This dissertation presents solid-state NMR studies that probe the dynamic and conformational properties of polymers adsorbed on solid surfaces in the dry state. The systems studied include a series of ethylene based random copolymers where the binding group is modified, and two diblock copolymer systems where the blocks have different intrinsic mobilities and surface interactions. The thesis begins by looking at the structures formed by the adsorption of poly ethylene-co-acrylic acid) PEA), poly ethylene- co-vinyl alcohol) EVOH), poly ethylene-co-vinyl acetate) EVA), and polyethylene PE) on metal oxide powders zirconia and alumina). NMR spectroscopy, FTIR-PAS, and TGA were used to characterize the surface behaviour of the systems with comparisons made between the bulk and adsorbed copolymers. 13C CPMAS, 1H and T 1 relaxation measurements were all recorded with the aim of correlating the microscopic structure of the surface with changes in NMR data. The chain conformation of adsorbed ethylene copolymers was found to strongly depend on the binding strength of the polar sticker groups with the substrates. The chain dynamics of adsorbed diblock copolymers in the dry state are reported for the first time. Poly styrene)-b-poly t-butyl acrylate) PS-PtButA) and poly styrene)-b-poly acrylic acid) PS-PAA) were selected to vary both the block size and the binding strength. Once again the primary surface characterization methods are NMR spectroscopy, FTIR-PAS, and TGA. 13C CPMAS, 1H, T1, and T1rho relaxation measurements were all recorded with the aim of correlating the surface structures with changes in NMR data. For the most part, the observed trends in the chain mobilities of the anchor PAA) and buoy PS) blocks with block size can be correlated with the predicted mushroom, intermediate and extended brush structures which collapse upon removal of the solvent. However, the chain mobility of the PS buoys decreases with increasing anchor block size. Although the chain mobility of the PS buoys are moderately enhanced relative to the bulk state, the mobility is sufficiently restricted to comfirm the picture of a thin glassy layer with adhesive properties similar to the surface of bulk polystyrene. The diblock copolymers poly 2-vinylpyridine), poly isoprene)- b-poly 2–vinylpyridine), PI-P2VP) and poly isoprene)- b-poly 4-vinylpyridine) PI-P4VP) were selected to complement the PS-PAA system as both systems have been studied by surface force microscopy. The large contrast in chain mobilities of the PI and PVP blocks allowed spectral editing through variation of the 13C cross polarization parameters. The trends in mobility with block size differ from that of PS-PAA in that the segmental mobility of the buoys increases with anchor block size as expected. The chain mobility of the collapsed PI brushes is significantly enhanced as compared to the bulk state, again supporting the interpretation of surface microscopy studies which require an entropically unfavorable flattened, yet rubbery, surface structure.

Nanotechnology is a multidisciplinary scientific field undergoing explosive development. One of the greatest promises of nanotechnology is in the development of new and effective medical treatments, such as nanomedicine. Many approaches are being pursued towards nanomedicine. One of the approaches is to develop nanoparticles as carriers for drug molecules to achieve enhanced bioavailability. Nanoparticles are one attractive system as nanocarriers since they have demonstrated the abilities to help the therapeutics to achieve improved solubility, increased loading capacity, and prolonged circulation time. Moreover, their polyvalency provides nanoparticles the possibility to incorporate therapeutics, imaging agents, and targeting ligands into one single formulation for more effective treatment. Various nanoparticles have been investigated for therapeutic delivery, among which shell crosslinked knedel-like SCK) nanoparticles are one promising strategy. SCKs are well-defined nanoparticles fabricated from the self assembly of amphiphilic block copolymers into micelles with core-shell morphologies, followed by shell crosslinking with difunctional crosslinkers. In this dissertation, as an expansion of the SCK fundamental design and preparation methodology, an amphiphilic block copolymer, polymethyl acrylate)- b-polyN-acryloyloxy)succinimide-co- N-acryloylmorpholine)) PMA-b-PNAS-co-NAM)), with built-in functionality was synthesized by sequential reversible addition–fragmentation chain transfer RAFT) polymerizations and studied for convenient shell crosslinking and functionalization for facile preparation of SCKs. Then, well-defined SCKs were explored as capsules to incorporate silver species for the development of advanced antimicrobial agents, and the resulting silver-SCK complexes were evaluated in vitro for their antimicrobial efficacies. As an ideal therapeutic carrier, the nanoparticle vehicle should also be biocompatible and bioresorbable. Two approaches were explored for the incorporation of degradability into the SCK system. An acid-labile crosslinker with a central UV-active chromophore was synthesized and used for the construction of hydrolytically-degradable SCKs with acid-sensitive crosslinks. On the other hand, a polylactic acid) PLA)-based amphiphilic block copolymer was synthesized and used as a polymer precursor for the preparation of SCKs with biodegradable cores. Furthermore, SCKs, containing either degradable or non-degradable crosslinks, were investigated as carriers for the uptake and release of doxorubicin DOX), as a model chemotherapeutic agent.

