There has been a recent surge of interest in applications exploiting self-assembled systems like micellar solutions, microemulsions, lipid-bilayers etc. as reaction media. Among these systems, microemulsions have emerged as a popular choice for a number of diverse applications. Microemulsions represent thermodynamically stable dispersions of water in oil (or vice versa), owing their stability to the presence of an amphiphile at the interface between the constituents. In view of the ``Janus-faced'' constitution of the microemulsion (presence of both polar and non polar solvents within the homogeneous continuum), it is not hard to comprehend the reasons for the popularity of these systems as reaction media. Not surprisingly, these systems are presently used in some preparative organic synthesis as an alternative to the conventional framework employing two-phase systems with added phase transfer reagents. Further, microemulsions are also proving to be popular in the context of effecting bio-organic reactions like lipase catalyzed reactions.

The phase behavior of these ternary mixtures have been extensively studied and can be considered well understood. Thermodynamic studies have shown that depending on the concentration of the different constituents, the structure of microemulsions can range from a dispersion of spherical droplets (at dilute concentrations of either oil or water) to complex interweaving bicontinuous networks of oil and water  (at higher concentrations). The observed phase behavior of these microemulsions have also presented interesting opportunities for the creation of novel materials also presented interesting opportunities for the creation of novel materials by appropriate reactions within these media. A number of efforts are presently underway to ``fix'' these nanoscale structures of the microemulsion by reactions within the system. For instance, polymerization reactions have been carried out in microemulsions to produce the nanoscale analog of the latex particles conventionally produced by emulsion polymerization techniques. Bicontinuous networks have also been fixed to create reticulated frameworks envisaging biomineralization applications. Numerous other applications utilizing reactions in these microemulsion phases have also been suggested and implemented in contexts relating to catalysis, drug delivery etc.

Considering the practical utility of such systems, the study of chemical reactivity in these systems is bound to possess important ramifications. Despite the fact that some of the conventional conceptions of reactions might require revalidation in these systems (for instance, the mechanism of the reactions might themselves change due to the possible orientational effects presented by the interfacial structure, nevertheless it is still possible to identify a number of generic and broader aspects possessing relevance for different applications. In this context, it is pertinent to observe that most of the applications utilizing microemulsions as reaction media fall broadly into two generic classes: (i) those involving reactions within either or both (and possibly also at the interface) phases; and (ii) those involving only reactions at the interface. It is to be noted here that there has been a few investigations on problems within the former category, focusing specifically on the effect of confining the reactants to ``restricted'' spaces. In this work, we directed our considerations to the problems encompassed in the latter category. Within such a framework, we examined the effects (if any) of an oft-neglected issue in the consideration of reactions in these complex fluid systems, viz., the impact of thermal fluctuations upon the kinetics of interfacial reactions. Based on our (brief) description (in the preceding paragraph) of the different
possible structures in these systems, it would be erroneous to conclude that the different phase structures observed in these systems are rigid and static. On the contrary, the surfactant interfaces that define the structure of the microemulsion, possess bending moduli of the order of a few k_B T, thereby making them highly susceptible to the influence of thermal fluctuations. Indeed, microemulsion phases owe their existence to the destruction of more ordered mesophases by thermal fluctuations. One may speculate that, these fluctuations which dynamically modulate the interfaces, might also influence
the kinetics of reactions occurring on these ``fluctuating'' surfaces. It is to the examination of such effects that our analysis was directed.

In this research we addressed the generic effects arising from the interplay of thermal fluctuations and reactions. This was accomplished by considering specifically the kinetics of reactions effected in microemulsion media. In the first part of the research we considered the kinetics of bimolecular reaction in bicontinuous microemulsion media, wherein the solutes are assumed to be preferentially attracted to water and oil respectively. We formulated the diffusion and reaction of these solutes in a field-theoretical framework within which the fluctuations of the background microemulsion were embedded. We then employed mean-field arguments and a perturbative Wilson type renormalization group (RG) approach to discern the relevance, at long length scales, of the background fluctuations. Our analysis indicated that the dynamic fluctuations of the microemulsion prove irrelevant in impacting the asymptotic kinetics of the reaction.

In view of the fact that our field-theoretic approach enables us to probe only the long time characteristics, moreover only in the weak coupling limit, in the second part of the research we analyzed similar issues in the context of the droplet phase of microemulsions. This enables us to surmount some of the restrictions placed upon the results of the first part of the research. In the second part, our analysis focuses upon a simpler, quench reaction, wherein the solute which is present only in the water phase is anhiliated upon contact with the fluctuating interfaces of the droplets. We employed a standard diffusion equation framework to formulate the transport and reaction. The fluctuations of the microemulsion are manifest in the boundary condition positing the vanishing concentration of the reactant. We then employed a perturbation scheme to the solution of the diffusion equation, and thereby discerned the explicit effects of the fluctuations of the sinks. Our formulation enables, in a sequentially improvable asymptotic manner, the explicit computation of the time-dependent and the steady state fluctuation contributions to the reaction rate.