ioonivahetusvaigud

ioonivahetusvaigud are synthetic polymers that contain charged functional groups capable of exchanging ions with a surrounding solution. These materials are typically insoluble in water and are designed to selectively bind and release specific ions. The fundamental principle behind their operation is an equilibrium reaction where ions in the solution are exchanged for ions that are attached to the polymer matrix.

There are two main types of ion exchange resins: cation exchangers and anion exchangers. Cation exchangers have negatively charged functional groups, such as sulfonic acid (-SO3-) or carboxylic acid (-COO-), which attract and bind positively charged ions (cations). Anion exchangers have positively charged functional groups, such as quaternary ammonium (-NR3+), which attract and bind negatively charged ions (anions). The specific functional groups determine the selectivity and capacity of the resin for different ions.

The process of ion exchange involves several steps. First, the resin is typically conditioned or "regenerated" by exposing it to a concentrated solution of the desired counter-ion to saturate the exchange sites. Then, the solution containing the ions to be removed or exchanged is passed through the resin bed. As the solution flows, ions from the solution are adsorbed onto the resin, while ions from the resin are released into the solution. Once the resin's capacity is exhausted, it can be regenerated again by flushing it with a regenerant solution, typically an acid or a base, to displace the bound ions and restore the resin to its original state.

Ion exchange resins have a wide range of applications. They are commonly used in water treatment for softening (removing calcium and magnesium ions), demineralization (removing all dissolved salts), and purification. In chemical industries, they are employed in catalysis, separation and purification of chemical compounds, and in the pharmaceutical industry for drug purification and controlled release. They are also utilized in analytical chemistry for sample preparation and pre-concentration of trace elements.