In Situ Processing of Graphene/Leucite Nanocomposite Through Graphene Oxide/Geopolymer

Abstract

Graphene/leucite nanocomposites (rGO/leucite) were prepared through in situ reduction of graphene oxide/geopolymer (rGO/ KGP) composites. The effects of rGO on the microstructure and mechanical properties with respect to the geopolymer matrix after the high-temperature treatment were investigated systematically. The results show that GO is first partially reduced in the geopolymeric solution and then completely under the post high-temperature treatment. The rGO sheets undergo no interfacial reactions with the matrix even after thermal treatment. The rGO/geopolymer composites fully transform to rGO/leucite composites after being treated at 1000°C for 30 min in an argon atmosphere. Significant improvements in mechanical properties were achieved through rGO reinforcement giving flexural strength, elastic modulus, and fracture toughness of 91.1 MPa, 60.5 GPa, and 2.04 MPaÁm 1/2 , increased by 120%, 8%, and 1.5%, respectively, compared with the leucite matrix alone.

Effects of graphene oxide on the geopolymerization mechanism determined by quenching the reaction at intermediate states

“…Meanwhile, the presence of rGO contributed to the enhancement of mechanical performance of geopolymer. As reported in our previous studies, 23,24 compared with pure geopolymer, improvements in mechanical properties were achieved through rGO reinforcement of 0.05-1 wt% at room temperature. With 1 wt% GO addition, the fracture toughness and exural strength of rGO/geopolymer composites increased by approximately 30% and 7%, respectively, attributing to the proper interface bonding, crack deection and propagation and rGO pull-out.…”

“…[15][16][17] As a new nano ller material, it provided considerable potential in the fabrication of multifunctional polymers and ceramic matrix composites. [18][19][20] In our previous works, 9,12,13,[21][22][23][24][25] we have investigated Al 2 O 3 , 9 cenospheres, 21 carbon bers 12,13 and graphene oxide (GO) [22][23][24][25] reinforced geopolymer composites. However, the effects of graphene oxide addition on the geopolymerization mechanism of the rGO/geopolymer (rGO/KGP) during the processing was also not been investigated.…”

Effect of high temperature on the mechanical properties of hierarchical porous cenosphere/geopolymer composite foams

“…44 The pure KGP presents an exotherm peak at 1020°C and the weight loss is ~15 wt.%, which is attributed to the crystallization of leucite. 36 As for TG curve of the FHCs/KGP foams, weight loss of the FHCs/KGP foams is 11.17 wt.%. The DTA curve of H2 sample shows a peak centered at 300°C, which may be mainly caused by organic decomposition in the foams.…”

“…Such mechanical improvement is also reported for graphene/leucite composites. 36 Kovářík et al 37 found that geopolymer foams transformed into leucite-based ceramic foams with open cell when sintering at 1300°C. Thus, it is worthy studying high-temperature performance of geopolymer foams to evaluate its thermal stability.…”

Structural Applications of Thermal Insulation Alkali Activated Materials with Reduced Graphene Oxide

“…Particularly, reduced graphene oxide (rGO) is used in construction for its large specific surface area, favorable mechanical strength, and high toughness [44][45][46][47]. In addition to this superior performance, rGO can effectively disperse in the highly alkaline environment of AAMs matrix (pH~12.5) due to electrostatic stabilization and significantly improve its mechanical properties [48][49][50].…”