formation with various surfactant concentrations and applied potentials.
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Selective Separation Of Wood Components In Internal Process Waters Originating From Mechanical PulpingZasadowski, Dariusz January 2014 (has links)
Dissolved and Colloidal substances (DSC) and metals are released from woodduring thermomechanical pulp (TMP) production. These components have atendency to accumulate in process waters, as the water circulation systems inintegrated paper mills are closed. Disturbances such as pitch depositions in thepaper machine (pitch problems), specks in the paper, decreased wet and drystrength, interference with cationic process chemicals, and impaired sheetbrightness and friction properties appear when DSC are present. Transition metalions such as manganese results in higher consumption of bleaching chemicals(hydrogen peroxide) and lowers the optical quality of the final product, andaddition of complexing agents, such as EDTA or DTPA, to prevent this is needed.The never ending trends to decrease water consumption and increase processefficiency in pulp and paper production emphasizes that it is very important bothto know the effects of wood substances on pulping and papermaking and to beable to remove them in an efficient way. From a biorefinery point of view, DSCcomponents can be promising renewable raw materials for biofuels, bio‐basedchemicals and materials.In this thesis, a new approach using induced air flotation (IAF) without a cationicpolyelectrolyte addition for the removal of pitch and metal ions from mechanicalpulp mill process waters is presented. The induced air flotation of different processwaters is facilitated by the addition of a chelating surfactant and different foamingagents. The influence of the pH value, temperature and foaming agentconcentration on the flotation efficiency has been investigated. The investigations presented show that the disturbing components can be removed from TMP presswater to a high extent. A 90% decrease in turbidity and a 91% removal of lipophilicextractives (i.e. resin and fatty acids, triglycerides, sterols and steryl esters) fromunbleached and bleached TMP process water can be obtained by addition of acationic surfactant as foaming agent during flotation. Lower amount of foamingagent is needed to purify efficiently bleached TMP process water, than unbleached.Additionally, fibres located in TMP press water are not removed with the foamfraction but purified. A retained concentration of hydrophilic extractives (i.e.hemicelluloses and lignans) in the process water indicates that the flotation isselective. Moreover, by introduction of a new recoverable surface activecomplexing agent, a chelating surfactant, manganese ions in the form of chelatescan be successfully removed from the pulp fibres and separated from the processwater in the same flotation process. Furthermore, from the purified unbleachedTMP process water a 90% recovery of dissolved hemicelluloses by anti‐solventprecipitation was obtained.The findings presented above indicate new possibilities for the internal watercleaning stage to decrease DSC emissions to recipient and for recovery of valuableraw materials from purified process water if flotation technology is applied in anintegrated mechanical pulp mill. / FORE
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Μελέτη αποδέσμευσης ιόντων δισθενούς χαλκού σπό σύμπλοκα πολυηλεκτρολυτών με αντίθετα φορτισμένες επιφανειοδραστικές ενώσειςΟικονόμου, Ευδοκία 22 December 2009 (has links)
Στην παρούσα διατριβή διερευνήθηκαν οι παράμετροι που ελέγχουν τη δέσμευση/αποδέσμευση ιόντων Cu2+ ή/και κατιοντικών επιφανειοδραστικών ενώσεων, όπως το βρωμιούχο δεκαεξυλοτριμεθυλαμμώνιο (CTAB) ή το βρωμιούχο δεκαεξυλοτριμεθυλo φοσφώνιο (PC16) από αντίθετα φορτισμένους πολυηλεκτρολύτες. Mελετήθηκαν διαφορετικές πολυμερικές μήτρες που αποτελούνται είτε από εμπορικά διαθέσιμα πολυμερή είτε συντεθήκαν για αυτό το σκοπό, έτσι ώστε να γίνει κατανοητή η επίδραση της χημικής δομής του πολυμερούς στη ταχύτητα δέσμευσης και αποδέσμευσης των δραστικών συστατικών. Καθώς τα ιόντα αυτά έχουν βιοστατική δράση, απώτερος πρακτικός στόχος της διερεύνησης είναι η πιθανή εφαρμογή τέτοιων υβριδικών πολυμερικών υλικών σε υφαλοχώματα που θα εμποδίζουν την απόθεση θαλάσσιων βιοαποθέσεων και θα χαρακτηρίζονται από ιδιότητες «αυτοκαθαρισμού».
