Advances in understanding the mechanisms of particle dispersion and performance of superplasticisers in alkali-activated materials – a systematic literature review

Chemical admixtures, such as superplasticisers, are urgently needed to support the widespread adoption of low-carbon cements for a net-zero future. This study presents a critical, systematic literature review of 100 publications, focusing on the mechanisms of dispersion, particle-surface interactions, and performance of superplasticisers in alkali-activated materials (AAMs). Key gaps remain in understanding the interactions between metakaolin particles and superplasticisers. Most research centres on alkali-activated slag systems and their interaction with polycarboxylate ethers (PCEs), recommending high-molecular-weight, highly anionic PCEs with short side chains. The high pH and ionic strength of AAM pore solutions, along with shifts in surface particle zeta potential, impair superplasticiser performance due to solubility issues, partial degradation and polymer agglomeration. Future progress will focus on advances in molecular design, the development of novel or modified PCEs, and a deeper understanding of nanoscale and atomic-level interactions. This review outlines existing knowledge and the critical challenges ahead in engineering next-generation admixtures for sustainable cement technologies.