The electroactivity of zeolite-encapsulated redox-active transition metal complexes, {M(L)}Z, was explored for Co(salen) and [Fe(bpy)3] formed in NaY zeolite (where salen ) N,N′-bis(salicylidene)ethylenediamine and bpy ) 2,2′-bipyridine). The zeolite boundary was characterized via X-ray photoelectron spectroscopy (XPS) and cyclic voltammetry in nonaqueous electrolyte at either zeolite-modified ...

Ammonia occurs in marine waters including effluents, receiving waters, and sediment interstitial waters. At sufficiently high concentrations, ammonia can be toxic to aquatic species. Toxicity identification evaluation (TIE) methods provide researchers with tools for identifying aquatic toxicants. For identifying ammonia toxicity, there are several possible methods including pH alteration and vo...

Over the years, many strategies have been developed to address the problem of sintering of nanoparticle catalysts, including encapsulating metal nanoparticles in protective shells, and trapping nanoparticles in the cavities of certain zeolites in post-synthesis steps. In general, materials that contain metal nanoparticles that are only accessible via zeolite micropores are intriguing, specifica...

Improper use of urea may cause environmental pollution through NH3 volatilization and NO3 (-) leaching from urea. Clinoptilolite zeolite and compost could be used to control N loss from urea by controlling NH4 (+) and NO3 (-) release from urea. Soil incubation and leaching experiments were conducted to determine the effects of clinoptilolite zeolite and compost on controlling NH4 (+) and NO3 (-...

Stabilization techniques for low-valent organometallic species in acidic forms of large-pore zeolite Y are reported. The intrazeolite surface chemistry and thermal stability of MesSnCo(CO)4 in HY zeolites (I&NaloA155Si1370384 and H16Na39A155Sil370384) were studied with X-ray absorption spectroscopy (Sn, Co edge EXAFS) and in-sifu FTIR/TPD-MS techniques. The acidic zeolite Y host offers a chemic...

Poly(p-phenylene) (PPP) was chemically synthesized via oxidative polymerization using benzene and doped with FeCl(3). The electrical conductivity response of the doped PPP (dPPP) towards CO, H(2) and NH(3) is investigated. dPPP shows no electrical conductivity response towards the first two gases (CO and H(2)), but it shows a definite negative response towards NH(3). The electrical conductivity...

Zeolite-geopolymer hybrid materials have been formed when kaolin was used as a starting material. Their characteristics are of interest because they can have a wide pore size distribution with micro- and meso-pores due to the zeolite and geopolymer, respectively. In this study, Zeolite-geopolymer hybrid bulk materials were fabricated using four kinds of kaolinitic clays (a halloysite and three ...

Zeolite-based technology can provide a cost effective solution for stormwater treatment for the removal of toxic heavy metals under increasing demand of safe water from alternative sources. This paper reviews the currently available knowledge relating to the effect of properties of zeolites such as pore size, surface area and Si:Al ratio and the physico-chemical conditions of the system such as...

An evaluation of natural zeolite as a microorganism carrier in nitrifying reactors operated in batch mode was carried out. Specifically, the influence of zeolite particle sizes of 0.5, 1.0 and 2.0 mm in diameter on microorganism adherence to zeolite, ammonium adsorption capacity and the identification of microbial populations were assessed. The greatest amount of total biomass adhered was obser...

Chitosan-zeolite Na-X composite beads with open porosity and different zeolite contents were prepared by an encapsulation method. Preparation conditions had to be optimised in order to stabilize the zeolite network during the polysaccharide gelling process. Composites and pure reference components were characterized using X-ray diffraction (XRD); scanning electron microscopy (SEM); N₂ adsorptio...