This dissertation is part of an effort to understand and to facilitate the modeling of the ordering kinetics of block copolymers in solution during the extraction of solvent from a solution-cast film. Central to this work was determining a suitable method for measuring the ordering kinetics during solvent removal and being able to interpret the measurements in terms of structure development. It was also necessary to assess a model for quantifying the ordering kinetics to use in conjunction with a mass transfer model to predict structure formation during solvent extraction. Changes in the dynamic mechanical response (DMR) over time of block copolymer solutions at fixed concentrations following solvent removal were explored as a means to track the growth of ordered domains. It was found that DMR measurements performed following solvent extraction were sensitive to the nucleation and growth process of the phase separation process over a wide range of concentrations, beginning near the order-disorder transition concentration. Based on complimentary small angle X-ray measurements, it was determined that the changes in the DMR are caused by the development of individual microstructures, The SAXS experiments also indicated that the DMR is insensitive to late stages of the growth process. Ultimately, DMR measurements under-predicted the ordering times at several concentrations and did not detect ordering at concentrations above which SAXS data indicated ordering was still occurring. The ability to use the parallel and series rules of mixtures for determining ï ¦(t) in conjunction with the Avrami equation to quantitatively model the ordering kinetics was also determined. These models allowed the ordering kinetics during solvent removal to be qualitatively analyzed. However, using the two different rules of mixtures resulted in a wide range of possible ordering times for a given copolymer concentration, making these approximations unsuitable for modeling a real solvent extraction process. Further, the parameters of the model were insensitive to the type of microstructures developing. As a continuation of this work, a new apparatus to track block copolymer ordering in situ during solvent extraction was designed. Experiments using the apparatus allowed the ordering kinetics and domain dimensions as a function of concentration to be monitored in real-time under several solvent removal conditions. These experiments study the ordering kinetics is a manner more akin to real processing conditions and will allow future assessment of the ability of iso-concentration ordering kinetics to predict phase separation during film processing. / Ph. D.

Submitted by Marilene Donadel (marilene.donadel@unioeste.br) on 2019-03-21T18:49:10Z No. of bitstreams: 1 Wanessa_Scheidt_2018.pdf: 2637303 bytes, checksum: fd114adf03634dc5d338b2141788ea64 (MD5) / Made available in DSpace on 2019-03-21T18:49:10Z (GMT). No. of bitstreams: 1 Wanessa_Scheidt_2018.pdf: 2637303 bytes, checksum: fd114adf03634dc5d338b2141788ea64 (MD5) Previous issue date: 2018-10-24 / The search for new materials with physicochemical properties for use in devices and sensors are reasons for the study of metal phthalocyanines. Phthalocyanines are highly conjugated macrocyclic compounds of blue or green color and high thermal and chemical stability. They are very used in the formation of fine films well ordered by the casting method. Generally, phthalocyanines exhibit ptype semiconductor properties, but substitutions in their peripheral rings may alter this n-type semiconductivity. Fluorinated phthalocyanines have presented films with good molecular organization, attracting attention to study in solar cells. This work deals with the formation of thin films, using the casting technique, of zinc hexadecafluorophthalocyanines (F16ZnPc) and cadmium (F16CdPc), and the investigation of crystallinity in these films. The objectives of the work were: to analyze the solubility of the compounds the solubility of the compounds in volatile organic solvents; prepare thin films on glass substrates coated with fluorine-doped tin oxide (FTO) and characterize them before and after the heating. Absorption spectroscopy in the ultraviolet-visible (UV-Vis.) region, for solutions of these compounds, have shown that the solvent may influence the observation of the monomeric or dimeric forms. The films show spectra with wider bands and formation of type J aggregates. Changes observed after the heat treatment, carried out at 300 oC for 3 h, suggest the reordering of the molecules on the substrates. Atomic force microscopy (AFM) images showed that there was an elongated preferential arrangement in F16CdPc films and some loss of material for F16ZnPc. Scanning electron microscopy (SEM) crystallites were observed for F16CdPc, but few changes have been observed for F16ZnPc. X-ray diffraction (XRD) results revealed crystalline films, where rings could have different orientations on the substrate. However, after heating, they may have adopted a single orientation, called face on, where the molecules would be in a horizontal position in relation to the substrate. / A busca por novos materiais com propriedades físico-químicas para uso em dispositivos e sensores são motivos para o estudo de ftalocianinas metálicas. As ftalocianinas são compostos macrocíclicos altamente conjugados de coloração azul ou verde e alta estabilidade térmica e química. São muito utilizadas na formação de filmes finos bem ordenados pelo método casting. Geralmente, as ftalocianinas apresentam propriedades semicondutoras do tipo-p, porém substituições em seus anéis periféricos podem alterar essa semicondutividade para tipo-n. Ftalocianinas fluoradas têm apresentado filmes com boa organização molecular, atraindo atenção para estudo em células solares. Este trabalho aborda a formação de filmes finos, usando a técnica casting, das hexadecafluoroftalocianinas de zinco (F16ZnPc) e cádmio (F16CdPc), e a investigação da cristalinidade nesses filmes. Os objetivos do trabalho foram analisar a solubilidade dos compostos em solventes orgânicos voláteis, preparar filmes finos sobre substratos de vidro recoberto com óxido de estanho dopado com flúor (FTO) e caracterizar os mesmos antes e após aquecimento. Espectroscopia de absorção na região do ultravioleta-visível (UV-Vis.), para soluções desses compostos, mostraram que o solvente pode influenciar na observação das formas monomérica ou dimérica. Os filmes apresentam espectros com bandas mais alargadas e formação de agregados tipo J. Alterações observadas após o tratamento térmico, realizado a 300 oC por 3 h, sugerem reordenamento das moléculas sobre os substratos. As imagens de microscopia de força atômica (AFM) mostraram que houve uma organização preferencial alongada em filmes da F16CdPc e alguma perda de material para a F16ZnPc. Nas imagens de microscopia eletrônica de varredura (MEV) foram observados cristalitos para a F16CdPc, porém poucas alterações foram observadas para a F16ZnPc. Resultados de difração de raio X (DRX) revelaram filmes cristalinos, onde anéis apresentariam diferentes orientações sobre o substrato, podendo ter passado para uma única orientação após aquecimento, denominada face on, onde as moléculas estariam em posição horizontal em relação ao substrato.