An Ion Exchange Resin is a resin or Polymer that acts as a medium for Ion Exchange. It is an insoluble matrix (or support structure) normally in the form of small (0.25–0.5 mm radius) microbeads, usually white or yellowish, fabricated from an organic polymer substrate. The beads are typically porous, providing a large surface area on and inside them. The trapping of ions occurs along with the accompanying release of other ions, and thus the process is called Ion Exchange. There are multiple types of ion-exchange resin. Most commercial resins are made of Polysterene Sulfonate

 

Ionexchange resins are widely used in different Separation, Purification, and Decontamination processes. The most common examples are Water Softening and Water Purification to produce deionized water. These resins are composed of organic polymer chains that have charged functional groups built into the resin bead. Cation resin has a negative functional group and therefore attracts positively charged ions and Anions resins have positive functional group and therefore attracts negative charged ions. Specialised ion exchange resins are also known such as chelating resins

Ion exchange
ion exchange
ion exchange

Four main types of ion-exchange resins differ in their functional group

Strongly Acidic, typically featuring Sulfonic Acid Group groups.
Strongly Basic, typically featuring quaternary Amino groups.
Weakly Acidic, typically featuring Carboxylic Acid groups.
Weakly Basic, typically featuring primary, secondary, and/or tertiary Amino groups
Besides being made as bead-shaped materials, ion-exchange resins are also produced as membranes. These Ion Exchange Membranes, which are made of highly cross-linked ion-exchange resins that allow passage of ions, but not of water, are used for electrodialysis.

Applications

Water Treatment

Softening
Dealkalisation
Demineralisation
Mixed bed polishing
Condensate polishing
Ultrapure water
Drinking water

Sugar Industry

Softening of water used for sugar extraction
Softening of sugar juices before evaporation
The NRS softening process
The Gryllus softening process
Demineralisation of sugar juices before evaporation
Colour removal from sugar syrups after evaporation
Sugar recovery from molasses

Other Food Industry

Dairy products
Beverages
Fruit juices
Recovery of polyphenols
Citric acid
Aminoacids
Sorbitol demineralisation
Gelatine demineralisation

Miscellaneous Application

Mining industry
Enzyme immobilisation
Hydroculture
Oil removal by coalescence

Pharmaceutical

Extraction and purification of antibiotics
Slow-release formulations
Resins used as drugs
Taste-masking
Production chromatography