Dissertations / Theses on the topic 'POSS'

Made available in DSpace on 2016-04-04T18:22:06Z (GMT). No. of bitstreams: 1 LILIANE ALVES BENATTI.pdf: 9103577 bytes, checksum: 7896dfbd619623aa555a4f6ee28c77a2 (MD5) Previous issue date: 2013-06-14<br>To contribute to discussions involving the solving of urban environmental problems, the thesis assumes that certain approaches, by themselves suffice to situational analyzes, are powerless to deal with the structural nature of the lining. In the Brazilian case, and with regard to territorial public policies, such as urban planning and urban and regional planning,discussions generally restricted to the field of administrative law, predominantly instrumental in character, whose effects invariably limited to specific actions, topical and devoid of virtue to reach the root causes of urban issue. And more. They reappear with the contemporary environmental crisis. Another factor that affects decisively reflection and proposition urban instruments developed with a view to solving the urban problems is the application of the concept applied to management of public affairs. Originally conceived in the context of organizations, employment management, to migrate to public administration, reduces the understanding of the political dimension to the city's plan merely negotiated territorial management. This also proves insufficient, which will be addressed through a particularly significant that relates environmental and urban issues: the National Policy on Solid Waste.<br>Visando contribuir nos debates que envolvem o equacionamento da problem?tica urbanoambiental, a disserta??o parte do pressuposto de que certas abordagens, por se bastarem ?s an?lises conjunturais, s?o impotentes para lidar com a natureza estrutural que as revestem. No caso brasileiro, e no que diz respeito ?s pol?ticas p?blicas territoriais, como o urbanismo e o planejamento urbano e regional, as discuss?es geralmente restringem-se ao campo do direito administrativo, de car?ter predominantemente instrumental, cujos efeitos invariavelmente limitam-se ?s a??es pontuais, t?picas e desprovidas da virtude de atingir as causas origin?rias da quest?o urbana. E mais. Elas recrudescem com a crise ambiental contempor?nea. Outro fator que compromete, decisivamente, a reflex?o e a proposi??o de instrumentos urban?sticos desenvolvidos, com vistas ao equacionamento da problem?tica urbana, ? a aplica??o da no??o de gest?o aplicada ? coisa p?blica. Originariamente concebida no contexto das organiza??es, o emprego da gest?o, ao migrar para a administra??o p?blica, reduz o entendimento da dimens?o pol?tica da cidade ao plano meramente negociado de gest?o territorial. Isso tamb?m se mostra insuficiente, o que ser? abordado por meio de um caso particularmente significativo que relaciona quest?es urbanas e ambientais: a Pol?tica Nacional de Res?duos S?lidos.

Beginning with a survey of functional variation methods in classical physics, we derive the Hartree-Fock theory from canonical quantization. Following a development of density functional theory, many-body perturbation theory, and other techniques of computational condensed matter physics, we perform a systematic study of metal-polyhydride impurities in T8 and T12 polyhedral oligomeric silsesquioxane (POSS) cage molecules. Second-quantized methods motivate the derivations throughout.

Throughout the study of polymeric Langmuir monolayers at the air/water (A/W) interface, the Wilhelmy plate and Langmuir-Blodgett (LB) techniques along with Brewster angle microscopy (BAM) have been identified as key methods for acquiring structural, thermodynamic, rheological and morphological information. These techniques along with surface light scattering (SLS), a method for probing a monolayerâ s dynamic dilational rheological properties, will be used to characterize homopolymers, poly(ethylene oxide) (PEO) and poly(ethylene glycol) (PEG), and a new class of novel polymeric surfactants, telechelic (POSS-PEG-POSS) and hemi-telechelic (POSS-PEG) polyhedral oligomeric silsesquioxane (POSS) derivatives of PEG. PEO with number average molar mass, Mn > ~ 18 kgâ ¢mol-1 form stable spread Langmuir films at the A/W interface, while oligomeric PEG have ï -A isotherms that deviate from high molar mass PEO. Nonetheless, SLS reveals that the dynamic dilational viscoelastic properties of any Mn PEG(PEO) only depend on ï and not Mn. Likewise, POSS-PEG-POSS telechelics exhibit molar mass dependent ï -A isotherms, where low ï regimes (ï < 1 mNâ ¢m-1) have PEG-like behavior, but high ï regimes were dominated by POSS-POSS interactions. SLS studies reveal that the dynamic dilational moduli of POSS-PEG-POSS are greater than either PEO or an analogous POSS compound, trisilanolcyclohexyl-POSS. The ability to control rheological properties and the hydrophilic-lipophilic balance even allows one POSS-PEG-POSS (PEG Mn = 1 kgâ ¢mol-1) to form Y-type LB-multilayer films. For POSS-PEG systems, comparisons at comparable POSS:PEG ratios reveal short PEG chains (PEG Mn ~ 0.5 kgâ ¢mol-1) yield similar viscoelastic properties as POSS-PEG-POSS (PEG Mn ~ 1 kgâ ¢mol-1), while longer PEG chains (PEG Mn ~ 2 kgâ ¢mol-1) yield lower modulus films than comparable POSS-PEG-POSS. These differences are attributed to brush-like PEG conformations in short POSS-PEG versus mushroom-like PEG conformations in long POSS-PEG at the A/W interface. These results provide insight for designing PEG-based amphiphilic nanoparticles with controlled interfacial rheology.<br>Ph. D.

For over a century, Langmuir films have served as excellent two-dimensional model systems for studying the conformation and ordering of amphiphilic molecules at the air/water (A/W) interface. With the equipment of Wilhelmy plate technique, Brewster angle microscopy (BAM), and surface light scattering (SLS), the interfacial phase and rheological behavior of Langmuir films can be investigated. In this dissertation, these techniques are employed to examine Langmuir films of polyhedral oligomeric silsesquioxane (POSS), polymer blends, and magnetic nanoparticles (MNPs). In a first time, SLS is employed to study POSS molecules. The interfacial rheological properties of trisilanolisobutyl-POSS (TiBuP) indicate that TiBuP forms a viscoelastic Langmuir film that is almost perfectly elastic in the monolayer state with a maximum dynamic dilational elasticity of around 50 mNâ m-1 prior to film collapse. This result suggests that TiBuP can serve as model nanofiller with polymers. As an interesting next step, blends of TiBuP and polydimethylsiloxane (PDMS) with different compositions are examined via surface pressure (surface pressureâ surface area occupied per molecule (A) isotherms and SLS. The results show that TiBuP, with its attendant water, serves as a plasticizer and lowers the dilational modulus of the films at low surface pressure. As surface pressure increases, composition dependent behavior occurs. Around the collapse pressure of PDMS, the TiBuP component is able to form networks at the A/W interface as PDMS collapse into the upper layer. Blends of non-amphiphilic octaisobutyl-POSS (OiBuP) and PDMS are also studied as an interesting comparison to TiBuP/PDMS blends. In these blends, OiBuP serves as a filler and reinforces the blends prior to the collapse of PDMS by forming â bridgeâ structure on top of PDMS monolayer. However, OiBuP is non-amphiphilic and fails to anchor PDMS chains to the A/W interface. Hence, OiBuP/PDMS blends exhibit negligible dilational viscoelasticity after the collapse of PDMS. Furthermore, the phase behavior of PDMS blended with a trisilanol-POSS derivative containing different substituents, trisilanolcyclopentyl-POSS (TCpP), is also investigated via the Wilhelmy plate technique and BAM. These TCpP/PDMS blends exhibit dramatically different phase behavior and morphological features from previously studied POSS/PDMS blends, showing that the organic substituents on trisilanol-POSS have considerable impact on the phase behavior of POSS/PDMS blends. The interfacial rheological behavior of tricarboxylic acid terminated PDMS (PDMS-Stabilizer) and PDMS stabilized MNPs are investigated and compared with â regularâ PDMS containing non-polar end groups. The tricarboxylic acid end group of the PDMS-Stabilizer leads to a different collapse mechanism. The PDMS stabilized MNPs exhibit viscoelastic behavior that is similar to PDMS showing all the tricarboxylic acid end groups are bound to the magnetite cores. Studying the interfacial behavior of different Langmuir films at the A/W interface provides us insight into the impact of molecule-molecule and molecule-subphase interactions on film morphology and rheology. These results are able to serve as important guides for designing surface films with preferred morphological and mechanical properties.<br>Ph. D.

Made available in DSpace on 2015-04-14T14:13:13Z (GMT). No. of bitstreams: 1 339892.pdf: 8399527 bytes, checksum: 799e9e6c94fd60ceaf4df52427f64977 (MD5) Previous issue date: 2005-10-20<br>Esta disserta??o apresenta uma pesquisa realizada com alunos de Matem?tica, de sexta s?rie, em uma escola particular da cidade de Lajeado, RS. O trabalho tem como objetivo investigar a aplica??o de conceitos matem?ticos em atividades que associam Matem?tica e Arte. A pesquisa tem uma abordagem qualitativa, a partir de question?rios aplicados aos alunos, observa??es das atividades desenvolvidas e entrevistas realizadas com professores de Matem?tica. Os alunos se manifestaram favor?veis ao trabalho com tais atividades, mostrando que essas propiciam ao professor conhecer o ritmo pr?prio do educando, habilidades e compet?ncias. Os professores entrevistados consideraram que existe a possibilidade de trabalhar Matem?tica associada ? Arte, em atividades que envolvem desenho, medidas e no??es de Geometria, bem como as que oportunizam, ao aluno, construir o seu pr?prio material. Pelos dados obtidos por meio dos instrumentos de pesquisa utilizados, conclui-se que a rela??o entre Matem?tica e Arte motiva os estudantes para o trabalho com os conceitos matem?ticos subjacentes ?s atividades. Vincular Matem?tica e a Arte constitui-se em uma maneira de levar o educando a ver a Matem?tica como uma obra constru?da pelo esp?rito humano, com equil?brio, harmonia, beleza e delicadeza nos detalhes.

