Revealing the solid-like nature of glycerol at ambient temperature

Noirez, Laurence; Baroni, Patrick

doi:10.1016/j.molstruc.2010.02.013

Cited by 52 publications

(101 citation statements)

References 46 publications

(42 reference statements)

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“…In 2005, L. Noirez and co-authors reported on elastic behaviors in the isotropic phase of SCLCPs using a conventional rheometer and at the millimeter scale [14]. Then, solid-like behaviors (G′ and G″ constant with G′ > G″) were identified using the total wetting protocol [28] in various glass formers (glycerol, o-terphenyl) and ordinary polymers [29][30][31][32]. In 2007, S-Q Wang [55] reproduced the results of [15] using the same protocol.…”

Section: Discussionmentioning

confidence: 99%

“…The understanding of the shear-induced phase has thus to be related to a cohesive property hitherto neglected in the isotropic phase. Since 2005, we have been working on, and demonstrating, that improved dynamic measurements enable access to this cohesive property via the identification of a low frequency shear elasticity (solid-like character) in the liquid state in various glass formers away from any phase transition [28][29][30][31][32]. We apply this improved protocol first to the isotropic phase of the SCLCP, PANO2, compare it to an ordinary polymer chain (polybutylacrylate melt (PBuA)) of the same degree of polymerization, and finally examine the case of a short alkyl chain assimilated to a spacer: The heptadecane.…”

Section: Figurementioning

confidence: 99%

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Richness of Side-Chain Liquid-Crystal Polymers: From Isotropic Phase towards the Identification of Neglected Solid-Like Properties in Liquids

et al. 2012

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Very few studies concern the isotropic phase of Side-Chain Liquid-Crystalline Polymers (SCLCPs). However, the interest for the isotropic phase appears particularly obvious in flow experiments. Unforeseen shear-induced nematic phases are revealed away from the N-I transition temperature. The non-equilibrium nematic phase in the isotropic phase of SCLCP melts challenges the conventional timescales described in theoretical approaches and reveal very long timescales, neglected until now. This spectacular behavior is the starter of the present survey that reveals long range solid-like interactions up to the sub-millimetre scale. We address the question of the origin of this solid-like property by probing more particularly the non-equilibrium behavior of a polyacrylate substituted by a nitrobiphenyl group (PANO2). The comparison with a polybutylacrylate chain of the same degree of polymerization evidences that the solid-like response is exacerbated in SCLCPs. We conclude that the liquid crystal moieties interplay as efficient elastic connectors. Finally, we show that the "solid" character can be evidenced away from the glass transition temperature in glass formers and for the first time, in purely alkane chains above their crystallization temperature. We thus have probed collective elastic effects contained not OPEN ACCESSPolymers 2012, 4 1110 only in the isotropic phase of SCLCPs, but also more generically in the liquid state of ordinary melts and of ordinary liquids.

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Section: Discussionmentioning

confidence: 99%

Section: Figurementioning

confidence: 99%

Richness of Side-Chain Liquid-Crystal Polymers: From Isotropic Phase towards the Identification of Neglected Solid-Like Properties in Liquids

et al. 2012

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“…Recent experimental developments have shown that reinforcing the surface contacts using high energy surface improves the measurement of the dynamic response [14][15][16][17][18][19][20][21]. When the liquid molecules are strongly in interaction with the surface, the noise observable at low frequency grows and forms a well-defined signal, stronger than the viscous response (Fig.…”

Section: The Key Role Of the Surface In Dynamic Relaxation Measurementsmentioning

confidence: 99%

Importance of Interfacial Interactions to Access Shear Elasticity of Liquids and Understand Flow Induced Birefringence from Liquid Crystals to Worm-Like Micellar Solutions

Noirez

2017

Oil Gas Sci. Technol. – Rev. IFP Energies nouvelles

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-This work points out the importance of the substrate boundary conditions to lower the dissipation in the dynamic measurement and access the closest dynamic characteristics of liquids, in particular to access the low frequency shear elasticity. The liquid/surface interface is a source of dissipation that enters and impacts the measurement. Examples of steady-state shear flows or flow birefringence are presented to highlight the non-universality of the behavior with respect to the nature of the substrate or the sheared thickness. Additionally the present development completes and extends the identification of low frequency shear elasticity made at sub-millimeter gaps in various one-component liquids to salt-free aqueous solutions (CTAB-water (Hexadecyl-TrimethylAmmonium Bromide)).Résumé -Importance des interactions interfaciales pour accéder à l'élasticité de cisaillement des liquides et comprendre la biréfringence d'écoulement des cristaux liquides aux solutions micellaires -Nous montrons par une approche expérimentale, l'importance de l'interaction liquide/substrat (mouillage) pour diminuer la dissipation et améliorer la mesure dynamique, en particulier pour accéder à l'élasticité de cisaillement à basse fréquence peu accessible par la mesure viscoélastique conventionnelle. L'interface liquide/surface est une source de dissipation qui a un impact dans la mesure. À titre d'exemple, des mesures d'écoulement en cisaillement continu ou de biréfringence d'écoulement sont présentées pour mettre en évidence la non-universalité du comportement par rapport à la nature du substrat ou à l'épaisseur cisaillée. Enfin, nous étendons la mesure de l'élasticité de cisaillement basse fréquence réalisée à l'échelle sub-millimétrique dans les liquides purs à des solutions lyotropes de micelles géantes (CTAB-water (HexadecylTrimethylAmmonium Bromide)).