Έτσι, παρασκευάστηκαν στατιστικά ή συσταδικά αμφίφιλα συμπολυμερή, στα οποία το υδρόφιλο μονομερές μπορεί να δεσμεύσει τα ιόντα Cu2+ ή/και τις αντίθετα φορτισμένες επιφανειοδραστικές ενώσεις, όπως το στυρενοσουλφονικό νάτριο (SSNa), το μηλεϊνικό (ΜΑc) και το ακρυλικό οξύ (ΑΑ), ενώ το υδρόφοβο μονομερές, το οποίο εισάγεται για τον έλεγχο του ισοζυγίου υδροφιλικότητας/υδροφοβικότητας, είναι ο μεθακρυλικός μεθυλεστέρας (ΜΜΑ). Έτσι, χρησιμοποιήθηκαν ομοπολυμερές PSSNa αλλά και συμπολυμερή του MAc με το SSNa (P(SSNa50-co-MANa). Επιπλέον, για συγκριτικούς λόγους παρασκευάστηκε και το συμπολυμερές του ΜΑc με οξικό βινυλεστέρα, (P(VAc-co-MAc), ενώ χρησιμοποιήθηκε και το εναλλασσόμενο συμπολυμερές του μηλεϊνικού οξέος με αιθυλένιο, P(Eth-alt-MAc). Τα στατιστικά αμφίφιλα συμπολυμερή P(MMAx-co-SSNa), P(MMAx-co-AA) παρασκευάστηκαν με συμπολυμερισμό ελευθέρων ριζών, ενώ τα συσταδικά αμφίφιλα συμπολυμερή PMMAx-b-PSSNa και PSSNa-b-PMMAx παρασκευάστηκαν με πολυμερισμό ελευθέρων ριζών μέσω μεταφοράς ατόμου (ΑΤRP), χρησιμοποιώντας ως μακροεκκινητή είτε PMMA είτε PSSNa, αντίστοιχα. Τα μοριακά βάρη των συμπολυμερών χαρακτηρίστηκαν με SEC, ενώ η χημική τους δομή ταυτοποιήθηκε με 1H-NMR και FT-IR. Η εκατοστιαία σύσταση των συμπολυμερών σε μονάδες ΜΜΑ, x, κυμαίνεται στην περιοχή 10-65 mol%, όπως προσδιορίστηκε με 1H-NMR και TGA. Από τη συγκριτική μελέτη της αυτοοργάνωσης σε υδατικό διάλυμα των συσταδικών και των στατιστικών αμφίφιλων συμπολυμερών, P(MMAx-co-SSNa) και PSSNa-b-PMMAx) με ιχνηθέτηση με φθορίζοντες ιχνηθέτες διαπιστώθηκε πως τα συσταδικά συμπολυμερή εμφανίζουν σημαντικότερη τάση αυτοοργάνωσης, καθώς έχουν σημαντικά μικρότερη κρίσιμη συγκέντρωση μικκυλοποίησης και χαρακτηρίζονται από υψηλότερα επίπεδα υδροφοβικότητας.
Η δέσμευση των ιόντων Cu2+ από τα παραπάνω συμπολυμερή σε αραιά υδατικά διαλύματα πραγματοποιήθηκε μέσω ιονoανταλλαγής χρησιμοποιώντας τη μετά νατρίου άλατος μορφή των συμπολυμερών ή μέσω εξουδετέρωσης της όξινης μορφής των συμπολυμερών με Cu(OH)2 και διερευνήθηκε με φυσικοχημικές μεθόδους, όπως η θολομετρία, η ιξωδομετρία τριχοειδούς και η φασματοσκοπία υπεριώδους-ορατού. Διαπιστώθηκε πως σε αραιά διαλύματα η δέσμευση των ιόντων Cu2+ οδηγεί σε συρρίκνωση των πολυμερικών αλυσίδων (ιξωδομετρία τριχοειδούς). Μάλιστα, σε αντίθεση με τα συμπολυμερή που περιέχουν SSNa, στα πολυμερή που περιέχουν καρβοξυλικές ομάδες, η συρρίκνωση είναι ιδιαίτερα ισχυρή και οδηγεί σε διαχωρισμό φάσεων καθώς η αναλογία των ιόντων Cu2+ προς τις καρβοξυλικές ομάδες προσεγγίζει τη στοιχειομετρία (θολομετρία), ως αποτέλεσμα του σχηματισμού συμπλόκων ένταξης μεταξύ των ιόντων Cu2+ και των καρβοξυλικών ομάδων (φασματοσκοπία υπεριώδους-ορατού). Μάλιστα, στην περίπτωση του P(Eth-alt-MAc), η φασματοσκοπία υπεριώδους-ορατού έδωσε σαφείς ενδείξεις για το σχηματισμό διπύρηνων συμπλόκων χαλκού με τις ομάδες καρβοξυλίου, τα οποία έχουν τη δυνατότητα να δράσουν ως σταυροδεσμοί δικτυώνοντας τις πολυμερικές αλυσίδες. Ως αποτέλεσμα, σε ημιαραιά διαλύματα σχηματίζονται υδροπηκτώματα. Ιδιαίτερο ενδιαφέρον έχει το γεγονός πως οι ιξωδοελαστικές ιδιότητες των σχηματιζόμενων υδροπηκωτμάτων εξαρτώνται σημαντικά από το χρόνο ανάμιξης των συμπολυμερών με τα ιόντα Cu2+.
Στην επόμενη φάση διερευνήθηκε ο σχηματισμός μικτών συσσωματωμάτων (συμπλόκων) μεταξύ των πολυηλεκτρολυτών που περιέχουν SSNa και της αντίθετα φορτισμένης επιφανειοδραστικής ένωσης, CTAΒ. Στην περίπτωση του ομοπολυμερούς PSSNa ή των συσταδικών αμφίφιλων συμπολυμερών PSSNa-b-PMMAx παρατηρείται διαχωρισμός φάσεων, καθώς η αναλογία των αλληλεπιδρώντων ειδών προσεγγίζει τη στοιχειομετρία φορτίων. Αντίθετα, όταν χρησιμοποιούνται τα στατιστικά αμφίφιλα συμπολυμερή P(MMAx-co-SSNa) με x=33-47mol%, σχηματίζονται ιξώδη διαλύματα ή ασθενή πηκτώματα. Η ρεολογική διερεύνηση του φαινόμενου κατέδειξε πως εξαρτάται από τη συγκέντρωση του πολυμερούς, τη γραμμομοριακή αναλογία CTAΒ/SSNa και την ιοντική ισχύ του υδατικού διαλύματος.