Made available in DSpace on 2015-04-14T14:48:01Z (GMT). No. of bitstreams: 1 423359.pdf: 236129 bytes, checksum: 73a911e944323d0ea9ae2f917341b87d (MD5) Previous issue date: 2010-01-14<br>Esta disserta??o busca inserir-se numa atitude coletiva, considerando a multiplicidade inapreens?vel das culturas e imagin?rios. Adverte-se: assume-se a (im)possibilidade de ser mais que uma tentativa do imposs?vel. O estudo simboliza o desenrolar leituras e impress?es, especialmente sobre a experi?ncia de uma pesquisa emp?rica em um Juizado de Viol?ncia Dom?stica, local onde Criminologia e feminismos obrigatoriamente imbricam-se. A viv?ncia etnogr?fica permeia todo o texto, o estar-junto na sala de audi?ncias ? insepar?vel das teorias. Aproxima-se feminismos e Criminologias, assumindo sua temporalidade, olhando-os na limita??o de seu tempo e, simultaneamente, num constante retorno e re-significa??o. A totaliza??o ? impossibilitada: o retorno sempre ? diferente.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2016-04-18T12:05:55Z No. of bitstreams: 1 TES_ALINE_ROCHA_MENDES_COMPLETO.pdf: 1705036 bytes, checksum: b7ec9e051c3f542910c634a6408f9c62 (MD5)<br>Made available in DSpace on 2016-04-18T12:05:55Z (GMT). No. of bitstreams: 1 TES_ALINE_ROCHA_MENDES_COMPLETO.pdf: 1705036 bytes, checksum: b7ec9e051c3f542910c634a6408f9c62 (MD5) Previous issue date: 2016-01-05<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES<br>This research is quantitative and aimed to develop 10 Workshops - Emotional Life, with a group of 12 students (experimental group) of the 9th grade of Middle School, in a Municipal School of Porto Alegre Net of Education, comparing with control group (n = 28). By analyzing the responses of students, through two scales of self-report, a Self-Esteem (SE) and another Positive Affections (PA) and Negative Affections (NA), we find the pre-test, which students had mean levels for high PA; low levels of NA; and average levels for SE high, accounting for the entire sample (n = 40). When the scales were applied, we ask students to take into account the school context. We developed in the following thematic workshops: emotions and feelings, his action in the conduct of daily life and school. With the study of self-concept, with its self-image and self-esteem components, it is aimed to positively stimulate the perception and self-esteem. Deal of empathy and assertiveness, for the understanding and use of these concepts in relationships, can promotes emotional connections. We work also with the functioning of the brain as the center of thought, emotions, sensations, behavior and memory. To compare, through an ANOVA, the results of the averages of students in both scales, before and after the workshops, the experimental and control groups, we found that the experimental group had lower mean PA and SE, in the pretest, than the control group, and higher levels of NA. We found that the experimental group in the post-test, showed statistically significant increase in mean the PA. NA and SE also changed in the expected direction, reducing the NA and increasing in SE, although not significant. The control group remained with the average virtually unchanged from pre to post-test. Results of school performance, the experimental group showed improvement after the workshops. We believe that all of these results can indicate that our study was relevant for revealing positive results, showing that when the emotional dimension is intentionally developed, through an educational activity organized in the educational context, it can change positively the students levels of PA, NA and SE, that fact can lead to positive repercussions in the students academic and personal life.<br>A presente pesquisa do tipo quantitativa objetivou desenvolver 10 Oficinas de Ensino ? Vida Emocional, com um grupo de 12 discentes (grupo experimental) do 9? ano do EF, de uma escola da Rede Municipal de Ensino de Porto Alegre, comparados com um grupo controle (n= 28). Ao analisarmos as respostas dos estudantes, por meio de duas escalas de autorrelato, uma de Autoestima (AE) e outra de Afetos Positivos (AP) e Afetos Negativos (AN), verificamos, pelo Pr?-teste, que os estudantes apresentaram n?veis m?dios para altos de AP; baixos n?veis de AN; e n?veis m?dios para altos de AE, contabilizando a amostra toda (n= 40). Quando as escalas foram aplicadas solicitamos aos alunos levarem em conta o contexto escolar. Desenvolvemos nas Oficinas as seguintes tem?ticas: as emo??es e sentimentos, sua a??o nas condutas do cotidiano e da escola. Com o estudo do autoconceito, com seus componentes autoimagem e autoestima, se teve a finalidade de estimular positivamente a percep??o e a estima de si. Tratamos da empatia e da assertividade, pois o entendimento e a sua utiliza??o desses conceitos nas rela??es, favorece as conex?es emocionais. Trabalhamos, ainda, com o funcionamento do enc?falo como o centro do pensamento, das emo??es, das sensa??es, do comportamento e da mem?ria. Ao compararmos, por meio de uma ANOVA, os resultados das m?dias dos estudantes nas duas escalas, antes e depois das Oficinas, dos grupos experimental e controle, constatamos que o grupo experimental apresentou m?dias mais baixas de AP e AE, no pr?-teste, do que o grupo controle, e n?veis mais altos de AN. Verificamos que, o grupo experimental, no P?s-teste, teve aumento estatisticamente significativo nas m?dias nos AP. Os AN e a AE, tamb?m modificaram na dire??o esperada, reduzindo nos AN e aumentando na AE, embora n?o tenham sido significativos. O grupo controle permaneceu com as m?dias praticamente sem altera??es, do Pr? para o P?s-teste. Os resultados do desempenho escolar, do grupo experimental, apresentaram melhora, ap?s as Oficinas. Acreditamos que todos esses resultados, podem indicar que, nosso estudo foi relevante por ter revelado resultados positivos, mostrando que quando a dimens?o emocional ? intencionalmente desenvolvida, por meio de uma a??o educativa organizada no contexto escolar, pode modificar de forma positiva os n?veis de AP, AN e AE dos estudantes, fato que pode levar a repercuss?es positivas na vida acad?mica e pessoal dos alunos.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2017-02-13T19:21:44Z No. of bitstreams: 1 2015 - Simone Ramos.pdf: 3006092 bytes, checksum: be7e0f821c94ac23a229118fadd1d990 (MD5)<br>Made available in DSpace on 2017-02-13T19:21:44Z (GMT). No. of bitstreams: 1 2015 - Simone Ramos.pdf: 3006092 bytes, checksum: be7e0f821c94ac23a229118fadd1d990 (MD5) Previous issue date: 2015-12-22<br>This research had as objective recognize ways to present subjectivity knowledge building process triggered by game. For the realization of this study the building game MMO (Massive Multiplayer Online) called Minecraft was chosen for the field research. The hypothesis is that the high level of interoperability and immersion presented in digital media of games come driving a more intuitive, sensible, imagetic and practical cognition. This way, it is intended to initially define what is cognition from the cognition sciences and technologies perspective based on the autopoiesis theory. The next step proposes the theoretical understanding of electronic or computer game beginning with its definition and from the concepts of non-immersive virtual reality, interactivity and immersion. Finally, it will be discussed the relationship between the cognitive potential in games and the autopoietic knowledge. As methodological aspects for field research were used procedures of field research and derived netnography as the process conductors. Data were collected through a questionnaire, through material published on the blog created for research (Videos and comment on the participation in the metaverse made by the research subjects), and the non- structured interview guided and supported by systematic observation. The data analysis was performed from the triangulation between the technique of Talking Dynamics, the data collected in immersion in the metaverse and the theoretical basis used. As a result the research was considered non-conclusive regarding the sample used, but indicates routes to be followed in future researches.<br>O presente trabalho de pesquisa teve como objetivo identificar os modos de subjetiva??o presente no processo de constru??o de conhecimento deflagrado pelo videogame. Para a realiza??o desse estudo foi escolhido o game de constru??o MMO (Massive Multiplayer Online) denominado Minecraft para a pesquisa de campo. A hip?tese levantada ? de que o alto n?vel de interoperabilidade e imers?o presente na m?dia digital dos games venha acionando uma cogni??o mais intuitiva, sens?vel, imag?tica e com predom?nio da pr?tica. Neste percurso, pretende-se inicialmente definir o que ? cogni??o a partir das ci?ncias e tecnologias da cogni??o (CTC) e tomando como base a teoria da autopoiesi. Em seguida, prop?e-se a compreens?o te?rica acerca do jogo eletr?nico ou computacional a partir de sua defini??o e dos conceitos de realidade virtual n?o-imersiva, interatividade e imers?o. Finalmente, ser? discutida a imbrica??o entre o potencial cognitivo presente nos games e o conhecer autopoietico. Como aspectos metodol?gicos para a pesquisa de campo foram utilizados os procedimentos de pesquisa netnogr?fica derivada e de campo como condutores do processo. Os dados foram coletados por meio de question?rio, pelo material publicado (v?deos e observa??es sobre as incurs?es no metaverso feitos pelos sujeitos da pesquisa) no blog criado para a pesquisa, e pela entrevista n?o-estruturada guiada e apoiada pela observa??o sistem?tica. A an?lise dos dados foi realizada a partir da triangula??o entre a t?cnica da Din?mica das Conversa??es, os dados coletados em minha imers?o no metaverso e a base te?rica utilizada. Como resultado a pesquisa foi considerada n?o-conclusiva em rela??o a amostragem utilizada, mas aponta caminhos a serem percorridos em pesquisas futuras.

Submitted by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-11-17T13:36:51Z No. of bitstreams: 1 SergioAlvesGarciaDissertacao2017.pdf: 4316638 bytes, checksum: 43c7ee6b4d3adf2966b2240bcbeb4f44 (MD5)<br>Approved for entry into archive by Sara Ribeiro (sara.ribeiro@ucb.br) on 2017-11-17T13:37:07Z (GMT) No. of bitstreams: 1 SergioAlvesGarciaDissertacao2017.pdf: 4316638 bytes, checksum: 43c7ee6b4d3adf2966b2240bcbeb4f44 (MD5)<br>Made available in DSpace on 2017-11-17T13:37:07Z (GMT). No. of bitstreams: 1 SergioAlvesGarciaDissertacao2017.pdf: 4316638 bytes, checksum: 43c7ee6b4d3adf2966b2240bcbeb4f44 (MD5) Previous issue date: 2017-08-31<br>The objective of this work was to characterize the organizational culture of a large company of the health segment with national performance and to identify the relations that are established with the innovation. These themes have aroused the interest of researchers, mainly due to the relation with organizational performance linked to the competitiveness in the market. The research used a mixed method of two-step analysis. In the first, a quantitative research was carried out with the application of the internationally validated Organization Culture Assessment Instrument (OCAI) by Cameron and Quinn (2011). The qualitative stage had the application of the structured questionnaire to identify the determinants of the culture, proposed by Martins and Terblanche (2003). The result of the first phase, with a sample of 274 subjects, characterized the predominance of the Market type culture and, in the subsequent phase, the organizational profile of the Innovative Culture was identified with the leaders participating in the interviews, with traits of flexibility, rewards, recognition, error tolerance, teamwork, open communication, the organizational culture being the basis of the innovation process. This study contributes to support the organizational strategy of disseminating the dimensions of a pro-innovation culture.<br>O objetivo desse trabalho foi o de caracterizar a cultura organizacional de uma empresa de grande porte do segmento de sa??de com atua????o nacional e identificar as rela????es que se estabelecem com a inova????o. Esses temas v??m despertando o interesse de pesquisadores, principalmente em raz??o da rela????o com desempenho organizacional vinculado ?? competitividade no mercado. Na pesquisa foi utilizado um m??todo misto de an??lise em duas etapas. Na primeira, utilizou-se uma pesquisa quantitativa, com a aplica????o do question??rio de diagn??stico cultural Organization Culture Assessment Instrument (OCAI) de Cameron e Quinn (2011), validado internacionalmente. A etapa qualitativa contou com a aplica????o do question??rio estruturado para identifica????o dos determinantes da cultura, proposto por Martins e Terblanche (2003). O resultado da primeira fase com uma amostragem de 274 sujeitos, caracterizou a predomin??ncia da cultura do tipo Mercado e, na fase subsequente, identificouse junto ??s lideran??as participantes das entrevistas o perfil organizacional de Cultura Inovativa, com tra??os de flexibilidade, recompensas, reconhecimentos, toler??ncia a erros, trabalho em equipe, comunica????o aberta, estando a cultura organizacional na base do processo de inovar. Este estudo contribui para sustentar a estrat??gia organizacional de dissemina????o das dimens??es de uma cultura pr?? inova????o.

Made available in DSpace on 2016-04-04T18:29:44Z (GMT). No. of bitstreams: 1 miriam.pdf: 1518623 bytes, checksum: 260be23e5c071b069ca2bc9465ef8da1 (MD5) Previous issue date: 2001-08-31<br>Within a Piagetian and a micro genetic approach, it was investigated the dialectic thought and the construction of possibilities in the solution and comprehension of a computer game. A previous study with a group of adolescents, made up of 40 boys and 26 girls from 6th. to 8th. grades, showed personalized preferences, without a group tendency and linked to complex games. The need for non-experienced subjects in such games and for starting studies making use of a simpler game, led to the research of Tetris solution by two female university students. The procedure, which was individual and videotaped, consisted of a 4-proof pre-evaluation of possibilities, 9 sessions using Tetris (more than 30 games and about 10-hour filming per person) and 3 self-evaluations (after session-1; before sessions 4 and 9). The pre-evaluation revealed a formal level of thought for both subjects. A quantitative analysis showed great progress of the subjects: throughout the sessions, there was a fall in the average number of games, associated to long lasting games, to a larger production of lines and to a larger punctuation, with the advance from the building of unitary to double, triple and quadruple lines. The micro genetic analysis demonstrated the presence of equilibration as well as the dynamic of dialectic constructions and dialectic thoughts underlying the procedural and conceptual schemes. Although the final solutions have achieved a III-Level (Subject 1) and a II-III Level (Subject 2), there were initial possibilities and more elementary mistakes than it was hypothesized to people who had formal thought. On the other hand, the constructed interdependences, both initial and global, comprised larger complexity and scope than it was foreseen. The obtained results suggested that, when solving the Tetris, it was as if the subjects were remaking the cognitive evolution course, projecting their progress to the top level of their cognitive structures or tending to this level.<br>Com uma abordagem piagetiana e microgen?tica, investigou-se o pensamento dial?tico e a constitui??o de poss?veis na resolu??o e compreens?o de um jogo computadorizado. Um estudo pr?vio com adolescentes, 40 meninos e 26 meninas de 6? a 8? s?ries, mostrou prefer?ncias personalizadas, sem tend?ncia grupal e ligadas a jogos complexos. A necessidade de sujeitos inexperientes nestes jogos e de estudos iniciais com um jogo mais elementar levou ? pesquisa do processo resolutivo do Tetris por duas universit?rias. O procedimento, individual e filmado, incluiu pr?-avalia??o com 4 provas de poss?veis, 9 sess?es com o Tetris (mais de 30 jogos e cerca de 10 h de v?deo por sujeito) e 3 autoavalia??es (ap?s a sess?o-1; antes das sess?es 4 e 9). A pr?-avalia??o revelou n?vel formal de pensamento para os dois sujeitos. Uma an?lise quantitativa mostrou acentuado progresso dos sujeitos: ao longo das sess?es, queda no n?mero m?dio de jogos, associada ? sua maior dura??o, maior produ??o de linhas e maior pontua??o, com avan?o da forma??o de linhas unit?rias para compostas (duplas, triplas e qu?druplas). A an?lise microgen?tica da resolu??o indicou a presen?a de equilibra??o e da din?mica de constru??es dial?ticas e pensamento dial?tico, subjacentes aos esquemas procedurais e conceituais. Embora as solu??es finais tenham sido de N?vel-III (Sujeito 1) e N?vel II-III (Sujeito 2), ocorreram poss?veis iniciais e erros mais elementares do que o hipotetizado para sujeitos com pensamento formal. De outro lado, as interdepend?ncias criadas, iniciais como globais, comportaram abrang?ncia e complexidade maiores do que o previsto. Pelos dados obtidos, ao resolverem o Tetris, os sujeitos como que refizeram o percurso da evolu??o cognitiva, com seu progresso projetado at? o patamar de suas estruturas cognitivas ou tendendo a este patamar.

