Molecular or polymeric glasses have the capability to undergo extreme nanoconfinement when they are introduced into self-assembled nanoparticle (NP) films by Capillary Rise Infiltration (CaRI). The controllability of the features of this emerging category of nanocomposites prepared by CaRI is facilitated by manipulating the size and shape of NPs, as well as the chemical composition of both the glass and NPs. As a result, these nanocomposites demonstrate significant promise as scalable materials for multifunctional coatings and membranes. In this thesis, we investigate the thermal and photo- stability of glassy materials confined in the nanoporous system, and demonstrate their improved bonding properties when the nanoporous medium is employed as an adhesive layer. In the molecular glass system, I demonstrate that the incorporation of indomethacin (IMC) molecules into silica NPs leads to an increase in the glass transition temperature Tg of ~ 30 K when IMC is confined within nanopores of 3 nm in average size under N2. The observed increase in Tg suggests that the motion of molecules is significantly restricted within the highly confined system. This increase in Tg corresponds to a reduction in the rate of thermal degradation by a factor of 10 as well as a 70 kJ/mol increase in the activation energy required for degradation at higher temperatures (Tg + 137 to 157 K). Moreover, the photodegradation rates of the confined IMC are slower in both low oxygen and ambient environments at room temperature (Tg - 20 K), but photodegradation follows distinct reaction pathways depending on the environment. The improved thermal and photo- stability can be attributed to the reduced molecular dynamics within the nanoporous medium, which acts as a gas barrier. In the polymeric glass system, the use of highly confined nanocomposite is a versatile approach and functions as a bonding layer that facilitates adhesion between a surface and a polymer. I performed proof-of-concept experiments to understand the adhesive behaviors of the highly confined nanocomposites as bonding layers. The results demonstrate adhesive strength is significantly enhanced when polystyrene (PS) is confined within the nanoporous medium. The increased adhesion is more prominent when the thickness of the NP layer decreases and the PS molecular weight increases. The extent of enhancement in adhesion is dependent on the level of confinement and the polymer interchain entanglement density.