The preparation of responsive multilayered structures with quarter-wave design based on layer-by-layer deposition of sol-gel derived Nb₂O₅ films and spin-coated MEL type zeolite is demonstrated. The refractive indices (n) and thicknesses (d) of the layers are determined using non-linear curve fitting of the measured reflectance spectra. Besides, the surface and cross-sectional features of the multilayered structures are characterized by scanning electron microscopy (SEM). The quasi-omnidirectional photonic band for the multilayered structures is predicted theoretically, and confirmed experimentally by reflectance measurements at oblique incidence with polarized light. The sensing properties of the multilayered structures toward acetone are studied by measuring transmittance spectra prior and after vapor exposure. Furthermore, the potential of the one-dimensional photonic crystals based on the multilayered structure consisting of Nb₂O₅ and MEL type zeolite as a chemical sensor with optical read-out is discussed.

Enriching oxygen content within nanosized zeolite X (as synthesized Na-X) by insertion of cerium (ion exchanged Ce-X) and functionalization with bromoperfluoro-n-octane (fluorinated F-X) is reported. The materials were fully characterized by powder X-ray diffraction (XRD), dynamic light scattering (DLS), zeta potential, thermogravimetric analysis (TGA), nitrogen adsorption, and nuclear magnetic resonance (¹⁹F NMR). The O₂ adsorption in the zeolite samples at various concentrations (0 to 165 Torr) at −196 °C was studied by in situ FTIR. The modification of nanosized zeolites did not alter their colloidal stability, crystallinity, porosity, and particle size distribution. The inclusion of cerium and bromoperfluoro-n-octane considerably increase the oxygen capacity by 33% for samples Ce-X and F-X in comparison to the as-synthesized Na-X zeolite. Further, toxicity tests revealed that these materials are safe, which opens the door for their implementation in medical applications, where controlled delivery of oxygen is highly desirable.

Lubricant oils take significant part in current health and environmental considerations since they are an integral and indispensable component of modern technology. Antioxidants are probably the most important additives used in oils because oxidative deterioration plays a major role in oil degradation. Zeolite nanoparticles (NPs) have been proven as another option as green antioxidants in oil formulation. The anti-oxidative behavior of zeolite NPs is obvious; however, the phenomenon is still under investigation. Herein, a study of the effect of extra-framework cations stabilized on Linde Type L (LTL) zeolite NPs (ca. 20 nm) on inhibition of oxidation in palm oil-based lubricant oil is reported. Hydrophilic LTL zeolites with a Si/Al ratio of 3.2 containing four different inorganic cations (Li+, Na+, K+, Ca2+) were applied. The oxidation of the lubricant oil was followed by visual observation, colorimetry, fourier transform infrared (FTIR) spectroscopy, 1H NMR spectroscopy, total acid number (TAN), and rheology analyses. The effect of extra-framework cations to slow down the rate of oil oxidation and to control the viscosity of oil is demonstrated. The degradation rate of the lubricant oil samples is decreased considerably as the polarizability of cation is increased with the presence of zeolite NPs. More importantly, the microporous zeolite NPs have a great influence in halting the steps that lead to the polymerization of the oils and thus increasing the lifetime of oils.

The purification of water using nanosized EMT-type zeolite grown on luffa fibers (zeolite/luffa composite) has been carried out. The degree of crystallinity, porosity, and morphology of the pure zeolite, pure luffa and zeolite/luffa composite are characterized prior their use. It is found that the luffa fibers preserve the semi-crystalline structure under hydrothermal treatment thus resulting in the zeolite/luffa composite with enhance mechanical strength and long-term stability. The zeolite/luffa composite is used to remove heavy metal ions (Cu2+, Co2+, Fe3+, and Mn2+) from water; the sorption behavior is studied by UV-vis spectroscopy. Zeolite/luffa composite has shown high capacity for heavy metal removal from water, thus resulting in 85–95% elimination of Cu2+, Co2+, Fe3+ and Mn2+ within 250 minutes. The performance of the zeolite/luffa composite is explained by enhanced mechanical strength and long-term stability, fast diffusion, high contact area and high ion exchange and sorption capacity of both the zeolite nanocrystals and the natural luffa fibers.