Πριν τις τελικές δοκιμές σε πραγματικές συνθήκες παρασκευάστηκαν αιδιάλυτα στο νερό υβριδικά υλικά πολυμερούς-χαλκού, ενδεχομένως παρουσία CTAΒ ή PC16 χρησιμοποιώντας όλες τις προηγούμενες οικογένειες συμπολυμερών αλλά και εμπορικά διαθέσιμα πολυμερή αντίστοιχης δομής. Χρησιμοποιώντας κατάλληλο εκλεκτικό αντιδραστήριο (bathocuproine) μελετήθηκε φωτομετρικά η αποδέσμευση των ιόντων Cu2+ σε υδατικό διάλυμα NaCl 1 M. Έτσι, διευκρινίστηκε η επίδραση διαφόρων παραγόντων στο ρυθμό αποδέσμευσης των ιόντων Cu2+, όπως η ύπαρξη υδρόφοβων μονομερών, το είδος και το ποσοστό αυτών, η αρχιτεκτονική (στατιστική ή συσταδική) των συμπολυμερών, η εισαγωγή και το είδος της επιφανειοδραστικής ένωσης, ο τρόπος εισαγωγής και το είδος της αλληλεπίδρασης με τα ιόντα Cu2+.
Στο τελευταίο στάδιο, διερευνήθηκε η συμβατότητά/αναμιξιμότητα των παρασκευασθέντων βιοστατικών υλικών με τυπικές πολυμερικές μήτρες που μπορούν να χρησιμοποιηθούν σε υφαλοχρώματα. Στις περιπτώσεις που διαπιστώθηκε ικανοποιητική συμβατότητα/αναμιξιμότητα (συστήματα PSSNa/CTAB, PSSNa/PC16, P(SSNa50-co-MANa)/CuPC16, P(VAc-co-MANa)/Cu) και ήταν εφικτό, παρασκευάστηκαν τα αντίστοιχα υφαλοχρώματα. Η συμπεριφορά αυτών των υφαλοχρωμάτων διερευνήθηκε εργαστηριακά με ηλεκτρονική μικροσκοπία σάρωσης (SEM), όσον αφορά τις μορφολογικές μεταβολές της επιφάνειας και τις μεταβολές του πάχους του χρώματος σε επιταχυνόμενες συνθήκες αποδέσμευσης βιοστατικού (υδατικό διάλυμα 5M NaCl). Επίσης, μελετάται και η συμπεριφορά τους σε πραγματικές συνθήκες με τη βοήθεια ειδικής διάταξης σε ελεγχόμενο θαλάσσιο χώρο. / At this thesis, the parameters that influence the interaction and the release of copper ions and/or of cationic surfactants as hexadecyltrimethyl ammonium bromide (CTAB) or hexadecyltrimethyl phosphonium bromide (PC16) from opposite charged polyelectrolytes, are studied. Different polymeric matrixes that are consisted either by commercially available polymers or by polymers that were synthesized for this purpose, were used in order, the influence of the polymer structure to the release rate of copper ions, to be identified. As these ions can behave as biocides, the practical purpose of this study is the possible application of these polymers to self-polishing antifouling paints.
Random or block amphiphilic copolymers, whose hydrophilic monomer can interact with copper ions and/or the surfactants, such as styrene sulfonate (SSNa), maleic acid (MAc) and acrylic acid (AA), while the hydrophobic one, which is introduced for the hydrophilicity/hydrophobicity control, such as methyl methacrylate (MMA), were prepared. In addition, for comparison, the copolymer of maleic acid with vinyl acetate (VAc), (P(VAc-co-MAc)) was prepared. The alternative copolymer of maleic acid with ethylene was also used. The random copolymers P(MMAx-co-SSNa), P(MMAx-co-AA) were synthesized by free radical polymerization while the block copolymers PMMAx-b-PSSNa and PSSNa-b-PMMAx were synthesized through atom transfer polymerization (ATRP), using either PMMA or PSSNa as macroinitiator. The molecular weights of the copolymers were determined by SEC while their structure was identified by 1H-NMR and FT-IR. The copolymer composition in MMA untis is between 10-65 mol% as it was determined by 1H-NMR and TGA. The ability of self-assembling of random and block copolymers (P(MMAx-co-SSNa) και PSSNa-b-PMMAx) in aqueous solution was studied by pyrene fluorescence probing. The block copolymers was found to present self-assembling properties as they have lower critical micellization concentration.
The binding of Cu2+ by the above mentioned polymers in dilute solutions was achieved through ion-exchange procedure using the sodium salt form of the copolymers or through neutralization of the acid form of the polymers using Cu(OH)2. Tholometry, viscometry and UV-Vis spectrometry were used to study this binding. The interaction of Cu2+ with the polymers leads to the shrinkage of the polymer chains. To the copolymers that contain carboxylic groups this shrinkage is more intense and leads to macroscopic phase separation, as the ratio of Cu2+ to the carboxylic groups is near the stoichiometry, as a consequence of complexes formation. The UV-Vis study of P(Eth-alt- MAc) denoted the formation of binuclear complexes between the Cu2+ and the carboxylic groups. These complexes can behave as crosslinks of the polymer chains. As a result, in semi-dilute solutions, gels are formed. Interestingly, the viscoelastic properties of these gels are dependent on the time elapsed from the mixture of the Cu2+ with the polymer.
