Geopolymer monoliths with controlled lamellar macroporosity and total porosity ranging from 60% to 70% were prepared by ice-templating a partially eopolymerized slurry. Both the maturation treatment of the starting mixture and the water specifically added for freeze-casting were tailored to modify both the geopolymerization and viscosity of the slurry, and, consequently, its freezing behavior, in order to optimize the final lamellar architecture. Following a room temperature maturation treatment, a 50% water content added for freezing developed thick lamellae and wide pores. A lower water content (30%) and curing at 80 C after maturation at room temperature (for both 50% and 30% H2O) was conducive to a narrow lamellar pore width distribution in the 30–130 mm range. However, the consumption of water due to geopolymerization in samples cured at 80 C led to a decreased length and thickness of the lamellae. Lastly, the interparticle meso- and macropores (0.003 to 1 mm) within the geopolymer lamellae were only slightly modified by the maturation treatment.
Papa, E., Medri, V., Benito Martin, P., Vaccari, A., Bugani, S., Jaroszewicz, J., et al. (2016). Insights into the macroporosity of freeze-cast hierarchical geopolymers. RSC ADVANCES, 6, 24635-24644 [10.1039/c6ra02232d].
Insights into the macroporosity of freeze-cast hierarchical geopolymers
PAPA, ELETTRA;BENITO MARTIN, PATRICIA;VACCARI, ANGELO;BUGANI, SIMONE;
2016
Abstract
Geopolymer monoliths with controlled lamellar macroporosity and total porosity ranging from 60% to 70% were prepared by ice-templating a partially eopolymerized slurry. Both the maturation treatment of the starting mixture and the water specifically added for freeze-casting were tailored to modify both the geopolymerization and viscosity of the slurry, and, consequently, its freezing behavior, in order to optimize the final lamellar architecture. Following a room temperature maturation treatment, a 50% water content added for freezing developed thick lamellae and wide pores. A lower water content (30%) and curing at 80 C after maturation at room temperature (for both 50% and 30% H2O) was conducive to a narrow lamellar pore width distribution in the 30–130 mm range. However, the consumption of water due to geopolymerization in samples cured at 80 C led to a decreased length and thickness of the lamellae. Lastly, the interparticle meso- and macropores (0.003 to 1 mm) within the geopolymer lamellae were only slightly modified by the maturation treatment.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
