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...

In this paper, the properties of concrete containing zeolite and tuff as partial replacements of cement and sand were studied. The compressive strength, water absorption, chloride ion diffusion and resistance to acid environments of concretes made with zeolite at proportions of 10% and 15% of binder and tuff at ratios of 5%, 10% and 15% of fine aggregate were investigated. The results showed th...

A hierarchical zeolite CaA with microporous, mesoporous and macroporous structure was hydrothermally synthesized by a ”Bond-Blocking” method using organo-functionalized mesoporous silica (MS) as a silica source. The characterization by XRD, SEM/TEM and N2 adsorption/desorption techniques showed that the prepared material had well-crystalline zeolite Linde Type A (LTA) topological structure, mic...

Zeolite–sepiolite inorganic nanoheterostructures have been hydrothermally synthesized by adding a dispersion of colloidal sepiolite to a solution able to produce a nanocrystalline zeolite (silicalite). The obtained product could be recovered in good yield by simple filtration only when the relative sepiolite concentration exceeded a threshold of 1.8 wt% in the synthesis mixture (amounting to 1:...

Highly b-oriented zeolite ZSM-5 films are critical for applications in catalysis and separations and may serve as models to study diffusion and catalytic properties in single zeolite channels. However, the introduction of catalytically active Al3+ usually disrupts the orientation of zeolite films. Herein, using structure-directing agents with hydroxy groups, we demonstrate a new method to prepa...