This work details the method development of a bench top process designed to fabricate highly defined particles of uniform shape and size. In this method, perfluorinated elastomeric molds were patterned off of etched silicon wafers and other substrates. These molds were then filled with a pre-particle solution that was subsequently solidified by UV photoradical initiated polymerization. Particle harvesting by physical agitation and a variety of sacrificial adhesive layers was examined. Purification of particles was also explored using multiple techniques including: centrifugation, dialysis, and a variety of filtration techniques. Regioselective chemical and metallic surface functionalization was demonstrated. Direct particle analysis was performed using microscopic techniques and indirect analysis of particle loading and surface chemistry was performed using spectrophotometric, fluorescence, and mass spectrometry techniques. Micron scale particles were fabricated with a variety of shapes, sizes, chemistries, and cargos for materials applications. It was determined that particle shape dictated how particles with an induced dipole moment aligned and crystallized in alternating electric fields. Control over chaining and alignment with respect to particle orientation was gained when particles were loaded with superparamagnetic cargo. Nanometer scale particles with different form factors were also fabricated for in vivo imaging and biodstribution studies in small animals. The particles ranged in size from 80 nm to 2000 nm in length. Particles were surface modified with polyethylene glycol) for protection from the reticuloendothelial system. The particles contained or were surface modified with one or more contrast agent including near infrared fluorescent dye, iron oxide nanoparticles for Magnetic Resonance Imaging), or Cu64 for Positron Emission Tomography. This research laid the groundwork for future experiments in targeted delivery of therapeutics to tumors using the template based particle fabrication technology.

Natural saccharides are involved in numerous biological and although the full spectrum of their functions and mechanism has not been revealed yet, saccharides have drawn increasing interest in the biomedical field. However, the application of natural saccharides has been limited due to difficulties in their synthesis and modification. Glycopolymers have been sought as surrogates. In this thesis, new polymerization techniques for the synthesis of saccharide mimics are discussed. Recent advancement in the synthesis of glycopolymers by controlled radical polymerization CRP) techniques is discussed in Chapter 1. Chapter 2 describes the synthesis of aminooxy end-functionalized poly N-isopropylacrylamide) pNIPAAm) by reversible addition-fragmentation chain transfer RAFT) polymerization. pNIPAAm was conjugated to bovine serum albumin BSA) modified with ketone groups. pNIPAAm was also immobilized on a gold surface and an aldehyde-modified heparin a sulfated polysaccharide) was then conjugated to the pNIPAAm surface via oxime chemistry. This technique could be used for the stabilization and storage of growth factors on surfaces. In Chapter 3, synthesis of a pyridyl-disulfide glycopolymers with N-acetyl-D-glucosamine pendant groups by atom transfer radical polymerization ATRP) is discussed. The polymer was patterned on a surface by microcontact printing and was visualized by fluorescence microscopy. The glycopolymers was also conjugated to double-stranded short interfering RNA siRNA). This highly efficient synthesis and one-step conjugation system offers great potential for the study of sugar-targeted siRNA gene therapy. Chapter 4 and 5 describes the uses of sulfonated polymers as heparin mimics. In Chapter 4, polysodium 4-styrene sulfonate-co-polyethylene glycol) methacrylate) pSS-co-pPEGMA) was synthesized via RAFT polymerization and immobilized on a gold surface. The surface was employed to study the binding of pSS-co-pPEGMA towards vascular endothelial growth factor VEGF) and basic fibroblast growth factor bFGF) by surface plasmon resonance SPR). In Chapter 5, a series of sulfonated polymers were investigated as potential heparin mimics. The polymers utilized in the study were polysodium 4-styrene sulfonate- co-2-hydroxyethyl methacrylate) pSS-co-pHEMA), polysodium polysodium 2-acrylamido-2-methyl propane sulfonate-co-2-hydroxyethyl methacrylate) pAMPS-co-pHEMA), and polypotassium 3-methacryloyloxy)-1-propane sulfonate-co-2-hydroxyethyl methacrylate) pSPMA-co-pHEMA). SPR studies were performed in order to screen their binding affinities to VEGF. These results suggest that these sulfonated copolymers could serve as heparin mimics.

