The self-assembly of chiral biopolymer systems involves both intra- and inter-molecular interactions. The contribution of these forces to protein hydration and stability and their influence on DNA chiral interactions is investigated. The osmotic stress technique is utilized to vary water activity in solution through the addition of a neutral osmolyte, such as poly(ethylene glycol). For the osmotic stress experiments, the osmotic pressure of the stressing solutions and its temperature dependence is needed. Since traditional methods, such as vapor pressure osmometry, static light scattering, and membrane osmometry, are not suitable for the concentration and temperature range of interest, a new method is devised using sedimentation equilibrium ultracentrifugation. We are using this method to measure the osmotic pressure of aqueous poly(ethylene glycol) solutions over a concentration range of 0 to 50 wt% and over a temperature range of 10 to 40°C. Hydration changes accompanying protein folding are investigated using the helix-coil transition in poly(glutamic acid) as a model system. Circular dichroism spectropolarimetry is used to follow this transition as a function of osmotic pressure, temperature, and pH. The energetics of the helix-coil transition allow the number of water molecules associated with the conformational change to be calculated. We find that osmotic pressure raises the helix-coil transition temperature by favoring the more compact α-helical state over the more hydrated coil state. To provide a better understanding of chiral interactions between biopolymers, measurements of short fragment (146 bp) DNA cholesteric pitch and twist angle are made as a function of DNA interaxial spacing and salt concentration. The cholesteric pitch and DNA interaxial spacing are followed by polarizing optical microscopy and X-ray scattering, respectively, and the microscopic twist angle between DNA molecules then can be calculated. Increasing ionic strength results in enhanced chiral interactions as evidenced by the increase in twist angle for a fixed interaxial spacing. In addition, we have created hybrid liquid crystals of short fragment DNA and elastin-like peptides that exhibit a cholesteric phase structure and undergo thermal contraction upon heating. These liquid crystalline systems are useful in studying chiral interactions between biopolymers and potentially could be utilized as biosensors.

Hybrid organic-inorganic materials is a new class of materials having important technological potential. In this thesis, Polyhedral Oligomeric Silsesquioxane (POSS) is used as an inorganic building block which is tethered to an organic polymer. The influence of POSS on the thermal properties as well as the morphology of the final hybrid is the main focus of this work. Different polymerization chemistries were utilized to incorporate POSS into an organic polymer. Cyclooctadiene was copolymerized with CpPOSS norbornene via Ring-Opening Metathesis Polymerization. The poly(butadiene-r-POSS) series showed lamellae formation after film casting for POSS loading higher than 30 wt%. IbuPOSS-NCO was then attached to a series of well-defined alcohol-terminated polystyrene (PSOH). The alcohol-terminated polystyrene were synthesized by the anionic polymerization of styrene, terminating the reaction with the endcapping of the living polymer by ethylene oxide, which enabled precise control over the molecular weight and the polydispersity (PDI<1.1). Increased thermal resistance was observed upon POSS addition to the PSOH series. Block copolymers of polystyrene and poly(HEMA-POSS) were then synthesized. A series of poly(styrene- b-HEMA) were first synthesized by anionic polymerization under high vacuum and POSS-NCO was reacted with the pendant alcohol of the HEMA block. By varying the volume fraction of each block, lamellar and cylindrical morphologies could be obtained. Long range order was observed by Small Angle X-ray Scattering in the samples having a lamellar morphology. Film casting provided orientation of the lamellae parallel to the surface of the beaker. A manifold for the safe polymerization of ethylene oxide and butadiene was designed. A diblock copolymer of poly(butadiene-b-ethylene oxide) was synthesized to show the versatility of the manifold.

Block copolymers are ideal templates for the fabrication of polymer-metal nanocomposites since they self-assemble into ordered, well-defined arrays of nanometer size domains. In this research, well aligned, microphase-separated structures of styrene-2-vinylpyridine block copolymers were used to prepare polymer-metal nanocomposites. Under optimal conditions, templates were prepared as thin films, confined in aluminum oxide membranes or sheared and metallized without disturbing the ordered structure. Using these methods, we developed a procedure that deposits metal within the polymer using supercritical carbon dioxide-soluble metal precursors. Supercritical carbon dioxide was used to allow for selective metallization of the polymer without disruption to its morphology. In addition, similar procedures have been investigated using metal salts and acids. Using these techniques, metals and metal-sulfides including silver, gold, platinum, iron and zinc sulfide were each selectively deposited.

