Thesis (Ph.D.)--Chemical Engineering, Georgia Institute of Technology, 2009. / Committee Chair: Prof. Sankar Nair; Committee Co-Chair: Prof. Samuel Graham; Committee Member: Prof. Amyn S. Teja; Committee Member: Prof. Mo Li; Committee Member: Prof. Peter Ludovice.

Thesis (Ph. D. in Chemical Engineering)--Vanderbilt University, Dec. 2009. / Title from title screen. Includes bibliographical references.

Thesis (M. Eng.)--Memorial University of Newfoundland, 1997. / Bibliography: leaves 95-101.

Στη παρούσα διατριβή πραγματοποιήθηκε ανάπτυξη αισθητήρων που αποτελούνται από μαγνητοελαστικό έλασμα τύπου Metglas στην επιφάνεια του οποίου έγινε επικάλυψη με ευαίσθητο εκλεκτικό υμένιο. Στη μεγάλη πλειοψηφία των περιπτώσεων ως τέτοιο υμένιο χρησιμοποιήθηκε ζεόλιθος. Διαφορετικοί τύποι ζεόλιθων συνετέθησαν έπειτα από υδροθερμική σύνθεση και προσκολλήθηκαν ισχυρά στην εξωτερική επιφάνεια (και από τις δύο πλευρές) των Metglas. Ένας τέτοιος αισθητήρας συνδυάζει τις ροφικές ικανότητες του εκλεκτικού υμενίου με την ιδιότητα του Metglas να μετατρέπει φορτίσεις μάζας και αλλαγές των ελαστικών ιδιοτήτων του σε μετρούμενες μεταβολές της συχνότητας συντονισμού του. Η συνδυασμένη αυτή ικανότητα του αισθητήρα χρησιμοποιήθηκε για την ανίχνευση Πτητικών Οργανικών Ουσιών (VOC’s). Πιο συγκεκριμένα για τον ίδιο σκοπό χρησιμοποιήθηκαν υμένια ζεόλιθων (FAU, MFI και LTA) και πολυμερούς (Bayhydrol-110). Τα VOC’s των οποίων η ανίχνευση εξετάστηκε με τους παραπάνω αισθητήρες είναι: αιθυλεστέρας, πάρα-ξυλόλιο, όρθο-ξυλόλιο, βενζόλιο, κυκλο-εξάνιο, κανονικό-εξάνιο, προπάνιο και προπυλένιο. Δεύτερος στόχος της διατριβής ήταν ο υπολογισμός μηχανικών ιδιοτήτων των ζεόλιθων. Στη βιβλογραφία έχει αποδειχθεί ότι η ρόφηση αερίων επηρεάζει (εκτός από τη μάζα του) και τις μηχανικές ιδιότητες των ζεόλιθων μέσω της μεταβολής του μεγέθους της μοναδιαίας κυψελίδας των. Επομένως η ρόφηση αναμένεται να επηρεάζει εφαρμογές τους (π.χ ζεολιθικές μεμβράνες), των οποίων η απόδοση εξαρτάται άμεσα από τις μηχανικές τους ιδιότητες. Για το λόγο αυτό αναπτύχθηκε πειραματική μεθοδολογία με την οποία υπολογίζονται το μέτρο ελαστικότητας Ε των ζεολιθικών φιλμ, και οι τάσεις/παραμορφώσεις που αναπτύσσονται στο ζεολιθικό υμένιο κατά τη ρόφηση αερίων. Ο υπολογισμός για την εύρεση του μέτρου ελαστικότητας βασίζεται στη καταγραφή των μεταβολών της συχνότητας συντονισμού fR πολλαπλών αισθητήρων Metglas/ζεόλιθος διαφορετικού πάχους υμενίου ο καθένας. Η συγκεκριμένη μέθοδος γενικεύεται και βρίσκει εφαρμογή για τον υπολογισμό του μέτρου ελαστικότητας E του Young οποιαδήποτε μικροπορώδους ομοιόμορφου και καλά προσκολλημένου στην επιφάνεια του Metglas υμενίου. Ο υπολογισμός των τάσεων που αναπτύσσονται στο φιλμ κατά τη ρόφηση επιτυγχάνεται με χρήση δύο διαφορετικών μεθόδων. Η πρώτη μέθοδος, εφαρμόζεται σε αισθητήρες στους οποίους επικάλυψη με συνεχές υμένιο ζεόλιθου υπήρχε και από τις δύο πλευρές του Metglas. Με συνδυασμένη χρήση κατάλληλης θεωρίας και μαθηματικού μοντέλου της βιβλιογραφίας για τα μαγνητοελαστικά υλικά υπολογίζονται οι τάσεις που αναπτύσσονται στους ζεόλιθους FAU, LTA και σιλικαλίτη-1 κατά τη ρόφηση υγρασίας. Η δεύτερη μέθοδος υπολογισμού τάσεων εφαρμόστηκε σε αισθητήρα Metglas/MFI, στον οποίο επικάλυψη με συνεχές υμένιο ζεόλιθου υπήρχε μόνο από τη μία πλευρά του ελάσματος. Η μέθοδος εφαρμόζεται σε αισθητήρα Metglas/MFI κατά τη ρόφηση VOC’s, και βασίζεται