MgAl-Layered Double Hydroxide Nanoparticles as Smart Nanofillers To Control the Rheological Properties and the Residual Porosity of Cement-Based Materials

Abstract

Nanotechnology in building materials has still not been widely explored, despite its great potential in developing a new generation of smart and eco-efficient cementitious materials based on the addition of nanoparticles. In this context, layered double hydroxides (LDH) are a family of anionic clays that can regenerate their nanostructure after thermal decomposition to the corresponding mixed oxides (MO). This memory effect involves the reversible recrystallization of the LDH nanoparticles from nanocrystalline MO in contact with water or anionic solutions. It has shown promise in the immobilization of different anions, such as chloride and carbonate, that could compromise the durability of reinforced concrete. This study proposes the incorporation of nanocrystalline MO in the cementitious matrix to control the rheological properties of the paste and reduce the porosity of the cement because the regeneration of the lamellar nanostructure occurs by the dissolution and reprecipitation of LDH nanoparticles inside the pores formed during the consolidation of the paste. Time-resolved wide-angle X-ray scattering (WAXS) was used to study the mechanism of regeneration of the LDH structure following contact of the MO with the cement pore solution. The results showed that the regeneration of the LDH, which occurs by an aggregative growth of anisotropic nanoparticles, changed the rheological behavior by increasing the elastic modulus (G′) and consequently contributing to the consolidation of the paste, demonstrating the potential of these materials for application in threedimensional (3D) printing. Regarding the pore structure of the hydrated cement, a porosity reduction of up to 20% was observed with the addition of 2.0 wt % of MO. Furthermore, after 28 days of hydration, the specific surface area of the cement was reduced from 60 to 36 m 2 g −1 with the incorporation of 1.0 wt % of MO. The use of LDH nanoparticles as a cement smart nanofiller proved to be advantageous in the kinetic control of cement curing and improvement of the porous structure of the hydrated cement.

Effects of carboxylated styrene‐butadiene latex nanoparticles on channeling leakage and pore structure of oil well cement

“…It is reported that nanostructured styrene-butadiene latex (SBR) polymer materials can improve the flow performance of cement and control the thickening of cement to a certain extent while improving the properties of cement-based materials. [13][14][15] However, it is not clear how the film-forming property of styrene-butadiene latex affects the phenomenon of interlayer gas migration in the gel state stage of cement. Wichaita et al 16 regulated the nanomicrostructure and composition of natural latex by surface functional modification, which provided theoretical guidance for the modification research and engineering application of latex nanoparticles.…”

“…It is reported that nanostructured styrene‐butadiene latex (SBR) polymer materials can improve the flow performance of cement and control the thickening of cement to a certain extent while improving the properties of cement‐based materials 13–15 . However, it is not clear how the film‐forming property of styrene‐butadiene latex affects the phenomenon of interlayer gas migration in the gel state stage of cement.…”

Effects of Layered Double Hydroxide Nanosheets with Different Cations on the Compressive Strength of Cement Composites

“…Layered double hydroxides (LDH) are anionic clay materials that have attracted increasing attention due to their superior layer nanostructures. , A general formula [M 1– x 2+ M x 3+ (OH) 2 ] x + [(A n – ) x / n · m H 2 O] x − is used to express the chemical composition of LDH, where A n – is an n -valent anion and M 2+ and M 3+ are divalent and trivalent metal cations, respectively. − The nanonucleation effect of LDH plays an important role in the early hydration process of cement. , Dong et al prepared CaAl-LDH and MgAl-LDH to increase the crystallization rate of poly­(ethylene terephthalate) (PET). However, CaAl-LDH and MgAl-LDH had different effects on the mechanical properties of PET.…”

“…10−12 The nanonucleation effect of LDH plays an important role in the early hydration process of cement. 13,14 Dong et al 15 LDH to increase the crystallization rate of poly(ethylene terephthalate) (PET). However, CaAl-LDH and MgAl-LDH had different effects on the mechanical properties of PET.…”

Ecological synthesis of nickel–zinc–aluminium layered double hydroxides (Ni–Zn–Al LDH) in flow infrared radiated agitated tubular reactor (flow-IR-ATR)

“…

M 2+ denotes divalent metal cations, most commonly Zn, Mg, Ca, and M 3+ denotes trivalent metal cations, typically Al. Anions present between the cation layers include carbonate, nitrate, and hydroxide groups [2,3]. Both cations and anions can be substituted in the ion exchange process.

…”