4. Ion Exchange
• Process in which ions of one substance are replaced by similarly
charged ions of another substance.
• Ion exchange is an adsorption phenomenon.
• It is basically a reversible chemical process.
5. Ion Exchangers
• An ion exchannger is an insoluble framework or matrix which
carries positive or negative electric charged ion.
• The positive or negative ions are exchanged by the medium ions.
• The insoluble frameworks are made of up crosslinked polymer.
• Ionic functional groups are attached to this framework
• Also known as ion-exchange resin or ion-exchange polymer.
6.
7. Types of Ion Exchanger
• Ion exchangers are two types
A. Cation exchanger
B. Anion exchanger
8. A. Cation exchanger
• Exchange positive ions or cations
(Structure of a cation exchanger)
• Solid-H+ + M+ Solid-M+ + H+
(Cation exchanger) (solution) (solution)
9. Types of Cation exchanger
Cation exchangers are two types,
1. Inorganic Cation exchanger
2. Organic Cation exchanger
12. • Generally Synthetic Organic Cation exchangers are widely used.
• These are two types
i. Strongly Acidic Cation Exchanger
ii. Weakly Acidic Cation Exchanger
13. i. Strongly Acidic Cation Exchanger
• Contain Sulphonic acid (—SO3
– H+ ) as functional groups
(Structure of Strongly Acidic Cation Exchanger)
14. Examples of Strongly Acidic Cation Exchanger:
AmberliteTM IR120 Na DowexTM Marathon C puroliteTM C100
15. ii. Weakly Acidic Cation Exchanger
• Contain Carboxylic acid (—COOH) as a functional groups.
(Structure of weakly Acidic Cation Exchanger)
17. B. Anion exchanger
• Exchange negative ions or anion
(Structure of a anion exchanger)
• Solid-OH- + A- Solid-A- + OH-
(anion exchanger) (solution) (solution)
18. Types of Anion exchanger
Anion exchangers are two types
1. Inorganic anion exchanger
Natural
Kaolinite, Apatite, Fluorapatite, Hydroxyapatite etc
2. Organic anion exchanger
Syntetic
Polymerization of an aromatic amine and formaldehyde.
19. • Generally Synthetic Organic ation exchangers are widely used.
• These are two types
i. Strongly Basic Anion Exchanger
ii. Weakly Basic Anion Exchanger
20. i. Strongly Basic Anion Exchanger
• Contain Quaternary ammonium (—N(CH3)3
+ OH–) as functional
groups
(Structure of strongly basic Cation Exchanger)
21. Examples of Strongly Basic Anion Exchanger:
DowexTM Marathon A LewatitTM MP600PuroliteTM A400
22. ii. Weakly Basic Anion Exchanger
• Contain Amines [—N(CH3)2 ] as a functional group
(Structure of weakly basic Cation Exchanger)
23. Examples of Weakly Basic Anion Exchanger:
PuroliteTM A100 AmberliteTM ira 94 AmberliteTM ira 400
24. Applications of Ion Exchanger
• Softening of water
• Demineralisation or deionisation of water
• Purification of some solutions to be free from ionic impurities
• Separation of inorganic ions
• Organic separations: mixture of pharmaceutical compounds ca be
separated
• Biochemical separations like isolation of drugs
• Removal or recovery of metal