στην ευκαμψία και ελαστικότητα που επιδεικνύει ο συγκεκριμένος αισθητήρας κατά τη διεργασία αυτή. Η διαφοροποίηση των δύο επιφανειών ως προς την ομοιομορφία του φιλμ του αισθητήρα, σε συνδυασμό με τη ρόφηση προκαλούν τη κάμψη του, ορατή ακόμα και με γυμνό μάτι, από το μέγεθος της οποίας υπολογίζονται οι τάσεις που αναπτύσσονται στο φιλμ του ζεόλιθου. Σε όλες τις περιπτώσεις ακολουθεί σύγκριση των πειραματικών αποτελεσμάτων μας με τη βιβλιογραφία. / In the current thesis the development of sensors comprised of magnetoelastic ribbon (Metglas) its surface was coated with selective sensitizing layer was examined. In most cases, zeolites were selected as sensitive layers. Different types of zeolites were synthesized and bounded in both outer surfaces of Metglas using the hydrothermal synthesis technique. Such a sensor combines the adsorptive abilities of sensitizing layer with the inner ability of Metglas to convert mass loadings and changes in the elastic properties in corresponding changes of the measured resonance frequency of the ribbon. That combined ability has been used for the detection of Volatile Organic Compounds (VOC’s). More particularly, for the same purpose zeolite layers (FAU, MFI and LTA) and polymer (Bayhydrol-110) have been used. The detected VOC’s are: ethyl-acetate, para-xylene, ortho-xylene, benzene, cyclohexane, n-hexane, propane and propylene. The second target of the current thesis was the calculation of mechanical properties of zeolites. In the literature has been proved that gas adsorption upon zeolites affects not only its mass but also its mechanical properties through the unit cell changes. Thus, adsorption is expected to affect applications such as zeolite membranes the performance of which is directly affected by their mechanical properties and possible changes. Hence, a new method is proposed which unable the calculation the Young modulus of zeolite films, and the stresses/deformations induced in the zeolite film upon adsorption. The calculation of Young modulus is based on the recording of resonance frequency changes of multiple sensors with different zeolite thickness each. The methodology is general and can be used for measuring Young modulus of any microporous film as long as it can be deposited as uniform layer on a magnetoelastic ribbon. The calculation of adsorption induced stresses is succeeded with two different methods. The first method is applied in sensors in which zeolite coating existed on both surfaces of Metglas ribbon. Combined use of appropriate theory and mathematical model from the literature for the magnetoelastic materials, stresses induced on FAU, LTA and silicalite-1 zeolites upon humidity adsorption were calculated. The second method was applied in Metglas/MFI sensor in which uniform polycrystalline MFI layer existed only from the one side of the ribbon. The method was applied during the adsorption of VOC’s and is based on the bending and elasticity shown by the sensor during the adsorption process. The differentiation of the two surfaces concerning the cohesion of the film, combined with adsorption phenomena cause remarkable bending, visible even with a naked eye, from the magnitude of which stresses induced on zeolite film are calculated. In all cases there is a comparison of our experimental results with corresponding from the literature.

