Mineral Trioxide Aggregate (MTA)

Zeolites are widely used for their catalytic abilities and storage potential in a diverse range of industries. They are used to treat contaminated wastewaters and as soil conditioners. Zeolites are aluminosilicates with variable Si/Al ratios. Both natural and synthetic zeolites are available that have become increasingly important due to their versatile physical and chemical properties. Zeolites have extensive applications as adsorbents, molecular sieves, membranes, ion exchangers, and catalysts in pollution control as well as in soil remediation.

Zeolite is the crystalline structure of aluminosilicates and it has porous molecular structure; several ions such as zinc and silver are embedded in these pores. Incorporation of silver-zeolite into MTA increased its solubility, resulted in the release of calcium, and decreased its setting time.

Zeolites are crystalline aluminosilicates with open 3D framework structures built of SiO4 and AlO4 tetrahedra linked to each other by sharing all the oxygen atoms to form regular intra-crystalline cavities and channels of molecular dimensions. A defining feature of zeolites is that their frameworks are made up of 4-coordinated atoms forming tetrahedra. The framework structure may contain linked cages, cavities or channels, which are big enough to allow small molecules to enter. The system of large voids explains the consistent low specific density of these compounds.

In zeolites used for various applications, the voids are interconnected and form long wide channels of various sizes depending on the compound. These channels allow the easy drift of the resident ions and molecules into and out of the structure. The aluminosilicate framework is negatively charged and attracts the positive cations that reside in cages to compensate negative charge of the framework. Unlike most other tectosilicates, zeolites have largeer cages in their structures.

Zeolites are crystalline solids structures made of silicon, aluminum and oxygen that form a framework with cavities and channels inside where cations, water and/or small molecules may reside. They are often also referred to as molecular sieves. Many of them occur naturally as minerals, and are extensively mined in many parts of the world finding applications in industry and medicine.