Types of Gel

Types of Gel

1. Chemical Gels

   • Bonds linking the subunits are covalent.
     • Thermosetting resins
       • Short polymer with reactive groups mixed with a hardener.
     • Sol-gel glasses
       • Organic derivatives of silicon and metal oxides dissolved in solvents and hydrolysed in water.
     • Vulcanised rubbers
       • The process starts with an entangled polymer. Cross linking agents are then used to connect the chains together (natural rubber = PI + sulphur).

2. Physical Gels

   • Bonds linking the subunits are physical interactions.
     • Bonds can be broken by heating. Thermoreversible gels.