This thesis describes the synthesis and properties of boron-containing compounds intended for use in Neutron Capture Therapy of Cancer, a binary form of treatment based on the cytotoxic radiation, which arises after capture of a thermal neutron by a boron-10 nuclide and the resulting fission reaction. The success of this therapy is based on the delivery of large numbers of boron atoms to cancerous cells in a selective fashion. Dendritic and nanoparticle-based boron-carriers are the best candidates to meet these requirements. Thus, this study initially focuses on the preparation of molecular constructs that can be described as resulting from the coupling of neutral polyhedral carboranes containing ten boron atoms with dendritic compounds of various chemical composition and size, such as generation-1 polyester- and polyamide-based dendrons and generation-2 polyesters. These compounds are designed to be biocompatible contain up to 60 boron atoms and retain a reactive center that will allow their incorporation into more complex structures. An alternative approach involves the design of small silica spheres and their use to initiate the growth of various polymers that possess functionalizable side chains. These reactive centers are then coupled with carborane-containing moieties, resulting in polymer-silica hybrid nanoparticles approximately one hundred nanometers in size and carrying a very large boron-payload several hundreds of thousands of boron atoms). In addition, these nanoparticles can also be made fluorescent by introducing a layer of dye within their core. Several of the boron-containing dendritic constructs are currently being used in primary biological evaluations while it is envisioned that fluorescent silica nanoparticles carrying heavy boron payloads in the form of boron-containing polymers and capable of targeting the neovasculature of growing tumors will perform astonishingly in neutron capture therapy applications.

Electrospinning is becoming an increasingly popular method for producing polymer fibers, since it can attain microscale to nanoscale control of fiber dimensions, morphology, and functionality. Hence electrospun fiber technology is now prevalent in numerous applications ranging from tissue engineering, active filtration systems, and super strong materials design. The electrospinning technique has attracted much attention in its biomedical applications in recent years, such as preparation of scaffolds for tissue engineering applications. Here we present a systematic study of the manner in which the cells interact with electrospun scaffolds and the effects of the scaffolds have on basic cell functions, such as morphology, proliferation, and migration. We obtained electrospun polymer fibers of different diameters, ranging from hundreds of nanometers to several micrometers. Furthermore, we aligned the fibers and formed multilayered structures where both the fiber spacing and pore size could be varied. We found that cells preferred to oriented along the fiber axis when the fiber diameter was above 1 micrometer. Cell measurement on the other hand, indicated that the proliferation on the aligned fibers was more efficient than the flat surface since the oriented cells did not become confluent as quick as on the polymer thin film. The average migration velocity of the cells on the aligned fibrous scaffold, was lower than that on the planar surface, but remained constant in time. Efficient filtration of ions and very small particles often requires small pores which restrict the liquid flow and consumes large amounts of energy. Here we show that electrospun fibers can be used to create an active filter, with nearly unrestricted flow. We addressed the use of electrospun fibers to encapsulate microbes of industrially relevant genera. Although the electrospinning typically uses harsh organic solvents and extreme conditions that generally are harmful to bacteria, we describe techniques that overcome these limitations. The encapsulated microbes were viable for up to several months, and the exchange of nutrient between the microbes and their environment was not affected by immobilization. Since polymeric chains have multiple degrees of freedom, confinement alone can impart special properties. For example, in semicrystalline polymers, which constitute the largest group of commercially useful polymers, confinement can change the melting point while at the same time improving the mechanical properties. My last area of research therefore includes the confinement effects brought by electrospinning semicrystalline polymers into very thin fibers, and the impact of viscosity and nano-additives such as clay. In this chapter I will try to explain these effects by introducing a model based on the viscosity properties of the electrospinning solutions.