The interaction of polyelectrolytes that contain SSNa units, with opposite charged surfactant CTAΒ was studied. The interaction of homopolymer PSSNa or of the blocks copolymers PSSNa-b-PMMAx with CTAB leads to phase separation as the ratio of these compounds is near the stoichiometry. On the contrast, the interaction of CTAB with random copolymers P(MMAx-co- SSNa) where x=33-47mol%, leads to the formation of very viscous solutions or weak gels. By the study of the rheological properties of these systems, the influence of the polymer concentration, the molar ratio CTAΒ/SSNa and the ionic strength was found.
All the above mentioned polymers where used for the preparation of hybrid materials that contain Cu2+. CTAΒ ή PC16 were also introduced to some of them in order to take a water insoluble material. The final purpose of this thesis was to control the release of Cu+2 ions from the prepared hybrid materials in aqueous NaCl 1M solution. The Cu+2 -release studies were performed photometrically using a selective dye (bathocuproine). As a result, the influence of many parameters such as the presence of hydrophobic monomers, their type and their content, the architecture of the copolymers (random or blocks), the introduction and the type of surfactants, the way of introduction of copper ions to the polymers and the type of their interaction was studied.
The compatibility of all these materials with matrixes which are used in the antifouling paints was studied. In case that this compatibility was satisfying, antifouling paints using these polymeric materials (PSSNa/CTAB, PSSNa/PC16, P(SSNa50-co-MANa)/CuPC16, P(VAc-co-MANa)/Cu) were prepared. The morphology of the surface of these paints and the changes to their thickness was studied by SEM after staying in aqueous solution of NaCl 5M. Their behavior to real conditions (sea) is being studied.
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Morfologia, morfometria do arco aórtico e perfil lipídico sérico de ratos tratados com surfactante /Castro, Karina Ferreira de. January 2010 (has links)
Resumo: A aterosclerose é uma doença multifatorial, lenta e progressiva e a hiperlipidemia um dos fatores potenciais no desenvolvimento de doenças cardíacas ateroscleróticas. As vantagens da indução das dislipidemias experimentais são a produção de lesões ateromatosas em curto espaço de tempo; adequado controle dietético e fatores ambientais; a possibilidade de estudos sobre a reversibilidade de lesões ateroscleróticas e ensaios pré clínicos de substâncias hipolipidêmicas. Este estudo visou avaliar a capacidade do surfactante na indução aterogênica na região do arco aórtico de ratos por meio de estudos morfológico e morfométrico das túnicas íntima, média e adventícia da aorta, bem como analisar o perfil lipídico sérico. Foram utilizados 28 ratos Wistar, machos, albinos, adultos e hígidos. Estes foram distribuídos em quatro grupos experimentais formados por sete animais cada, a saber: Grupo I - (controle); Grupo II - tratado com tyloxapol, na dose de 500 mg/Kg de peso corporal, via intraperitoneal a cada 48 horas, durante duas semanas; Grupo III - tratado com tyloxapol na dose de 500 mg/Kg de peso corporal, via intraperitoneal a cada 48 horas, durante três semanas; Grupo IV - tratado com tyloxapol na dose de 500 mg/Kg de peso corporal, via intraperitoneal a cada 48 horas, durante quatro semanas. A análise morfológica do arco aórtico dos animais dos grupos II, III e IV evidenciou características histológicas semelhantes às do grupo I nas túnicas íntima, média e adventícia. No estudo morfométrico, os valores da espessura, em μm, da túnica íntima indicaram que o grupo III diferiu significativamente dos grupos I, II e IV. Os valores da espessura, em μm, encontrados para a túnica média e adventícia revelaram que não houve diferença significativa entre os grupos I, II, III e IV. Na avaliação do perfil lipídico os valores de colesterol total... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Atherosclerosis is a multifactorial, progressive and slow disease, and hyperlipidaemia is one of the potential factors in the development of atherosclerotic cardiac diseases. The experimental dyslipidaemia carrying out advantages are the production of atheromatous lesions in a short period of time, an adequate dietetic control and environmental factors, the possibility of studies concerning reversibility of atherosclerotic lesions, and pre-clinic experiments with hypolipidaemic substances. This study aims at evaluating tyloxapol ability in atherogenic inducing, in the rats' aortic arch region, through morphologic morphometric studies, in intima, media and adventitia tunicas of the aortic arch, as well as analyzing serum lipid levels. Twenty-eight healthy Wistar adults' albino male rats, weighing an average of 200 g were utilized. They were distributed into four experimental groups with seven animals each, as follows: Group I - (control); Group II - treated with tyloxapol at a dose of 500mg/Kg of body weight, through intraperitoneal via each 48 hours, for two weeks; Group III - treated with tyloxapol at a dose of 500mg/Kg of body weight, through intraperitoneal via each 48 hours, for three weeks; Group IV - treated with tyloxapol at a dose of 500mg/Kg of body weight, through intraperitoneal via each 48 hours, for four weeks. Morphological analysis of the aortic arch of the animals from groups II, III and IV, showed similar histological characteristics to group I at intima, media and adventitia tunicas. The intima tunica values at the morphometric study indicated that group III has significant differed from groups I, II and IV. The media and adventitia tunicas values revealed that there were no significant differences between groups I, II, III, and IV. As lipid profile evaluation is concerned, the values of total cholesterol, triglycerides and HDL have indicated... (Complete abstract click electronic access below) / Orientadora: Maria Rita Pacheco / Coorientador: Silvana Martinez Baraldi Artoni / Banca: Lucia Helena Vasques / Banca: Mirela Tinucci Costa / Mestre
