Hierarchical ZSM-5 zeolite is hydrothermally synthesized in a single step with cetyltrimethylammonium (CTA) hydroxide acting as mesoporogen and structure-directing agent. Essential to this synthesis is the replacement of NaOH with KOH. An in-depth solid-state NMR study reveals that, after early electrostatic interaction between condensed silica and the head group of CTA, ZSM-5 crystallizes arou...

The relative contributions of external and intracrystalline acidic sites of small pore H-RHO zeolite for the selective synthesis of methylamines from methanol and ammonia have been studied. Nonselective surface reactions which produce predominantly trimethylamine can be eliminated by "capping" the external acidic sites with trimethylphosphite (TMP) and other reagents, thus improving the selecti...

Diels-Alder cycloaddition between cyclopentadiene and p-benzoquinone has been studied in the confined space of a pure silica zeolite Beta and the impact on reaction rate due to the concentration effect within the pore and diffusion limitations are discussed. Introduction of Lewis or Brønsted acid sites on the walls of the zeolite strongly increases the reaction rate. However, contrary to what o...

Background & Aims of the Study:  Nitrate is one of the most important pollutants that its reduced form, nitrite, can cause serious problems for human health and environment. Adsorption with cheap sorbents such as Zeolite is the best way for removal of this pollutant. So this study aimed to apply modified Clinoptilolite Zeolite for nitrate removal. Materials & Methods...

Batch and column experiments were conducted to evaluate the efficiency of a clinoptilolite zeolite as an inexpensive sorbent material to remove cationic surfactant from water. With an initial surfactant concentration greater than its critical micelle concentration, the removal of surfactant is achieved by admicellar sorption onto the zeolite surface. Although the sorption capacity of hexadecylt...

This work investigates the impact of mud from a zinc-plating plant and zeolite saturated with zinc on early hydration processes of ordinary Portland cement. During the first 48 hours of hydration, the addition of mud significantly affects the cement hydration kinetics. The partial replacement of cement with zeolite saturated with zinc ions, reduces the negative impact of mud on the hydration pr...

The protective performance of zeolite coating on AZ91D magnesium alloy was evaluated using potentiodynamic polarisation and electrochemical impedance spectroscopy (EIS) in 0.1 M sodium chloride solution (NaCl). Electrical equivalent circuit (EEC) was developed based upon hypothetical corrosion mechanisms and simulated to correspond to the experimental data. The morphology and the chemical natur...

The synthesis of zeolite NaA from silica by-product was carried out in the presence of 20 kHz ultrasound at room temperature. Zeolites obtained in this type of synthesis were compared to zeolites obtained by performing conventional static syntheses under similar conditions. The sonication effects on zeolite NaA synthesis were characterized by phase identification, crystallinity etc. The effects...

Zeolite LTA was synthesized in the laboratory and loaded with silver ions by isomorphous substitution technique. The silverloaded zeolite A (Ag-LTA) was characterized by X-ray diffraction (XRD) analysis, scanning electron microscopy (SEM), energy dispersive X-ray (EDX) and Fourier transformed infrared (FTIR) spectroscopy. XRD and SEM analysis showed little or no changes in the phase purity of a...

Self-assembly of chromophores nanoconfined in porous materials such as zeolite L has led to technologically relevant host-guest systems exploited in solar energy harvesting, photonics, nanodiagnostics and information technology. The response of these hybrid materials to compression, which would be crucial to enhance their application range, has never been explored to date. By a joint high-press...