Neste trabalho, foram sintetizados poliuretanos termoplásticos (TPU) via solução em reator e via extrusão reativa em extrusora dupla rosca. Os TPUs foram obtidos com o uso de pré-polímero 4,4‟-difenilmetano (MDI) e poliol poliéster, a hidroquinona bis-2-(hidróxietil)-éter (HQEE), e o n-fenilaminopropil-POSS. Os reagentes e produtos foram caracterizados através de análises de Espectroscopia no Infravermelho com Transformada de Fourier (FTIR), Calorimetria Diferencial de Varredura (DSC), análise Termogravimétrica (TGA) e reometria capilar (exclusivamente para os produtos). As análises de DSC mostraram que a presença do POSS influenciou a entalpia de fusão (ΔHm) dos TPUs sintetizados via solução. As amostras polimerizadas por extrusão reativa a 80 ºC apresentam Tm comparativamente menores que as amostras sintetizadas a 90 ºC, porém com ΔHm superior, indicando que a temperatura possivelmente favorece a formação de um número maior de cristais com um tamanho médio inferior. Também foram observados fenômenos exotérmicos durante o aquecimento das amostras sintetizadas via extrusão reativa, provavelmente devido a disponibilidade de grupos isocianato livres, detectados via FTIR, na região de ~2253 cm-1. A estabilidade térmica dos TPUs via solução também foi alterada pela adição de POSS, enquanto o polímero obtido através da extrusão reativa apresentou valores mais elevados no início da degradação. Os ensaios de TGA em isoterma apresentaram valores de perda de massa progressivamente inferiores nas amostras sintetizadas via extrusão reativa, demonstrando que tanto o POSS quanto a temperatura de síntese influem nas propriedades do polímero. Ensaios de resistência térmica nas amostras apresentaram perdas de massa inferiores nas amostras vi8a xetrusão reativa. Em ensaios de reometria capilar, a inserção do POSS levou a um aumento progressivo da viscosidade intrínseca do polímero, indicando aumento da massa molar média do TPU sintetizado via solução. Os mesmos ensaios executados com as amostras via extrusão reativa mostraram viscosidades aparentes similares, provavelmente influenciados por processos de degradação do material na célula de carga, levando a comportamentos de viscosidade sem uma tendência observável.<br>Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-03T18:10:51Z No. of bitstreams: 1 Dissertacao Gabriel Hoyer Lopes.pdf: 2245249 bytes, checksum: 97ec28c68a7d73e9ca22b258465c50c6 (MD5)<br>Made available in DSpace on 2014-06-03T18:10:51Z (GMT). No. of bitstreams: 1 Dissertacao Gabriel Hoyer Lopes.pdf: 2245249 bytes, checksum: 97ec28c68a7d73e9ca22b258465c50c6 (MD5)<br>In this work, thermoplastic polyurethanes (TPU) were synthesized in solution process and reactive extrusion in twin-screw extruder. The TPUs were obtained with the use of pre-polymer based on 4,4´-Methylenediphenyl diisocyanate (MDI) and a polyester functionalized polyol, the bis-2-(hidroxyethyl)ether hidroquinone and the n-phenylaminopropyl-POSS as a second chain extender. The reagents and products were characterized using Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), Thermogravimetric Analysis (TGA), and also capillary rheometry (only for those products). The DSC analysis presence influenced the melting enthalpy (ΔHm) of the TPU synthesized by solution. The samples synthesized through reactive extrusion at 80 ºC presented a higher Tm compared to the 90 ºC TPUs, with a higher ΔHm, suggesting that the temperature favors the formation of a greater number of crystals with a lower medium size. Exothermic phenomena were observed during the heating of samples synthesized in reactive extrusion, probably due to the availability of free isocyanate groups, which were detected by FTIR in the ~2253 cm-1 region. The thermal stability of the TPUs was enhanced by the addition of POSS, while the polymers obtained through reactive extrusion presented higher onset degradation temperatures. The TGA analysis in isothermal conditions showed progressively lower mass loss values in samples obtained by reactive extrusion, demonstrating that the amount of POSS, as well the synthesis temperature, had influence in the final properties of the TPU. The thermal resistance of samples polymerized in reactive extrusion. In capillary rheometry tests, the insertion of POSS in the polymer led to a progressively higher value of intrinsic viscosity of the TPUs, indicating an increase in the mean molar mass of the TPUs obtained through solution synthesis. The same method was applied to the samples obtained through reactive extrusion, which showed similar apparent viscosities, yet the analysis was probably influenced by the degradation of the TPU inside the loading cell, leading to no measurable tendency in the viscosity of the polymer.

Polyhedral oligomeric silsesquioxanes (POSS) have attracted substantial academic interest for many years as hybrid materials and nanofillers for controlling thermal and mechanical properties, and providing thermal and chemical resistance while retaining ease of processing. A natural extension of these studies has been POSS-based amphiphiles and thin film coatings. Studies at the air/water (A/W) interface have shown that trisilanol-POSS derivatives are amphiphilic and form uniform Langmuir films, whereas closed-cage POSS derivatives are hydrophobic and aggregate. In previous work, a triester (POSS-triester) and a triacid (POSS-triacid) were synthesized from PSS-(3-hydroxypropyl)-heptaisobutyl (POSS-OH) and Weisocyanate and fully characterized by surface pressure – area per molecule (Π-A) isotherm and Brewster angle microscopy (BAM) studies at the A/W interface. The results indicated that POSS-triester is surface active forming a liquid expanded (LE) monolayer, whereas POSS-triacid forms a liquid condensed (LC) monolayer that is only weakly affected by pH. A face-on conformation was proposed and examined to understand the packing of POSS-based amphiphilic molecules at the A/W interface. The face-on/vertex-on comparison is rarely discussed for Langmuir monolayers at the A/W interface. In this thesis, three other POSS-based esters were synthesized from POSS-OH and aminopropylisobutyl-POSS (POSS-NH₂) using Weisocyanate and a similar isocyanate containing two tert-butyl protected carboxylic acids. The synthesized materials are characterized by Π-A isotherm and BAM. For POSS-OH based diester (PAlDE) and POSS-NH2 based diester (PAmDE), LE/LC phase transitions were observed in Π-A isotherms over part of the experimentally accessible temperature range and were attributed to a change from a vertex-on to face-on conformation. Apparent BAM images confirmed LC islands coexisted with the LE phase. The experimentally observed dynamic estimates of the critical temperatures (Tc) were estimated from a two-dimensional Clausius-Clapeyron analysis and were consistent with the temperature dependence of the Π-A isotherms. These LE/LC phase transitions are the first observed for POSS amphiphiles.<br>Ph. D.

Polyhedral oligomeric silsesquioxanes (POSS) have attracted substantial academic interest for many years as hybrid materials and nanofillers for controlling thermal and mechanical properties, and for providing thermal and chemical resistance while retaining ease of processing. A natural extension of these studies has been working on POSS-based amphiphiles and thin film coatings. Studies at the air/water (A/W) interface have shown that trisilanol-POSS derivatives are amphiphilic and form uniform Langmuir films, whereas closed-cage POSS derivatives are hydrophobic and aggregate. In this study, two novel POSS derivatives were synthesized from PSS-(3-hydroxypropyl)-heptaisobutyl substituted (POSS-OH) and completely characterized. Weisocyanate reacted with POSS-OH, and a POSS-based triester (POSS-triester) was obtained. Trifluoroacidolysis of the POSS-triester at room temperature afforded the corresponding triacid (POSS-triacid). Purified POSS-OH, POSS-triester, and POSS-triacid were studied by using surface pressure - area per molecule (? -A) isotherms as well as Brewster angle microscopy (BAM) at the air/water (A/W) interface. Compared with previous work on trisilanol-POSS derivatives, the results indicated that POSS-triester was surface active and formed a liquid-expanded (LE) monolayer. In contrast, POSS-triacid monolayers were more condensed (LC) and were not dramatically affected by changes in pH. Results for the lift-off areas (Alift-off), limiting areas (A0), collapse areas (Ac), and collapse pressures (? c) of POSS-OH, POSS-triester, and POSS-triacid were compared to trisilanolisobutyl-POSS (TiBP) and were interpreted in terms of possible molecular conformations. Whereas, TiBP has been hypothesized to exist in a vertex-on conformation, POSS-OH and POSS-triacid packing at the A/W interface was consistent with face-on conformations. For POSS-triester, the isotherm was consistent with a vertex-on conformation at low ? , but a face-on conformation at high ? .<br>Master of Science