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N,N,N-trimetilquitosana e N-(2-hidróxi)-propil-3-trimetilamônio quitosana: preparação, caracterização e estudo de suas interações com decanossulfonato de sódio / N,N,N-trimethylchitosan and N-(2-hidroxy)-propyl-3-trimethylchitosan: preparation, characterization and study of its interactions with sodium 1-decanesolfonateTonimar Domiciano Arrighi Senra 26 March 2015 (has links)
O presente trabalho estudou duas vias reacionais para a preparação de derivados cationizados de quitosana (QCat), sendo que a N-metilação extensiva via reação de quitosana com iodometano (CH3I) resultou em N,N,N-trimetilquitosana (TMQ) enquanto que a reação de quitosana com cloreto de glicidiltrimetilamônio (CGTMA) produziu N-(2-hidroxi)-propil-3-trimetilamônio quitosana (HPTAQ). Planejamento fatorial completo 23 foi aplicado para analisar os efeitos das condições reacionais sobre o rendimento das reações (R) e as características de TMQ e HPTAQ. As características estruturais da quitosana de partida e seus derivados foram analisadas por espectroscopias na região de infravermelho (FTIR) e de ressonância magnética nuclear de hidrogênio (RMN-1H), sendo que esta última também foi utilizada para determinar os graus médios de acetilação (GA), de quaternização (GQ) e de substituição (GS) de quitosana, TMQ e HPTAQ, respectivamente. Viscosimetria capilar foi utilizada para determinar a viscosidade intrínseca ([η]) de quitosana, TMQ e HPTAQ, permitindo estimar a ocorrência de despolimerização e sua relação com as condições reacionais. Todas as amostras de TMQ foram solúveis em água e o valor de GQ variou no intervalo 21,0 - 67,0%; a [η] variou entre 13,7 mL/g - 213,0 mL/g e o rendimento da reação atingiu até 82,0%, sendo que entre as variáveis analisadas a concentração de hidroxido de sódio e excesso de CH3I são as mais relevantes. Quanto às amostras de HPTAQ, apenas aquelas com GS > 12,0% foram solúveis em água,GS ficou no intervalo 1,0 % - 45,5%; [η] variou entre 283,0 mL/g - 446,0 mL/g e o rendimento não foi superior a 33,0%, e entre as variáveis analisadas, temperatura e excesso de CGTMA foram as mais importantes na produção de HPTAQ. As amostras TMQ2 GQ = 46,0%; [η] = 290,0 mL/g) e HPTAQ6 GS = 33,0%; [η] = 293,0 mL/g) foram empregadas em estudo visando a formação de complexos surfactante/polieletrólito (CSP) com decanossulfonato de sódio (DS). As propriedades condutimétricas e tensiométicas dos TMQ2, HPTAQ6 e CSP\'s foram estudadas e mostraram que todos apresentam atividade interfacial (γ <= 52,0 mN.m-1), além de elevado valor de módulo de elasticidade (E >= 31,0 mN.m-1), indicando que as espécies analisadas geram filmes interfaciais com boas propriedade mecânicas e por isso podem ser aplicados como agentes estabilizantes de emulsões. As emulsões do tipo óleo/água preparadas pela incorporação de QCat (TMQ ou HPTAQ) ou de CSP (TMQ/DS ou HPTAQ/DS) foram estáveis por mais de 4 meses, conforme avaliado por medidas de fluorescência e de turbidez. / In this work were studied two different methods for preparing cationized derivatives of chitosan (ChCat), a consisted extensive N-methylation by chitosan reaction with iodomethane (CH3I) resulted in N,N,N-trimethylchitosan (TMCh), and other a reaction of chitosan with chloride glycidyltrimethylammonium (GTMAC) resulted in N-(2-hydroxy)-propyl-3-trimethylammonium chitosan (HPTACh). A complete factorial design (23) was used to analyze the influence of reaction conditions on the yield of the reaction (R) as well as the characteristics of TMCh and HPTACh produced. The structure of chitosan pattern and its derivatives were characterized by infrared spectroscopy (IR) and nuclear magnetic resonance (1H-NMR), considering that the latter was also used to determine the average degree of acetylation (DA), quaternization (DQ) and substitution (DS) of chitosan, TMCh and HPTACh, respectively. Capillary viscometry was used to determine the intrinsic viscosity ([η]) of chitosan, TMCh and HPTACh, allowing to estimate the occurrence of depolymerization and its relationship with the reaction conditions. All samples of TMCh were soluble in water and it was found that DA ranged as 21.0% - 67.0%; the [η] ranged as 13.7 mL/g - 213.0 mL/g and the yield reaction was up to 82.0%, among the variables studied, the concentration of sodium hydroxide and excess CH3I were the most relevant. The HPTACh samples were soluble in water with DS > 12.0%, DS ranged as 1.0% - 45.5%; the [η] ranged as 283.0 mL/g - 446.0 mL/g and the yield was lower than 33.0%, among the variables studied temperature and excess CGTMA were the most important in the production of HPTACh. Among the reaction conditions studied for the synthesis of TMCh the best condition was 2, while for HPTACh the best condition was 6. The samples TMCh2 DQ = 46.0%, [η] = 290.0 ml/g) and HPTACh6 DS = 33.0%, [η] = 293.0 mL/g) were used in a study aiming at the formation of surfactant/polyelectrolyte complex (SPEC) with sodium 1-decanessulfonate (SD). The conductivity and surface tension properties of TMCh2, HPTACh6 and SPEC\'s have been studied and show that all have interfacial activity (γ <= 52.0 mN.m-1), and high value of elasticity modulus (E >= 31.0 mN.m-1), indicating that all species generate interfacial film with good mechanical property and thus can be applied as a stabilizing agent in emulsions emulsions oil/water that were prepared by incorporating ChCat synthesized and SPEC\'s in their formulations, they were stable for more than 4 months, as evaluated by fluorescence and turbidity measurements.
