History of ion exchange

Chronology

The table below shows the main development steps of ion exchange.
 

~1400 BC	Moses experiments water debittering (Exodus 15, 22 - 25)
~330 BC	Aristotle finds that sea water loses part of its salt contents when percolated through certain sand.
1850	Discovery of ion exchange by Thompson & Way (England).
1876	Zeolites recognised as carriers of base exchange in soils (Lemberg).
1901	Artificial zeolites used for removal of potassium from sugar juices.
1905	Commercial use of ion exchange with inorganic aluminosilicates (zeolites) developed by Gans (Germany).
1935	Industrial manufacture of sulphonated coals for water softening filters (Liebknecht and Smit).
1935	Synthetic ion exchange resins (phenol-formaldehyde polycondensates) invented by Adams & Holmes.
1940	First commercial phenol-formaldehyde ion exchange resins; both strongly acidic and weakly basic exchangers. Examples: Duolite C3 and Duolite A7.
1944	First patent for sulphonated polystyrene resin (D'Alelio, USA).
1946	McBurney invents strongly basic anion exchangers made by chloromethylation and amination of polystyrene.
1947	First commercial strongly acidic cation exchangers based upon cross-linked polystyrene.
1948	First commercial strongly basic anion exchangers based on McBurney's invention.
1948	Rohm and Haas introduces the first weakly acidic cation exchanger (methacrylic Amberlite IRC50).
1949	First commercial use of Mixed-bed resin technology.
1950	First use of weakly acid resins for recovery of antibiotics (streptomycin) from fermentation broth.
1950	First commercial synthesis of styrene-based weakly basic anion exchanger (Amberlite IRA45).
1950	Development of ion exchange resins in powdered form for sodium reduction therapy.
1951	First use of ion exchange resins for treatment of sugar.
1952	First commercial use of anion exchange resins for recovery of uranium from leach liquor.
1952	Invention and development of chelating polymers (Gregor).
1953	Rohm and Haas develops acrylic based weakly basic anion exchange resin (now Amberlite IRA67).
1957	Rohm and Haas introduces liquid anion exchange materials (Amberlite LA1, LA2).
1959	Discovery of phase extension polymerisation technique for production of macroporous ion exchange resins. Patents in Germany (Bayer), USA (Rohm and Haas) and UK (Permutit). Rohm and Haas used to call the products macroreticular.
1961	Rohm and Haas introduces macroreticular (macroporous) ion exchange resins for use as catalysts.
1963	Bayer files a patent for the "floating bed" (Schwebebett) packed bed ion exchange technology.
1965	New macroreticular polymeric adsorbents (Amberlite XAD2, XAD4, etc.) introduced.
1974	First commercial use of boron-specific resin (Amberlite IRA743, methyl-glucamine).
1988	Dow Chemical introduces uniform particle size Dowex Monosphere resins.

A few more details

As can be seen from the preceding table, the most active development period of ion exchange resins has been the middle of the 20^th Century. Today, the technology is mature, and only small improvements are made in application process and column design, but little in the synthesis of resins, where chemistry has reached its limits.

Aluminosilicates

Natural and synthetic sodium aluminosilicates (often called zeolites, have been used for water softening in the first part of the 20^th Century. Capacity was low, and the silicates are somewhat soluble at high pH. One of the last products sold commercially in the 1970s was Decalso Y produced by Zerolit Ltd in the UK. Today, they are no longer used in ion exchange columns. However, aluminosilicates are still widely used as a component of washing powders for their water softening capability.

A natural zeolite called clinoptilolite is also still used in the nuclear industry for its high affinity for caesium. After the 2011 Fukushima disaster, bags of this zeolite have been dumped in the power station site in an attempt to eliminate radioactive ¹³⁷Cs, or at least to prevent its propagation into the sea.

Sulphonated coal

In the 1930s through 1950s, this product has been a major cation exchanger. It can be used either in sodium or hydrogen cycle. However, its capacity is only about 1/4 of the capacity of a modern sulphonated polystyrene resin, so it has been totally superseded by synthetic products.

Synthetic resins

These are now the only significant products used in industrial ion exchange techology. About 95 % of the resins are based on styrenic polymers, 4 % on acrylates and only a very little fraction on other polymers. You can read more about resin structure and resin types in dedicated pages.