Orientador: José de Alencar Simoni<br>Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química<br>Made available in DSpace on 2018-08-25T07:32:13Z (GMT). No. of bitstreams: 1 Riaz_Ali_D.pdf: 5855772 bytes, checksum: b17d5626ad22333e3c2a8cff516ddc1a (MD5) Previous issue date: 2014<br>Resumo: Este trabalho apresenta a síntese e caracterização de compostos silsesquioxanos gaiola cúbica (POSS) com cadeias orgânicas pendentes. O projeto foi iniciado com a idéia de sintetizar os silsesquioxanos cúbicos com cadeias organofuncionalizadas ancoradas, capazes de capturar os metais pesados, corantes e CO2. Mas foram enfrentadas algumas dificuldades como baixo rendimento (30-37%) e longo tempo de reação (5-35 dias). As reações foram investigadas para melhorar o rendimento, bem como para reduzir o tempo de reação. Algumas modificações em rotas de reação foram introduzidas, o que trouxe melhorias notáveis nos resultados, onde o rendimento aumentou cerca de 64 % e o tempo de reação foi reduzido para 24 horas em média. Na sequência, os produtos sintetizados foram caracterizados para elucidar suas estruturas, utilizando diferentes técnicas físicas tais como FTIR, CHN, XRD, MEV, TGA, 13CNMR e 29SiNMR no estado sólido, onde as gaiolas Si-O de todos os compostos foram evidenciadas por meio de 29SiRMN e dos seus espectros de FTIR, enquanto as cadeias ancorados às gaiolas de POSS foram confirmadas utilizando os resultados de 13CRMN, juntamente com seus respectivos espectros de FTIR. Os compostos sintetizados também foram testados quanto à sua estabilidade térmica utilizando a técnica de TGA. Após a otimização da síntese de silsesquioxanos cúbicos, os híbridos PAA-13-3, PAA-MTC e PAA-Ph foram avaliados por suas habilidades de captação de cátions bivalentes, tais como Cu2+, Cd2+ e Pb2+ de suas soluções aquosas, sendo que o Cu2+ apresentou maior afinidade de sorção em relação aos dois metais. Estes sistemas de sorção foram analisados através ICP-OES. Para explicar o comportamento de sorção destas amostras alguns modelos estatísticos como Langmuir, Freundlich, Temkin e Redlich-Peterson foram aplicadas, onde os dados de sorção de Cu2+ em PAA-13-3 foram melhor ajustados pelo modelo Langmuir, mostrando ser uma sorção monocamada, enquanto que no caso do PAA-MTC e PAA-Ph modelo de melhor ajuste foi o Freundlich, confirmando a sorção de múlti camadas. Um dos materiais sintetizados (PAA-13-3) foi avaliado quanto à sua capacidade de adsorver CO2 gasoso, mostrando-se promissor na remoção de CO2, mesmo a baixas pressões (máx. 100 mm Hg). A adsorção de CO2 no material também foi estudada por calorimetria de adsorção gás-sólido, em um calorímetro especialmente desenvolvido para tal, observando-se valores de entalpia de adsorção entre -36 e -7 kJ mol-1<br>Abstract: This report presents the synthesis and characterization of POSS compounds having cubic silsesquioxane cage to which the organic pendant chains are anchored. The project was started with the idea to synthesize the cubic silsesquioxanes with organofunctionalized pendant chains, which are able to capture heavy metals, dyes and some acids like CO2. But in the beginning the hurdles like low % yields (30-37 %) and long reaction times (5-35 days) were to be faced. The reactions were worked out to enhance the % yields as well as to reduce the reaction time. Some modifications in reaction routes have been introduced, which brought up remarkable improvements in the results, where yield was increased upto 64 % and reaction time was reduced to 1 day. All the synthesized products were then characterized for their structure elucidations using different physical techniques like FTIR, CHN, TGA, 13CNMR & 29SiNMR in solid state, where Si¿O cages of all compounds were elaborated through 29Si-NMR in solid state as well as through their respective FTIR patterns, while the pendant chains anchored to the POSS cages were confirmed using 13C-NMR results along with their respective FTIR spectra. The synthesized compounds were then tested for their thermal stability using the TGA technique. After optimizing the synthesis of cubic silsesquioxanes, hybrids PAA-13-3, PAA-MTC and PAA-Ph were worked out for their abilities of capturing divalent cations like Cu2+, Cd2+ and Pb2+ from their aqueous solutions, where Cu2+ showed higher affinity of sorption than other two bivalent metals. These sorption systems were analyzed using the ICP-OES. To explain the sorption behaviour of these samples some statistical models like Langmuir, Freundlich, Sips, Temkin and Redlich-Peterson were applied to the sorption data, where the data for Cu2+ on to PAA-13-3 was best fitted by Langmuir adsorption isotherm model showing the sorption to be monolayer, while in case of PAA-MTC and PAA-Ph Freundlich model was found to be a best fit, confirming multilayer sorption. One of the synthesized materials (PAA-13-3) was also evaluated for its ability to adsorb gaseous CO2 and was proved to be promising in removing CO2, even at low pressures (max. 100 mmHg). The adsorption of CO2 in the material is also studied by solid-gas adsorption calorimetry through a calorimeter especially developed for this system, where enthalpy of adsorption values were found to be between -7 and -36 kJ mol-1<br>Doutorado<br>Quimica Inorganica<br>Doutor em Ciências

There is currently an unmet clinical need for biocompatible conductive materials used for biomedical applications, which is crucial for the next generation surgical implants and medical devices development. Metallic alloys are ubiquitous in conductive materials, but in medical applications may not be suitable due to their toxicology. The aim of this work was development of conductive materials using graphene nanoparticles incorporated with polymer. This thesis started with the characterization of pristine monolayer nano-diamond and terminated ND with hydrogen and oxygen. First, the monolayer NDs coated on the cover slip then terminated with hydrogen and finally terminated with oxygen. The AFM indicated the RMS roughness of ND, HND, and OND increased respectively. The contact angle indicated the most hydrophilic on the oxygen terminated ND sample, due to the oxygen termination, its C-O, or C=O polar bonding. In contrast the hydrogen terminated ND showed the least hydrophilicity, due to its hydrogen bonding. I also cultured Schwann cell on all samples and results showed promising metabolic activity and cell proliferation in comparison with TCP. The thesis continued with investigation on the development and subsequent elucidation of a novel biocompatible conductive material applying polyhedral oligomeric silsesquioxane (POSS) nano-cages incorporated into modified poly[caprolactone based urea-urethane] (PCL)/graphene hybrid nanocomposite, POSS-PCL-G. Manufacturing methods, characterizations and biological assays are presented to establish the role of the biocompatible conductive POSS-PCL-G with unique physiochemical surface properties. Multilayer graphene flakes were homogeneously dispersed into POSS-PCL using two methods, non-thermally and thermally controlled with different concentration ranges and then casted. Methods of processing were binary mixing and solution intercalation (non-thermally controlled) at range of 0.1 to 10wt.%. In second method (thermally controlled), the graphene and POSS-PCL were mixed in presence of hydrazine hydrate and the temperature maintained at 100°C at ranges 0.08 to 4wt.% respectively. Chemical properties on both methods indicated the non-covalent bonding, and Raman spectroscopy depicted the higher G peak as the graphene concentration increased. The Raman spectroscopy also indicated less disorder as the graphene concentration increased. The morphology measured by AFM showed the phases are merged at the interfaces on both methods. Furthermore, SEM illustrated that the POSS particle in the POSS-PCL observed at the surface and as the graphene concentration increased the POSS particles covered by graphene. Mechanical properties on the non-thermally controlled indicated at 10wt.% the Young modulus drastically increased. However, on thermally controlled method the Young modulus introduced very small change and almost the same as POSS-PCL. Electrical conductivity was measured with Impedance spectroscopy and the electron mobility and charge concentration conducted by Hall measurement. The Impedance spectroscopy measurement was implemented from 0.1Hz to 1MHz, and the Hall effect voltage measured within the temperature range 10 to 50oC.In the non-thermally controlled method, the electrical conductivity of 1.30x10-4 SCm-1 achieved at 10wt.%. In contrast the thermally controlled showed 4wt.% with electrical conductivity of 9.34x10-5Scm-1, which is approximately the same conductivity as the 10wt.% with previous method. From the non-thermally controlled method the percolation threshold occurred at 5wt.% graphene flakes concentration with conductivity of 2x10-5SCm-1 and thereafter used for biomedical application. Subsequently, the thermally controlled solution intercalation of the graphene and POSS-PCL was conducted to reduce the percolation threshold to 0.08wt% and resulted in conductivity of 1.49x10-7SCm-1. In addition the electron concentration observed at 5.0 and 10.0wt.% on the non-thermally controlled with 2x1015 and 4x1017cm-3 respectively, and the mobility showed 4 and 10cm2/Vs respectively at room temperature. In contrast I could measure the electron concentration at 1.6 and 4.0wt% on thermally controlled method with 9x1014 and 9x1017cm-3 respectively, and the mobility showed 2.5 and 7.5cm2/Vs respectively. There weren't any mobility observed at 2.0wt.% on the non thermally controlled. In addition, on the non-thermally controlled even 3.0 or 4.0% didn't show any electrical conductivity. Material characterization and toxicity study performed on the finished product demonstrated superior and optimum graphene flakes composite into polymer forming conductive polymer. In vitro metabolic activity and proliferation based on Schwann cells cultured on the samples studied. All samples indicated better metabolic activity and proliferation compared to the POSS-PCL. One-way analysis of variance (ANOVA) used to analysed the data. A statistically significant result justifies the null hypothesis rejection, for a probability less than 0.05, 0.01, and 0.005 (significance level). It is therefore envisioned that the conductive graphene-POSS-PCL may be used as a novel biomaterial for medical applications. In my knowledge this is first bio absorbable conductive Nanocomposite material developed for biomedical application.

Neste trabalho foram estudados compósitos que apresentam como matriz polimérica uma blenda composta por polietileno de alta densidade (HDPE) e copolímero etileno acetato de vinila (EVA) e como nanocarga, silsesquioxano poliédrico oligomérico (POSS). Os compósitos foram processados em câmara de mistura fechada e caracterizados quanto às propriedades térmicas e morfológicas. Para a preparação dos compósitos foram variadas as concentrações dos componentes da blenda (0, 25, 50, 75 e 100%) e da nanocarga (0, 0,5, 1, 1,5, 2, 5 e 10%). Os resultados de processamento mostraram que o aumento da concentração de POSS na matriz polimérica provocou a agregação do mesmo na matriz polimérica. As análises de calorimetria diferencial de varredura e termogravimetria indicaram que o POSS não afetou as temperaturas de fusão, cristalização e degradação da matriz polimérica. Os resultados de raios X indicaram que a presença do EVA no compósito promoveu o aparecimento de domínios cristalinos em concentrações menores de POSS. A microscopia eletrônica de varredura indicou que as amostras com 1% de POSS apresentam distribuição homogênea na matriz polimérica. Por outro lado, ocorreu a formação de agregados nas amostras com 5% de POSS. Os valores de Tg obtidos por análise térmica dinâmico-mecânica indicaram que o POSS causou um efeito plastificante na fase HDPE e uma redução da mobilidade na fase EVA. Ocorreu um aumento nos valores de módulo de armazenamento com a incorporação de POSS na matriz polimérica.<br>Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-05-22T19:03:21Z No. of bitstreams: 1 Dissertacao Patricia Scapini.pdf: 2020883 bytes, checksum: 2c7249d3915135dd5f3cba151cf459db (MD5)<br>Made available in DSpace on 2014-05-22T19:03:21Z (GMT). No. of bitstreams: 1 Dissertacao Patricia Scapini.pdf: 2020883 bytes, checksum: 2c7249d3915135dd5f3cba151cf459db (MD5)<br>In this study composites with a polymeric matrix comprising a blend of high density polyethylene (HDPE) and the copolymer ethylene vinyl acetate (EVA), and with polyhedral oligomeric silsesquioxane (POSS) as the nanoclay, were processed and characterized. The composites were processed in a closed mixing chamber and characterized in terms of their thermal and morphological properties. For the preparation of the composites the concentrations of the blend components (0, 25, 50, 75 and 100%) and of the nanoclay (0, 0.5, 1, 1.5, 2, 5 and 10%) were varied. The results of the processing showed that an increase in the POSS concentration in the polymeric matrix caused the aggregation of the system. The differential scanning calorimetry and thermogravimetry analyses indicated that the POSS did not affect the melt, crystallization and degradation temperatures of the polymeric matrix. The X-ray results indicated that the presence of EVA in the composite led to the appearance of crystalline domains at lower POSS concentrations. Scanning electron microscopy indicated that the samples with 1% of POSS have a homogeneous distribution in the polymeric matrix. However, the formation of aggregates occurred in samples with 5% of POSS. The Tg values obtained from the thermo dynamic mechanical analysis indicated that the POSS had a plasticizing effect on the HDPE phase and caused a reduction in the mobility of the EVA phase. There was an increase in the storage modulus values with the incorporation of POSS into the polymeric matrix.

