Thermodynamics of Surfactants, Block Copolymers and Their Mixtures in Water: The Role of the Isothermal Calorimetry

Abstract Graphene (G) and graphene oxide (GO) have been shown to significantly improve the mechanical properties of cement-based materials. In this study, the effect of the G/GO on cement hydration was investigated. First, the zeta potential of G/GO in simulated solutions was tested, and the interaction between G/GO’s surface and Ca2+ was explored. Subsequently, scanning electron microscopy was used to observe the morphology of C–S–H nucleation and growth on the cement surface in the cement paste containing G/GO. Furthermore, XRD and TGA analyses were carried out on the hydration products of the sample. At last, isothermal calorimetry was applied to investigate the influence of G/GO on the early hydration of cement. The results showed that the addition of G/GO significantly accelerates C–S–H nucleation and growth on the cement surface. It is indicated that the high mobility ions derived by G/GO in the cement paste dominate the reason for the accelerated hydration of cement. The presence of G, especially GO, facilitates the mobility of ions, especially Ca2+, thus enhances the interaction between the cement surface and the ions. This strong interaction promotes the C–S–H nucleation and growth, and therefore, the hydration of the cement.

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Formation of hybrid colloids by suspension polycondensation in the presence of hydrophilic block copolymers

MRS Proceedings ◽

10.1557/proc-726-q7.5 ◽

2002 ◽

Vol 726 ◽

Cited By ~ 6

Author(s):

Corine Gerardin ◽

Valérie Buissette ◽

François Gaudemet ◽

Olivier Anthony ◽

Nicolas Sanson ◽

...

Keyword(s):

Block Copolymers ◽

Colloidal Suspensions ◽

Surface Charges ◽

Inorganic Particles ◽

Hydrous Oxides ◽

Stabilization Phase ◽

Metal Ratio ◽

Forced Hydrolysis ◽

Hydrolysis Of

AbstractDouble hydrophilic block copolymers were used to control the growth of inorganic particles and directly prepare hybrid colloidal suspensions. Colloids of metal hydrous oxides were obtained by forced hydrolysis of metal ions in presence of the copolymers. The block copolymers contain a metal-complexing polyelectrolyte block and a stabilizing neutral block. The role of the first block is to ensure a controlled growth of the inorganic phase, while simultaneously, the second block ensures the colloidal stabilization. Phase diagrams presenting the conditions under which precipitation is inhibited are established. The nanoparticles are then characterized in terms of sizes, morphologies and surface charges. The main parameters controlling the size were identified: the copolymer-to-metal ratio and the metal prehydrolysis ratio. The synthesis steps were characterized. First, a key step of induced micellization of the hydrophilic copolymers leads to hybrid core-shell assemblies. The second step consists in mineralization of the micellar core. The suspension polycondensation leads to hairy particles whose morphologies depend on the nature of the metal and on synthesis parameters.

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Role of dissimilar interfaces in thin films of cylinder-forming block copolymers

The Journal of Chemical Physics ◽

10.1063/1.1632475 ◽

2004 ◽

Vol 120 (2) ◽

pp. 1127-1137 ◽

Cited By ~ 48

Author(s):

K. S. Lyakhova ◽

G. J. A. Sevink ◽

A. V. Zvelindovsky ◽

A. Horvat ◽

R. Magerle

Keyword(s):

Thin Films ◽

Block Copolymers

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The Role of Temperature on Hydration of Binary System of Metakaolin/Portland Cement

Materials Science Forum ◽

10.4028/www.scientific.net/msf.851.51 ◽

2016 ◽

Vol 851 ◽

pp. 51-56 ◽

Cited By ~ 1

Author(s):

Martin Boháč ◽

Radoslav Novotný ◽

Jakub Tkacz ◽

Miroslava Hajdúchová ◽

Martin Palou ◽

...

Keyword(s):

Binary System ◽

Portland Cement ◽

Isothermal Calorimetry ◽

Chemical Characterization ◽

Exothermic Peak ◽

Early Hydration ◽

Different Temperatures ◽

C 50

The role of temperature of metakaolin/Portland cement binary system was studied by isothermal calorimetry. Sample with 50 % of metakaolin replacement were monitored at 30 °C, 40 °C, 50 °C and 60 °C. Structural and chemical characterization of hardened pastes was obtained by scanning electron and Raman microscopy. Paper deals with kinetics of main exothermal reactions during early hydration of the system. Activation energies were calculated for processes related to each exothermic peak. The nature of hydration products at different temperatures was revealed by microstructural studies.

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