We will discuss predictions for the stability and structures of all-silica zeolitic structures. We will show that we have derived a new shell model potential, based on ab initio calculations , which gives good predictions for the structure and stability of all-silica structures. We will compare three shell model predictions with two rigid-ion model predictions for the structure and stability of...

Zeolites due to their structures can be used as molecular sieves for purification of materials and solutions. Zeolites with PHI and SOD structure are so common and applicable for this purpose. Hydroxy sodalite and phillipsite are the more abundant members of zeolites which display good selectivity for very small molecules and some ions such as Sr, Pb, Zn, Cu and Rb. There is not any pure natura...

in present study, molecular dynamics simulation of cadmium (ii), lead (ii) and copper (ii) removal from aqueous electrolyte solutions using the ion-exchange process with the zeolite particles was done. the results showed that, most of the particles had the highest affinity of ion exchanging with lead (ii) and the lowest affinity with copper (ii). the calculated mean ion-exchange ratios showed t...

Borosilicate zeolites have recently been studied in many aspects because they are useful in substitution of framework metal ions (to Al or Ga) and in catalyzing chemical reactions that use relatively weak acid strength. Boron shows a great extent of flexibility in coordination conversion between trigonal boron, B[3], and tetrahedral boron, B[4]. Such conversion takes place in the framework of b...

To examine the detoxification effect of mineral-encaged zeolites on cells impaired by pollutant-intoxication, we used a bioassay system involving Euglena gracilis Z as the model organism and TBTCl as a pollutant. TBTCl exposure causes Euglena cells to quickly change shape from a spherical to spindle form, with the process being reversible by detoxification. Taking advantage of this morphologica...

In order to study and develop an economical solution to environmental pollution in water, a wide variety of materials have been investigated. Natural zeolites emerge from that research as the best in class of this category. Zeolites are natural materials which are relatively abundant and non biodegradable, economical and serve to perform processes of environmental remediation. This paper contai...

Zeolites have been increasingly used in various application areas such as industry, agriculture, environmental protection, and even medicine. Although, there are no certain figures on the total amount of these minerals the world, some countries e.g. Cuba, USA, Russia, Japan, Italy, South Africa, Hungary and Bulgaria, have important reserves and production potentials. According to reports of 200...

The selective catalytic reduction (SCR) of NO by methane in the presence of excess oxygen has been studied on a series of Pd catalysts supported on sulfated zirconia (SZ). This support is not as sensitive to structural damage by steaming as the acidic zeolites, such as H-ZSM-5 and H-Mor. In previous studies, it was shown that this type of acidic zeolites are able to stabilize Pd2+ ions and prom...

Nitric oxide can be stored in and produced from zeolites in a simultaneous and cooperative process.