This study is primarily concerned with the adsorption characteristics of ethyl(hydroxyethyl)cellulose (EHEC), a water soluble polymer with many pharmaceutical appliations. / Thesis (PhD in AppSc)--University of South Australia, 2001.

This study is primarily concerned with the adsorption characteristics of ethyl(hydroxyethyl)cellulose (EHEC), a water soluble polymer with many pharmaceutical appliations.

In this work a finite element model is proposed to describe the swelling of poly(acrylic acid) hydrogels under the influence of an external electric field. The specific application of this model is for optical applications, but the design could be used equally well for other applications such as sensors and actuators.The model is proposed as five individual modules, which work in conjunction with each other but which can also function independently. This independence allows the model to provide intermediate results to the user, and also permits each module to be improved or adjusted individually without affecting the operation of the overall model. The first module is the Electrical module, which calculates the external electric field present in the hydrogel by solving Laplace's equation. The second module is the Chemical module, which uses the electric field to calculate the diffusion and migration of ions through the hydrogel/solvent regions. The third module is the Force module, which uses the change in ion concentrations to calculate the resulting change in osmotic pressure (force). This force is then used in the Mechanical module to calculate the deformation of the hydrogel, based on the assumption of linear elasticity. Finally, the fifth module is the Optical module, which uses the deformation to calculate the theoretical change in focal length.To verify the operation of the model, numerous experiments were conducted with the deformation of a poly(acrylic acid) hydrogel being measured under various external voltages with different electrode configurations. Overall, the model agrees quite well with the experimental results, but also highlights some interesting discrepancies that will need to be considered in future work. There is also some scope for improvement in the experimental method used, but again this is left for future work.

Thesis (Ph. D.)--University of Texas at Austin, 2008. / Vita. Includes bibliographical references.

Thesis (Ph.D)--Chemistry and Biochemistry, Georgia Institute of Technology, 2009. / Committee Chair: Lyon, L. Andrew; Committee Member: Barry, Bridgette; Committee Member: Fahrni, Christoph J.; Committee Member: Hud, Nicholas V.; Committee Member: Le Doux, Joseph M. Part of the SMARTech Electronic Thesis and Dissertation Collection.

Call number: LD2668 .T4 1964 Y94 / Master of Science

No description available.

No description available.

In batch experiments at pH's 5 and 7, the partitioning of MS-2 between water and silica (unbonded) was compared with the partitioning between water and silica with 6.5 percent of the surface covered by hydrophobic C18 chains (bonded). The roles of double-layer and van der Waals forces in partitioning were explored by modeling the potential energies of interaction. MS-2 adsorption to unbonded silica was negligible at pH 7, but did occur at pH 5. Adsorption was independent of pH with the bonded silica and approximately 2.6 orders of magnitude greater than the unbonded at pH 5, suggesting the importance of hydrophobic partitioning. The total potential energies of interaction, which closely approach the pH-independent van der Waals potentials, are similar in magnitude for all pH's or silica types, and have no positive (repulsive) values. The insignificant contribution of the double-layer potentials suggests that these pH-dependent forces may not account for the pH-dependent adsorption observed with the unbonded silica.

Sol-gel derived silica coatings were deposited on soda-lime-silica by dip-coating. An absorbing metallic layer was sputtered onto the surface of the gel to couple near-infrared radiation from a Nd:YAG laser into the transparent coating. Laser energy was utilized to heat the ceramic coating on a substrate which has a lower glass transition temperature than the coating. Scanning the sample across the beam's path resulted in the formation of a 50 mum wide channel. The characteristics of a channel were altered by varying laser power, sol-gel coating thickness, and scanning speeds. Profilometry and SEM analysis verified that the coating can be heated to high temperatures without damaging the substrate.