Zeolite thin films and membranes have been widely investigated over the last 15 years, mainly as separation membranes and membrane reactors. Their uniform microporosity and the ability to fine-tune their chemical composition and physical architecture lead to important macroscopic properties that can be exploited in a growing number of applications. The diversity in their use is demonstrated in this work through the exploration of zeolites as low-dielectric constant (low-k) films for computer microprocessors and as catalysts for biomass conversion. Next-generation microprocessors require smaller feature sizes, but the slow development of new low-k films with better material properties is reducing progress toward improved computing performance. Pure-silica-zeolites (PSZ) are a strong candidate for replacement low-k materials because their intrinsic porosity and crystallinity give them a low k value and strong mechanical properties. Several other characteristics, including hydrophobicity, wet-etch chemical resistance, pore size distribution, and thermal conductivity were evaluated and optimized for low-k applications. In order to obtain the desired aforementioned properties, PSZ films were carefully engineered through different synthesis and modification techniques, including pre- and post-synthesis functionalization techniques and "on-wafer" crystallization synthesis methods at ambient pressures. Successful device integration of a viable new low-k alternative requires that all of these properties meet minimum specifications. As a result of the methods developed in this work, PSZ low-k films are a leading low-k candidate and considerably outperform other alternative materials. As an essential catalyst in the oil refining industry, zeolites may also play a key role in the conversion of biomass to fuels and commodity chemicals. Studies are currently being performed to investigate the interaction between the kinetics and molecular dimensions of Sn-containing zeolites and biomass-derived sugars. New and novel nanostructured zeolite catalysts are also being prepared through the use of hierarchical synthesis strategies and innovative organic structure-directing agents. These zeolites with designed architectures may be useful as multifunctional catalysts or as thin films with unique optical and structural properties.