Amine containing polymers are regarded as some of the most versatile and useful polymers. Preparation of amine containing polymers is usually not straightforward due to the high reactivity of amino functionality. A feasible route to synthesize a simple amine polymer through hydrogenation of pyridine rings was demonstrated. Heterogeneous catalytic hydrogenation of poly(vinylpyridine)s was carried out using various platinum metal catalysts to obtain saturated polymers, poly(vinylpiperidine)s. The hydrogenated polymers retain their well defined structures inherited from the precursor polymers, while they obtain unique characters such as water solubility, high basicity, and improved thermal stability which the precursor polymers do not possess. The stereoregular polymer, isotactic poly(2-vinylpiperidine) exhibits some helical conformation order in the solid state and in the solution state. Heterogeneous hydrogenation of block copolymers containing vinylpyridine could yield polymers with fully hydrogenated for both blocks or selectively hydrogenated for one block. When the block copolymer has an olefinic unsaturated structure, hydrogenation reaction occurred in both olefinic and pyridine blocks. Hydrolysis and hydrogenation on poly(t-butylacrylate-b-2-vinylpyridine) gave us two kinds of polymers, poly(acrylic acid-b-2-vinylpyridine) and poly(acrylic acid-b-2-vinylpiperidine). The former was an amphiphilic polymer and the latter was a water soluble, amphoteric polymer. Poly(styrene-b-2-vinylpyridine) was hydrogenated selectively by tweaking of the reaction conditions. In stoichiometrically acidic condition, pyridine block was exclusively hydrogenated over styrene block. When hydrogenation was carried out in the selective solvent with strong acidic condition, the styrene block was selectively reduced. The morphology of well defined poly(styrene-b-2-vinylpiperidine) was investigated using TEM, STXM, and RSXS which shows a unique phase separation where piperidine blocks aggregate in sphere forms dispersed in polystyrene matrix. This morphology and thermal behavior of the hydrogenated block copolymer were found to be similar to those of ionomeric block copolymers. Various vinyl polymers and diallyl amino cyclopolymers having heteroaromatic rings were also synthesized and hydrogenated. Poly(2-vinylpyrazine) was readily hydrogenated to yield poly(2-vinylpiperazine). Poly(2-vinylpyrimidine), poly(2-amino-5-vinylpyrimidine), poly(N,N-diallylamino-2-pyridine), and poly(N,N-diallylamino-2-pyrimidine) were partially hydrogenated to yield tetrahydro compounds. The resulting guanidine or amidine structures endowed these polymers with highly basic characters in aqueous solution. Tetrahydro poly(N,N-diallylamino-2-pyridine) was then hydrolyzed in the existence of water to generate poly(N,N -diallylamine) and δ-valerolactam.

Ultrathin (10 nm ∼ 1 μm) poly(ethyl 2-cyanoacrylate) (PECA) films were prepared on flat surfaces via vapor deposition without experiencing the liquid phase. System pressure, monomer temperature, as well as surface initiators were studied in the process of controlling the thickness and roughness of polymer films. The growth of poly(ethyl 2-cyanoacrylate) film from patterned initiating surfaces resulted in patterned polymer films. Bulk and surface modifications have been studied in this dissertation to expand the application of poly(ethyl 2-cyanoacrylate) thin films. Polymer/metal composites were prepared using supercritical carbon dioxide. It was found that platinum formed homogeneous particles in poly(ethyl 2-cyanoacrylate) films, when poly(ethyl 2-cyanoacrylate)/poly(para-xylylene) (PPX) multilayer thin films were used as substrate for the platinum deposition, particles formed continuous layer in PECA layer while Transmission electron microscopy (TEM) did not show any platinum particles in PPX layer, which enabled the preparation of alternative conducting-isolating layers. Different functionalities can be introduced to the surface of poly(ethyl 2-cyanoacrylate) films after anhydrides, isocyanates and acyl chlorides reacted with PECA film which was reduced by LiAlH4 and BH3. X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM) and contact angle measurement indicated that the reaction yield was not high, but for special applications, this method may still be useful. Vapor deposition of ethyl 2-cyanoacrylate was also applied to the nano channels of anodized aluminum membrane (AAM). PECA layers with different thicknesses can be obtained on the inner wall of the nano channels by tuning vapor flow rate, temperature and vapor deposition time. PECA nanotubes were obtained after the removal of the anodized aluminum membrane. PPX/PECA coaxial nanotubes with PPX-outer shell and PECA-inner shell were prepared by using vapor deposition of ethyl 2-cyanoacrylate (ECA) on the AAM-supported PPX nanotubes. Platinum deposition has been applied in the coaxial PPX-PECA nano tubes, platinum particles can be seen by SEM and TEM in the PECA layer or on the PECA inner surface. Gold nano particles were also formed inside of the PECA nanotubes using electroless gold deposition.

