Thesis (Ph. D.)--University of Wisconsin--Madison, 1970. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (Ph. D.)--University of Wisconsin, 1966. / Typescript. Vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

No description available.

No description available.

Este trabalho reporta sínteses e caracterizações de complexos do tipo [RuCl2(S-dmso)2(N)III)2], onde NIII = piridina, isonicotinamida e nicotinamida. Os complexos foram aplicados em ROMP de norborneno de modo investigar os efeitos cooperativos entre os ligantes ancilares dmso e aminasneste tipo de reação. O complexo com nicotinamida apresentou a maior atividade catalítica em 60 min a 50 ºC (20% de rendimento; Mw / Mn = 1,98). Os outros complexos derivados foram praticamente inertes para ROMP. Usando uma solução envelhecida por 140 min a 50 ºC do complexo com isonicotinamida, não foi observada mudanças significativas na atividade catalítica por 60 min a 50 ºC (17% de rendimento; Mw / Mn = 4,24). Experimentos com uma solução do complexo com isonicotinamida na presença do sal NBu4ClO4, o rendimento foi de 19% (Mw / Mn = 1,78) mediante as mesmas condições. Usando soluções irradiadas com luz branca (5-10 min) à temperatura ambiente, os complexos com piridina e isonicotinamida mostraram rendimentos de 36% (Mw / Mn = 1,8) e 26% (Mw / Mn = 1,7) por 60 min a 50 ºC, respectivamente. O complexo [RuCl3 (Ph2SO) 3] foi também isolado e sua atividade em ROMP para norborneno foi de 33% (Mw / Mn = 1,32) à temperatura ambiente por 5 min. O rendimento aumentou para 58% (Mw / Mn = 1,41) a 50 ºC por 30 min. Na presença do sal NBu4ClO4, o rendimento de reação não apresentou mudanças significativas. Dos resultados obtidos, conclui-se que os ligantes dmso e as aminas estudadas podem ser empregados como ligantes ancilares em complexos de Ru(II) para as reações de ROMP, considerando um efeito cooperativo de sintonia eletrônica. / This work reports the synthesis and characterizations of [RuCl2(S-dmso)2(N)III)2] complexes, where NIII = pyridine, isonicotinamide and nicotinamide. The complexes were applied in ROMP of norbornene in order to investigate the cooperative effects among the dmso and amines as ancillary ligands in this kind of reaction. The complex with nicotinamide showed the highest catalytic activity for 60 min at 50 ºC (20% yield; Mw / Mn = 1,98). The other derivatives were roughing inert for ROMP. Using an aged solution for 140 min at 50 ºC of the isonicotinamide complex, it was observed a significant change in their catalytic activity for 60 min at 50 ºC (17% yield; Mw / Mn = 4,24). Experiments using isonicotinamide complex solution in presence of the salt NBu4ClO4, the yield was 19% (Mw / Mn = 1,78) under similar conditions. When using irradiated solution with white lamp (5-10 min) at room temperature, the pyridine (for 10 min) and isonicotinamide (for 5 min) complexes showed yields of 36% (Mw / Mn = 1,8) and 26% (Mw / Mn = 1,7) for 60 min at 50 ºC respectively. The complex [RuCl3 (Ph2SO) 3] was also isolated and the ROMP active for norbornene was 33% (Mw / Mn = 1,32) at room temperature for 5 min. The yield increased to 58% (Mw / Mn = 1,41) at 50 ºC for 30 min. In the presence of the salt NBu4ClO4, the yield showed no significant changes. It is concluded that the ligands dmso and the studied amines can be selectively used as ancillary ligands in Ru(II) complexes for ROMP reactions inside of an electronic tuning cooperative effect.