Η Τέφρα Φλοιού Ρυζιού (ΤΦΡ) είναι ένα από τα κυριότερα γεωργικά απόβλητα και προέρχεται από την καύση του φλοιού ρυζιού (ΦΡ) στις ορυζοβιομηχανίες για παραγωγή ενέργειας ή και μείωσης του όγκου των αποβλήτων. Η τέφρα φλοιού ρυζιού αποτελεί περίπου το 18-20% του φλοιού του ρυζιού, ο οποίος αποτελεί περίπου το 20% του ακατέργαστου ρυζιού ενώ συνήθως είναι κρυσταλλική. Καθώς ο παγκόσμιος όγκος της ετήσιας παραγωγής σε ρύζι και κατ’ επέκταση σε τέφρα φλοιού ρυζιού αυξάνεται διαρκώς, εγείροντας περιβαλλοντικά και οικονομικά ζητήματα, η ανεύρεση ενός αποδοτικού και οικολογικού τρόπου εκμετάλλευσης της είναι θέμα μείζονος σημασίας. Παράλληλα, τα υψηλά ποσοστά της ΤΦΡ σε διοξείδιο του πυριτίου την καθιστούν πιθανή πηγή πυριτίου για πολλές εφαρμογές, μία από τις οποίες είναι και οι σύνθεση ζεόλιθων. Στην παρούσα εργασία μελετήθηκε η αξιοποίηση κρυσταλλικής ΤΦΡ στην σύνθεση τεσσάρων τύπων ζεόλιθων και συγκεκριμένα των MFI, FAU, BEA και LTA. Για τον σκοπό αυτό αρχικά χαρακτηρίστηκε η πρώτη ύλη, δηλαδή η ΤΦΡ, τόσο ως προς την χημική της σύσταση και περιεκτικότητα σε άκαυτο άνθρακα όσο και ως προς την κρυσταλλική δομή της. Στη συνέχεια εξακριβώθηκαν οι συνθήκες καύσης του ΦΡ οι οποίες οδηγούν στην μετατροπή από την άμορφη στην κρυσταλλική δομή του διοξειδίου του πυριτίου, η οποία ονομάζεται χριστοβαλίτης. Εφόσον αυτή η κρυσταλλική δομή είναι ακατάλληλη για την παραγωγή ζεόλιθων, μελετήθηκε η δυνατότητα διαλυτοποίησης της ΤΦΡ σε υδατικό διάλυμα καυστικού νατρίου ώστε να καταστραφούν οι κρύσταλλοι και να παραληφθεί άμορφο διοξείδιο του πυριτίου. Για το σκοπό αυτό, επιλέχθηκαν οι μοριακές αναλογίες των πρώτων υλών που οδηγούν στη σύνθεση καθενός από τους τέσσερεις τύπους ζεόλιθων και η ΤΦΡ επεξεργάστηκε με την κατάλληλη αναλογία καυστικού νατρίου σε υδατικό διάλυμα σε διάφορες θερμοκρασίες και συνθήκες. Παρατηρήθηκε κρυστάλλωση του επιθυμητού τύπου ζεόλιθου σε κάθε μία από τις περιπτώσεις που εξετάστηκαν, ενώ το ποσοστό της διάλυσης του χριστοβαλίτη βρέθηκε ότι είχε την σημαντικότερη επίδραση στην απόδοση της διεργασίας και την καθαρότητα του προϊόντος. Ταυτόχρονα διαπιστώθηκε ότι το ποσοστό της διάλυσης του χριστοβαλίτη εξαρτάται κυρίως από την αναλογία μαζών RHA/NaOH και βρέθηκαν οι κατάλληλες τιμές. Καθώς το μεγαλύτερο ποσοστό διαλυμένου χριστοβαλίτη παρατηρήθηκε στην περίπτωση της σύνθεσης του ζεόλιθου LTA, η οποία επιπλέον δεν χρειάζεται οργανικό παράγοντα δομής ούτε υψηλές θερμοκρασίες, επιλέχθηκε να χρησιμοποιηθεί για την μελέτη και την βελτιστοποίηση της διεργασίας. Συγκεκριμένα, εξετάστηκαν διαφορετικές μέθοδοι επεξεργασίας της ΤΦΡ με καυστικό νάτριο, σε μεγάλο θερμοκρασιακό και χρονικό εύρος, ώστε να μελετηθεί η κινητική της διάλυσης του χριστοβαλίτη και να βρεθεί η ενέργεια ενεργοποίησης της. Στη συνέχεια μελετήθηκε η επίδραση της θερμοκρασίας και της διάρκειας στην κρυστάλλωση του ζεόλιθου LTA ώστε να μελετηθεί η κινητική της αντίδρασης και να βρεθεί η ενέργεια ενεργοποίησης της καθώς και οι βέλτιστες συνθήκες απόδοσης της διεργασίας και καθαρότητας του τελικού προϊόντος. Τέλος, εξετάστηκε η επίδραση δύο σημαντικών παραμέτρων, της θερμοκρασίας σύνθεσης και της ταχύτητας ανάδευσης στην ποιότητα του τελικού προϊόντος και βρέθηκαν οι βέλτιστες τιμές τους. Τα αποτελέσματα και τα συμπεράσματα από την παρούσα εργασία, έχουν κατατεθεί στον Οργανισμό Βιομηχανικής Ιδιοκτησίας (Ο.Β.Ι.), για την χορήγηση Διπλώματος Ευρεσιτεχνίας (Δ.