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Estudo térmico e adsortivo de argisolo caulinítico da região amazônica / Estudo térmico e adsortivo de argisolo caulinítico da região amazônicaSilva, Matheus Antônio da [UNESP] 08 July 2016 (has links)
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Previous issue date: 2016-07-08 / Tratou-se e modificou-se o argisolo caulinítico da região amazônica, a fim de se obter novos materiais para remoção de contaminantes da fase aquosa. As modificações fora realizadas por dois métodos: tratamento térmico em presença de fibra de cana de açúcar e modificação com surfactantes em solução; com posterior utilização dos materiais modificados na adsorção do corante Azul de Metileno (AM), usado como sonda espectrofotométrica. Tratou-se o argisolo com ataque ácido e troca de cátions e posterior calcinação a 400 0C com e sem fibra, e a 800 0C sem fibra. Os sólidos foram caracterizados por difratometria de raios X, espectrofotometria na região do infravermelho e análise térmica. Procedeu-se também a adsorção do AM em argisolo em presença de surfactante catiônico, Brometo de Cetiltrimetilamônio, e aniônico, Dodecil Sulfato de sódio. O argisolo sem calcinação apresentou apenas argila caulinita e quartzo como constituintes com cristalinidade. As amostras calcinadas a 400 0C com fibra e a 800 0C sofreram o processo de desidroxilação, ocasionando a mudança de fase da caulinita presente no argisolo; com a amostra calcinada a 400 0C sem fibra mantendo a estrutura característica da caulinita e do quartzo. Por meio da análise térmica, foi possível notar que a energia liberada pela fibra é suficiente para promover a mudança de fase da caulinita em temperaturas mais baixas em relação à mesma sem fibra, promovendo o processo de desidroxilação do material em condições ambientais mais brandas. Os estudos de variação no tempo de calcinação e de razão fibra:solo indicaram que ambos influenciam na desidroxilação do material e razões fibra:solo maiores que 1:2 e o tempo de três horas são as condições mais indicadas para a formação da metacaulinita. As isotermas de adsorção de AM evidenciam uma mudança na forma da isoterma de adsorção, onde o argisolo calcinado a 400 0C sem fibra e sem calcinação possuem isotermas do tipo L e maior correlação ao modelo de Freundlich, característicos de adsorção favorável e em multicamadas; enquanto os materiais calcinados a 800 0C e a 400 0C com fibra exibem isotermas do tipo C e correlação com o modelo de Langmuir, comuns a materiais de superfície microporosa e em monocamada. Os estudos de adsorção na presença de surfactantes evidenciaram que a interação do surfactante catiônico com o argisolo e do corante aniônico com o AM desfavoreceram a adsorção e resultaram em menor remoção do corante da fase aquosa. / Kaolinitic clay soil of Amazon region was treated and modified,in order to obtain new materials for removal of contaminants from aqueous phase. The modification was performed by two methods: thermal treatment in presence of sugar cane fiber and modification with surfactants; using the new materials in adsorption of Methylene Blue (AM), used as spectrophotometric probe. The clay soil was treated with acid attack, cation change and after calcination at 400 0C with and without sugar cane fiber, and at 800 0C. All material was characterized by X-ray Diffraction, Infrared spectrophotometry and thermal analysis. Adsorption of AM was proceed in presence of cationic (Cetyltrimethylammonium Bromide) and anionic (Sodium Dodecyl Sufate) surfactants. Samples of clay soil without calcination presents only kaolinite and quartz as compounds with cristallinity. Clay soil calcined at 400 0C with fiber and 800 0C were dehydroxyled, causing a phase change form kaolinite to metakaolin; when the kaolinite structure was maintained in clay soil calcined at 400 0C without fiber. In thermal analysis, the energy released by the fiber is sufficient to cause the phase change of kaolinite at lower temperatures relative to the same without fiber, promoting the process of dehydroxylation of the material in softer environmental conditions. The variation in time of calcination studies and ratio fiber:clay evidence that both influence the dehydroxylation and rates fiber:clay larger than 1:2 and the time of three hours are the best conditions for formation of metakaolin. Adsorption isotherms of AM exhibit changes in isotherms format, clay soil calcined at 400 0C without fiber and clay soil without calcination shows L-type isotherms and best correlation with Freundlich model, typical for favourable multiple layered adsorption; when the materials calcined at 400 0C with fiber and 800 0C shows C-type and correlation with Langmuir isotherms, typical monolayered adsorption in materials with microporous surface. The study of adsorption in presence of surfactants indicated that interactions among cationic surfactant with claysoil and anionic surfactant with AM prejudicing the adsorption of AM and results in less dye remotion of aqueous phase.
