Publications associées à Effect of alkali hydroxide on calcium silicate hydrate (C-S-H)

Silicon microresonator arrays: A comprehensive study on fabrication techniques and pH-controlled stress-induced variations in cantilever stiffness

Luis Guillermo Villanueva Torrijo, Annalisa De Pastina

We introduce a detailed design and fabrication process of Silicon microcantilever arrays for biomolecular detection in liquid environment, utilized with laser readout. We present typical fabrication problems and provide related solutions to obtain high qua ...

Elsevier2024

Palladium-based supramolecular assemblies: from complex structures to water-soluble anion-receptors

Sylvain Alexandre Marie Sudan

The combination of palladium salts and bipyridyl ligands can lead to the formation of a large variety of coordination complexes, with different shapes and sizes, displaying a very versatile host-guest chemistry. Increasing their structural complexity remai ...

EPFL2024

Atomic-Level and Surface Structure of Calcium Silicate Hydrate Nanofoils

Paul Bowen, Karen Scrivener, Aslam Kunhi Mohamed, Ziga Casar

Deciphering the calcium silicate hydrate (C-S-H) surface is crucial for unraveling the mechanisms of cement hydration and property development. Experimental observations of C-S-H in cement systems suggest a surface termination which is fundamentally differ ...

AMER CHEMICAL SOC2023

The role of Zn in C-S-H atomic structure, nucleation and growth

Anna Morales Melgares

The most promising solution towards cementitious materials with a lower carbon footprint is the partial substitution of the clinker by supplementary cementitious materials (SCMs) such as fly ash, blast furnace slag, limestone and calcined clays. The produc ...

EPFL2023

Atomistic modeling of C-S-H: bulk and surface

Ziga Casar

By replacing part of Portland cement with so-called supplementary cementitious materials (SCMs) it is possible to reduce the CO2 footprint of the cement industry. These SCMs are commonly limestone, calcined clay, slag and fly ash. While doing so the early ...

EPFL2023

Effect of alkali, aluminium and equilibration time on calcium-silicate-hydrates

Yu Yan

Calcium silicate hydrate (C-S-H) is the main hydration product in Portland and blended cements, and greatly affects durability and mechanical properties of the hydrated cement. In the presence of Al-rich supplementary cementitious materials (SCMs), C-(A-)S ...

EPFL2022

Al uptake in calcium silicate hydrate and the effect of alkali hydroxide

Karen Scrivener, Yan Yan, Barbara Lothenbach

The effect of Al and of pH on the structure of calcium silicate hydrate (C-S-H), the most important hydration product in Portland and blended cement, was studied at Ca/Si similar to 1.0. The presence of Al led to higher amounts of secondary phases, larger ...

Pergamon-Elsevier Science Ltd2022

Effect of different ions on dissolution rates of silica and feldspars at high pH

Karen Scrivener, Barbara Lothenbach, Mahsa Bagheri, Mahdieh Shakoorioskooie

The dissolution kinetics of silica-containing minerals in aggregates influences strongly the process of ASR in concrete. In this paper, the effect of different ions on the dissolution rates of SiO2 (amorphous and quartz) and feldspars at high pH values was ...

Pergamon-Elsevier Science Ltd2022

The effect of paste composition, aggregate mineralogy and temperature on the pore solution composition and the extent of ASR expansion

Karen Scrivener, Barbara Lothenbach, Mahsa Bagheri

The reaction kinetics of the alkali silica reaction depends on the composition of the pore solution. The evolution of the pore solution composition in different cement pastes and concretes was studied. Pastes containing silica fume or metakaolin had the lo ...

SPRINGER2022

In Situ Monitoring of the Surface Evolution of a Silver Electrode from Polycrystalline to Well-Defined Structures

Yunchang Liang

Capturing the surface-structural dynamics of metal electrocatalysts under certain electrochemical environments is intriguingly desired for understanding the behavior of various metal-based electrocatalysts. However, in situ monitoring of the evolution of a ...

