The Guest Host Mode of LCD is doped the dichroic dyes in liquid crystal and it have anisotropic absorbefacient. This operation mode can produce dark or brightness to achieve display target by the electric field and this can operate in the non-polarizer type to achieve high reflectance. Because of market requirement in the e-paper display, so the reflective LCD by the guest host mode is a focal once again. In this study, we will doped the black dichroic dyes in liquid crystal and than we fill into the homogenous alignment cell by difference rubbing direction and homeotropic alignment cell to investigate the optical-electric characteristic in the non-polarizer and polarizer type, because in the difference alignment condition can influence the behavior of dichroic dyes, and we fabricate the double cell to improve the optical-electric characteristic. The reflective type guest host display still have many research space, like dope the dichroic dye in PDLC(polymer dispread liquid crystals) or cholesteric liquid crystal to achieve flexible and bistable characteristic.

Cyclodextrins are well known for their ability to encapsulate molecules and have captured the attention of scientists for many years. This ability alone makes cyclodextrins attractive for study, research, and applications in many fields including food, cosmetics, textiles, and the pharmaceutical industry. In this thesis, we specifically look at the ability of the three native cyclodextrins, alpha, beta, and gamma cyclodextrin (α-CD, β-CD, and γ-CD, respectively), to encapsulate the drug molecule, quinine, a small hydrophobic, lipophilic molecule used to treat malaria, leg cramps, and other similar conditions. This encapsulation process is driven by the molecular interactions, which have been studied by NMR techniques at different temperatures (288 K, 293 K, 298 K, 303 K, 308 K) and pH values (7.4, 11.5). These factors (temperature and pH) influence these molecular interactions, which in turn significantly affects the entire encapsulation process. Detailed studies of the influences of temperature and pH on the interactions that drive the encapsulation may suggest some new directions into designing controlled drug release processes. Results obtained throughout the course of this work indicate that β-CD is the best native cyclodextrin to bind quinine, and that binding is best at pH = 11.5. It was found that temperature does not significantly affect the binding affinity of quinine to either α-CD, β-CD, or γ-CD.

In this study, we focus on the electric optical characteristic of guest/host polymer system. The charge transfer chromophore Wu182 which contain fluorine atom in it was mixed with polymer PMMA and solved in chloroform, while DR1/PMMA served as reference sample. The wu182/PMMA and DR1/PMMA thin films were produced by spin coating. The thin film was poled at the temperature above glass transition temperature until the second harmonic generation signal was present. The poled thin film was placed in one arm of Mach-Zehnder interferometer. Voltage modulation applied to the polymer films can cause phase changes in the interferometer from that we estimate the electro-optic coefficient. From our experiments, we found that modulating frequency had significant influence on the electro-optic effect. The result shows that Wu182 possess large nonlinear optical coefficient. The valid electro-optic coefficient r13 was obtained to be 2.620 pm/V when the frequency was above 6 kHz.

No description available.

The laser-induced molecular reorientation effect of guest-host dye-doped liquid crystals in isotropic phase has been studied by measuring the signals of optical Kerr effect using pulsed frequency-doubling Nd:YAG laser as a pumping source. The critical behavior near the isotropic-nematic transition has been observed when the temperature approaches to the phase transition of liquid crystal. The relaxation time constant is about several hundreds of ns as the temperature is far above the clearing point of liquid crystals and that is longer than 1500 ns as the temperature is close to the clearing point of liquid crystals. According to Landau¡¦s second phase transition theory, the interaction between liquid crystal molecules will be increased and the nonlinearity effect of liquid crystal will be enhanced when the temperature is near the clearing point of liquid crystal. The relaxation time constant of molecular reorientation is a function of viscosity and temperature of liquid crystal, the relationship can be fitted as£b0*exp(f/T)*(1/T-T*),where £b0 is the viscosity coefficient and T* is the clearing point of the sample. The optical Kerr signal is found to be proportional to the energy density of pumping source. The optical Kerr signal can be sustained as long as 20£gs when the energy density of pumping source reaches to 1J/cm sq. The enhancement of molecular reorientation effect is also observed by increasing the concentration of dye.