Ε.), με αριθμό αίτησης: 20120100391. / Rice husk ash (RHA) is one of the major agricultural wastes and results from the combustion of rice husk (RH) at rice in milling facilities for energy production or waste volumes reduction. Rice husk ash is about 18-20% of the cortex of the rice, which is approximately 20% of raw rice and is usually in its crystalline form. As the global volume of annual production in rice and hence rice husk ash is increasing, raising environmental and economic issues, finding an efficient and ecological way of RHA exploitation is a major issue. In addition, the high rates of RHA on silica render possible silicon source for many applications, one of which is the synthesis of zeolites. In this study, the use of crystalline RHA in the synthesis of four zeolite types, namely MFI, FAU, BEA and LTA was investigated. For this purpose, the raw material, i.e. RHA, was characterized both in terms of its chemical composition and unburned carbon content as well as its crystalline structure. Afterwards, the combustion conditions of RH which lead to the conversion from the amorphous to the crystalline structure of silica, called cristobalite, were determined. Since this crystalline structure is unsuitable for the production of zeolites, the possibility of solubilizing RHA in aqueous sodium hydroxide solution was investigated, in order to destroy the crystals and receive amorphous silica. For this purpose, the molar ratios of the raw materials which would result in the synthesis of each of the four types of zeolites were selected and RHA was treated with the appropriate amount of sodium hydroxide in aqueous solution at various temperatures and conditions. The crystallization of the desired zeolite type in each of the cases examined was verified, while the rate of dissolution of cristobalite was found to have the most significant effect on the process efficiency and the product purity. Simultaneously, it was found that the rate of dissolution of cristobalite mainly depends on the mass ratio of RHA / NaOH and the most suitable values were determined. As the majority of dissolved cristobalite was observed in the case of LTA synthesis, which moreover does not require organic structure directing agent nor high temperatures, it was chosen to be used for the study of design and optimization process. Specifically, several methods of RHA treatment with sodium hydroxide at high temperature and time range were examined, in order to study the kinetics of dissolution of cristobalite and to find the activation energy. Then, the influence of temperature and duration on the crystallization of LTA was examined in order to study the kinetics of the reaction and to determine the activation energy as well as the optimum conditions of the process in terms of efficiency and final product purity. Finally, the effect of two important parameters, the temperature of the synthesis and the stirring speed, on the final product quality was investigated and the optimal values were found. The results and the conclusions of this study, have been submitted to the Hellenic Industrial Property Organization for the grant of Patent with application number: 20120100391.

The purpose of this study is to understand mineral diagenesis authigenic mineral and the effect of climate on mineral of Pleistocene-Holocene sediment deposits in the Southern Kenya Rift. Lake Magadi unique geologic settings are characterized by extreme alkalinity and high silica activities. The mineralogical analysis was achieved by X-Ray diffraction (XRD) and Scanning Electron Microscopy (SEM) applications. The bulk mineralogy (quartz, halite, calcite) is the same on all localities due to similar volcaniclastics compositions throughout the Kenya Rift Valley. The clay mineralogy significantly differ among the groups of sample localities. The differences reflect different tectonic settings and ambient climate regime. In humid climate at higher elevation detrital clay minerals are abundant (feldspars, phillipsite). At lower elevation like Lake Magadi, the clay fractions dominated by authigenic minerals (zeolites and silicate minerals found with zeolites). These results show the potential of clay minerals as terrestrial climate proxies.