Poliuretanos termoplásticos (TPU) foram sintetizados em batelada, utilizando-se um misturador fechado (reômetro de torque), em três diferentes temperaturas (70, 80 e 90°C), a partir de dois pré-polímeros com diferentes teores de isocianato (NCO) (10,5 e 18% em massa), obtendo-se dois TPU com diferentes quantidades de fase rígida (45 e 65% em massa). Também foi avaliada a reação entre o diisocianato de 4,4’-difenilmetano (MDI) e o 1,4- butanodiol (BDO), bem como a reação do MDI com o oligômero poliédrico de silsesquioxano trisilanol de isooctila (POSS). A cinética de polimerização de TPUs contendo 0, 0,23, 0,57, 1,14 e 2,28% em massa de POSS foi estudada a partir de ensaios de calorimetria exploratória diferencial (DSC) e de reometria oscilatória. Por fim, foram sintetizados TPUs contendo POSS através de um processo contínuo, utilizando-se uma extrusora dupla-rosca co-rotante interpenetrante, a uma temperatura de 70°C. As amostras foram caracterizadas por espectroscopia de infravermelho com transformada de Fourier (FTIR), difração de raios-X (DRX), microscopia eletrônica de varredura (MEV), cromatografia por exclusão de tamanho (SEC), DSC, análise termogravimétrica (TGA), análise térmica simultânea (SDT) acoplada a espectrômetro de infravermelho e análise termo-dinâmico-mecânica (DMA). Os resultados das amostras sintetizadas em batelada mostraram que o aumento na quantidade de fase rígida promoveu um aumento na temperatura de transição vítrea (Tg) da fase flexível do TPU. Com a modificação das variáveis nas sínteses em batelada, houve modificações nos comportamentos de cristalização, perda de massa, e no mecanismo de degradação, indicando a ocorrência de reações laterais. O polímero obtido a partir de MDI e POSS apresentou maior estabilidade térmica. Houve uma tendência de aumento nos valores de energia de ativação de síntese com o aumento da quantidade de POSS. A adição de POSS nos TPUs obtidos via extrusão reativa não afetou a massa molecular dos poliuretanos, mas ocasionou a formação de domínios ricos em POSS, observados nas análises de DRX e MEV. A incorporação de POSS aumentou a estabilidade térmica do poliuretano, tornando este material menos propenso a mudanças nos processos de fusão e cristalização em função da exposição a temperaturas elevadas. A incorporação de até 1,14% em massa promoveu um aumento na energia de ativação de degradação. A adição de POSS modificou o mecanismo de degradação do poliuretano, bem como alterou a mobilidade dos segmentos flexíveis, conforme observado nas análises de DMA.<br>Thermoplastic polyurethanes (TPU) were synthesized in an instrumented batch mixer (torque rheometer) at three different temperatures (70, 80 and 90°C) from two pre-polymers with different amounts of isocyanate (NCO) (10.5 and 18% by weight), yielding two TPU with different rigid phase contents (45 and 65% by weight). Also, the reactions between 4,4'- diphenylmethane (MDI) and 1,4-butanediol (BDO), or MDI and polyhedral oligomeric silsesquioxane of isooctyl-trisilanol (POSS) were studied. The polymerization kinetics TPUs containing 0, 0.23, 0.57, 1.14 and 2.28 wt% of POSS were studied from differential scanning calorimetry (DSC) and oscillatory rheometry analysis. Later, TPUs containing POSS were synthesized in a continuous process, by a co-rotating interpenetrating twin-screw extruder at 70°C. The samples were characterized by Fourier transform infrared spectroscopy (FTIR), Xray diffraction (XRD), scanning electron microscopy (SEM), size exclusion chromatography (SEC), DSC, thermogravimetric analysis (TGA), simultaneous thermal analysis coupled to an infrared spectrometer (SDT) and thermo-dynamic mechanical analysis (DMA). The samples synthesized in the batch mixer showed that the increase in the rigid phase content promoted an increase in glass transition temperature (Tg) of the rubber phase. Changing the variables of the synthesis promoted changes in crystallization behavior, weight loss, and degradation mechanism, indicating the occurrence of side reactions. The polymer obtained from MDI and POSS showed higher thermal stability. There was an increase trend in activation energy values with increasing in POSS content. The addition of POSS in the TPUs obtained by reactive extrusion did not affect the molecular weight of polyurethanes, but led to the formation of POSS-rich domains, observed in the XRD and SEM analysis. The incorporation of POSS increased the thermal stability of polyurethane, making the melting and crystallization processes less sensitive of exposure to high temperatures. The incorporation of up to 1.14 wt% caused an increase in the activation energy of degradation. The addition of POSS modified the degradation mechanism of polyurethane, as well changed the soft segments mobility, as observed in the DMA analysis.

Le présent travail vise la synthèse d’organosilices nano-structurées à partir de briques élémentaires de silsesquioxanes polyédriques fonctionnalisées (T8-POSS) de structure cube (RSiO1,5)8. L’assemblage de briques fonctionnelles T8-POSS a été étudié selon deux voies : par des interactions fortes en formant des liaisons covalentes et par des interactions faibles en formant des liaisons hydrogène.La première partie décrit la formation de réseaux hybrides covalents à partir de structure T8 POSS portant huit fonctions aldéhydes. La synthèse et la structure cristalline de ces « cubes » fonctionnalisés sont décrites et la réactivité des fonctions aldéhydes est examinée. La formation de liaisons C=N par réaction d’amines conduit à des réseaux tridimensionnels grâce à la formation de ponts organiques bis-imines joignant les unités silsesquioxanes. Bien que la formation d’imine soit réversible, les solides obtenus ne présentent pas d’ordre à longue distance. La formation de liaisons C=C, dans des conditions de synthèse non réversibles, par réaction de bis-ylures de phosphonium avec les aldéhydes a également été étudiée. Ces réactions de type Wittig engendrent la formation de réseaux hybrides amorphes contenant des sous-structures phenylène-vinylènes dotées de propriétés de fluorescence. La deuxième partie décrit la synthèse de nouvelles molécules de T8-POSS, possédant des fonctions organiques amines ou acides carboxyliques capables d’interactions intermoléculaires grâce à des liaisons hydrogène. Ces interactions permettent l’assemblage des dérivés du T8-POSS fonctionnalisés par huit fonctions acides carboxyliques en un réseau 3D ordonné. Les briques élémentaires T8- POSS s’auto-assemblent par dimérisation des fonctions acides pour engendrer des silices hybrides cristallines. Les structures ont été déterminées par diffraction de rayons X. Les fonctions acides carboxyliques sont intéressantes non seulement par leur capacité à former des liaisons hydrogènes mais également par leur aptitude à former des carboxylates métalliques. Ces derniers ouvrent des perspectives pour la formation de réseaux d’oragnosilices incorporant des métaux<br>The present work aimed at synthesising nano-structured organosilicas using polyhedral silsesquioxane building blocks (T8-POSS) having a cube structure. The assembly of T8-POSS building blocks to form a 3D network was studied in two ways: first by formation of strong covalent bonds and secondly by formation of weak hydrogen bonds.The first part described the formation of covalent hybrid networks from T8-POSS structures with eight aldehyde functional groups. The synthesis and crystal structure of these functionalised silsesquioxane cubes is described and the reactivity of the aldehyde groups is studied. The formation of C=N bonds upon reaction with amines lead to tree-dimensional networks upon formation of bis-imine bridges linking the silsesquioxane units. Despite the imine formation was reversible, the resulting solids were amorphous materials and exhibited no long distance order. The formation of C=C bonds, under non-reversible reaction conditions, was achieved by reaction of phosphonium bis-ylides. The Wittig type reactions generated amorphous hybrid networks containing bridging phenylene-vinylene substructures with fluorescence properties.The second part described the synthesis of new functionalised T8-POSS cubes with eight amine or carboxylic acid functions capable of intermolecular interactions by hydrogen bonding. It allowed the assembly of the octa-carboxylique acid cubes to form an ordered 3D hybrid network. The T8-POSS building blocks self-assembled upon dimerization of the acid groups and generated crystalline hybrid silicas. The crystal structures were determined by X-ray diffraction. The use carboxylic acid groups is interesting because of its ability to form hydrogen bonds and also because of its ability to form metal carboxylate derivatives. It could lead to hybrid metal organic silica frameworks