The development of a new technique capable of analyzing compounds crystallographically without first needing to crystallize them has been recently described. The present thesis aims to demonstrate the potential of such a technique, which utilizes crystalline sponges, in order to regularly order guest compounds in a porous media. The structural stability of the molecular sponges, which are highly porous metal-organic frameworks (MOFs), is first investigated, revealing that the Co-based MOF, 1, undergoes two remarkable transformations. This thesis also demonstrates how the technique can be employed to visualize the motion and occupancy of gaseous guests in a MOF. The Zn-based MOF, 4, was found to physisorb and chemisorb molecular iodine, leading to the formation of a variety of polyiodide species. The flexible nature of the host was determined to be an essential component in the exceptionally large iodine uptake capacity of the MOF. These results illustrate that the crystalline sponge method can be an effective strategy for directly visualizing guest molecules and obtaining vital information on the interactions formed between the host and guest.

Líquidos iônicos imidazólios (LIIs) associados a ânions com caráter básico foram sintetizados, caracterizados e seu comportamento estudado em solução. Inicialmente a troca isotópica H/D preferencial no grupo C2-CH3 de sais de 1-nbutil-2,3-dimetilimidazólio (BMMI) foi avaliada. Ficou evidente que o contato entre os pares de íons e a atuação do ânion como uma base neutra influenciaram fortemente a deuteração. Após a análise dos resultados de RMN, cálculos de DFT (Teoria do Funcional de Densidade) e Difração de Raios X, um complexo entre uma molécula de água e alguns LI foi sugerido, modificando fortemente a estrutura organizacional e afetando também a troca isotópica nestes sais. Através do mecanismo reacional proposto, surgiu a possibilidade de deuteração de novos substratos contendo H ácidos, usando os LIIs como catalisadores. A reação de troca isotópica em alcinos e cetonas foi estudada e bons resultados foram obtidos. O efeito da variação de cátions e ânions na atividade catalítica foi analisado, assim como a variação dos substituintes dos substratos. Além disso, um estudo cinético foi realizado através de análises de RMN de 1H e o mecanismo reacional foi proposto. Por fim, a capacidade de formação de pares iônicos em soluções aquosas de LIIs foi avaliada na captura de CO2. Ótimos resultados foram obtidos e atribuídos à ocorrência de sorção física e química devido à ativação da água pelo LII. / Imidazolium based ionic liquids (ImIL) associated with basic anions were synthesized, characterized and studied. Initially the preferred H/D isotopic exchange to C2-CH3 group of 1-nbutyl-2,3-dimethylimidazolium salts (BMMI) was studied. In this context, it became evident that the ion-pairing formation and the anion action as a neutral base strongly influence the deuteration reaction. NMR analysis, theoretical calculation (Density Functional Theory) and X-ray Diffraction have been performed and a complex between a water molecule and the IL have been suggested, strongly modifying the IL structure and characteristics. The isotope exchange reaction in alkynes and ketones was studied using imidazolium based ionic liquids as catalysts and good results obtained. The effect of cation and anion variation on the catalyst activity were analyzed, also a variation of the substrate substituent’s. Also, a kinetic study was performed by 1H NMR analyzes and the reaction mechanism were proposed. Finally, the ability to form ion pair contact of ILs in aqueous solutions was evaluated for CO2 capture. Great results were obtained and this success can be attributed to the occurrence of physical and chemical sorption due to water activation by the IL.

