MATERIALS TODAY COMMUNICATIONS, cilt.33, 2022 (SCI-Expanded)
In this study, graphene-based materials such as graphene oxide, reduced graphene oxide, and boron-doped reduced graphene oxide were synthesized, and their effects on the microstructure and mechanical properties of gypsum plaster were investigated. The graphene oxide (GO) sample was synthesized by modified Hummers' method, and reduced graphene oxide (rGO) was obtained with the thermal reduction of GO. Boron doped reduced graphene oxide (B-rGO) was prepared via the impregnation method. The synthesized graphene-based materials were characterized using H2-TPR, TGA-DTA, XRD, FT-IR, SEM-EDS, TEM, Raman, and N2 adsorption-desorption analysis. Analysis results confirmed that 450 degrees C was a sufficient temperature under an H2 atmosphere to reduce GO and preserve rGO structure. XRD results revealed the presence of multilayer graphene structure in the rGO and B2O3 crystals in the B-rGO sample. Multilayer graphene formation was also determined from the I2D/IG ratio (0.1) of Raman analysis. Mechanical strength studies showed that while GO had a negative effect on both bending and compressive strength of gypsum plaster, rGO enhanced its bending and compressive strength. The addition of 0.1 wt% rGO added gypsum plaster increased the bending strength by 15.1 % and compressive strength by 3.70 %. SEM, He Pycnometry, and N2 adsorption-desorption analyses revealed that rGO addition significantly changed the microstructure of gypsum plaster. The addition of B-rGO positively affected the compressive strength of the plaster and the highest increase was obtained as 8.6 %; however, no significant change was observed in the microstructure of gypsum.