O monômero-ligante (3amdpy)2NBE foi sintetizado e caracterizado por análise elementar (CHN), infravermelho e RMN (1H e 13C), tratando-se de um novo ligante quelante que apresenta duas piridinas conectadas ao monômero norborneno via grupos amidas. Esse monômero-ligante foi ligado a um centro de Ru(II)-polipiridínico e o complexo resultante foi caracterizado por análise elementar (CHN), infravermelho, RMN (1H e 13C) e espectrometria de massa como sendo cis-[Ru(bpy)2((3amdpy)2NBE)](PF6)2. O espectro eletrônico do novo complexo apresentou absorção no visível em 460 e 480 nm. Essa bandas são típicas de MLCT com valores de ε na ordem de 104 L cm-1 mol-1. O voltamograma cíclico em CH3CN apresentou um processo redox com potencial de meia-onda de 0,89 V vs Ag/AgCl que é de 60 unidades mais positivo do que o complexo precursor cis- [RuCl2(bpy) 2]. O novo metalo-monômero foi submetido à irradiação a λ= 480 nm, demonstrando ser fotoquimicamente inerte em DMSO, CH3CN, acetona e DMF. A emissão do complexo obtido variou em função do solvente e apresentou maior intensidade de emissão em acetonitrila (λem= 720 nm). A variação do solvente não levou ao deslocamento do máximo de emissão do complexo. O monômero-ligante foi polimerizado via metátese catalisada por catalisador de Grubbs, com 23% de rendimento a 50 °C por 5 min. O polímero foi caracterizado por IV e RMN de 1H. Foi solúvel em água e apresentou um ponto de fusão de 288ºC. / The monomer-ligand (3amdpy)2NBE was synthesized and characterized by elemental analysis (CHN), infrared and NMR (1H and 13C) as a new chelate ligand that features two pyridines connected to the monomer norbornene via amide groups. This monomer-ligand was coordinated to a Ru(II)-polypyridinic center and the resulting complex como sendo cis- [Ru(bpy) 2 ((3amdpy) 2NBE)](PF6)2 was characterized by elemental analysis (CHN), IR, NMR (1H and 13C) and mass spectrometry. The electronic spectrum of the new complex showed absorptions in the visible with bands at 460 and 480 nm. These bands are typical of MLCT with ε values in the order of magnitude of 104 L cm-1 mol-1. The cyclic voltammetry in CH3CN showed a redox process with half-wave potential of 0,89 V vs Ag/AgCl which is ca. 60 units higher than the halfwave potential for the cis-[RuCl2(bpy)2] precursor complex. The new complex was photochemically inert when irradiated at 480 nm either in DMSO, CH3CN, acetone or DMF. The emission of the complex depends on the solvent and presented large emission intensity in acetonitrile (λem = 720 nm). The variation of the solvent does not shift the emission maximum. Ring opening metathesis polymerization of the monomer-ligand (3amdpy)2NBE was carried out at 50 °C for 5 min with 23% of yield using Grubbs type catalyst. The resulting polymer was characterized by IR and NMR-1H. It was water-soluble and showed a melting point of 288°C.

O monômero-ligante (3amdpy)2NBE foi sintetizado e caracterizado por análise elementar (CHN), infravermelho e RMN (1H e 13C), tratando-se de um novo ligante quelante que apresenta duas piridinas conectadas ao monômero norborneno via grupos amidas. Esse monômero-ligante foi ligado a um centro de Ru(II)-polipiridínico e o complexo resultante foi caracterizado por análise elementar (CHN), infravermelho, RMN (1H e 13C) e espectrometria de massa como sendo cis-[Ru(bpy)2((3amdpy)2NBE)](PF6)2. O espectro eletrônico do novo complexo apresentou absorção no visível em 460 e 480 nm. Essa bandas são típicas de MLCT com valores de ε na ordem de 104 L cm-1 mol-1. O voltamograma cíclico em CH3CN apresentou um processo redox com potencial de meia-onda de 0,89 V vs Ag/AgCl que é de 60 unidades mais positivo do que o complexo precursor cis- [RuCl2(bpy) 2]. O novo metalo-monômero foi submetido à irradiação a λ= 480 nm, demonstrando ser fotoquimicamente inerte em DMSO, CH3CN, acetona e DMF. A emissão do complexo obtido variou em função do solvente e apresentou maior intensidade de emissão em acetonitrila (λem= 720 nm). A variação do solvente não levou ao deslocamento do máximo de emissão do complexo. O monômero-ligante foi polimerizado via metátese catalisada por catalisador de Grubbs, com 23% de rendimento a 50 °C por 5 min. O polímero foi caracterizado por IV e RMN de 1H. Foi solúvel em água e apresentou um ponto de fusão de 288ºC. / The monomer-ligand (3amdpy)2NBE was synthesized and characterized by elemental analysis (CHN), infrared and NMR (1H and 13C) as a new chelate ligand