Immobilising oils in geopolymer cements using pickering emulsions

Silica fume was investigated as a potential Pickering agent as an alternative route of immobilisation of organic oils (Nevastane oil or TPB/dodecane) in potassium geopolymer cement. The Pickering emulsion was able to immobilise up to 30 wt% Nevastane loading in the geopolymer cement. The formation of the Pickering emulsion was able to decrease the initial and final setting times, whilst, increasing the early compressive strength of the Pickering samples in comparison to non-emulsified Nevastane samples. The X-ray tomography data further showed the successful dispersion of the Nevastane droplets throughout the geopolymer matrix, with good uniformity of the droplet distribution. However, the Pickering emulsion was unable to successfully immobilise the TBP/dodecane at any weight loading, suggesting that this immobilisation route was not suitable for this particular organic oil. Hence, Pickering emulsions could be used as an alternative route for the immobilisation of selected organic oils into geopolymer cements.