No description available.

As características vulcanológicas e geoquímicas das rochas vulcânicas da Formação Serra Geral (Eo-Cretáceo da Bacia do Paraná, América do Sul) foram integradas para avaliar os aspectos genéticos e a distribuição dos minerais secundários que são encontrados nas cavidades (vesículas, etc) dessas rochas. Mais de 70 afloramentos e pedreiras em uma área de 65.000 km2 no NE do estado do Rio Grande do Sul (Brasil) permitiram o reconhecimento dos padrões locais e regionais de distribuição dos minerais secundários. Sua distribuição em três pedreiras é apresentada em detalhes, evidenciando alterações quantitativas e qualitativas da mineralogia secundária a distâncias que podem ser inferiores a dez metros. Sete fatores principais definem os minerais que se formam nas cavidades. A composição do derrame de lava hospedeiro e as porosidades primárias e secundárias dos derrames de lava individuais e da seqüência vulcânica são muito importantes. Voláteis vulcânicos do próprio derrame de lava que abriga as cavidades foram responsáveis pela cristalização de minerais secundários nessas cavidades provavelmente apenas em circunstâncias muito específicas. O baixo gradiente geotérmico e a ausência de outras fontes de calor na bacia intracratônia do Paraná restringem o metamorfismo de soterramento como agente formador de minerais secundários provavelmente apenas a grandes profundidades. Metamorfismo de contato, representado pelo impacto de calor e de voláteis vulcânicos dos derrames de lava sobre derrames pré-existentes, é o principal processo de formação de minerais secundários de temperaturas mais altas (T>100ºC). Fenômenos meteorológicos (tempestades de poeira e chuva) durante o extravasamento dos derrames de lava e a interação dos derrames com águas superficiais criaram condições específicas e muito localizadas de formação de minerais secundários. Fluidos ascendentes do aqüífero Botucatu-Pirambóia sotoposto e fluidos descendentes do aqüífero contido no edifício vulcânico são os principais responsáveis pela formação de minerais de baixas temperaturas (T<100ºC). Essa interação de vários fatores e processos genéticos de intensidades variáveis foi responsável pela distribuição dos minerais secundários por "domínios". Domínios são definidos como volumes muito variáveis de rocha, de um ou mais derrames de lava, cujas cavidades abrigam as mesmas espécies minerais secundários com as mesmas morfologias e propriedades físicas (cor). Domínios normalmente são formados por rochas de derrames com as mesmas características vulcanológicas e da mesma composição química, apresentando tamanhos decamétricos a quilométricos. Os minerais cristalizam em todos os tipos de cavidades das rochas vulcânicas, mudam com o tipo e o tamanho das cavidades e se distribuem aleatoriamente nas paredes das cavidades. Muito freqüentes são pseudomorfoses, perimorfoses e minerais com feições de dissolução, demonstrando que os minerais secundários são os produtos de várias fases de cristalização e de dissolução que se sucederam nas cavidades. As temperaturas elevadas (T>100ºC) necessárias para a cristalização de apofilita, laumontita, escolecita, heulandita, estilbitaestellerita e mordenita restringem a formação desses minerais à duração do evento vulcânico Serra Geral. Minerais de temperaturas mais baixas (T<100ºC) e ampla distribuição são chabasita, calcita e minerais do Grupo da Sílica (calcedônia, ágata e quartzo macrocristalino), cada qual com condicionantes genéticos específicos. / The volcanological and geochemical characteristics of the volcanic rocks of the Serra Geral Formation (Eo-Cretaceous of the Paraná Basin, South America) were integrated to evaluate the genetic aspects and the distribution of the secondary minerals found in the cavities (vesicles, etc.) of these rocks. More than 70 outcrops and quarries in an area of 65.000 km2 in the NE of the state of Rio Grande do Sul (Brazil) made it possible to recognize local and regional distribution patterns of the secondary minerals. Their distribution in three quarries is presented in detail, showing quantitative and qualitative changes, sometimes at distances of less than ten meters. Seven main factors define the kind of secondary minerals in the cavities. The composition of the host lava flow and the primary and secondary porosities of the individual lava flows and of the volcanic succession are very important. Volcanic