that features two pyridines connected to the monomer norbornene via amide groups. This monomer-ligand was coordinated to a Ru(II)-polypyridinic center and the resulting complex como sendo cis- [Ru(bpy) 2 ((3amdpy) 2NBE)](PF6)2 was characterized by elemental analysis (CHN), IR, NMR (1H and 13C) and mass spectrometry. The electronic spectrum of the new complex showed absorptions in the visible with bands at 460 and 480 nm. These bands are typical of MLCT with ε values in the order of magnitude of 104 L cm-1 mol-1. The cyclic voltammetry in CH3CN showed a redox process with half-wave potential of 0,89 V vs Ag/AgCl which is ca. 60 units higher than the halfwave potential for the cis-[RuCl2(bpy)2] precursor complex. The new complex was photochemically inert when irradiated at 480 nm either in DMSO, CH3CN, acetone or DMF. The emission of the complex depends on the solvent and presented large emission intensity in acetonitrile (λem = 720 nm). The variation of the solvent does not shift the emission maximum. Ring opening metathesis polymerization of the monomer-ligand (3amdpy)2NBE was carried out at 50 °C for 5 min with 23% of yield using Grubbs type catalyst. The resulting polymer was characterized by IR and NMR-1H. It was water-soluble and showed a melting point of 288°C.

Este trabalho reporta sínteses e caracterizações de complexos do tipo [RuCl2(S-dmso)2(N)III)2], onde NIII = piridina, isonicotinamida e nicotinamida. Os complexos foram aplicados em ROMP de norborneno de modo investigar os efeitos cooperativos entre os ligantes ancilares dmso e aminasneste tipo de reação. O complexo com nicotinamida apresentou a maior atividade catalítica em 60 min a 50 ºC (20% de rendimento; Mw / Mn = 1,98). Os outros complexos derivados foram praticamente inertes para ROMP. Usando uma solução envelhecida por 140 min a 50 ºC do complexo com isonicotinamida, não foi observada mudanças significativas na atividade catalítica por 60 min a 50 ºC (17% de rendimento; Mw / Mn = 4,24). Experimentos com uma solução do complexo com isonicotinamida na presença do sal NBu4ClO4, o rendimento foi de 19% (Mw / Mn = 1,78) mediante as mesmas condições. Usando soluções irradiadas com luz branca (5-10 min) à temperatura ambiente, os complexos com piridina e isonicotinamida mostraram rendimentos de 36% (Mw / Mn = 1,8) e 26% (Mw / Mn = 1,7) por 60 min a 50 ºC, respectivamente. O complexo [RuCl3 (Ph2SO) 3] foi também isolado e sua atividade em ROMP para norborneno foi de 33% (Mw / Mn = 1,32) à temperatura ambiente por 5 min. O rendimento aumentou para 58% (Mw / Mn = 1,41) a 50 ºC por 30 min. Na presença do sal NBu4ClO4, o rendimento de reação não apresentou mudanças significativas. Dos resultados obtidos, conclui-se que os ligantes dmso e as aminas estudadas podem ser empregados como ligantes ancilares em complexos de Ru(II) para as reações de ROMP, considerando um efeito cooperativo de sintonia eletrônica. / This work reports the synthesis and characterizations of [RuCl2(S-dmso)2(N)III)2] complexes, where NIII = pyridine, isonicotinamide and nicotinamide. The complexes were applied in ROMP of norbornene in order to investigate the cooperative effects among the dmso and amines as ancillary ligands in this kind of reaction. The complex with nicotinamide showed the highest catalytic activity for 60 min at 50 ºC (20% yield; Mw / Mn = 1,98). The other derivatives were roughing inert for ROMP. Using an aged solution for 140 min at 50 ºC of the isonicotinamide complex, it was observed a significant change in their catalytic activity for 60 min at 50 ºC (17% yield; Mw / Mn = 4,24). Experiments using isonicotinamide complex solution in presence of the salt NBu4ClO4, the yield was 19% (Mw / Mn = 1,78) under similar conditions. When using irradiated solution with white lamp (5-10 min) at room temperature, the pyridine (for 10 min) and isonicotinamide (for 5 min) complexes showed yields of 36% (Mw / Mn = 1,8) and 26% (Mw / Mn = 1,7) for 60 min at 50 ºC respectively. The complex [RuCl3 (Ph2SO) 3] was also isolated and the ROMP active for norbornene was 33% (Mw / Mn = 1,32) at room temperature for 5 min. The yield increased to 58% (Mw / Mn = 1,41) at 50 ºC for 30 min. In the presence of the salt NBu4ClO4, the yield showed no significant changes. It is concluded that the ligands dmso and the studied amines can be selectively used as ancillary ligands in Ru(II) complexes for ROMP reactions inside of an electronic tuning cooperative effect.

