Corrosion is a major factor for the failure of metallic medical implants. Testing a metal’s suseptability to corrosion prior to implantation is key to a successful implantation. Electrochemical processes were used in this study to evaluate the characteristics of corrosion of both AISI 316 stainless steel and titanium alloy Ti6Al4V, welded and non-welded. Linear, potentiodynamic, and cyclic polarization curves were produced by the PARC 2273 potentiostat showing the corrosion tendencies of the metals in four unique solutions 3.5% NaCl, 0.35% NaCl, phosphate buffered saline solution (PBS), and Butterfield phosphate buffered solution (BPS). The concentration of chloride ions in solutions affected the passivation current (Ipassive) and the passivation range of both AISI 316 and Ti6Al4V. In general, larger concentrations of the chloride ions increased the passivation current and decreased the passivation range. Both AISI 316 and Ti6Al4V exhibited passive behavior. Ti6Al4V proved to be the more corrosion resistant metal in the test solutions, showing the ability to repassivate and resist pitting.

The purpose of this study was to examine the performance of several generic types of organic protective coatings as a corrosion protection method for the interior of subsea pipelines in sour gas media. The sour gas environment was simulated in the laboratory by the use of an Autoclave and the performance of the organic coatings was studied via the use of Electrochemical Impedance Spectroscopy (EIS) and Linear Polarization Resistance (LPR) tests to determine the coatings resistance, capacitance and corrosion behavior before and after the exposure to sour gas environment. The coating degradation and the corrosion products formed were examined by the use of SEM/EDS. The results indicated that both FBE and Novolac Epoxy coatings had excellent adhesion properties and chemical resistance. The Amine-Cured Novolac Epoxy coating exhibited good adhesion properties and chemical resistance. However, the Phenolic Epoxy coating started to degrade over time and corrosion took place under the coating.

It has long been known from Thermodynamics and written in technical literature that, in principal, instant energy can be made available when dilute and concentrated solutions are mixed. For example, a river flowing into the sea carries with it a physical-chemical potential energy in its low salt content, some of which should be recoverable. As also known, a naturally occurring, diffusion-driven, spontaneous transport of ions occurs throughout a solution matrix, thru barrier interfaces, or thru ion-selective membranes from the side containing the salts of higher concentration to the compartments containing the more dilute solution to effect the equalization of concentration of the ionic species. Since this ion movement consists, preferentially, of either cations or anions, it leads to a charge separation and potential difference across the membrane, otherwise known as a membrane potential. Eventually, when the concentrations in the compartment are the same, the cell ceases to function. However, if operated as a fuel cell with its respective concentrations continually replenished, equilibrium at a specific value of potential difference is established. To capture the energy of this potentially significant albeit low power energy source, a suitable energy extraction device is required. The focus of this Ph.D. research effort is to address the concept, research and evaluation of a Bi-Polar membrane based seawater concentration cell and its suitability as a low power energy source for Energy Harvesting/MEMS devices (patent pending).