MersV1, Main, Exploration, bibRecord, 000423

Pretransitional behavior of viscoelastic parameters at the nematic to twist-bend nematic phase transition in flexible n-mers.

Identifieur interne : 000423 ( Main/Exploration ); précédent : 000422; suivant : 000424

Pretransitional behavior of viscoelastic parameters at the nematic to twist-bend nematic phase transition in flexible n-mers.

Auteurs : Zeinab Parsouzi [États-Unis] ; Greta Babakhanova ; Mojtaba Rajabi ; Rony Saha ; Prabesh Gyawali ; Taras Turiv ; Hao Wang ; Alan R. Baldwin ; Chris Welch ; Georg H. Mehl ; J T Gleeson ; Antal Jakli ; Oleg D. Lavrentovich ; Samuel Sprunt

Source :

Physical chemistry chemical physics : PCCP [ 1463-9084 ] ; 2019.

RBID : pubmed:31168534

Abstract

We report dynamic light scattering measurements of the orientational (Frank) elastic constants and associated viscosities among a homologous series of a liquid crystalline dimer, trimer, and tetramer exhibiting a uniaxial nematic (N) to twist-bend nematic (N_TB) phase transition. The elastic constants for director splay (K₁₁), twist (K₂₂) and bend (K₃₃) exhibit the relations K₁₁ > K₂₂ > K₃₃ and K₁₁/K₂₂ > 2 over the bulk of the N phase. Their behavior near the N-N_TB transition shows dependency on the parity of the number (n) of the rigid mesomorphic units in the flexible n-mers. Namely, the bend constant K₃₃ in the dimer and tetramer turns upward and starts increasing close to the transition, following a monotonic decrease through most of the N phases. In contrast, K₃₃ for the trimer flattens off just above the transition and shows no pretransitional enhancement. The twist constant K₂₂ increases pretransitionally in both even and odd n-mers, but more weakly so in the trimer, while K₁₁ increases steadily on cooling without evidence of pretransitional behavior in any n-mer. The viscosities associated with pure splay, twist-dominated twist-bend, and pure bend fluctuations in the N phase are comparable in magnitude to those of rod-like monomers. All three viscosities increase with decreasing temperature, but the bend viscosity in particular grows sharply near the N-N_TB transition. The N-N_TB pretransitional behavior is shown to be in qualitative agreement with the predictions of a coarse-grained theory, which models the N_TB phase as a "pseudo-layered" structure with the symmetry (but not the mass density wave) of a smectic-A* phase.

DOI: 10.1039/c9cp00984a
PubMed: 31168534

Affiliations:

