| Small dimensions, generally on the order of a few microns or less, and corresponding short times are used to scale experiments down such that molecular motion and the dynamics of solution can be more easily studied and modeled. The first part of this thesis involves the use of small dimensions for studies involving electrogenerated chemiluminescence (ECL). Chapter 2 deals with chemically controlling the pathway and character of emissive states that can occur in ECL. It is demonstrated here that ECL has several advantages in this field over photochemistry for the generation of emissive states, despite an inherent difference that prevents ideal behavior. In chapter 3 ECL is generated in a two electrode thin layer cell. This setup allows for better measurements of efficiency than have previously been reported and concludes that most of the losses in ECL studies are related to the experimental setup, rather than poor quantum efficiency. Chapter 4 successfully uses an existing, fully implicit digital simulation program (DigiSimRTM) to model ECL from a system in which the reactions are well known. This serves as a model for others studying ECL to do quick checks on the possibility of various mechanisms. The last two chapters do not deal with ECL, but are still taking advantage or studying small dimensions. Chapter 5 puts forward a general equation that defines the current to any planar electrode, regardless of shape, and verifies it by comparing elliptical electrodes to disks, both in theory and experimentally. The last chapter involves improving scanning electrochemical microscopy, by moving to a more selective, though less quantitative, technique---fast scan cyclic voltammetry---which also has other advantages with respect to irreversibly reactive surfaces and, potentially, resolution. |