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Influência da rota alcoólica no processo de organofilização de argilas bentoniticas para uso em fluidos de perfuração não aquosos. / Influence of alcohol in the process of route organophilization bentonite clay for use in non-aqueous drilling fluidsDantas, Suylan Lourdes de Araújo 24 July 2013 (has links)
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Previous issue date: 2013-07-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Bentonite clays may be defined as a clay consisting predominantly of the smectite group clay minerals, particularly montmorillonite. There is naturally organophilic bentonite clays, these can be modified by specific treatments with surfactants (ionic or nonionic), passing to its hydrophobic nature hidofílica. Organophilic clays are widely used in drilling fluids non-aqueous, these fluids are mixtures of different components used in a well bore. One of the basic characteristics of drilling fluids is to minimize physical and chemical changes of the formations to be drilled. Recent studies have demonstrated the influence of clay, and presence of a dispersant surfactant rheology of the fluids. In this study we verified the influence of clay and surfactant in the production of organoclays using a route alcoholic and was therefore analyzed the rheology of non-aqueous fluids. Therefore, we performed the characterization of samples of clays; through thermogravimetric analysis, X-ray Diffraction, Differential Thermal Analysis and Particle Size Analysis for the organoclays were characterized by XRD and X-ray fluorescence were eventually produced in non-aqueous fluids according to Petrobras to perform normalization of rheological tests. The results indicated that the influence of the ratio clay / surfactant and the route alcoholic on the rheology of non-aqueous drilling fluids. / Argilas bentoníticas podem ser definidas como sendo uma argila constituída essencialmente de argilominerais do grupo das esmectitas, especialmente a montmorilonita. Não sendo as argilas bentoníticas naturalmente organofílicas, estas podem ser modificadas através de tratamentos específicos com tensoativos(iônicos ou não-iônicos), passando sua natureza de hidofílica para hidrofóbica. As argilas organofilicas são amplamente utilizadas em fluidos de perfuração não-aquosos, estes fluidos são misturas de diferentes componentes utilizados em uma perfuração de poço, ao acréscimo de aditivos aos fluidos é com intuito de otimizar suas propriedades como por exemplo: suportar a parede do maciço, limpeza do poço, evitar a invasão do filtrado e os danos na formação e o controle da pressão e teor de cascalhos em suspensão. Uma das características básicas dos fluidos de perfuração é minimizar alterações físicas e químicas das formações a serem perfuradas. Estudos recentes demonstraram a influência do tipo de argila, tensoativo e presença de defloculante na reologia dos fluidos. Neste trabalho verificamos a influência do teor de argila e tensoativo na produção de argilas organofilicas, utilizando uma rota alcoólica e conseqüentemente foi analisado a reologia dos fluidos não aquoso. Os resultados evidenciaram que existe influência da razão argila/tensoativo na reologia dos fluidos de perfuração não aquosa.
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Remo??o conjugada de metais e ?leo de ?gua produzidaNunes, Shirlle Katia da Silva 06 March 2009 (has links)
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Previous issue date: 2009-03-06 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Petroleum can be associated or not with natural gas, but in both cases water is always present in its formation. The presence of water causes several problems, such as the
difficulty of removing the petroleum from the reservoir rock and the formation of waterin-oil and oil-in-water emulsions. The produced water causes environmental problems,
which should be solved to reduce the effect of petroleum industry in the environment. The main objective of this work is to remove simultaneously from the produced water the
dispersed petroleum and dissolved metals. The process is made possible through the use of anionic surfactants that with its hydrophilic heads interacts with ionized metals and
with its lipophilic tails interacts with the oil. The studied metals were: calcium, magnesium, barium, and cadmium. The surfactants used in this research were derived from: soy oil, sunflower oil, coconut oil, and a soap obtained from a mixture of 5wt.% coconut oil and 95wt.% animal fat. It was used a sample of produced water from Terminal de S?o Sebasti?o, S?o Paulo. As the concentration of the studied metals in
produced water presented values close to 300 mg/L, it was decided to use this concentration as reference for the development of this research. Molecular absorption and
atomic absorption spectroscopy were used to determine petroleum and metals concentrations in the water sample, respectively. A constant pressure filtration system was used to promote the separation of solid and liquid phases. To represent the behavior of the studied systems it was developed an equilibrium model and a mathematical one.
