چكيده به لاتين
This study investigates the interactions of two-dimensional (2D) materials—specifically
graphene quantum dots (GQDs) and molybdenum disulfide (MoS₂)—in a cementitious-like
solution. Due to their unique physical and chemical properties, such as high specific surface
area, these materials have attracted considerable attention from researchers. The primary
objective of this research is to identify the factors influencing thermal conductivity variations
in a cementitious matrix upon the addition of semiconductor nanostructures, including
carbon-based semiconductors like GQDs and transition metal dichalcogenides like MoS₂. The
main challenges addressed in this study involve the synthesis of nanomaterials, achieving
their uniform dispersion in the cement-like solution, and enhancing structural bonds under
harsh environmental conditions.Both individual and hybrid samples were prepared to
evaluate the effects of GQDs and MoS₂, and their mechanical and microstructural properties
were characterized using various techniques. Initially, different volumetric concentrations of
GQDs (0.5, 1, 2, 4, 6, and 8 mL) were added to the cementitious solution. Based on UV–Vis
spectroscopy results, three optimal concentrations were selected. Subsequently, varying
weights of MoS₂ (0.0011, 0.0025, and 0.0032 g) were introduced. Twelve composite samples
containing different weight ratios of the two nanomaterials were fabricated and analyzed.
Fourier-transform infrared (FTIR) spectroscopy was employed to assess agglomeration and
investigate structural and energetic interactions, while photoluminescence (PL) spectroscopy
was used to examine electronic and optical properties. The sample containing 1 mL of GQDs
and 0.0025 g of MoS₂ exhibited the highest degree of interaction. Thermal conductivity
testing, conducted to assess the materials' heat transfer capabilities, revealed that the GQD–
MoS₂ composite reduced the thermal conductivity coefficient to 14 W/m·K at 25°C,
representing a 2.3% decrease compared to the reference sample. Furthermore, the hybrid
sample demonstrated a 5.4% and 6.6% reduction in thermal conductivity compared to
samples containing only GQDs or MoS₂, respectively. These results were corroborated by
luminescence analysis, FTIR spectroscopy, and cyclic voltammetry.Overall, this research
highlights the significant potential of 2D materials such as GQDs and MoS₂ in enhancing the
properties of cementitious composites.