A mechanism based on the competitive inhibition of Michaelis-Menten kinetics has been proposed for the Zr-catalyzed carboalumination of alpha-olefins and the Zr-catalyzed chain growth of aluminum alkyls. In this mechanism AlMe 3 plays two roles. First, it binds to the active catalyst in a rapidly maintained equilibrium to form a Zr/Al heterobimetallic that controls the reactivity of the system by inhibiting polymerization. Second, it acts as a fast transmetallating agent to transfer chains from the active Zr center. The proposed mechanism has been verified by studying the kinetics of both carboalumination and catalyzed chain growth. Both reactions have been shown to be first-order in [olefin] and [catalyst], and inverse first-order in [AlR3], in accordance with the proposed mechanism and rate law. The rapidly maintained equilibrium between Zr/Al heterobimetallic and free zirconium alkyl cation may be quantified by use of a Dixon plot, yielding equilibrium dissociation constants of K ＝ 1.13) x 10-4 M, 4.75) x 10-4 M, and 7.67) x 10-4 M at 40&deg；C in benzene for the catalyst species [rac -EBI)Zrmicro-Me)2AlMe2＋[BC 6F5)4-], [Cp2Zrmicro-Me) 2AlMe2＋][BC6F5) 4-], and [Me2CCp)2Zrmicro-Me) 2AlMe2＋][BC6F5) 4-] respectively. These equilibrium constants are consistent with the observed solution behavior seen for the [Cp2Zrmicro-Me) 2AlMe2＋][BC6F5) 4-] system, for which all the relevant species are observable by 1H NMR. Alternative mechanisms for the Zr-catalyzed carboalumination of olefins involving singly-bridged Zr/Al adducts may be discounted based on kinetics or 1H NMR EXSY experiments. New enantiopure catalysts for the asymmetric carboalumination of olefins have been developed. In the methylalumination of allylbenzene, only modest ees are observed. The catalysts may be activated for ethylalumination by stirring with AlEt3 and then subsequently adding [Ph3C][BC 6F5)4] to produce an active green solution. Ethylalumination of allylbenzene proceeds smoothly without side products and in most cases with greater selectivity than the corresponding methylalumination. The greatest enantioselectivity is observed with 4-substituted Me2Si-bridged bis)indenyl zirconocenes.

The focus of this research is to develop novel polymer gel electrolytes that overcome the drawbacks of conventional polymer electrolytes involving aqueous solvents or small organic molecules. In order to reach this aim, a series of novel polymer gel electrolytes were developed using crosslinked polymer matrix as a physical container acting to form cage around electrolytes. This structure leads to high ion conductivity under the applied electric field while maintaining mechanical integrity. The following gel electrolytes were prepared by varying the polymer hosts and type of electrolytes. The ion gels based on free radical polymerization of methylacrylate MMA) in ionic liquid IL), 1-butyl-3-methylimidazolium hexafluorophosphate BMIMPF6) were transparent, self-standing and flexible with high ambient ionic conductivity in the range of 10-4&sim；10-3 S/cm. The coupling effects between PMMA matrix and IL decrease with increasing the concentration of IL. The temperature dependence of ion conductivity followed Arrhenius Law, indicating a thermally activated ionic motion. Therefore, the high conductivity is considered to be due to the movement from both cations and anions to electrodes and weak polymer-ion interaction. Based on its high ion conductivity, the three layer poly3,4-ethylenedioxythiophene)-polystyrenesulfonate) PEDOT/PSS) coated electroactive actuators were also developed, which exhibited a bending behavior under electrical field. The lithium polymer gels based on PMMA and modified siloxane PEMPS) with LiTFSI exhibited transparency, flexibility and mechanical integrity, and remained miscible under all use conditions. This gel showed an ion conductivity 10-4 S/cm at 70&deg；C. The conductivity showed a maximum when the salt concentration increased for the composition of MMA/PEMPS ＝ 30/70 and 40/60. At low concentration regime of solvent/salt PEMPS/LiTFSI), the conductivity showed an increase with salt LiTFSI) concentration. Beyond a critical salt concentration, the viscosity of the medium became high and this led to decrease of diffusion of ions in the medium and the decrease of conductivity. The conductivity was also increased with the decrease of PMMA/electrolyte ratio. The swelling ratio of PMMA network was also found to exhibit a maximum as the salt concentration increased. The swelling ratio increased as the PMMA/electrolyte ratio was decreased. The FTIR study indicates lithium salt was mostly dissociated by PEMPS, and had little interaction with PMMA polymer hosts. At last, polyvinyl alcohol PVA)/KOH and polyacrylic acid PAA)/KOH based aqueous gels were studied for the application in Ni-Zn batteries. The crystallization and chain entanglements formed physical crosslink for the PVA/KOH gel, while the copolymerization between acrylic acid and crosslinking agent formed the chemical crosslink for the PAA/KOH based gel. Both gels showed high ambient ion conductivity around 10-2 S/cm, satisfying the mechanical and ion conductivity requirements of the membrane for successful construction of Ni-Zn batteries.