Le document en format XML

<record><TEI><teiHeader><fileDesc><titleStmt><title xml:lang="en">Pretransitional behavior of viscoelastic parameters at the nematic to twist-bend nematic phase transition in flexible n-mers.</title>
<author><name sortKey="Parsouzi, Zeinab" sort="Parsouzi, Zeinab" uniqKey="Parsouzi Z" first="Zeinab" last="Parsouzi">Zeinab Parsouzi</name>
<affiliation wicri:level="2"><nlm:affiliation>Department of Physics, Kent State University, Kent, OH 44242, USA. olavrent@kent.edu ssprunt@kent.edu.</nlm:affiliation>
<country xml:lang="fr">États-Unis</country>
<wicri:regionArea>Department of Physics, Kent State University, Kent, OH 44242</wicri:regionArea>
<placeName><region type="state">Ohio</region>
</placeName>
</affiliation>
</author>
<author><name sortKey="Babakhanova, Greta" sort="Babakhanova, Greta" uniqKey="Babakhanova G" first="Greta" last="Babakhanova">Greta Babakhanova</name>
</author>
<author><name sortKey="Rajabi, Mojtaba" sort="Rajabi, Mojtaba" uniqKey="Rajabi M" first="Mojtaba" last="Rajabi">Mojtaba Rajabi</name>
</author>
<author><name sortKey="Saha, Rony" sort="Saha, Rony" uniqKey="Saha R" first="Rony" last="Saha">Rony Saha</name>
</author>
<author><name sortKey="Gyawali, Prabesh" sort="Gyawali, Prabesh" uniqKey="Gyawali P" first="Prabesh" last="Gyawali">Prabesh Gyawali</name>
</author>
<author><name sortKey="Turiv, Taras" sort="Turiv, Taras" uniqKey="Turiv T" first="Taras" last="Turiv">Taras Turiv</name>
</author>
<author><name sortKey="Wang, Hao" sort="Wang, Hao" uniqKey="Wang H" first="Hao" last="Wang">Hao Wang</name>
</author>
<author><name sortKey="Baldwin, Alan R" sort="Baldwin, Alan R" uniqKey="Baldwin A" first="Alan R" last="Baldwin">Alan R. Baldwin</name>
</author>
<author><name sortKey="Welch, Chris" sort="Welch, Chris" uniqKey="Welch C" first="Chris" last="Welch">Chris Welch</name>
</author>
<author><name sortKey="Mehl, Georg H" sort="Mehl, Georg H" uniqKey="Mehl G" first="Georg H" last="Mehl">Georg H. Mehl</name>
</author>
<author><name sortKey="Gleeson, J T" sort="Gleeson, J T" uniqKey="Gleeson J" first="J T" last="Gleeson">J T Gleeson</name>
</author>
<author><name sortKey="Jakli, Antal" sort="Jakli, Antal" uniqKey="Jakli A" first="Antal" last="Jakli">Antal Jakli</name>
</author>
<author><name sortKey="Lavrentovich, Oleg D" sort="Lavrentovich, Oleg D" uniqKey="Lavrentovich O" first="Oleg D" last="Lavrentovich">Oleg D. Lavrentovich</name>
</author>
<author><name sortKey="Sprunt, Samuel" sort="Sprunt, Samuel" uniqKey="Sprunt S" first="Samuel" last="Sprunt">Samuel Sprunt</name>
</author>
</titleStmt>
<publicationStmt><idno type="wicri:source">PubMed</idno>
<date when="2019">2019</date>
<idno type="RBID">pubmed:31168534</idno>
<idno type="pmid">31168534</idno>
<idno type="doi">10.1039/c9cp00984a</idno>
<idno type="wicri:Area/PubMed/Corpus">000511</idno>
<idno type="wicri:explorRef" wicri:stream="PubMed" wicri:step="Corpus" wicri:corpus="PubMed">000511</idno>
<idno type="wicri:Area/PubMed/Curation">000511</idno>
<idno type="wicri:explorRef" wicri:stream="PubMed" wicri:step="Curation">000511</idno>
<idno type="wicri:Area/PubMed/Checkpoint">000420</idno>
<idno type="wicri:explorRef" wicri:stream="Checkpoint" wicri:step="PubMed">000420</idno>
<idno type="wicri:Area/Ncbi/Merge">002246</idno>
<idno type="wicri:Area/Ncbi/Curation">002246</idno>
<idno type="wicri:Area/Ncbi/Checkpoint">002246</idno>
<idno type="wicri:Area/Main/Merge">000426</idno>
<idno type="wicri:Area/Main/Curation">000423</idno>
<idno type="wicri:Area/Main/Exploration">000423</idno>
</publicationStmt>
<sourceDesc><biblStruct><analytic><title xml:lang="en">Pretransitional behavior of viscoelastic parameters at the nematic to twist-bend nematic phase transition in flexible n-mers.</title>
<author><name sortKey="Parsouzi, Zeinab" sort="Parsouzi, Zeinab" uniqKey="Parsouzi Z" first="Zeinab" last="Parsouzi">Zeinab Parsouzi</name>
<affiliation wicri:level="2"><nlm:affiliation>Department of Physics, Kent State University, Kent, OH 44242, USA. olavrent@kent.edu ssprunt@kent.edu.</nlm:affiliation>
<country xml:lang="fr">États-Unis</country>
<wicri:regionArea>Department of Physics, Kent State University, Kent, OH 44242</wicri:regionArea>
<placeName><region type="state">Ohio</region>
</placeName>
</affiliation>
</author>
<author><name sortKey="Babakhanova, Greta" sort="Babakhanova, Greta" uniqKey="Babakhanova G" first="Greta" last="Babakhanova">Greta Babakhanova</name>
</author>
<author><name sortKey="Rajabi, Mojtaba" sort="Rajabi, Mojtaba" uniqKey="Rajabi M" first="Mojtaba" last="Rajabi">Mojtaba Rajabi</name>
</author>
<author><name sortKey="Saha, Rony" sort="Saha, Rony" uniqKey="Saha R" first="Rony" last="Saha">Rony Saha</name>
</author>
<author><name sortKey="Gyawali, Prabesh" sort="Gyawali, Prabesh" uniqKey="Gyawali P" first="Prabesh" last="Gyawali">Prabesh Gyawali</name>
</author>
<author><name sortKey="Turiv, Taras" sort="Turiv, Taras" uniqKey="Turiv T" first="Taras" last="Turiv">Taras Turiv</name>
</author>
<author><name sortKey="Wang, Hao" sort="Wang, Hao" uniqKey="Wang H" first="Hao" last="Wang">Hao Wang</name>
</author>