volatiles of the cavity-hosting lava flow itself very rarely allowed the crystallization of secondary minerals in its cavities, probably only in very specific settings. The low geothermal gradient and the absence of other heat sources in the intracratonic Paraná Basin limit burial metamorphism as a secondary mineral forming agent probably only to great depths. Contact metamorphism, represented by the impact of heat and volcanic volatiles of lava flows over earlier flows, is considered the main process for the generation of secondary minerals of higher temperatures (T>100oC). Meteorological phenomena (dust storms and rain) during the emplacement of the lava flows and the interaction of the flows with superficial waters created very specific and localized mineral-forming conditions. Ascending fluids from the underlying Botucatu-Pirambóia aquifer and descending fluids of the aquifer hosted in the volcanic edifice were responsible for low-temperature (T<100oC) minerals. This interaction of different genetic factors and processes of variable intensities generated a distribution of secondary minerals in "domains". Domains are very variable volumes of rocks, belonging to one or several lava flows, whose cavities host the same species of secondary minerals, with the same morphologies and physical properties (colors). Domains are usually formed by rocks from flows with the same volcanological characteristics and the same chemical composition, with sizes ranging from decametric to quilometric. The secondary minerals crystallize in all types of cavities of the volcanic rocks. They change according to the kind and the size of the cavities and occur randomly distributed on the walls of the cavities. Very frequent are pseudomorphosis, perimorphosis and minerals with dissolution features, proving that the secondary minerals are the product of several phases of crystallization and dissolution which happened in the cavities. The higher temperatures (T>100oC) necessary to crystallize apophyllite, laumontite, scolecite, heulandite, stilbite-stellerite and mordenite limit the formation of these minerals to the time of the volcanic Serra Geral event. Very frequent minerals of lower temperatures (T<100oC) are chabazite, calcite and minerals of the silica group (chalcedony, agate and macrocrystalline quartz), each one with specific genetic conditions.

174 f. / Submitted by Ana Hilda Fonseca (anahilda@ufba.br) on 2013-08-20T15:49:02Z No. of bitstreams: 1 Tese de doutorado - Ingrid - VERSÃO FINAL - UFBA.pdf: 5563445 bytes, checksum: 8345d9745885c1103c219247c69338fc (MD5) / Approved for entry into archive by Ana Hilda Fonseca(anahilda@ufba.br) on 2013-08-20T15:51:20Z (GMT) No. of bitstreams: 1 Tese de doutorado - Ingrid - VERSÃO FINAL - UFBA.pdf: 5563445 bytes, checksum: 8345d9745885c1103c219247c69338fc (MD5) / Made available in DSpace on 2013-08-20T15:51:20Z (GMT). No. of bitstreams: 1 Tese de doutorado - Ingrid - VERSÃO FINAL - UFBA.pdf: 5563445 bytes, checksum: 8345d9745885c1103c219247c69338fc (MD5) Previous issue date: 2012 / O rincoforol (2-metil-5(E)hepteno-4-ol) é o maior constituinte do feromônio de agregação do macho do Rhynchophorus palmarum L. (Coleoptera: Curculionidade), um besouro que ataca diversas espécies de palmeiras e é o principal vetor do nematódeo Bursaphelenchus cocophylus, agente causador da doença do anel vermelho.No Brasil, esse besouro ataca principalmente o coqueiro e o dendezeiro, culturas de grande relevância econômica para o país. Esse feromônio vem sendo utilizado em iscas do tipo eppendorf com um orifício na tampa para controlar a população do besouro. Esse dispositivo facilita a liberação lenta quando comparada à evaporação direta do estado líquido. No entanto, a validade dessas iscas depende da velocidade de evaporação do rincoforol através do dispositivo, que libera quantidade excessiva do feromônio. Com o objetivo de prolongar o tempo de liberação do rincoforol, diferentes zeólitos foram sintetizados, caracterizados e avaliados em relação à sua utilização como adsorvente para o rincoforol. Para isso, a influência de variáveis como: estrutura do zeólito, razão Si/Al, natureza do cátion de compensação, dimensão de poros e acidez foi verificada para o processo de adsorção. Devido à falta de informações referente à estabilidade do rincoforol, foi realizado um estudo termogravimétrico sobre seu comportamento térmico. Estudos