Matrix Assisted Laser Desorption Ionization–Time of Flight MALDI-TOF) mass spectroscopy is used in the characterization of synthetic polymers. MALDI allows for determination of: modal, most probable peak MP), molecular number average MN), molecular weight average MW), polydispersity PD), and polymer spread PSP). We evaluate a new sample preparation method using Induction Based Fluidics IBF) to kinetically launch and direct nanoliter volumes to a target without contact. IBF offers signal improvement via field enhanced crystallization. This is the first study to discuss filed enhanced crystallization in MALDI sample preparation. IBF can increase signal/noise S/N) and signal intensity for polystyrene PS), polymethyl methacrylate) PMMA), and polyethylene glycol) PEG) across a mass range of 2,500 to 92,000 Da showing more accurate PSP. Increases in S/N range up to: 279% for PS, 140% for PMMA, and 660% for PEG. Signal intensities increased up to: 438% for PS, 115% for PMMA, and 166% for PEG. Cross-polarization microscopy indicates dramatic morphology differences between IBF and micropipette. Finally, we speculate as to why IBF nanoliter depositions afford higher S/N values in experiments conducted in different instrumental configurations even without optimization. Next we sought to investigate whether nanoliter volumes of concentrated polar liquids and organic monomers launched to targets using IBF can be verified through the real time charge measurements. We show that using a nanoliter IBF dispensing device and nanocoulomb meter, charge measurements made on nanoliter drops in real time are correlated with the droplets surface area following Gausss Law. We infer the “induction only” formation of the double layer showing the ability to determine nanoliter volumes, nearly instantaneously, in real time. Implications are presented from these IBF measurement observations on improving/monitoring MALDI quantitation and its quality control. Polymer-dye interactions were further investigated using PMMA composites made from a polar metalloporphyrin [5-4,4,5,5-tetramethyl[1,3,2]dioxaborolan-2-yl)-10,20-diphenylporphyrinato]zincII) ZnII)Bpin-DPP) in select weight %s wt%s). Fluorescence spectroscopy has revealed that the porphyrin was well dispersed within the composite. Differential Scanning Calorimetry DSC) showed that porphyrin acted as an antiplasticizer raising the glass transition Tg) from 105&deg；C to 123&deg；C. Dielectric Analysis DEA) was performed in the frequency range of 0.3 Hz to 100 kHz between – 150 to 270&deg；C. Permittivity epsilon), loss factor epsilon) and dielectric response of beta beta), alpha beta alphabeta), and conductivity relaxations were studied. Previous DEA data was limited to 190&deg；C. This study brings analysis to 270&deg；C which is start point for the first part of PMMA degradation. Thus forwarding DEA can be used to evaluate PMMA degradation. The electric modulus formalism is used to reveal the beta and conductivity relaxations. The apparent activation energies Ea) for the molecular relaxations are presented. AC sigmaAC) and DC sigma DC) conductivity are also evaluated. Tan delta delta), dissipation factor, evaluated between 1 Hz to 100 kHz was shown to increase with porphyrin loading although locally affected by free volume restriction. Havriliak-Negami H-N) equation was fit using the complex electric modulus M*) modified form and was performed on the conductivity region 160 to 190&deg；C and degradation region 190 to 270&deg；C. Relaxations above the Tg were proven to be conductivity relaxations using four proofs. This is the first study to investigate PMMA degradation DEA with the complex electric modulus, M*,revealing a unique occurrence of increasing central relaxation times s-1) and reducing electric loss modulus M) frequency maxima Hz) after the degradation temperature of 220&deg；C was reached supporting current literature of the first of a two part degradation process that proceeds via end chain scission.

This dissertation explores the self-assembly of diblock copolymers as a way to control the morphology of photoactive layer in organic solar cells. Heterojunction formation between electron donor and electron acceptor materials needs to be controlled on the nanometer scale to have high power conversion from organic photovoltaic cells. Two approaches were developed to direct the assembly of electron-donors and electron-acceptors into heterojunction structures. The first one involves the synthesis of acid cleavable diblock copolymer to create porous polymer films, which can be used as templates to form well ordered donor-acceptor heterojunctions on the nanometer scale. Here, we demonstrate that nanoporous templates could be prepared under moderate conditions, which do not interfere with photovoltaic device fabrication. The second approach involves the use of conjugated diblock copolymers as the structure directing agents. Incompatible packing of the side chains was investigated to provide microphase segregation in conjugated polymer/fullerene blends. Packing of the materials within the domain has been shown to be a very important parameter for photovoltaic performances.