This PhD thesis investigated the incorporation of Polyhedral Oligomeric Silsesquioxanes (POSS) in thermoplastic base materials via melt-blending procedures. Particularly, a focus is taken on the enhancement of the thermal resistance through the addition of different types of POSS on two popular engineering plastics known by their low thermal stability, one being a semi-crystalline copolymer i.e. polyoxymethylene (POM) and the other an amorphous copolymer i.e. acrylonitrile butadiene styrene grafted with maleic anhydride (ABS-g-Ma). Different nanocomposites have been produced, from which its morphology, miscibility, structure, thermal properties and appearance behaviour before and during the thermoxidative degradation is herein quantified and discussed together with the resulting benefits and drawbacks. All the nanocomposites have been produced via melt-blending, using the nanofillers Glycidyl, Glycidyl-Isobutyl, Aminopropyl-isobutyl and Poly(ethylene-glycol) for the POM matrix, and Amino-Propyl Isobutyl, Glycidyl, and Trisilanol for the ABS-g-Ma matrix. The incorporation adequacy of the nanofillers into the matrix has been pre-assessed with the Hoy¿s solubility calculation method and later on corroborated with scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The quantification of the thermal degradation behaviour of each sample at different temperatures and exposure times was carried out through Fourier transform infrared spectrography (FTIR), thermogravimetric analysis (TGA) including the degradation kinetics and, ultimately, the sample appearance progress has been assessed in terms of yellowing by means of colour spectrophotometry (Cielab). The results showed that the presence of different POSS's used with the POM matrix improves dramatically the thermal stability of the base material and that such improvement is proportionate to the solubility compatibility between matrix and the nanofiller. The best performance was found with Aminopropyl-isobutyl, whereby the temperature of maximum rate of degradation (TMAX) increased by 22ºC. Said improvement is also seen in the conditions at which the nanocomposite developed only 2% of carbonyl yield and 8% of yellowing compared to the standard POM copolymer, which is taken as the base reference with 100% deterioration suffered in the above two indicators. However, the performance of the different nanocomposites produced in this work with ABS-g-Ma has not been as encouraging as the POM-based nanocomposites described above. Although the SEM morphological analysis show adequate incorporation and miscibility of the nanofillers into the matrix, the GPOSS and the TPOSS nanocomposites provided no relevant improvements in thermal stability when compared to the base ABS-g-Ma, and the APOSS blend exhibits a very slight decay in almost all the quantitative analysis carried out in this work.<br>Los avances producidos en años recientes en el campo de la nanotecnología y sus aplicaciones en los materiales están aportando grandes mejoras en el rendimiento de los mismos en áreas como la resistencia mecánica, estabilidad térmica, propiedades ópticas y eléctricas, entre otras. Por otro lado, el mundo de la ingeniería y el diseño de componentes plásticos está llevando los materiales cada vez más a su límite, con el fin de poder ofrecer el máximo rendimiento al mínimo coste. Esta realidad implica la necesidad creciente de customizar estructuras poliméricas con propiedades mejoradas en áreas específicas para cada aplicación. A pesar de los desarrollos que se han estado produciendo últimamente en nanocompuestos termoplásticos, el conocimiento en este campo es aún limitado, y requiere de más iniciativas de investigación y desarrollo sobre el amplio campo de posibilidades que nos ofrecen los nanocompuestos. El objetivo de esta tesis es contribuir en el conocimiento de los nanocompuestos a través del estudio de los efectos de varias nanocargas del tipo Polyhedral Oligomeric Silsesquioxanes (POSS) en el comportamiento de la resistencia térmica del copolímero semicristalino polióxido de metileno (POM) y del terpolímero amorfo acrilonitrilo‐butadieno‐estireno (ABS), los cuales son dos plásticos técnicos susceptibles a la termoxidación. Diferentes nanocompuestos se han elaborado con el fin de estudiar su morfología, miscibilidad, estructura, propiedades térmicas y apariencia, así como los beneficios y contrapartidas que resultan de ellos. Los nano‐compuestos han sido elaborados mediante el método de mezcla en estado fundido (melt‐blending), utilizando cuatro nano‐cargas distintas para el POM, siendo Glicidil, Glicidil‐Isobutil, Aminopropil‐isobutil y Poli(etilen‐glicol), y tres nano‐cargas para el ABS, siendo Amino‐Propil Isobutil, Glicidil y Trisilanol La compatibilidad teórica de las nano‐cargas se ha calculado mediante el método de solubilidad de “Hoy”, y se ha corroborado con microscopia electrónica de barrido (SEM) y calorimetría diferencial de barrido (DSC). Posteriormente, cada material base y sus distintas variantes de nano‐compuestos se han sometido a diferentes condiciones de termo‐oxidación en términos de temperatura y tiempo de exposición. El comportamiento a la degradación de cada muestra se ha cuantificado mediante los métodos de espectroscopia de infrarrojos por transformada de Fourier (FTIR), análisis de termogravimetría (TGA) incluyendo cinética de degradación, y finalmente mediante espectrofotometría (Cielab) para definir el progreso de la apariencia de la muestra en términos de amarilleamiento. Los resultados derivados de la inclusión de los diferentes POSS utilizados en la matriz de POM han mejorado sustancialmente la estabilidad térmica del mismo, y dicha mejora es proporcional a la compatibilidad de solubilidades entre el POM y los POSS utilizados. El mejor comportamiento se produce con la incorporación de la nanocarga aminopropilisobutil, con una temperatura de máxima degradación (TMAX) incrementada en 22 ºC sobre la TMAX del POM original tomado como referencia. Esta mejora se refleja también con una reducción muy notable en la formación grupos carbonilo y en el amarilleamiento sufrido en la superficie de la muestra, siendo un 2% y 8% respectivamente comparados con los resultados obtenidos con la muestra equivalente del material POM original. En referencia a los nanocompuestos basados en ABS‐g‐Ma, a pesar de la adecuada solubilidad teórica entre la matriz y las diferentes nano‐cargas, así como la buena miscibilidad obtenida en la elaboración de las muestras y evidenciada en el análisis morfológico SEM, no se han podido obtener mejoras en términos de estabilidad térmica. Concretamente, la adición de GPOSS y TPOSS no han aportado beneficios relevantes en las propiedades del nanocompuesto final, y la nanocarga APOSS ha incluso afectado negativamente a la matriz con una ligera caída de la resistencia térmica.<br>Els avenços produïts en els últims anys tant en el camp de la nanotecnología com en les seves aplicacions en els materials, està contribuint en la millora del rendiment dels mateixos en àeras com la resistència mecànica, l’estabilitat tèrmica, i les propietats òptiques i elèctriques entre d’altres. Per altra banda, el món de l’enginyería i el disseny de components plàstics està portant els materials cada vegada més al seu límit amb la finalitat de poder oferir el màxim rendiment al mínim cost, i això comporta una necessitat creixent de customitzar les estructura polimèriques amb propietats especificament millorades en àreas molt concretes en funció de l’aplicació requerida. A pesar del desenvolupament que s’ha estat produint últimament en l’àrea de nanocompostos plàstics, el coneixement en aquest camp és encara limitat, i requereix de més iniciatives d’investigació per cobrir el potencial que ofereix aquesta classe de materials, així com conèixer també les seves limitacions. L’objectiu d’aquesta tesi es el de contribuïr en l’enteniment dels nanocompostos plàstics a través de l’estudi dels efectes de vàries nanocàrregues del tipus Polyhedral Oligomeric Silsesquioxanes (POSS) en el comportament de la resistència tèrmica del poli(òxid de metilè) (POM) com a material semicristalí, i l’acrilonitril‐butadiè‐estirè (ABS) com a material amorf. Val a dir que la selecció d’aquests dos polímers tècnics ha estat en part motivada per la seva susceptibilitat inherent a la termodegradació. Diferents nanocompostos basats amb aquests materials s’han elaborat amb la finalitat d’estudiar la seva morfología, miscibilitat, estructura, propietats tèrmiques i aparença, així com els beneficis i contrapartides que resulten d’ells. La preparació dels nanocompostos ha sigut mitjançant el mètode de barreja en estat fos (melt‐blending), util.litzant quatre nano‐càrregues diferentes per el POM, siguent glicidil, glicidil‐Isobutil, aminopropil‐isobutil y poli(etilenè‐glicol), i tres nano‐càrregues per el ABS, siguent amino‐propil isobutil, glicidil i trisilanol. La compatibilitat teòrica de les nano‐càrregues s’ha calculat mitjançant el mètode de solubitat de “Hoy”, i s’ha corroborat amb microscopia electrònica d’escombrat (SEM) i calorimetría diferencial d’escombrat (DSC). Posteriorment s’ha sotmès cada material base i les seves diferents variants de nanocompostos a diferents condicions de termo‐oxidació en termes de temperatura i temps d’exposició. El comportament a la degradació de cada mostra s’ha quantificat mitjançant els mètodes d’espectroscopía d’infraroigs per transformada de Fourier (FTIR), anàlisis de termogravimetría (TGA) incloent cinemàtica de degradació, i finalment mitjançant espectrofotometría (Cielab) per a definir el progrés de l’aparença de la mostra en termes d’engroguiment. Els resultats han mostrat, per una banda, que la inclusió dels diferents POSS util.litzats en la matriu de POM ha millorat substancialment l’estabilitat tèrmica del mateix, i aquesta millora és proporcional a la compatibilitat entre les solubitats del POM i del POSS. El millor comportament s’ha produït amb l’adició de la nano‐càrrega d’aminopropilisobutil, amb una temperatura de màxima degradació (TMAX) millorada en 22ºC en relació a la obtinguida amb la matriu de POM. Aquesta millora també es reflexa amb una reducció molt notable en la formació de grups carbonil i en l’engroguiment sofert en la superfície de la mostra, siguent un 2% i 8% respectivament comparats amb els resultats obtinguts amb la mostra equivalent del material POM original. En contrast, els nanocompostos basats en ABS‐g‐Ma no han ofert millores en termes d’estabilitat tèrmica, a pesar d’una adequada solubitat teòrica entre la matriu i les diferents nano‐càrregues util.litzades, així com la bona miscibilitat obtinguda en l’elaboració de les mostres i posteriorment evidenciada en l’anàlisi morfològic SEM. Concretament l’adició de GPOSS i de TPOSS no han aportat beneficis en les propietats del nanocompostos final, i la nano‐càrrega APOSS ha afectat negativament a la matriu amb una lleuguera caiguda de la resistència tèrmica

This work is generally aimed to synthesize POSS based BCPs via RAFT polymerization, to study their self-assembly behaviors, to research on the effect of POSS self-assembly structure on the bulk properties and to prepare nanostructured hybrid epoxy via self-assembly of POSS based copolymer. In Chapter1, We studied the RAFT polymerization of POSS macromers and capable to synthesize well defined POSS based BCPs with high POSS fraction and different topology such as AB，BAB and (BA)3. The vertex group and the morphology effect on thermo-mechanical properties of POSS based BCPs as well as the structure-property relationship was investigated. Dispersion RAFT polymerization in apolar solvent was applied and various aggregates with different morphology in Chapter2. Cooling induced reversible micelle formation and transition was found and the pathway selection in vesicle formation was investigated. Nano-construction of O/I hybrid epoxy materials based on POSS based copolymers was investigated in Chapter4. The effect of functional group content on miscibility of POSS based statistic copolymer and epoxy was investigated. A novel method to nanostructure epoxy hybrid involving self-assembly of POSS based BCPs in epoxy was presented. High homogeneity and well size/morphology control of core-corona structure containing rigid POSS core and soluble PMMA corona in networks were obtained.

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 2007.<br>Includes bibliographical references.<br>Polymers are known to exhibit strong time-dependent mechanical behavior. In different temperatures or frequency regimes, the rate sensitivities of polymers change as various primary and secondary molecular mobility mechanisms are accessed. The incorporation of nanoparticles can potentially alter the molecular level structure of polymer, offering the opportunity to tailor the rate-dependent mechanical deformation and failure behavior of the polymer. This study focuses on polyhedral oligomeric silsesquioxanes (POSS) enhanced polymeric systems. POSS are hybrid organic-inorganic nano-scale molecules which consist of a silica cage with functional groups attached to the cage comers. Various binary and ternary polymer blends were produced by incorporating methacryl-POSS (C56I88,28Si8) (mPOSS) and dioctyl phthalate (DOP) into poly(vinyl chloride) (PVC) through melt blending. mPOSS was found to be miscible with PVC up to 15 wt% added. Both mPOSS and DOP plasticize PVC and reduce the [alpha]-transition temperature. While mPOSS also reduces the secondary ([beta]) transition temperatures in PVC, DOP was found to restrict the p-relaxation motions.<br>(cont.) The rate-dependent yield and postyield behavior was characterized in compression testing over a wide range of strain rate (10-4/s to [approx.] 4000/s). Due to the geometric and size distinctions between the two molecules, mPOSS and DOP have different influences on PVC local molecular motions, resulting in dissimilar mechanical behavior. A clear rate-dependent sensitivity transition in yield was observed in the pure PVC and PVC/mPOSS blends in the intermediate strain rate regime, which is attributed to the need for stress-assisted activation of [beta]-motions at high strain rates. A transition in rate sensitivity was also identified in high DOP content compounds; this transition is due to the [alpha]-transition. The potential of using POSS as a plasticizer for PVC was evaluated. Through the use of ternary compositions, the proportion of mPOSS in PVC was increased substantially. The T8 of appropriately formulated ternary PVC/mPOSS/DOP compounds can be reduced to near room temperature, and these materials exhibit desirable ductile behavior. A constitutive model was used to predict the large deformation behavior of the PVC compounds. The two-process model is shown to capture the rate-sensitivity transitions in yield and the large deformation stress-strain behavior at low and high strain rates.<br>by Sharon Yu-Wen Soong.<br>Ph.D.

Auricular reconstruction using sculpted autologous costal cartilage following congenital microtia, trauma and cancer is effective, but complex, time consuming and may incur donor site morbidity. Current conventional synthetic alternatives are associated with infection and extrusion. A novel nanocomposite polymer based on polyhedral oligomeric silsesquioxane (POSS) covalently bonded to poly(carbonate-urea-urethane) (PCU), has developed and patented in our laboratory and displayed promising clinical applications in first-in-human. POSS-PCU has been utilised to develop synthetic 3D auricle construct for use as auricular cartilage replacement, which aims to reduce extrusion rates by mimicking the mechanical properties of human ears and by encouraging desirable cellular interactions. Methods & Material: A novel custom-made ear-shaped 3D negative glass-mould was fabricated from positive 3D-printing ear model of a CT scan obtained from the external part of the human ear. This glass-mould was used to manufacture 3D auricular scaffolds using POSS-PCU materials. Two novel fabrication techniques solvent-evaporation/porogen-leaching (POSS-PCUs) and phase-separation/porogen-leaching (POSS-PCUc) were developed to produce nanocomposite scaffolds. The fabrication, physicochemical properties (including nanoscale topography) and in-vitro cellular interactions of these novel fabricated nanocomposites were extensively studied and compared to current commercially available synthetic material (Medpor®). Further cell-material interactions were completed on the optimized POSS-PCUs and Medpor® to examine the angiogenic and inflammatory responses to these materials using human fibroblasts and macrophages. Finally, POSS-PCUs scaffolds with two different pore sizes ranging from 50-100µm & 150-250µm were subcutaneously evaluated compared with Medpor® in-vivo in a rodent model for up-to 3 months. Results: The glass-mould design using 3D-printing technology allowed the manufacture of customised auricular POSS-PCU scaffolds that replicated the original human auricle. Two different polymeric fabrication methods resulted in the production of two types of nanocomposite scaffolds with same average pore size (150µm) but different porosity (63.47±1.35% in POSS-PCUs & 85.21±1.19% in POSS-PCUc). POSS-PCUs had similar elastic modulus (5.73±0.17 MPa) to human ear cartilage (5.02±0.17 MPa) compared with POSS-PCUc (0.58±0.12 MPa) and Medpor® (140.9±0.04 MPa) elastic modulus which were significantly different (P<0.001). Optimised POSS-PCUs nanocompoiste showed greater protein adsorption, and subsequently increased fibroblast adhesion, growth, and collagen production in vitro, compared to Medpor®. A higher volume fraction of fibrotic tissue ingrowth with negligible capsular formation was achieved in vivo in POSS-PCUs with pore-sizes of 150-250µm than Medpor®. No evidence of chronic inflammation was observed in the implanted scaffolds. Conclusion: These findings as well as other clinical studies in man suggest that POSS-PCUs nanocomposite can be a promising biomaterial for auricular reconstruction.

