The Inhibitive Effect of Sebacate-Modified LDH on Concrete Steel Reinforcement Corrosion

Abstract

In recent decades, layered double hydroxides (LDH) have been proposed as innovative corrosion inhibitors for reinforced concrete. Their protective action is based on the ability to intercalate specific anions in the interlayer and on their ability to exchange the intercalated anion. In the present study, an organically charged LDH, with sebacate anions in the interlayer (LDH-S), is proposed as a water-repellent additive for mortar. The waterproofing efficiency of LDH-S and the associated corrosion inhibition ability has been evaluated in reinforced mortar samples. A 42% decrease in the water capillary absorption coefficient has been estimated when 3% LHD-S is added to a mortar. Both the passivation processes of the steel rebars during the curing period and the initiation of corrosion due to chloride exposure have been studied by electrochemical measurements. Three different mortars have been evaluated: reference mortar (REF), mortar with Mg-Al LDH (LDH), and mortar with LDH-sebacate (LDH-S). The latter has shown an important protective capacity for preventing the initiation of corrosion by chloride penetration, with an inhibitory efficiency of 74%. The presence of LDHs without sebacate in the interlayer also improved the performance of the mortar against rebar corrosion, but with lower efficiency (23% inhibitory efficiency). However, this protection is lost after continued chloride exposure over time, and corrosion initiates similarly to the reference mortar. The low corrosion current density values registered when LDH-S is added to the mortar may be related to the increased electrical resistance recorded in this mortar.

Unlocking the Potential of Sebacate: Investigating Its Role in the Inhibition of Filiform Corrosion on Organic Coated Steel

“…In this context, a dicarboxylate compound such as disodium sebacate (SB, C 10 H 16 Na 2 O 4 ), shown in Figure 1, is a suitable candidate to consider. Amidst the pursuit of environmentally benign inhibitors, in recent studies, SB has emerged particularly due to its potential for intercalation in the burgeoning field of a novel type of ceramic-based drug delivery system, namely layered double hydroxides, offering promise as an efficient smart pigment [5,13,25,26]. Thanks to the ion exchange properties inherent in such a lamellar ceramic structure, molecules such as corrosion inhibitors, once intercalated during synthesis or in a subsequent treatment phase, can be accommodated within the structure and gradually released in the presence of other ions, typically chlorides [27].…”

Experimental investigation on the physco-mechanical and protective properties of concrete incorporating Layered double hydroxide (LDH)

“…They found that LDHs have a positive impact on improving the carbonation resistance of cement paste. David Caballero et al [19] used an organically charged LDH with sebacate anions in the interlayer (LDH-S) as a water-repellent binder for mortar. They evaluate the waterproo ng e ciency and the corrosion inhibition ability of LDH-S in reinforced mortar samples.…”

A Themed Issue in Honor of Prof. Dr. Vicente Rives

“…This Special Issue has received eighteen contributions, six review papers [1][2][3][4][5][6], and twelve research papers [7][8][9][10][11][12][13][14][15][16][17][18]. Most of the papers originated from groups who have previously worked with Prof. Rives, but five of the contributions came from authors who had not previously worked with him [6,7,13,17,18]. The materials most studied by Prof. Rives throughout his career were LDHs.…”

“…The materials most studied by Prof. Rives throughout his career were LDHs. Therefore, it was not surprising that these materials were the basis of eight of the papers published in this Special Issue [2][3][4]10,11,[15][16][17]. Other materials included Ni-based catalysts [1], g-C 3 N 4 [5], mesoporous silica [6], MOFs [7], carbons [8,9], AlPO 4 [12], acid-modified clays [13], and porous aluminosilicates [17].…”

“…Therefore, it was not surprising that these materials were the basis of eight of the papers published in this Special Issue [2][3][4]10,11,[15][16][17]. Other materials included Ni-based catalysts [1], g-C 3 N 4 [5], mesoporous silica [6], MOFs [7], carbons [8,9], AlPO 4 [12], acid-modified clays [13], and porous aluminosilicates [17]. Finally, one of the papers was devoted to the study of cultural heritage conservation [14].…”