Unveiling the performance of graphene nanofiber additives in gypsum plasters: A solid vs liquid perspective

Abstract

Graphene nanofibers (GNFs) are promising additives for the gypsum industry. However, their impact in different forms and configurations remains unexplored. This study delves into the effects of different types of GNF additives on the properties of gypsum plasters. Findings reveal that high-surface-area (HS) GNFs and liquid low-surface-area (LS) GNFs induced significant microstructural alterations. While rheology remained unaffected, GNFs accelerated gypsum hydration, leading to fast setting. Furthermore, these GNFs promoted the appearance of anhydrite, resulting in a porous matrix with shorter crystals and poor bonding. These microstructural changes significantly reduced both flexural and compressive strength, with losses of approximately 25%. The incorporation of surfactants further exacerbated these negative effects by limiting crystal formation and growth. Consequently, liquid GNF additives exhibited the lowest performance and durability attributes. While GNFs may impart improved thermal performance to gypsum components, their implementation can also lead to significant reductions in mechanical strength and durability. More research is required to develop additives that are more compatible and do not compromise the performance of the resulting components. Building practices interested in implementing graphene-based materials should focus on powdered additives with very low specific surface area (<100 m2/g) to minimize toxicity and negative impacts on strength and durability.