AMER CHEMICAL SOC2022

Water Orientation at the Anatase TiO2 Nanoparticle Interface: A Probe of Surface pKa Values

Arianna Marchioro, Marie Bischoff

The acid-base properties of surfaces significantly influence catalytic and (photo)electrochemical processes. Estimation of acid dissociation constants (pKa values) for colloids is commonly performed through electroanalytical techniques or spectroscopic met ...

AMER CHEMICAL SOC2022

Reactive dicalcium silicate binders: Microstructure and transport properties

Adrian-Alexandru Pîrvan

The calcium silicate hydrates (C-S-H) are without doubt one of the most important hydration products in a hardened cement paste. Giving the complexity of the microstructure that forms by hydration of ordinary Portland cement (OPC) and the more recently use ...

EPFL2022

Investigation of femtosecond laser-enabled 3D micro-infiltration processes

Enrico Casamenti

In the last decades, the femtosecond laser micromachining of glass has attracted a lot of attention due to its three-dimensional manufacturing ability and flexibility both in terms of compatible substrates and modification types. Yet, to fully unravel its ...

EPFL2022

Abnormal temperature dependent elastic properties of fused silica irradiated by ultrafast lasers

Yves Bellouard, Pieter Vlugter

Materials with thermal-invariant elastic properties are of interest for resonant device frequency and dimensional stability of precision devices. Here, we demonstrate that the temperature coefficient of elasticity (TCE) of amorphous silica can be locally r ...

2022

Reactivity of Multimetallic Thorium Nitrides Generated by Reduction of Thorium Azides

Rosario Scopelliti, Marinella Mazzanti, Luciano Barluzzi, Fang-Che Hsueh

Thorium nitrides are likely intermediates in the reported cleavage and functionalization of dinitrogen by molecular thorium complexes and are attractive compounds for the study of multiple bond formation in f-element chemistry, but only one example of thor ...

2022

Strong silicon oxide inclusions in iron

Andreas Mortensen, Léa Deillon, Alejandra Inés Slagter, Joris Pierre Everaerts

Oxide inclusions are ubiquitous in steel and are known to affect, generally in a negative sense, the mechanical performance of steel products. Micromechanical properties of those phases are therefore important, yet they have remained largely unexplored. We ...

2022

The effect of alkali hydroxides and equilibration time on Al uptake by calcium silicate hydrates (C-S-H)

Sonya Barzgar

Cement production accounts for approximately 8% of man-made CO2 emissions. Lowering these CO2 emissions is currently one of the most important and urgent research topics within the cement community. To reduce these emissions, the Portland cement (PC) is pa ...

EPFL2021

Aggregate dissolution in different pore solutions

Mahsa Bagheri

The occurrence of cracking due to alkali silica reaction (ASR) affects the service life of concrete structures. The dissolution of silica-containing minerals within aggregates causes the formation of ASR products, which fill macroscopic cracks and cause th ...

EPFL2021

Grafting of Alkali Metals on Fumed Silica for the Catalytic Dehydrogenation of Methanol to Formaldehyde

Christophe Jean Baranowski, Oliver Kröcher, Alimohammad Bahmanpour, Jack Brandon

Water free, non-oxidative catalytic dehydrogenation of methanol to formaldehyde is an important process for the formation of anhydrous, molecular formaldehyde (FA). Sodium or sodium-containing salts were shown to catalyze the reaction, but their reaction m ...

Wiley-VCH Verlag2021

Promoting Persistent Superionic Conductivity in Sodium Monocarba-closo-dodecaborate NaCB11H12 via Confinement within Nanoporous Silica

Mirjana Dimitrievska

Superionic phases of bulk anhydrous salts based on large cluster-like polyhedral (carba)borate anions are generally stable only well above room temperature, rendering them unsuitable as solid-state electrolytes in energy-storage devices that typically oper ...

AMER CHEMICAL SOC2021