Indiana University-Purdue University Indianapolis (IUPUI) / The extracellular matrix (ECM) governs many cellular processes through biochemical and mechanical cues. Particularly, the effect ECM mechanical properties on cells fate has been well established over the years. Many hydrogel systems have been used to mimic the dynamic stiffening processes occurring in ECM. However, changes in ECM stiffness does not fully recapitulate the mechanics of native ECM, as viscoelasticity is also a major factor contributing to ECM dynamic property. This thesis describes the design and characterization of an enzyme-crosslinked hydrogel system that is not only capable of being stiffened on demand, but also can be tuned to obtain viscoelasticity. The first objective of this thesis was to utilize horseradish peroxidase (HRP) to crosslink thiol-norbornene hydrogel and use mushroom tyrosinase (MT) to create secondary DOPA-dimer crosslinks that stiffened the hydrogel. The cytocompatibility of HRP-mediated thiol-norbornene gelation and the effect of stiffening on cell fate was evaluated. The second objective of this thesis represented the first step towards developing a hydrogel system whose viscoelasticity could be dynamically tuned. Thiol-norbornene hydrogel was designed to yield dynamically adaptable boronic ester bonds via partial enzymatic reaction. Thiol-norborne hydrogel was made to contain hydroxyl phenol as well as boronic acid residues within its network. MT, in this case was used to oxidize the hydroxy phenol moieties into DOPA, which then complexed with boronic acid, created dynamic bonds, introducing viscoelasticity to an initial elastic hydrogel.

Cellulose nanocrystals (CNCs) are nanomaterials that have shown promise as reinforcement filler materials. Their small size, high modulus, and high aspect ratio makes CNCs good reinforcing materials. CNCs are typically introduced into softer polymer materials, which can have incompatible surface chemistry such as aliphatic chains, leading to aggregation and poor reinforcement of the material. The intrinsic hydrophobicity of the CNC surfaces suggests that dispersal into hydrophobic polymer matrices, which the CNCs could potentially reinforce, represent a significant challenge. Therefore, new non-traditional strategies are needed to introduce CNCs into polymer materials. The hydroxyl groups on the surfaces of CNCs can be functionalized using a variety of chemical techniques to yield materials that can interact better with solvents or polymers. Additionally, surface groups can allow the CNCs to react with environmental stimuli (smart materials). The primary focus of this work is the incorporation of CNCs in hydrophobic matrices. Herein we introduce a new method of dispersing CNCs in polyethylene (PE), a substance of legendary hydrophobicity that is also the most common synthetic polymer used in consumer packaging. The prospect of increasing the mechanical strength of PE by incorporating CNC materials as fillers may lead to the possibility of using less polymer to obtain the same strength. This thesis approaches the problem of dispersing CNCs within PE by first functionalizing the CNCs with a catalyst capable of polymerizing ethylene and other α-olefins. The catalyst 1,1'-bis(bromodimethylsilyl)zirconocene dibromide (catalyst 1) is equipped with anchoring groups that are capable of attachment to the surface hydroxyl groups of CNC particles. After immobilizing catalyst 1 onto various CNC samples, introduction of solvent, organoaluminum cocatalyst, and monomer (ethylene alone or ethylene plus 1-hexene) afforded high density polyethylene (HDPE) and linear low-density polyethylene (LLDPE) samples, respectively, containing well-dispersed CNCs as filler materials. Chapter 2 provided important information on the attachment of catalyst 1 to cellulose nanocrystals and the successful polymerization of ethylene from the cellulose nanocrystals. The resulting composite materials