Made available in DSpace on 2015-04-14T14:12:21Z (GMT). No. of bitstreams: 1 400100.pdf: 23677608 bytes, checksum: 4198966303b96f0d08f51404b89a14b4 (MD5) Previous issue date: 2007-12-18<br>Esse trabalho teve como objetivo principal investigar de que forma a Educa??o Matem?tica pode contribuir para a Educa??o para a Paz e o desenvolvimento de Valores Humanos como amor, coopera??o, respeito e honestidade. Foram propostos tr?s projetos, que foram analisados e validados, verificando como essas propostas estavam relacionadas com a Educa??o para a Paz, como repercutiram no aprendizado do aluno e em seu relacionamento com os outros. Para o desenvolvimento das atividades, utilizaram-se conhecimentos relacionados diretamente ? Etnomatem?tica, envolvendo alunos das 5? e 6? s?ries do Ensino Fundamental e a valoriza??o do conhecimento dos alunos, de suas fam?lias e de outros grupos da comunidade. Foram estudados textos, livros e artigos, principalmente de Jares, Guimar?es e Stephan, que tratam da import?ncia de Educar para a Paz. Para a an?lise das atividades, foi utilizada a Pesquisa Qualitativa. As atividades propostas tiveram repercuss?o direta na aprendizagem dos alunos e, foi poss?vel refletir a respeito de atitudes de cidadania, respeito, amizade, entre outros valores que contribuem para a Educa??o para a Paz. Percebe-se que a mudan?a ? poss?vel, mas n?o ? simples. Torna-se necess?rio buscar caminhos, o que deve ser uma tarefa di?ria do professor, da escola e de todos que querem uma verdadeira transforma??o na educa??o.

Developing methods to detect, adsorb, and decompose chemical warfare agents (CWAs) is of critical importance to protecting military and civilian populations alike. The sorption of dimethyl methylphosphonate (DMMP), a CWA simulant, into trisilanolphenyl-POSS (TPP) films has previously been characterized with reflection absorption infrared spectroscopy, x-ray photoelectron spectroscopy, and uptake coefficient determinations [1]. In our study, the quartz crystal microbalance (QCM) is used to study the sorption phenomena of DMMP into highly ordered Langmuir-Blodgett (LB) films of TPP. In a saturated environment, DMMP sorbs into the TPP films, binding to TPP in a 1:1 molar ratio. Although previous work indicated these DMMP-saturated films were stable for several weeks, DMMP is found to slowly desorb from the TPP films at room temperature and pressure. Upon application of vacuum to the DMMP-saturated films, DMMP follows first-order desorption kinetics and readily desorbs from the film, returning the TPP film to its original state. [1] Ferguson-McPherson, M.; Low, E.; Esker, A.; Morris, J. J. Phys. Chem. B. 2005, 109, 18914.<br>Master of Science

A series of hybrid component based on reactive polyhedral oligomeric silsesquioxane(POSS) precusors and its reactive copolymers of PGMA were synthesized and utilized to nanobuild in epoxy. Reactive POSS and copolymer dispersed in homogenous in matrix, overcomed POSS-POSS interaction, which resulted in macroscale phase separation. The nanocomposites obtained were analyzed by Scanning electron microscopy, Transmission electron microscopy, X-ray scattering and dynamic mechanical. An analogue of POSS (denoted as POSSMOCA) was synthesized via addition reaction, which had reactive amino group bonding into epoxy network and improved the thermostability, because of the structural silicon, nitrogen and halogen. Epoxy/polyhedral oligomeric silsesquioxanes (POSS) hybrid composites were prepared from prereaction between trifunctional silanol POSS-OH and diglycidyl ether of bisphenol A (DGEBA) via silanol and the oxirane group. Reactive POSS-PGMA was polymerized via Reversible addition-fragmentation transfer polymerization. It was easy to tail the compatibility of the epoxide block copolymer with a step-growth polymerized matrix, to form nanostructure via reaction with PGMA segements. In the case of inert POSS-PMMA copolymers modified epoxy, topology of copolymer defined the final morphology and interaction between epoxy and them, because of directional hydrogen bonding and dilution effect. Tg of different epoxide conversion, obeyed of Gordon-Taylor equation and Kwei equation, k which reflected the interaction of modifier and DGEBA/MEDA and epoxy/amine oligomers, was consistent of the rheology and dynamic results.

Made available in DSpace on 2015-04-14T13:38:59Z (GMT). No. of bitstreams: 1 452450.pdf: 562766 bytes, checksum: d4eadde7201fbd4b74a2d5b905511c83 (MD5) Previous issue date: 2013-08-30<br>El presente trabajo nace del amor por el lenguaje, sea como ciencia o como arte: la literatura. Agregase a eso las ganas de compartir ese encantamiento. La telenovela Avenida Brasil, de Jo?o Emanuel Carneiro surge como un objeto interesante para el debate del lenguaje y sus manifestaciones. De las narrativas primordiales surge la telenovela, un relato contempor?neo accesible por su lenguaje a todas las clases sociales. Adem?s de eso, Avenida Brasil trae como personaje la literatura, mostrando en la pantalla lecturas cl?sicas como DomCasmurro. Percibiendo la propuesta educativa de esa telenovela, se busc? una manera de mirar el g?nero por distintos ?ngulos, pero considerando las teor?as. La Metateor?a de las Interfaces sirve, entonces, como fundamento para las discusiones, estas que abarcan temas como telenovela, postcolonialismo, cr?nica y Teor?a Inferencial de las Implicaturas. Un caleidoscopio de sentidos que trae a la discusi?n un g?nero que pide m?s atenci?n.<br>O presente trabalho nasce do amor pela linguagem, seja como ci?ncia ou como arte: a literatura. Acrescenta-se a isso a vontade de compartilhar esse encantamento. Dentro disso, a telenovela Avenida Brasil, de Jo?o Emanuel Carneiro, aparece como um objeto interessante para a discuss?o da linguagem e suas formas. Das narrativas primordiais surge a telenovela, uma narra??o contempor?nea, acess?vel por sua linguagem coloquial a todas as classes. Avenida Brasil traz ainda a literatura como personagem, pondo em cena livros cl?ssicos como Dom Casmurro. Observando a proposta educativa dessa telenovela, buscou-se uma forma de olhar para o g?nero sob diversos ?ngulos, mas de forma te?rica. A Metateoria das Interfaces serve, ent?o, como escopo para discuss?es, estas que abarcam temas como telenovela, cr?nica e a Teoria Inferencial das Implicaturas. Um caleidosc?pio de sentidos, que traz para a discuss?o um g?nero que merece mais aten??o.

Made available in DSpace on 2015-04-14T14:23:03Z (GMT). No. of bitstreams: 1 421849.pdf: 10318443 bytes, checksum: 548e97a81a00388be3de5f173add20a0 (MD5) Previous issue date: 2010-01-11<br>A pesquisa qualitativa, tipo estudo de caso, visou identificar, junto aos profissionais de educa??o, que entendimento de educa??o ambiental possuem e como percebem as poss?veis contribui??es para a forma??o de um ser mais integral e a conquista da cidadania. O estudo fundamenta-se nos pressupostos te?ricos de Edgar Morin, Fritjof Capra, Bassarab Nicolescu, Ken Wilber e Leonardo Boff no que se refere a ser humano e mudan?a de paradigma, estabelecendo-se uma interlocu??o com a educa??o ambiental, a cidadania e a ?tica com base nos estudos de Humberto Maturana, Henrique Leff, Philippe Layrargues, Philippe Perrenoud e Hans Jonas. O campo emp?rico da investiga??o foi em uma escola municipal de ensino fundamental, localizada em Porto Alegre - RS. Os sujeitos participantes foram os professores das s?ries iniciais do ensino fundamental. Para a coleta dos dados, foram utilizadas diferentes fontes de evid?ncias: entrevistas, observa??es e an?lise documental. Da an?lise dos dados emergiram as categorias, que se interrelacionam, tiveram seus dados analisados e foram assim denominadas: ser humano, educa??o ambiental e cidadania al?m de dois aspectos que merecem destaque, a responsabilidade e o cuidado como atitudes fundamentais do ser humano. A educa??o ambiental na escola ? uma alternativa para a forma??o de um ser humano integral e para a constru??o da cidadania, desde que, entendida como um processo educativo em que a transdisciplinaridade seja objetivada e a transversalidade de conceitos efetivada, permitindo a aquisi??o de conhecimentos, habilidades e atitudes, bem como a amplia??o da consci?ncia.

Made available in DSpace on 2015-04-14T14:33:32Z (GMT). No. of bitstreams: 1 422102.pdf: 106503 bytes, checksum: f8aa3e3f462f41eb3cd8a90c2250bb77 (MD5) Previous issue date: 2009-12-22<br>O presente trabalho, que se insere na linha de pesquisa Efic?cia e Efetividade da Constitui??o e dos Direitos Fundamentais no Direito P?blico e no Direito Privado, vinculada ao Programa de P?s-Gradua??o em Direito (Mestrado e Doutorado) da Pontif?cia Universidade Cat?lica do Rio Grande do Sul - PUCRS, tem por objetivo analisar os limites impostos pela no??o de reserva do poss?vel no ?mbito da concretiza??o dos direitos sociais no Brasil. Uma vez que a Constitui??o Federal de 1988 consagrou os direitos sociais como direitos fundamentais, estes passaram a ter assegurada sua for?a normativa, na condi??o de direitos dotados de exigibilidade. No entanto, a partir da constata??o de que os direitos sociais t?m um custo (como, de resto, os direitos fundamentais de um modo geral), sua concretiza??o pressup?e a exist?ncia de recursos e meios, especialmente embora n?o exclusivamente financeiros. Quanto a este aspecto, assume relevo a no??o de reserva do poss?vel, originalmente reconhecida pela jurisprud?ncia do Tribunal Constitucional Federal da Alemanha, e que diz respeito ?s possibilidades e limites de se exigir da sociedade e do Estado presta??es sociais, com vistas ? satisfa??o de direitos fundamentais. Considerando o dever do Estado de realizar na maior medida poss?vel os direitos fundamentais, incontorn?vel o exame dos limites postos f?ticos e jur?dicos pela assim chamada reserva do poss?vel, de acordo, ali?s, com ampla produ??o doutrin?ria e jurisprudencial. Neste contexto, o presente trabalho analisa as diversas dimens?es da reserva do poss?vel, com o intuito de avaliar o quanto ela assume condi??es de argumento v?lido no sistema constitucional brasileiro, e, em caso afirmativo, em que circunst?ncias, especialmente tendo em conta as vincula??es constitucionais voltadas ? promo??o e financiamento dos direitos sociais.

Submitted by Setor de Tratamento da Informa??o - BC/PUCRS (tede2@pucrs.br) on 2015-04-17T17:11:06Z No. of bitstreams: 1 467295 - Texto Completo.pdf: 795302 bytes, checksum: aeedb738ba428907715a01a95b625009 (MD5)<br>Made available in DSpace on 2015-04-17T17:11:06Z (GMT). No. of bitstreams: 1 467295 - Texto Completo.pdf: 795302 bytes, checksum: aeedb738ba428907715a01a95b625009 (MD5) Previous issue date: 2015-01-15<br>This research approved by the Scientific Committee of this Faculty, under number 124/2014, had the intention to study the management of Marist schools in an attempt to reveal how the investigated schools articulate, in the exercise of management, the principles of Marist Philosophy with the imperative of coping indicators of educational setting, with a view to sustainability and survival of schools. The research sought its studies through a qualitative, descriptive and interpretive approach because requires the researcher the unveiling of the meaning and significance of her gaze on the data obtained. It was developed in schools located in different municipalities of Rio Grande do Sul state, with three principals of Marist schools selected as these characteristics: managers working in the same school unit for more than three years, and had proven results in the exercise of management to the educational community through evaluation offinancial indicators and academic performance. Its basic theoretical contribution was PEBM (2010), Covey (1994), Murad (2007), Boff (2013) and L?ck (2006). Semi-structured interviews were used with the selected managers and analysis of documents from the respective schools. The historical series of three years (2012/2014) offered the researcher conditions of mapping important indicators for these schools that cooperate with the elements set to compose the research. The results of interviews, Academic and Financial Performance Reports were used as basis for analyzing the data, anchored to analysis in Galiazzi Mor?es (2007) and Salvador (1986).I believe that the development of this theme made possible to offer a more qualified reflection to the performance of Schools Managers of PMRS in order to reconcile, on the job, the inseparability of Marist Philosophy with the indicators of the current educational landscape with a view to sustainability as well as indicating ways in the training of current and future managers of the Marist network.<br>A perspectiva da referida pesquisa aprovada pela Comiss?o Cient?fica desta Faculdade, sob o n? 124/2014, teve a intencionalidade de estudar a Gest?o dos Col?gios Maristas, na tentativa de desvelar como as escolas investigados articulam, no exerc?cio da gest?o, os Princ?pios da Filosofia Marista com a imperativa necessidade do enfrentamento de indicadores do cen?rio educacional, tendo em vista a sustentabilidade e a perenidade dos Col?gios. A pesquisa buscou percorrer seus estudos por meio de uma abordagem qualitativa, descritiva e interpretativa por exigir da pesquisadora o desvelamento do sentido e significado do seu olhar diante dos dados obtidos. Desenvolveu-se em col?gios situados em diferentes munic?pios do Rio Grande do Sul, tendo como sujeitos tr?s Diretores de Col?gios Maristas, assim selecionados: Gestores atuando na mesma unidade escolar por mais de tr?s anos que apresentaram comprovados resultados no exerc?cio da gest?o, junto ? comunidade educativa, mediante avalia??o de indicadores de desempenhos financeiros e acad?micos. Seu aporte te?rico b?sico: Projeto Educativo do Brasil Marista (2010), Covey (1994), Murad (2007), Boff (2013) e L?ck (2006). Foram utilizadas entrevistas semiestruturadas com os Gestores selecionados e an?lise de documentos dos respectivos col?gios. A s?rie hist?rica de tr?s anos (2012/2014) ofereceu ? pesquisadora condi??es de mapeamento de indicadores importantes para esses col?gios, que colaboraram no conjunto de elementos para compor a pesquisa. Como base para an?lise de seus dados foram utilizados os resultados de entrevistas, Relat?rios de Desempenho Acad?mico e Financeiro, ancorados para an?lise em Mor?es e Galiazzi (2007) e Salvador (1986). Acredito que o desenvolvimento desse tema, possibilitou oferecer: uma reflex?o mais qualificada no que tange ao desempenho dos Gestores de Col?gios da PMRS, no intuito de conciliar, no exerc?cio da fun??o, a inseparabilidade da Filosofia Marista com os indicadores do cen?rio educacional atual, tendo em vista a sustentabilidade, bem como indicar caminhos na forma??o dos atuais e futuros gestores da Rede.

