Incorporation of organic liquids into geopolymer materials: A review of processing, properties and applications

Geopolymers, composed of an amorphous three-dimensional inorganic network and synthesized by the activation of a solid alumino-silicate precursor with an alkaline activating solution, have attracted increasing attention because of their environmental benefits and favorable characteristics. This review deals with the development of hybrid organic/inorganic materials by the addition of organic liquids into inorganic geopolymer matrices. Firstly, the incorporation processing approaches are presented and are divided into three categories: (i) Direct incorporation, (ii) Pre-emulsification (iii) Solid impregnation. Their main advantages and drawbacks are discussed in relation to the aimed properties. Secondly, this review highlights the fact that geopolymers are low-cost candidates for the incorporation of various organic liquids, leading to technologically significant applications. Aside from the well-studied immobilization of industrial waste streams commonly known as stabilization/solidification (S/S), the development of highly porous materials and the design of reinforced organic/inorganic hybrid matrices are being notably investigated. This review aims at summarizing the main published results and fostering further investigations into developing innovative use of organic liquids incorporated into geopolymers for a wide range of applications