Geopolymer Alliance

The Inorganic Polymer Family

Inorganic Polymers

Geopolymers can be considered as a member of the family of silicon based inorganic polymers.

The simplest member of the family is that described by sol-gel silica technology (ref: Hench, L.L, "Sol-Gel Silica. Properties, Processing and Technology Transfer," Noyes Publications, 1998), where silicon ions are dissolved from a pure silica feedstock. The polymer chains so produced can be represented by;

 - Si - O - Si - O - Si -

The next most complex members are the geopolymers where some Si ions in the chain or net are replaced by Al ions, and represented by;

- Si - O - Si - O - Al(Na) - O - Si -      etc.

A more complex member of the family is commonly know as Alkali-Activated Cement. Here Ca is introduced into the geopolymer sol and the resultant hardened matrix consists of a mixture of phases;-

- geopolymer phases represented by;     - Si - O - Si - O - Al(Ca/Na) - Si - O - Si -    and

- calcium silicate hydrate phases (CSH).

Research into heavy metal ion encapsulation suggests that other metal ions can substitue into the chains or nets and that Fe also appears to play an active role in the polymerization process   

It is postulated that there are other possible members of the family (or another family) involving Zircon instead of Silicon.