Materiais híbridos, como poliedros oligoméricos silsesquioxanos (POSS), têm recebido especial atenção nos últimos anos pois são materiais que possuem uma combinação sinérgica de propriedades de materiais orgânicos e inorgânicos. Sua preparação necessita de elevados tempos de síntese e o uso de aquecimento dielétrico se apresenta promissor. Entretanto, reatores comerciais são caros e uma alternativa passa a ser a adaptação de fornos de uso domésticos. Neste contexto, este trabalho busca adaptar um forno de micro-ondas doméstico para a síntese de POSS, comparando materiais obtidos via aquecimento por microondas e convencional (banho em óleo). O POSS foi sintetizado através da condensação hidrolítica do viniltrietoxisilano (VTES) e da mistura VTES e tetraetil ortosilicato (TEOS). As amostras sintetizadas foram caracterizadas por FTIR, RMN de 1H, TGA, GPC, MEV, MET e DRX. O uso de micro-ondas possibilitou a obtenção de POSS com maior rendimento para os sistemas VTES e VTES/TEOS, apresentando taxas de reação respectivas de 47 e 59 vezes maior que a síntese convencional. Todas as amostras apresentaram bandas FTIR intensas em ~1090 e ~568 cm-1, ambas relacionadas a formação de gaiolas de silsesquixanos. Não foram observadas vibrações -O-CH2CH3 mostrando que a reação de hidrólise foi totalmente completa. A presença de deformações OH nas amostras VTES/TEOS indica a formação de estruturas não totalmente condensadas, confirmada pelos espectros de RMN de H1 onde é observada a presença de silanóis não condensados. Análises GPC para o POSS VTES apresentaram a maior fração (96,5%) de estruturas T8 via convencional, e (93,93%) via micro-ondas. A adição de TEOS reduziu a fração de estruturas T8 obtidas, (78,0%) via dielétrico e (33,0%) convencional. A análise TGA de todas as amostras mostraram uma única etapa de degradação, onde diferenças observadas no sistema VTES/TEOS são associadas ao tamanho da estrutura do POSS conforme a análise de GPC. Imagens de MEV mostraram a presença de estruturas cúbicas e esféricas em todas as amostras, e a adição de TEOS indicou uma tendência a redução de tamanho. Imagens por MET para o POSS VTES mostrou morfologia similar as observadas por MEV, e para VTES/TEOS, a presença de aglomerados esféricos regulares nanométricos. O DRX para o POSS VTES micro-ondas, convencional e VTES/TEOS micro-ondas, indicou a presença de uma rede cristalina de estrutura romboédrica, típica de POSS T8. O POSS VTES/TEOS via convencional apresentou um padrão de DRX de uma amostra amorfa. As nanopartículas híbridas de POSS VTES, via aquecimento convencional e dielétrico em refluxo, mostrou possuírem características químicas muito semelhantes, confirmadas pelas técnicas de análise realizadas. Entretanto, a mesma comparação entre o POSS obtido via mistura VTES/TEOS, a mesma semelhança não é observada. Isto se deve ao precursor VTES ser trifuncional e ao TEOS ser tetrafuncional, ou seja, possuem momentos dipolares diferentes, induzindo estruturas irregulares orientadas aleatoriamente e de diferentes tamanhos, principalmente no aquecimento convencional, onde a reação apresentada é mais lenta.<br>Submitted by Ana Guimarães Pereira (agpereir@ucs.br) on 2015-09-14T18:28:06Z No. of bitstreams: 1 Dissertacao Igor Luiz Penso.pdf: 3673859 bytes, checksum: f0f80b6c32267df60b2b04fa4df6d307 (MD5)<br>Made available in DSpace on 2015-09-14T18:28:06Z (GMT). No. of bitstreams: 1 Dissertacao Igor Luiz Penso.pdf: 3673859 bytes, checksum: f0f80b6c32267df60b2b04fa4df6d307 (MD5)<br>Coordenação de Aperfeiçoamento de Pessoal de Nível Superior.<br>Hybrid materials, such as polyhedral oligomeric silsesquioxanes (POSS), nowadays have received special attention because they are materials that have a synergistic combination of organic and inorganic materials properties. Their preparation requires high time of synthesis and the use of dielectric heating appears promising. However, commercial reactors are expensive and the adaptation of domestic microwave ovens becomes an alternative. In this context, this work aims to adapt a domestic microwave oven for the synthesis of POSS, comparing materials obtained by microwave and conventional (oil bath) heating. The POSS was synthesized by the hydrolytic condensation of vinyltriethoxysilane (VTES) and tetraethyl orthosilicate (TEOS) in different proportions. The synthesized samples were characterized by FTIR, 1H-NMR, TGA, GPC, SEM, TEM and XRD. The use of microwaves enable the manufacture of POSS with increased yield for VTES and VTES/TEOS systems, respectively with rates of 47 to 59 times higher than conventional synthesis. All samples showed intense FTIR bands at ~ 1090 and ~ 568 cm-1, both related to formation of silsesquioxane cages. It was not observed -O-CH2CH3 vibrations showing the hydrolysis reaction has been fully completed. The presence of OH deformations in the VTES/TEOS samples indicate the formation of non-fully condensed structures, confirmed by 1H NMR spectra, where it is observed the presence of non-condensing silanol. GPC analysis for the POSS VTES exhibited a major fraction (96.5%) of T8 structures via conventional, and (93.9%) via microwave synthesis. The addition of TEOS decreased the fraction of T8 structures, (78.0%) via dielectric and (33.0%) for conventional synthesis. TGA analysis of all samples showed a single stage of degradation, differences between VTES/TEOS samples are associated with the size of the POSS structure according to GPC analysis. SEM images showed the presence of spherical and cubic structures in all samples, and the addition of TEOS indicated a tendency to increase the size of these structures. TEM images for POSS VTES showed similar morphology to those observed by SEM. The presence of nanometric regular spherical agglomerates was observed in VTES/TEOS samples. The XRD for POSS VTES microwave, conventional and VTES/TEOS microwave synthesis, indicated the presence of rhombohedral lattice structure, typical POSS T8. The POSS VTES/TEOS conventional route showed a XRD pattern of an amorphous sample. The hybrid nanoparticles of POSS VTES, prepared via conventional and dielectric heating using reflux system, showed a very similar chemical properties as confirmed by the analytical techniques performed. However, the same comparison between the POSS obtained via mixing of VTES/TEOS, the same behavior is not observed. This is due to the VTES precursors be trifunctional and TEOS tetrafunctional, i.e. have different dipole moments, inducing randomly oriented irregular structures and different sizes, especially in the conventional heating where reaction is slower.

Made available in DSpace on 2014-12-17T14:20:20Z (GMT). No. of bitstreams: 1 AlineAMG.pdf: 269619 bytes, checksum: 320bd08aec4bf9b63b1c7c24ed004748 (MD5) Previous issue date: 2006-04-26<br>Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior<br>The present study aims at making a theoretically reflection about the reconstruction process of democracy that can be observed in the country since the opening political process, which took place with the Geisel?s government in 1974, passing through the first civil president, in 1985, the Constitution process, in 1986, and finally the Constitution promulgation in 1988. It interests to this study analyses the premise that the 1988 Constitution inaugurates the moment in which democracy starts to be reconstructed in the country, and that this reconstruction is made in such a brand new way, once it included the possibility of participation of the civil society in the deliberation of the public politics, what became possible with the creation of new spaces of a gestion shared by the three executive powers: federal; states; municipalities, and with the civil society, in the councils created in those spheres. In this way, this work wishes to focus the opening process to the civil society participation, wich became possible with the creation of the city councils of public politics. It?s about investigating the form in wich the relations set up in these hibrid spaces could be considered democratic, inclusive and promoters of effective participation, checking up tendencies, giving emphasis to regularities and some specifities encountered in the forms of participation, which have been observed in those councils. In order to comprehend the democratic process in construction in the country, the analysis of the relations established by the civil society and the local executive power in the obligatory municipal councils is taken as object of study, passing by the tensions wich evolves institutions and political practices, permeated by the local political culture. It starts from a briefly review of works already made on the subject<br>O presente trabalho pretende refletir teoricamente a respeito do processo de reconstru??o da democracia que podemos observar no pa?s, a partir, inicialmente, do processo de abertura pol?tica que tem in?cio no governo Geisel em 1974, prolongando-se com o primeiro presidente civil em 1985, pela Constituinte de 1986 e pela promulga??o da Constitui??o de 1988. Interessa ao trabalho analisar que a Constitui??o de 1988 inaugura o momento em que a democracia come?a se reconstruir no pa?s, e esta reconstru??o se d? de modo inovador, ao prever a inser??o da sociedade civil na delibera??o das pol?ticas p?blicas, com a cria??o de espa?os de gest?o compartilhada entre os executivos federal, estadual e municipal, e ? sociedade civil, nos conselhos gestores federais, estaduais e municipais. Neste sentido, o trabalho tem como preocupa??o focalizar o processo de abertura ? participa??o da sociedade civil que ocorre com a cria??o dos conselhos gestores municipais de pol?ticas p?blicas. Trata-se de investigar o formato em que, na pr?tica, as rela??es estabelecidas nesses espa?os h?bridos possam ser consideradas, enquanto democr?ticas, inclusivas e promotoras de uma participa??o efetiva, analisando tend?ncias, dando ?nfase ?s regularidades e algumas das especificidades encontradas nos formatos de participa??o, que se tem observado nestes conselhos. A fim de realizar o exerc?cio de compreens?o a respeito da democracia que se coloca em constru??o no pa?s, toma-se como objeto de estudo, a an?lise das rela??es estabelecidas entre sociedade civil e executivo local, nos conselhos gestores municipais obrigat?rios, passando pelas tens?es que envolvem institui??es e pr?ticas pol?ticas, permeadas pela cultura pol?tica local. Parte-se de um breve balan?o de disserta??es produzidas a cerca do presente tema

Thesis(Ph.D.)--Case Western Reserve University, 2010<br>Title from PDF (viewed on 2009-12-22) Department of Macromolecular Science and Engineering Includes abstract Includes bibliographical references and appendices Available online via the OhioLINK ETD Center