Líquidos iônicos imidazólios (LIIs) associados a ânions com caráter básico foram sintetizados, caracterizados e seu comportamento estudado em solução. Inicialmente a troca isotópica H/D preferencial no grupo C2-CH3 de sais de 1-nbutil-2,3-dimetilimidazólio (BMMI) foi avaliada. Ficou evidente que o contato entre os pares de íons e a atuação do ânion como uma base neutra influenciaram fortemente a deuteração. Após a análise dos resultados de RMN, cálculos de DFT (Teoria do Funcional de Densidade) e Difração de Raios X, um complexo entre uma molécula de água e alguns LI foi sugerido, modificando fortemente a estrutura organizacional e afetando também a troca isotópica nestes sais. Através do mecanismo reacional proposto, surgiu a possibilidade de deuteração de novos substratos contendo H ácidos, usando os LIIs como catalisadores. A reação de troca isotópica em alcinos e cetonas foi estudada e bons resultados foram obtidos. O efeito da variação de cátions e ânions na atividade catalítica foi analisado, assim como a variação dos substituintes dos substratos. Além disso, um estudo cinético foi realizado através de análises de RMN de 1H e o mecanismo reacional foi proposto. Por fim, a capacidade de formação de pares iônicos em soluções aquosas de LIIs foi avaliada na captura de CO2. Ótimos resultados foram obtidos e atribuídos à ocorrência de sorção física e química devido à ativação da água pelo LII. / Imidazolium based ionic liquids (ImIL) associated with basic anions were synthesized, characterized and studied. Initially the preferred H/D isotopic exchange to C2-CH3 group of 1-nbutyl-2,3-dimethylimidazolium salts (BMMI) was studied. In this context, it became evident that the ion-pairing formation and the anion action as a neutral base strongly influence the deuteration reaction. NMR analysis, theoretical calculation (Density Functional Theory) and X-ray Diffraction have been performed and a complex between a water molecule and the IL have been suggested, strongly modifying the IL structure and characteristics. The isotope exchange reaction in alkynes and ketones was studied using imidazolium based ionic liquids as catalysts and good results obtained. The effect of cation and anion variation on the catalyst activity were analyzed, also a variation of the substrate substituent’s. Also, a kinetic study was performed by 1H NMR analyzes and the reaction mechanism were proposed. Finally, the ability to form ion pair contact of ILs in aqueous solutions was evaluated for CO2 capture. Great results were obtained and this success can be attributed to the occurrence of physical and chemical sorption due to water activation by the IL.

Líquidos iônicos imidazólios (LIIs) associados a ânions com caráter básico foram sintetizados, caracterizados e seu comportamento estudado em solução. Inicialmente a troca isotópica H/D preferencial no grupo C2-CH3 de sais de 1-nbutil-2,3-dimetilimidazólio (BMMI) foi avaliada. Ficou evidente que o contato entre os pares de íons e a atuação do ânion como uma base neutra influenciaram fortemente a deuteração. Após a análise dos resultados de RMN, cálculos de DFT (Teoria do Funcional de Densidade) e Difração de Raios X, um complexo entre uma molécula de água e alguns LI foi sugerido, modificando fortemente a estrutura organizacional e afetando também a troca isotópica nestes sais. Através do mecanismo reacional proposto, surgiu a possibilidade de deuteração de novos substratos contendo H ácidos, usando os LIIs como catalisadores. A reação de troca isotópica em alcinos e cetonas foi estudada e bons resultados foram obtidos. O efeito da variação de cátions e ânions na atividade catalítica foi analisado, assim como a variação dos substituintes dos substratos. Além disso, um estudo cinético foi realizado através de análises de RMN de 1H e o mecanismo reacional foi proposto. Por fim, a capacidade de formação de pares iônicos em soluções aquosas de LIIs foi avaliada na captura de CO2. Ótimos resultados foram obtidos e atribuídos à ocorrência de sorção física e química devido à ativação da água pelo LII. / Imidazolium based ionic liquids (ImIL) associated with basic anions were synthesized, characterized and studied. Initially the preferred H/D isotopic exchange to C2-CH3 group of 1-nbutyl-2,3-dimethylimidazolium salts (BMMI) was studied. In this context, it became evident that the ion-pairing formation and the anion action as a neutral base strongly influence the deuteration reaction. NMR analysis, theoretical calculation (Density Functional Theory) and X-ray Diffraction have been performed and a complex between a water molecule and the IL have been suggested, strongly modifying the IL structure and characteristics. The isotope exchange reaction in alkynes and ketones was studied using imidazolium based ionic liquids as catalysts and good results obtained. The effect of cation and anion variation on the catalyst activity were analyzed, also a variation of the substrate substituent’s. Also, a kinetic study was performed by 1H NMR analyzes and the reaction mechanism were proposed. Finally, the ability to form ion pair contact of ILs in aqueous solutions was evaluated for CO2 capture. Great results were obtained and this success can be attributed to the occurrence of physical and chemical sorption due to water activation by the IL.

No description available.