Characterization of multi-scale porous structure of fly ash/phosphate geopolymer hollow sphere structures: From submillimeter to nano-scale

- Porous structure of HSS was characterized from sub-millimeter to nano-scale.
- Hollow fly ashes and sub-millimeter irregular open cells were found by CT and CSLM.
- Micro-sized open cell in gaps between fly ashes showed normal/bimodal distribution.
- PG was mainly composed of amorphous Al-O-P nano-pore area and α-Al2O3.
- Nano-pores (mainly from 10 to 100 nm) demonstrated a quasi-normal distribution.