Fluidizing efficiency of comb-like superplasticizers: The effect of the anionic function, the side chain length and the grafting degree

Dalas, Florent; Pourchet, Sylvie; Nonat, André; Rinaldi, David; Sabio, Serge; Mosquet, Martin

doi:10.1016/j.cemconres.2015.02.001

Cited by 90 publications

(47 citation statements)

References 41 publications

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“…These would correspond to surface B and would also account for a small fraction of the total surface area, making S c,B negligible in Equation (24). This leads to a direct proportionality between y B and n tot RU , explaining the experimentally observed proportionality between Dt and n tot RU or n tot RU À n Ett RU À Á , respectively, in Equations (20) and (23).…”

Section: Master Curve Rationalizationmentioning

confidence: 88%

“…19,20 This relies on structural variations to enhance their impact on rheology, something that numerous papers have addressed. [21][22][23][24][25] However, such organic compounds cause a retardation of cement hydration, (Figures 1D and S1) a process that remains largely unexplained 26 . More generally, the question of how cement hydration is affected by organic admixtures in relation to their structure can be considered as one of the big open challenges in cement research.…”

Section: Introductionmentioning

confidence: 99%

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Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Marchon

Juilland²,

Gallucci³

et al. 2017

J Am Ceram Soc

134

110

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The impact of organic compounds on the processing and reactivity of inorganic materials has been a source of inspiration for materials scientists for decades and continues to trigger novel and innovative applications in a broad range of disciplines. However, molecular design of such compounds to reach targeted properties remains challenging, particularly for reactive and multicomponent systems. This outstanding challenge is met here by combining a model cement, hosting different coupled reactions of dissolution, nucleation and growth, together with combcopolymers that offer large and well-controlled variations of their molecular architecture. We show that silicate reactivity is affected by a combination of molecular and submolecular scale effects of these polymers. The first can be described by scaling laws from polymer physics, whereas the second involves specific chemical interactions. In particular, the ability of these polymers to hinder dissolution appears to be crucial, something for which strong experimental evidence is provided. K E Y W O R D Scalcium silicate,

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Section: Master Curve Rationalizationmentioning

confidence: 88%

Section: Introductionmentioning

confidence: 99%

Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Marchon

Juilland²,

Gallucci³

et al. 2017

J Am Ceram Soc

134

110

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“…The PEO-free PCEs showed better cement dispersing capability than the SNF. PEO-free PCEs have a high density of anionic function groups of carboxyl on the backbone that are ionised in the alkaline pH of a cement suspension (pH > 12); these groups are thus adsorbed on the cement surface, which is positively charged due to the strong affinity of Ca 2+ with the surface (Dalas et al, 2015). The side chains of these terpolymers with cationic ammonium groups result in both electrostatic repulsion and steric hindrance, which overcome the attractive interparticle forces and disperse the cement particles.…”

Section: Resultsmentioning

confidence: 99%

Cement dispersion performance of superplasticisers in the presence of clay and interaction between superplasticisers and clay

Xing¹,

Wang²,

Fang³

2017

Advances in Cement Research

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A study of superplasticisers (SPs), including polyethylene oxide-free type polycarboxylate superplasticisers (PCEs), a conventional PCE and a polycondensate, was carried out to research their cement dispersion behaviour and interactional behaviour with clay. It was found that the cement dispersion performance of SPs in the presence of clay is dependent on both the cement dispersing capability and clay sensitivity. The sensitivity of superplasticisers to the presence of clay was investigated systematically through a study of water and SP adsorption (surface and interlayer) on the clay. It was found that clay sensitivity is dependent on the clay adsorption of both water and the SP. The behaviours of cations (surface and interlayer) of clay interacting with different SPs were also investigated and the interactional mechanism between SPs and clay was clarified. This work will aid further understanding of the effects of clay in concrete and help in the design of SPs with enhanced clay tolerance. NotationL 0 cement paste spread (cm) at water/cement (w/c) ratio of 0·49 without superplasticiser (SP) and clay L 1 cement paste spread (cm) with a certain dosage of SP and no clay at a w/c of ratio 0·49 L 2 cement paste spread (cm) with a certain dosage of SP and clay at a w/c of ratio 0·49 m 1 weight (g) of SP m 2 weight (g) of drying clay V volume (ml) of methylene blue solution consumed

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“…Recent studies have been conducted to develop new superplasticizers more resistant to ionic competition [16,17]. These new superplasticizers, based on the PCEs structure, were designed by changing the nature of anionic moieties, with dicarboxylate function [18], or phosphonic acid functions instead of carboxylic acids [19,20]. Pourchet et al have modified the monomer distribution along the macromolecule backbone, resulting in a gradient copolymer [17].…”

Section: Introductionmentioning

confidence: 99%

Synthesis of phosphonated comb-like copolymers and evaluation of their dispersion efficiency on CaCO3 suspensions part II: Effect of macromolecular structure and ionic strength

Tramaux¹,

Azéma²,

Bitouri³

et al. 2018

Powder Technology

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a b s t r a c tThe aim of this paper is to investigate effects of macromolecular structure and ionic competition phenomena induced by an increase of ionic strength on the dispersive action of new superplasticizers. These superplasticizers were synthesized and their structure is based on that of polycarboxylates. These superplasticizers are comb-like copolymers with phosphonic acids. Macromolecular parameters studied are the monomer repartition along the carbon backbone and the chain length. Ionic strength is increased either by adding sulfate or nitrate ions. The effects of these factors are then investigated using adsorption, stability and rheology results. It appears that statistical copolymers with phosphonic acids having the shortest chain length are the most efficient in terms of fluidity improvement even in the presence of sulfate or nitrate ions.

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Fluidizing efficiency of comb-like superplasticizers: The effect of the anionic function, the side chain length and the grafting degree

Cited by 90 publications

References 41 publications

Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Molecular and submolecular scale effects of comb‐copolymers on tri‐calcium silicate reactivity: Toward molecular design

Cement dispersion performance of superplasticisers in the presence of clay and interaction between superplasticisers and clay

Synthesis of phosphonated comb-like copolymers and evaluation of their dispersion efficiency on CaCO3 suspensions part II: Effect of macromolecular structure and ionic strength

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