Simultaneous measurements of molecular forces and electro-optical properties of a confined 5CB liquid crystal film using a surface forces apparatus

Using a surface forces apparatus (SFA), we studied the forces associated with the reorientation of molecules of a common nematic thermotropic liquid crystal, 4'-n-pentyl-4-cyanobiphenyl (5CB), confined between two conducting (silver) surfaces and its optical behavior under the influence of elec...

Description complète

Détails bibliographiques
Publié dans:Langmuir : the ACS journal of surfaces and colloids. - 1985. - 31(2015), 13 vom: 07. Apr., Seite 3965-72
Auteur principal: Kristiansen, Kai (Auteur)
Autres auteurs: Zeng, Hongbo, Zappone, Bruno, Israelachvili, Jacob N
Format: Article en ligne
Langue:English
Publié: 2015
Accès à la collection:Langmuir : the ACS journal of surfaces and colloids
Sujets:Journal Article
LEADER 01000caa a22002652 4500
001 NLM247115789
003 DE-627
005 20250218070711.0
007 cr uuu---uuuuu
008 231224s2015 xx |||||o 00| ||eng c
024 7 |a 10.1021/acs.langmuir.5b00144  |2 doi 
028 5 2 |a pubmed25n0823.xml 
035 |a (DE-627)NLM247115789 
035 |a (NLM)25774432 
040 |a DE-627  |b ger  |c DE-627  |e rakwb 
041 |a eng 
100 1 |a Kristiansen, Kai  |e verfasserin  |4 aut 
245 1 0 |a Simultaneous measurements of molecular forces and electro-optical properties of a confined 5CB liquid crystal film using a surface forces apparatus 
264 1 |c 2015 
336 |a Text  |b txt  |2 rdacontent 
337 |a ƒaComputermedien  |b c  |2 rdamedia 
338 |a ƒa Online-Ressource  |b cr  |2 rdacarrier 
500 |a Date Completed 03.06.2015 
500 |a Date Revised 07.04.2015 
500 |a published: Print-Electronic 
500 |a Citation Status PubMed-not-MEDLINE 
520 |a Using a surface forces apparatus (SFA), we studied the forces associated with the reorientation of molecules of a common nematic thermotropic liquid crystal, 4'-n-pentyl-4-cyanobiphenyl (5CB), confined between two conducting (silver) surfaces and its optical behavior under the influence of electric fields with varying magnitudes and field directions. A transient attractive force was observed due to partial reorientations of the liquid crystal molecules and the flow of free ions, in addition to a stronger constant capacitance attraction between the silver surfaces. At the same time, the optical properties of the liquid crystals were observed perpendicular to the silver surfaces. Observations of shifts and fluctuations of the extraordinary wave of the (multiple beam) interference fringes measure the refractive index of the director component parallel to the surface, which is sensitive to tilt motion (or reorientation) of the liquid crystal molecules that provided details of the anisotropic orientations of the molecules and domains. Any lateral differential refractive index change is easily observed by optical microscopy. The optical microscope imaging showed that the changes in the optical properties are due to convective flow at domain boundaries of the liquid crystal molecules (and possible free ions) between the two charged surfaces. At low electric fields, propagation of domain boundaries was observed, while at higher electric fields, hexagonal patterns of flowing molecules were observed. The interplay of the force measurements and optical observations reveal a complex dynamic behavior of liquid crystals subjected to varying electric fields in confined spaces 
650 4 |a Journal Article 
700 1 |a Zeng, Hongbo  |e verfasserin  |4 aut 
700 1 |a Zappone, Bruno  |e verfasserin  |4 aut 
700 1 |a Israelachvili, Jacob N  |e verfasserin  |4 aut 
773 0 8 |i Enthalten in  |t Langmuir : the ACS journal of surfaces and colloids  |d 1985  |g 31(2015), 13 vom: 07. Apr., Seite 3965-72  |w (DE-627)NLM098181009  |x 1520-5827  |7 nnns 
773 1 8 |g volume:31  |g year:2015  |g number:13  |g day:07  |g month:04  |g pages:3965-72 
856 4 0 |u http://dx.doi.org/10.1021/acs.langmuir.5b00144  |3 Volltext 
912 |a GBV_USEFLAG_A 
912 |a SYSFLAG_A 
912 |a GBV_NLM 
912 |a GBV_ILN_22 
912 |a GBV_ILN_350 
912 |a GBV_ILN_721 
951 |a AR 
952 |d 31  |j 2015  |e 13  |b 07  |c 04  |h 3965-72