Solution chemistry, aqueous sodium silicate

Solution Chemistry of Aqueous Sodium Silicate. The Iler DS... 

The chemistry of silica in aqueous systems (e.g., sodium silicate) is discussed in detail by Her (10). Silicon is hydrolyzed even in dilute acid and as shown in Fig. 5.4, silicic acid [Si(OH)4], often referred to as monosilicic acid, orthosilicic acid, or soluble silica, is the dominant mononuclear species in solution below pH values of 7 (11). The Si-OH group is called a silanol group, indicating that Si(OH)4 contains four silanol groups. Above pH 7, further hydrolysis produces anionic species ... 

Aqueous sol-gel chemistry is based on the condensation of solute precursors via pH modifications (Jolivet, 2000). Ionic dissociation and hydrolysis occur when a silicate salt is dissolved in water leading to more or less protonated silicate species [H Si04] ) . In the case of sodium silicate Na2Si03, a convenient commercial precursor for silica, a basic aqueous solution is obtained that contains Na and [SiO(OH)s] species at pH % 12. 

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