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This dissertation presents studies of the advancement and utilization of the techniques of small-angle light scattering (SALS) to investigate the morphology of deformed and undeformed spherulitic semicrystalline polymers. The technique advancements were made in the theoretical and instrumental aspects of SALS. The utilization of the latest techniques was made in four experimental SALS studies. The major theoretical advancement of SALS made in this work was the determination, by computer simulation, of the effects of spherulitic truncation on H(,v) SALS. The changes in the H(,v) SALS patterns and equations due to these effects were determined. The method can be readily extended to the SALS study of several other morphological phenomena. The major instrumental advancement made in this work was the development of a position sensitive SALS detector system. The device allows one to rapidly collect and analyze quantitative, two dimensional SALS data, which is essential to this and many other studies of polymers by SALS. In a study of the melting of polyethylene terephthalate (PET), it was found that the spherulites melt over a range of about 20(DEGREES)C without change in spherulite size, number or internal disorder. In a study of PET crystallization, it was found that, as the spherulites grow, there was an initial decrease and then a levelling off of both the internal disorder and the spherulite crystallinity. The quantitative H(,v) SALS intensities, corrected for experimental and internal and external disorder effects, were in moderate agreement with those calculated from the sample crystallinities, for both the melting and the crystallization studies. It was found in a study of low density polyethylene (LDPE) and polypropylene (PP) elongation that the van Aartsen and Stein affine model of spherulite deformation described the H(,v) SALS of LDPE and PP, but failed in the description of V(,v) and H(,h) SALS. The deformation mechanisms indicated by the H(,v) SALS were reasonable for LDPE and PP. It was found, and explained in terms of the Debye-Bueche theory, that the haze from films of phase separated polymer blends does not increase monotonically with the size of the phase separated particles.

Polymer electrolytes are neutral polymers that are complexed with salts. They may show promise for use in energy storage devices. However, the conductivity in polymer electrolytes is several orders of magnitude low for use in this application. A major hindrance to improving the conductivity is a lack of understanding of the conduction mechanism. The local structure in the amorphous polymer electrolyte, poly(propylene oxide)-zinc bromide ( (PPO) $\sb{\rm x}$ZnBr$\sb2$), was investigated to obtain a microscopic snapshot of the ionic structure in the conducting amorphous phase. This would provide insight into the conduction mechanism through elucidation of polymer-ion and ion-ion interactions. A combination of differential anomalous x-ray scattering (DAS) and extended x-ray absorption fine structure (EXAFS) were used to determine the structure around the Zn and Br ions in (PPO) $\sb{\rm x}$ZnSr$\sb2$, where x = 6,16. On average, two bromines and two oxygens were coordinated with each Zn. This represented a mixture of species described by the formula ZnBr$\sb{\rm 4-Y}$(O)$\sb{\rm Y}\sp{\rm Y-2}$, of which the majority were the tetrahedral species Zn(O)$\sb4\sp{2+}$ and ZnBr$\sb4\sp{2-}.$ The nature of the ionic groups implied that the conductivity in (PPO) $\sb{\rm x}$ZnBr$\sb2$ would not be high enough to be useful for many applications. This work was also important for the novel application of DAS for investigating polymer electrolytes. The accuracy of DAS in calculating coordination numbers was increased. Two approximations were tested for a weighting factor used when calculating coordination numbers from the peak areas in the differential Radial Distribution Functions (dRDF). A k-peak approximation was more accurate than a k-averaged approximation. Finally, Quasi-Elastic Neutron Scattering (QENS) was used to study the local motions of the polymer chains and to correlate them to the structure determined by DAS and EXAFS. Only preliminary results were obtained and a more complete analysis is needed before any conclusions about the chain motions can be made.