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Ordinary Portland cement (OPC) is the binding element in concrete materials and, CO2 emissions associated with its manufacturing and use is about 8% of the world's CO2 emissions. The engineering properties of hardened concrete depend on the amount of the hydrate phases in OPC. If the growth of the hydrate phases could be increased, the performance of concrete would be significantly improved, and the consumption of OPC will be decreased, and its environmental footprint will be reduced. In this paper, we present a new green approach for controlling the growth of the hydrate phases in OPC using bio flakes composed of staked carrot-based two-dimensional (2D) nanosheets (CNSs) synthesized from carrot waste. Density-functional theory and reactive molecular dynamics (DFT-MD) simulations were carried out in conjunction with analytical characterization to examine the interfacial interaction between CNS with tricalcium silicate Ca3SiO5 (C3S), the main constituent of OPC and understand how they influence the growth of the hydrate phases in OPC. The DFT-MD simulations results show the 2D CNS dissolves due to its interfacial interaction with the highly reactive C3S, leading to a series of fast proton exchange in C3S. This in return accelerates the dissolution rate of C3S thereby amplifying the growth of the hydrate phases. The DFT-MD simulations also show that the dissolution of the 2D CNS creates new several organic compounds that enhance the mobility and dynamics of protons that further amplify the dissolution rate of C3S. The analytical results from scanning electron microscope (SEM), X-ray diffraction (XRD), transmission electron microscopy (TEM), and thermography analysis (TGA) and differential scanning calorimetry (DSC) show a significant growth of the hydrate products in OPC due to interfacial dissolution of C3S and some CNS thus, confirming the DFT-MD results. This work demonstrates that the growth of the hydrate products in OPC can be amplified by the addition of green and renewable 2D bio-based nanomaterials. This green approach provides a base for the design and development of low-carbon cementitious materials.

Ordinary Portland cement (OPC) is the binding element in concrete materials and, CO2 emissions associated with its manufacturing and use is about 8% of the world's CO2 emissions. When OPC is mixed with water, a large quantity of OPC particles remain unhydrated or partially hydrated. If the dissolution and setting of calcium silicate phases of OPC could be increased, the performance of concrete would be improved, and the consumption of OPC will be decreased and its environmental footprint will be reduced. In this paper, we examine the origin of increased dissolution of tricalcium silicate (C3S) and dicalcium silicate (C2S) phases as a result of their interfacial chemical interactions with newly developed 2D carrot-based bio nanosheets (CNSs). Density-functional theory calculations and reactive molecular dynamics (DFT-MD) simulations were combined with experimental characterization to uncover the molecular chemical phenomena at the CNS/cement interface and understand how they influence the hydration of cement. The DFT-MD simulations results reveal that the observed increase in the degree of hydration of cement is due to the chemical interaction at the CNS/C3S interface. The dissolution of CNS by the highly reactive C3S leads to a series of proton exchange with higher diffusion rate in C3S. This increases the thickness of the hydration shell by as much as 3 nm. The DFT-MD simulations also show that the dissolution of CNS creates new organic compounds that enhance the mobility and dynamics of protons to further promote the dissolution of C3S. The experimental results support the DFT-MD simulation results. They confirm the dissolution of some CNS layers and the subsequent increased dissolution of C3S. The experimental results also show that CNS increases the degree of hydration of C3S and C2S by 6.3% at a maximum CNS concentration of 0.4-wt%. This work demonstrates that the kinetics of reaction of CNS in the cement environment amplify the hydration of OPC for enhanced performance and provides a base for the development of cementitious materials with low carbon footprint using green and renewable 2D nanomaterials.

Ordinary Portland cement (OPC) is the binding element in concrete materials and, CO2 emissions associated with its manufacturing and use is about 8% of the world's CO2 emissions. When OPC is mixed with water, a large quantity of OPC particles remain unhydrated or partially hydrated. If the dissolution and setting of calcium silicate phases of OPC could be increased, the performance of concrete would be improved, and the consumption of OPC will be decreased and its environmental footprint will be reduced. In this paper, we examine the origin of increased dissolution of tricalcium silicate (C3S) and dicalcium silicate (C2S) phases as a result of their interfacial chemical interactions with newly developed 2D carrot-based bio nanosheets (CNSs). Density-functional theory calculations and reactive molecular dynamics (DFT-MD) simulations were combined with experimental characterization to uncover the molecular chemical phenomena at the CNS/cement interface and understand how they influence the hydration of cement. The DFT-MD simulations results reveal that the observed increase in the degree of hydration of cement is due to the chemical interaction at the CNS/C3S interface. The dissolution of CNS by the highly reactive C3S leads to a series of proton exchange with higher diffusion rate in C3S. This increases the thickness of the hydration shell by as much as 3 nm. The DFT-MD simulations also show that the dissolution of CNS creates new organic compounds that enhance the mobility and dynamics of protons to further promote the dissolution of C3S. The experimental results support the DFT-MD simulation results. They confirm the dissolution of some CNS layers and the subsequent increased dissolution of C3S. The experimental results also show that CNS increases the degree of hydration of C3S and C2S by 6.3% at a maximum CNS concentration of 0.4-wt%. This work demonstrates that the kinetics of reaction of CNS in the cement environment amplify the hydration of OPC for enhanced performance and provides a base for the development of cementitious materials with low carbon footprint using green and renewable 2D nanomaterials.