showed a in Young's modulus that was three-fold that of PE samples we tested (1600 ± 100 vs 500 ± 30) and about 10% greater relative to a commercial high modulus PE sample (1450 MPa). The increase in Young's modulus along with the lack of macroscopic aggregates led to the conclusion that we have developed a viable method to disperse CNCs in polyolefin matrices. Chapter 3 focused on the dispersal of CNCs in a softer, more pliable polyethylene grade known as linear low-density polyethylene (LLDPE). LLDPE incorporates a small fraction of 1-hexene into polyethylene as a randomly inserted comonomer, giving rise to properties suitable for applications in plastic films and bags among other end uses. Catalyst 1 functionalized CNCs were added to a reaction vessel with both ethylene and 1-hexene to afford LLDPE CNC composites. Different loading of catalyst 1 on CNC aerogels afforded the same amount of catalyst in each reaction but allowed for different CNC loadings in each reaction. The composite materials showed increasing Young's modulus with increasing cellulose nanocrystal content. Chapter 4 describes how CNCs were functionalized with the intention of filling reverse osmosis membrane materials to have surface chemistry that could be impart antibacterial properties and increase flux. CNCs were functionalized with carboxylic acid by 2,2,6,6-tetramethylpiperidin-1-yl)oxyl (TEMPO)-mediated oxidation, then amine functionalization by carbodiimide coupling chemistry, and finally functionalized with a zwitterionic group by β-propiolactone ring opening. Amine coupling was confirmed with X-ray photoelectron spectroscopic analysis, and a second carboxylic acid peak was confirmed using infrared spectroscopy. These results were further verified with conductometric titration showing that after each respective reaction there were 1060 mmol kg-1 of carboxylic acid groups, 520 mmol kg-1 of amine groups, and 240 mmol kg-1 of zwitterionic groups. This CNC material was left to undergo future testing for desirable membrane properties. Chapter 5 assesses the possible value in creating a new composite material using a functionalized polynorbornene, poly(5-triethoxysilyl-2-norbornene) (PTESN). The composites were fabricated by using the solvent casting method, dispersing the CNCs in a toluene solution of polymer and drying. The composite materials showed an increase in Young's modulus with increased loading. The 20 wt% CNC in PTESN had a Young's modulus of 970 MPa, a significant increase over the Young's modulus of the polymer lacking the filler (540 MPa). In summary, this dissertation advances new techniques for the incorporation of CNCs as fillers in polymer-based nanocomposites. We are confident that further refinement and development of our results will find wide-ranging application. / Doctor of Philosophy / Cellulose nanocrystals (CNCs) are materials that can be added to polymers to form composite materials having increased stiffness. CNCs have the primary advantages over other filler materials of providing significant reinforcement without changing the color or increasing the density of the overall composite. CNCs are therefore good for designing polymer composites that need to be lightweight and aesthetically pleasing. Packaging materials (especially plastic bags and plastic films) are dominated by polyolefin materials such as polyethylene, which is already lightweight and colorless. The challenge of mixing polyethylene and CNCs is that their surface chemistry is incompatible, "like oil and water." To overcome the natural tendency for the CNC filler material to separate from the surrounding polyethylene matrix, a catalyst was attached to the surface of the CNCs and polymerization ensued from that catalyst leading to a composite material in which tiny CNC particles were trapped in the matrix Good dispersal of the component substances in the composite and of excellent overall reinforcement were proven by physical analysis.