<author><name sortKey="Baldwin, Alan R" sort="Baldwin, Alan R" uniqKey="Baldwin A" first="Alan R" last="Baldwin">Alan R. Baldwin</name>
</author>
<author><name sortKey="Welch, Chris" sort="Welch, Chris" uniqKey="Welch C" first="Chris" last="Welch">Chris Welch</name>
</author>
<author><name sortKey="Mehl, Georg H" sort="Mehl, Georg H" uniqKey="Mehl G" first="Georg H" last="Mehl">Georg H. Mehl</name>
</author>
<author><name sortKey="Gleeson, J T" sort="Gleeson, J T" uniqKey="Gleeson J" first="J T" last="Gleeson">J T Gleeson</name>
</author>
<author><name sortKey="Jakli, Antal" sort="Jakli, Antal" uniqKey="Jakli A" first="Antal" last="Jakli">Antal Jakli</name>
</author>
<author><name sortKey="Lavrentovich, Oleg D" sort="Lavrentovich, Oleg D" uniqKey="Lavrentovich O" first="Oleg D" last="Lavrentovich">Oleg D. Lavrentovich</name>
</author>
<author><name sortKey="Sprunt, Samuel" sort="Sprunt, Samuel" uniqKey="Sprunt S" first="Samuel" last="Sprunt">Samuel Sprunt</name>
</author>
</analytic>
<series><title level="j">Physical chemistry chemical physics : PCCP</title>
<idno type="eISSN">1463-9084</idno>
<imprint><date when="2019" type="published">2019</date>
</imprint>
</series>
</biblStruct>
</sourceDesc>
</fileDesc>
<profileDesc><textClass></textClass>
</profileDesc>
</teiHeader>
<front><div type="abstract" xml:lang="en">We report dynamic light scattering measurements of the orientational (Frank) elastic constants and associated viscosities among a homologous series of a liquid crystalline dimer, trimer, and tetramer exhibiting a uniaxial nematic (N) to twist-bend nematic (N<sub>TB</sub>
) phase transition. The elastic constants for director splay (K<sub>11</sub>
), twist (K<sub>22</sub>
) and bend (K<sub>33</sub>
) exhibit the relations K<sub>11</sub>
 > K<sub>22</sub>
 > K<sub>33</sub>
 and K<sub>11</sub>
/K<sub>22</sub>
 > 2 over the bulk of the N phase. Their behavior near the N-N<sub>TB</sub>
 transition shows dependency on the parity of the number (n) of the rigid mesomorphic units in the flexible n-mers. Namely, the bend constant K<sub>33</sub>
 in the dimer and tetramer turns upward and starts increasing close to the transition, following a monotonic decrease through most of the N phases. In contrast, K<sub>33</sub>
 for the trimer flattens off just above the transition and shows no pretransitional enhancement. The twist constant K<sub>22</sub>
 increases pretransitionally in both even and odd n-mers, but more weakly so in the trimer, while K<sub>11</sub>
 increases steadily on cooling without evidence of pretransitional behavior in any n-mer. The viscosities associated with pure splay, twist-dominated twist-bend, and pure bend fluctuations in the N phase are comparable in magnitude to those of rod-like monomers. All three viscosities increase with decreasing temperature, but the bend viscosity in particular grows sharply near the N-N<sub>TB</sub>
 transition. The N-N<sub>TB</sub>
 pretransitional behavior is shown to be in qualitative agreement with the predictions of a coarse-grained theory, which models the N<sub>TB</sub>
 phase as a "pseudo-layered" structure with the symmetry (but not the mass density wave) of a smectic-A* phase.</div>
</front>
</TEI>
<affiliations><list><country><li>États-Unis</li>
</country>
<region><li>Ohio</li>
</region>
</list>
<tree><noCountry><name sortKey="Babakhanova, Greta" sort="Babakhanova, Greta" uniqKey="Babakhanova G" first="Greta" last="Babakhanova">Greta Babakhanova</name>
<name sortKey="Baldwin, Alan R" sort="Baldwin, Alan R" uniqKey="Baldwin A" first="Alan R" last="Baldwin">Alan R. Baldwin</name>
<name sortKey="Gleeson, J T" sort="Gleeson, J T" uniqKey="Gleeson J" first="J T" last="Gleeson">J T Gleeson</name>
<name sortKey="Gyawali, Prabesh" sort="Gyawali, Prabesh" uniqKey="Gyawali P" first="Prabesh" last="Gyawali">Prabesh Gyawali</name>
<name sortKey="Jakli, Antal" sort="Jakli, Antal" uniqKey="Jakli A" first="Antal" last="Jakli">Antal Jakli</name>
<name sortKey="Lavrentovich, Oleg D" sort="Lavrentovich, Oleg D" uniqKey="Lavrentovich O" first="Oleg D" last="Lavrentovich">Oleg D. Lavrentovich</name>
<name sortKey="Mehl, Georg H" sort="Mehl, Georg H" uniqKey="Mehl G" first="Georg H" last="Mehl">Georg H. Mehl</name>
<name sortKey="Rajabi, Mojtaba" sort="Rajabi, Mojtaba" uniqKey="Rajabi M" first="Mojtaba" last="Rajabi">Mojtaba Rajabi</name>
<name sortKey="Saha, Rony" sort="Saha, Rony" uniqKey="Saha R" first="Rony" last="Saha">Rony Saha</name>
<name sortKey="Sprunt, Samuel" sort="Sprunt, Samuel" uniqKey="Sprunt S" first="Samuel" last="Sprunt">Samuel Sprunt</name>
<name sortKey="Turiv, Taras" sort="Turiv, Taras" uniqKey="Turiv T" first="Taras" last="Turiv">Taras Turiv</name>
<name sortKey="Wang, Hao" sort="Wang, Hao" uniqKey="Wang H" first="Hao" last="Wang">Hao Wang</name>
<name sortKey="Welch, Chris" sort="Welch, Chris" uniqKey="Welch C" first="Chris" last="Welch">Chris Welch</name>
</noCountry>
<country name="États-Unis"><region name="Ohio"><name sortKey="Parsouzi, Zeinab" sort="Parsouzi, Zeinab" uniqKey="Parsouzi Z" first="Zeinab" last="Parsouzi">Zeinab Parsouzi</name>
</region>
</country>
</tree>
</affiliations>
</record>

