Carbonation Competing Functionalization on Calcium-Silicate-Hydrates: Investigation of Four Promising Surface-Activation Techniques

Giraudo, Nicolas; Thissen, Peter

doi:10.1021/acssuschemeng.6b00870

Cited by 13 publications

(33 citation statements)

References 59 publications

(116 reference statements)

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“…1,44,45 In this regard, the direct chemical interactions of GO or rGO (with pH 3.01) with hydrated cement have a neutralizing effect on the highly alkaline medium of CP with a pH greater than 12.5 in the pore solution, inducing the acidic nature of the oxygen functional groups on the graphene layer surfaces in GO or rGO, such as carboxyl, hydroxyl, and epoxy. 18,21−23,38−46…”

Section: Resultsmentioning

confidence: 99%

Elucidation of Calcite Structure of Calcium Carbonate Formation Based on Hydrated Cement Mixed with Graphene Oxide and Reduced Graphene Oxide

Yaseen

Yiseen

Li³

2019

ACS Omega

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In this study, the carbonation of Portland cement by direct chemical interaction with graphene oxide (GO) and reduced graphene oxide (rGO) at 7 and 28 days was examined. During the carbonation reaction, the calcium-bearing phases (calcium hydroxide, calcium silicate hydrate, and ettringite) formed calcium carbonate polymorphs, along with amorphous silica gel, gypsum, and alumina gel. These reaction products were examined using XRD (X-ray diffraction), XPS (energy-dispersive spectrometry), and FTIR (Fourier transform infrared). XRD patterns showed that the intensities of the calcium hydroxide and calcium carbonate peaks in the hydrated cement mixed with GO and/or rGO are higher than the corresponding peaks in the hydrated cement without any additives. The morphology of the reaction products was also characterized by SEM (scanning electron microscopy) measurements, which showed that a needle-like phase of calcium carbonate develops on the hydrated cement. The obtained microstructure parameters enabled the development of a more precise carbonation model.

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Section: Resultsmentioning

confidence: 99%

Elucidation of Calcite Structure of Calcium Carbonate Formation Based on Hydrated Cement Mixed with Graphene Oxide and Reduced Graphene Oxide

Yaseen

Yiseen

Li³

2019

ACS Omega

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“…As it was explained in literature, 39,40 carbonates are formed through different kind of processes. The first mechanism is the diffusion of CO 2 into the empty pores of the surface where it will react with water from the pore solution, forming carbonic acid.…”

Section: Resultsmentioning

confidence: 98%

Effect of polymer-coated silica particles in a Portland cement matrix via in-situ infrared spectroscopy

Hafshejani

Feng

Wohlgemuth

et al. 2020

Journal of Composite Materials

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It is often of great importance in engineering to know precisely the properties of a material used with regard to its strength, its plasticity or its brittleness, its elasticity, and some other properties. For this purpose, material samples are tested in a tensile test by clamping the sample with a known starting cross-section in a tensile testing machine and loading it with a tensile force F. The force is then graphically displayed over the length change ΔL caused. This curve is called the force-extension diagram. In this study, a new measurement method enables for the first time, depending on the applied uniaxial stress, an insight at the atomic level into various energy dissipation processes at cement-based materials with the help of infrared spectroscopy. The samples are modified by adding SiO2 particles, which are coated by a polymer (PEG-MDI-DMPA) of different PEG molecular weights. Results show that elongating and breakage of [Formula: see text] and [Formula: see text] bonds play an essential role in the strain energy dissipation. Compared to the pure cement, the modified samples are affected more by elongating and breakage of [Formula: see text] as the admixture can effectively reduce the energy barrier of the hydrolytic reaction. The incorporating of particles into the cement matrix induces new mechanisms for energy dissipation by stretching of [Formula: see text] bending vibrations. Stretching vibration of the [Formula: see text] group indicates that part of the energy is dissipated by breakage of hydrogen bonding between the carboxyl group and PEG chains. Besides, a higher value of the ultimate fracture force following an increase in the molecular weight of PEG shows stronger bonding between particles and the cement matrix. As the chain-length of PEG is increased, less energy is absorbed through the other processes (especially at a higher level of strain). Thus, there is a balance between the whole deformation (toughness) and the strength of samples with the increase of the PEG molecular weight.

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“…In this study, the adsorption characteristics of the five types of alkanol-amine compounds on the C-S-H gel in alkaline liquid environment were studied by molecule dynamics. It is known that the carbonation and calcium leaching are two important processes that would occur on a concrete surface [31][32][33]. However, this paper is to study the adoption of organic inhibitors on the C-S-H gel, which usually occurs on the interface of cement hydration products and pore solution inside the concrete.…”

Section: Surface Adsorption Testmentioning

confidence: 99%

“…The upper and lower gel surfaces were spaced 35 Å for simulating the concrete pore [36]. Subsequently, the GCMC simulations were applied into the structure and energy analysis [33]. The adsorbates and water molecules were regarded as stiff small molecules.…”

Section: Pore Adsorption Testmentioning

confidence: 99%

Numerical Simulation of Adsorption of Organic Inhibitors on C-S-H Gel

et al. 2020

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Corrosion inhibitors are one of the most effective anticorrosion techniques in reinforced concrete structures. Molecule dynamics (MD) was usually utilized to simulate the interaction between the inhibitor molecules and the surface of Fe to evaluate the inhibition effect, ignoring the influence of cement hydration products. In this paper, the adsorption characteristics of five types of common alkanol-amine inhibitors on C-S-H gel in the alkaline liquid environment were simulated via the MD and the grand canonical Monte Carlo (GCMC) methods. It is found that, in the MD system, the liquid phase environment had a certain impact on the adsorption configuration of compounds. According to the analysis of the energy, the binding ability of MEA on the surface of the C-S-H gel was the strongest. In the GCMC system, the adsorption of MEA was the largest at the same temperature. Furthermore, for the competitive adsorption in the GCMC system, the adsorption characteristics of the inhibitors on the C-S-H gel were to follow the order: MEA>DEA>TEA>NDE>DETA. Both MD and GCMC simulations confirmed that the C-S-H gel would adsorb the organic inhibitors to a different extent, which might have a considerable influence on the organic inhibitors to exert their inhibition effects.

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Carbonation Competing Functionalization on Calcium-Silicate-Hydrates: Investigation of Four Promising Surface-Activation Techniques

Cited by 13 publications

References 59 publications

Elucidation of Calcite Structure of Calcium Carbonate Formation Based on Hydrated Cement Mixed with Graphene Oxide and Reduced Graphene Oxide

Elucidation of Calcite Structure of Calcium Carbonate Formation Based on Hydrated Cement Mixed with Graphene Oxide and Reduced Graphene Oxide

Effect of polymer-coated silica particles in a Portland cement matrix via in-situ infrared spectroscopy

Numerical Simulation of Adsorption of Organic Inhibitors on C-S-H Gel

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