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“…Moreover recent developments in stress dynamic measurements have shown that liquids as water, alkanes or polymer melts exhibit an elastic (solid-like) behavior in restricted geometry [9]. Sub-millimeter scale stress measurements highlight an intrinsic property supporting the hypothesis of a liquid formed by a weakly bound resilient selfassembly [10,11]. The present observation of a temperature fall still active at nearly 10 mm from the wall is the firm indication that cohesive intermolecular forces are long range correlated in the liquid bulk.…”

Section: Results -Discussionmentioning

confidence: 90%

“…The cohesive forces give rise to bulk and shear elasticity. The latter have been measured in the liquid state by different authors and methods [10][11][12][13][14].…”

Section: Discussionmentioning

confidence: 99%

Wall Effects induced by Ceramic in Quiescent Liquids

Noirez

Baroni

2017

J. Phys.: Conf. Ser.

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At the liquid-solid interface, the energy of the liquid is different from the bulk resulting from surface tension due to the balance between the attraction between molecules to each other (cohesion) and the attraction to the surface (wetting). While capillary effects are well known and described at the air/liquid/solid interfaces, much less is known on the effects induced in the bulk close to the wall. The present experimental study reveals that nonnegligible interfacial effects can be revealed in the bulk of the liquid using the high wetting power of ceramics. Close to the wall, thermal measurements reveal a progressive temperature drop in the liquid (about 0.15°C). This zone extends up to several millimeters, creates a nonequilibrium/equilibrium interface within the liquid and is balanced at larger distances by a temperature increase. This localized effect is highlighted with strong wetting metal oxide surfaces as ceramics.Keywords: ceramic, wetting, long range interactions, liquid/solid interface. IntroductionIn the bulk of the liquid, molecules are pulled in every direction by neighboring liquid molecules, resulting in a net force of zero. Close to a surface, the situation is different. The molecules at the boundary do not have other molecules on all sides of them and create some variation of internal pressure [1]. Thermal exchanges that take place in a liquid bulk close to an immersed wall or in between two walls are usually not explored, hardly modelled [2] and considered as restricted to very small length scales [3,4].Recently a submillimetre scale thermal study of liquids under flow has revealed that shearing liquids may induce a cooling effect at low shear rates in ordinary Newtonian liquids as water or low viscous polymer melts [5]. The detailed analysis of this non-equilibrium endothermic process indicates that the cooling is firstly generated at the walls and propagates in the fluid giving rise to the establishment of a thermal shear banding regime along the flow axis [5]. We report here on the situation where no external force is exerted on the liquid; i.e. the quiescent state. We examine the influence of a solid wall strongly interacting (total wetting) with the molecules of liquids as water, glycerol or alkanes on the thermal equilibrium. The liquid is observed in its quiescent bulk away from the liquid-air interface. We report on the identification of a slight temperature fall observed at the vicinity of a wetting wall followed by a slight temperature rise at larger distance from the wall. This situation is particularly observable when the liquid is in strong interaction with the wall (total wetting condition). The attraction energy exercised by the wetting surface to the liquid produces a pressure variation, in correlation with a slowing down of the molecules at the wall and correlatively creates a different thermodynamic equilibrium. The cooling zone is compensated away from the surface by a zone slightly warmer than the average temperature. These wall effects are induced in various d...

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Revealing the solid-like nature of glycerol at ambient temperature

Cited by 52 publications

References 46 publications

Richness of Side-Chain Liquid-Crystal Polymers: From Isotropic Phase towards the Identification of Neglected Solid-Like Properties in Liquids

Richness of Side-Chain Liquid-Crystal Polymers: From Isotropic Phase towards the Identification of Neglected Solid-Like Properties in Liquids

Importance of Interfacial Interactions to Access Shear Elasticity of Liquids and Understand Flow Induced Birefringence from Liquid Crystals to Worm-Like Micellar Solutions

Wall Effects induced by Ceramic in Quiescent Liquids

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