Pour manipuler ce document sous Unix (Dilib)

EXPLOR_STEP=$WICRI_ROOT/Sante/explor/MersV1/Data/Main/Exploration

HfdSelect -h $EXPLOR_STEP/biblio.hfd -nk 000423 | SxmlIndent | more

HfdSelect -h $EXPLOR_AREA/Data/Main/Exploration/biblio.hfd -nk 000423 | SxmlIndent | more

Pour mettre un lien sur cette page dans le réseau Wicri

{{Explor lien
   |wiki=    Sante
   |area=    MersV1
   |flux=    Main
   |étape=   Exploration
   |type=    RBID
   |clé=     pubmed:31168534
   |texte=   Pretransitional behavior of viscoelastic parameters at the nematic to twist-bend nematic phase transition in flexible n-mers.
}}

Pour générer des pages wiki

HfdIndexSelect -h $EXPLOR_AREA/Data/Main/Exploration/RBID.i   -Sk "pubmed:31168534" \
       | HfdSelect -Kh $EXPLOR_AREA/Data/Main/Exploration/biblio.hfd   \
       | NlmPubMed2Wicri -a MersV1

This area was generated with Dilib version V0.6.33.
Data generation: Mon Apr 20 23:26:43 2020. Site generation: Sat Mar 27 09:06:09 2021

Serveur d'exploration MERS

Pretransitional behavior of viscoelastic parameters at the nematic to twist-bend nematic phase transition in flexible n-mers.

Pretransitional behavior of viscoelastic parameters at the nematic to twist-bend nematic phase transition in flexible n-mers.

Source :

Abstract

Links toward previous steps (curation, corpus...)

Le document en format XML

Pour manipuler ce document sous Unix (Dilib)

Pour mettre un lien sur cette page dans le réseau Wicri

Pour générer des pages wiki

	Serveur d'exploration MERS
	Attention, ce site est en cours de développement ! Attention, site généré par des moyens informatiques à partir de corpus bruts. Les informations ne sont donc pas validées.