Open Access. Powered by Scholars. Published by Universities.®
- Keyword
- Publication
- Publication Type
Articles 1 - 5 of 5
Full-Text Articles in Chemistry
Sger: Supercritical Levitation Polymerization And Processing, Erdogan Kiran
Sger: Supercritical Levitation Polymerization And Processing, Erdogan Kiran
University of Maine Office of Research Administration: Grant Reports
In supercritical polymerization processes, polymer chains grow to molecular weights determined by their solubility under the prevailing density (or pressure and temperature) conditions of the solvent. Further growth in the chain length results in phase separation and leads to precipitation. In this project, polymerizations will be conducted under isopycnic conditions by adjusting the density of the solvent environment to be identical to the density of the polymer formed. This iso- density operation is expected to insure levitation by buoyancy and prevent precipitation of the phase-separated polymer. Density adjustments are readily achievable for supercritical solvents through manipulation of either the pressure …
Ir Studies Of The Interaction Of Surfactants And Polyelectrolytes Adsorbed On Tio2 Particles, Haiyan Li
Ir Studies Of The Interaction Of Surfactants And Polyelectrolytes Adsorbed On Tio2 Particles, Haiyan Li
Electronic Theses and Dissertations
Polymers/surfactants are used to control and modify the interfacial properties of particulate suspensions. The resulting properties are dependent on the amount of adsorbed surfactants/polymers on the surface as well as the nature of the aggregated structures. Often these interactions are complex and not well understood. In this thesis we have used Attenuated total reflection-Fourier transform infrared spectroscopy (ATR-FTIR) to identify surfactant, mixed surfactant, polyelectrolyte and mixed polyelectrolyte surfactant structures formed on charged Ti02 particles. In addition, the change occurring to the structure of an adsorbed polymer layer on Ti02 to flowing suspension of silica particles was studied. A …
Excimer Emission From Cathode Boundary Layer Discharges, Mohamed Moselhy, Karl H. Schoenbach
Excimer Emission From Cathode Boundary Layer Discharges, Mohamed Moselhy, Karl H. Schoenbach
Bioelectrics Publications
The excimer emission from direct current glow discharges between a planar cathode and a ring-shaped anode of 0.75 and 1.5 mm diameter, respectively, separated by a gap of 250 μm, was studied in xenon and argon in a pressure range from 75 to 760 Torr. The thickness of the “cathode boundary layer” plasma, in the 100 μm range, and a discharge sustaining voltage of approximately 200 V, indicates that the discharge is restricted to the cathode fall and the negative glow. The radiant excimer emittance at 172 nm increases with pressure and reaches a value of 4 W/cm2 for …
Solid State Nmr Characterization Of Conductive Polyanilines, Yanina Anatolievna Goddard
Solid State Nmr Characterization Of Conductive Polyanilines, Yanina Anatolievna Goddard
Dissertations, Theses, and Masters Projects
Different forms of ring deuterated polyaniline with different conductivity have been characterized by solid state deuteron nuclear magnetic resonance.;Quadrupole echo (QE) spectra of all forms of polyaniline consist of a superposition of lineshapes for nearly rigid aromatic rings and a small fraction of rings which undergo fast 180?? flips. The intensity of the fast flipping component is temperature dependent and different for conductive emeraldine salt (ES) and non-conductive emeraldine base (EB). This is a manifestation of the different structure and morphology of these polymers.;Simultaneous measurements of QE lineshapes and the relaxation time anisotropies allowed an accurate description of motion in …
Binding Studies On Molecularly Imprinted Polymers, Lucy Yue Hu
Binding Studies On Molecularly Imprinted Polymers, Lucy Yue Hu
Dissertations, Theses, and Masters Projects
Molecular imprinting is a rapidly developing technique for preparation of polymeric materials that are capable of molecular recognition for selective separation and chemical identification. to prepare molecularly imprinted polymers (MIPs), a functional monomer and a crosslinker are polymerized in the presence of a template molecule. Then the template is extracted leaving sites which are complementary in both shape and chemical functionality to those of the template. This resin then becomes capable of selectively absorbing the template species. Because of MIPs' stability, predesigned selectivity, and easy preparation, they have been used for separation, sensor, drug development and directed synthesis.;In this study, …