The obtained results showed that all used surfactants presented similar behavior with relation to metals extraction, being selected the surfactant derived from soy oil for this
purpose. The values of the partition coefficients between the solid and liquid phases " D " for the studied metals varied from 0.2 to 1.1, while the coefficients for equilibrium model
" K " varied from 0.0002 and 0.0009. The removal percentile for oil with all metals associated was near 100%, showing the efficiency of the process / O petr?leo pode estar associado ou n?o com o g?s natural, mas, em ambos os casos, a ?gua est? presente desde a sua forma??o. A presen?a da ?gua ocasiona diversos problemas, tais como a dificuldade de remover o petr?leo da rocha e a forma??o de emuls?es do tipo ?gua-em-?leo e ?leo-em-?gua. A ?gua de produ??o gera problemas ambientais, que devem ser solucionados para que o efeito da ind?stria do petr?leo no
meio ambiente seja minimizado. Este trabalho tem por objetivo remover associadamente o petr?leo disperso e os metais dissolvidos na ?gua de produ??o. O processo ? viabilizado
atrav?s da utiliza??o de tensoativos ani?nicos, que com suas partes hidrof?licas interagem com os metais ionizados e com suas partes lipof?licas interagem com o ?leo. Os metais
estudados foram: o c?lcio, o magn?sio, o b?rio e o c?dmio. Os tensoativos utilizados na pesquisa foram derivados dos ?leos de soja, girassol, coco e um sab?o oriundo de uma mistura de 5% do ?leo de coco e 95% de gordura animal. Utilizou-se uma amostra de ?gua produzida proveniente do Terminal de S?o Sebasti?o, em S?o Paulo. Como a concentra??o dos metais estudados nesta ?gua apresentavam valores pr?ximos a 300
mg/L, decidiu-se fixar esta concentra??o como refer?ncia para o desenvolvimento da pesquisa. Para determinar as concentra??es dos metais e do petr?leo na ?gua foram
utilizados os espectrofot?metros de absor??o at?mica e de absor??o molecular, respectivamente. Utilizou-se um sistema de filtra??o a press?o constante para promover a separa??o das fases s?lida e l?quida. Para representar o comportamento dos sistemas em estudo desenvolveu-se um modelo de equil?brio e outro matem?tico. Os resultados mostraram que todos os tensoativos desenvolvidos apresentavam comportamento similar com rela??o ? extra??o dos metais, sendo selecionado o tensoativo derivado do ?leo de
soja para este prop?sito. Os valores dos coeficientes de parti??o dos metais entre as fases s?lida e l?quida D variaram de 0,2 a 1,1, enquanto que os dos coeficientes do modelo de equil?brio K ficaram entre 0,0002 e 0,0009. O percentual de remo??o conjugada do ?leo com todos os metais foi praticamente igual a 100 %, o que comprovou a efici?ncia do processo
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An?lise dos Processos de Flota??o e Oxida??o Avan?ada para o Tratamento de Efluente Modelo da Ind?stria do Petr?leo / Analysis of flotation and advanced oxidation processes for the treatment of a wastewater model of the petroleum industrySilva, Syllos Santos da 22 February 2010 (has links)
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Previous issue date: 2010-02-22 / The generation of wastes in most industrial process is inevitable. In the petroleum industry, one of the greatest problems for the environment is the huge amount of produced water generated in the oil fields. This wastewater is a complex mixture and present great amounts. These effluents can be hazardous to the environmental without adequate treatment. This research is focused in the analysis of the efficiencies of the flotation and photo-oxidation processes to remove and decompose the organic compounds present in the produced water. A series of surfactants derivated from the laurilic alcohol was utilized in the flotation to promote the separation. The experiments have been performed with a synthetic wastewater, carefully prepared with xylene. The experimental data obtained using flotation presented a first order kinetic, identified by the quality of the linear data fitting. The best conditions were found at 0.029 g.L-1 for the surfactant EO 7, 0.05 g.L-1 for EO 8, 0.07 g.L-1 for EO 9, 0.045 g.L-1 for EO 10 and 0.08 g.L-1 for EO 23 with the following estimated kinetic constants: 0.1765, 0.1325, 0.1210, 0.1531 and 0.1699 min-1, respectively. For the series studied, the most suitable
surfactant was the EO 7 due to the lower reagent onsumption, higher separation rate constant and higher removal efficiency of xylene in the aqueous phase (98%). Similarly to the flotation, the photo-Fenton process shows to be efficient for degradation of xylene and promoting the
mineralization of the organic charge around 90% and 100% in 90 min / A gera??o de res?duos na maioria dos processos industriais ? quase que inevit?vel. Na ind?stria do petr?leo, um dos grandes vil?es para o meio ambiente ? o enorme volume de ?guas produzidas nos campos de petr?leo. Este efluente apresenta composi??o complexa e aliado ao grande volume envolvido pode-se tornar bastante danoso ao meio ambiente quando descartado
de forma inadequada. Esta pesquisa est? centrada na an?lise das efici?ncias dos processos de flota??o em coluna e oxida??o avan?ada por processo foto-Fenton para remo??o/degrada??o de org?nicos presentes na ?gua produzida. Uma s?rie de tensoativos derivados de ?lcool laur?lico foi utilizada na flota??o para promover a melhoria da cin?tica e efici?ncia de separa??o. Os experimentos foram realizados com efluente sint?tico contendo xileno como poluente modelo. Os dados experimentais obtidos da flota??o apresentaram cin?tica de 1? ordem, identificada pela qualidade dos ajustes lineares. As melhores condi??es encontradas foram 0,029 g.L-1 para o EO 7, 0,05 g.L-1 para o EO 8, 0,07 g.L-1 para o EO 9, 0,045 g.L-1 para o EO 10 e 0,08 g.L-1 para o EO 23 com as seguintes constantes de velocidade iguais a 0,1765, 0,1325, 0,1210, 0,1531, 0,1699 min-1, respectivamente. Para a s?rie estudada, o tensoativo mais adequado foi o EO 7 devido o menor consumo de reagente, maior constante cin?tica de separa??o e maior
efici?ncia de remo??o do xileno da fase aquosa (98%). De forma similar a flota??o, o processo foto-Fenton demonstrou ser eficiente para degrada??o do xileno alcan?ando efici?ncia de mineraliza??o da carga org?nica entre 90% e 100% em 90 min
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