Polyimides (PIs) such as Kapton are used extensively in spacecraft thermal blankets, solar arrays, and space inflatable structures. Atomic oxygen (AO) in low Earth orbit (LEO) causes severe degradation of Kapton. SiO2 coatings impart remarkable oxidation resistance and have been widely used to protect Kapton, yet imperfections in the SiO2 application process and micrometeoroid/debris impact in ...

Ab initio quantum mechanical calculations have been performed to establish the potentials for alkyl-substituted polyhedral oligomeric silsesquioxane (POSS) monomers RxH8-x(SiO1.5)8. More specifically, we have examined the unsubstituted POSS (SiO1.5H)8 cage as well as linear and cyclic alkyl-substituted cages where one of the terminating hydrogen atoms is replaced by a hydrocarbon group, that is...

Topographically rich surfaces were generated by spray-coating organic solutions of a polyhedral oligomeric silsesquioxane, octakis(dimethylsilyloxy)silsesquioxane (POSS), on Kapton® HN films and exposing them to radio frequency generated oxygen plasma. Changes in both surface chemistry and topography were observed. High-resolution scanning electron microscopy indicated substantial modification ...

Our continuing quest to improve the performance of polymer composites under moist and saltwater environments has gained momentum in recent years with the reinforcement of inorganic nanoparticles into the polymer. The key to mitigate degradation of composites under such environments is to maintain the integrity of the fiber/matrix (F/M) interface. In this study, the F/M interface of carbon/vinyl...

The effect of octaisobutyl-polyhedral oligomeric silsesquioxane (OIB-POSS) as a nanosized reinforcement on the cure kinetics, crosslinking density, and mechanical properties styrene-butadiene rubber (SBR) nanocomposites was examined in this study. For purpose, SBR compounds with various OIB-POSS nanoparticle loadings at 1, 3, 5 phr were prepared their results compared reference compound without...

The morphology, miscibility, and specific interactions of paclitaxel (PTx) with a family of polyhedral oligosilsesquioxane (POSS)-based biodegradable thermoplastic polyurethanes (POSS TPUs) were investigated systematically using wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), and Fourier transform infrared spectroscopy (FTIR). These POSS TPUs incorporate an alterna...

It has been well-recognized that many natural organisms exhibit elegant hierarchical porous architectures, which endow them with very unique properties. Inspired by nature, substances that are “made porous” have been one of the most intensively investigated topics involved in the approaches to construct hierarchically dimensioned materials. Vast potential applications can be envisaged for such ...

Hierarchical self-assembled structures provide a “bottom-up” method to utilize relatively simple and low cost processes to generate nanoscale patterns (usually through amphiphilic low molecular weight surfactants or block copolymers). These self-assembled structures from block copolymers are generally driven by a combination of repulsive and attractive interactions between the block segments an...