de recuperação demonstraram que houve interação entre o rincoforol e os zeólitos ZSM-5 e MCM-22 nas diferentes razões Si/Al, resultando na degradação do feromônio, inviabilizando seu uso como suporte para liberação prolongada. Os materiais silicalita-1, zeólito Y e zeólito L apresentaram bons resultados de recuperação e a liberação do rincoforol a partir desses materiais foi medida em uma termobalança em condição isotérmica. Resultados promissores foram observados quando a velocidade de liberação obtida a partir dos zeólitos foi comparada com o rincoforol comercial. Assim, os estudos realizados nesse trabalho permitiu selecionar zeólitos com grande potencial comercial como dispositivo liberador do rincoforol por um período prolongado. / Salvador

Zeolites are crystalline aluminosilicates of natural or synthetic origin, with a structure consisting of an extensive microporous three-dimensional network, routinely used as catalysts, ion exchange and adsorbents. The production of ferrierite and other zeolites are limited due to the high cost of the organic structure-directing agents used in synthesis. Many studies are conducted with the goal of finding a viable and more economical route to the possibility of industrial scale production. The purpose of this study was to obtain a methodology for synthesis of ferrierite without using organic structure-directing agents, by hydrothermal method, inserting seeds during the crystallization gel preparation and varying the alkaline concentration of the mixture in order to achieve shorter times of crystallization and lower cost production at a temperature of 200°C. For the synthesis of materials prepared in this work were used: fumed silica as silicon source, pseudoboehmite as a source of aluminum, sodium and potassium hydroxide as sodium and potassium sources, respectively. As seeds to crystallization, samples of commercial ferrierita were used. The synthesized samples were characterized by X-ray diffraction (XRD), spectroscopy of the Fourier transform infrared (FT-IR) and thermal analysis (TG/DTA). The X-ray diffraction patterns showed characteristic peaks of zeolite desired in all conditions of synthesis. The infrared spectra showed bands characteristic of ferrierite, as a further indication of the formation of zeolite. TG curves showed a mass loss of up to 10% in the temperature range from 23 to 400°C. The results of the analysis confirmed the formation of zeolite ferrierite with good crystallinity and purity, proving the efficiency of the methodology. / As zeólitas são aluminossilicatos cristalinos, de origem natural ou sintética, com estrutura constituída por uma extensa rede tridimensional microporosa, rotineiramente utilizadas como catalisadores, trocadores iônicos e adsorventes. A produção da ferrierita, e outras zeólitas, são limitadas devido ao alto custo do direcionador orgânico utilizado na síntese. Muitos estudos são realizados com o objetivo de encontrar uma rota mais econômica e viável para a possibilidade de produção em escala industrial. O objetivo deste trabalho foi obter uma metodologia para síntese da ferrierita sem utilizar direcionador orgânico, pelo método hidrotérmico, inserindo sementes de cristalização durante o preparo do gel e variando a concentração alcalina da mistura reacional, a fim de alcançar menores tempos de cristalização e menor custo de produção, numa temperatura de 200°C. Para a síntese do material preparado neste trabalho foram utilizados: sílica fumed como fonte de silício, pseudoboehmita como fonte de alumínio, e hidróxido de sódio e potássio como fontes de sódio e potássio, respectivamente. Já para sementes de cristalização, foram utilizadas amostras de ferrierita comercial. As amostras sintetizadas foram caracterizadas por difração de raios X (DRX), espectroscopia na região do infravermelho por transformadas de Fourier (FT-IR) e análises térmicas (TG/DTA). Os difratogramas de raios X mostraram picos característicos da zeólita desejada em todas as condições de síntese. Os espectros de infravermelho apresentaram bandas características da ferrierita, sendo mais um indício da formação da zeólita. As curvas de TG mostraram uma perda de massa de no máximo 10% numa faixa de temperatura de 23 a 400°C. Os resultados das análises realizadas comprovaram a formação da zeólita ferrierita com boa cristalinidade e pureza, comprovando a eficiência da metodologia proposta.