BLUE PHASE PRESENATATION

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Transcript of BLUE PHASE PRESENATATION

Results

Investigation of Potential of Blue Phase Liquid Crystals for Functional MaterialsWilliam Guy

Mentors: Emre Bukusoglu and Xiaoguang WangPI: Prof. Nicholas L. Abbott

BackgroundIntermediate Phase of chiral LCs between their cholesteric phase and isotropic phase

BPIIBPI50 m50 mBPIIBPI10 m-thick film of 35 wt% S-811/MLC2142 on glass substrate exposed to air.

= Wavelength of Reflected Lightn = Refractive Indexa = Lattice Parameter h,l,k = Miller Indices

MotivationInvestigation of blue phases for use for materials SensorsTemplated Materials

To develop an experimental system to study the underlying phenomena leading to a change in the optical appearance of the BP droplets upon addition amphiphilic molecules.

LC response to lipids (1)Scale bars: 5 mLC templated particle synthesis (2); Scale bars: 5 m

Goals for this SemesterDevelop a suitable experimental procedure to study consistently stable blue phasesGlass: Bare, PVA, DMOAPSolution: Pure water, PBSGrid: 75 mesh 10 m400 mesh 10 m75 mesh 40 mFilling: Overfill, NormalStudy effects of common simple adsorbates on the appearance of blue phases

75 mesh, 10 m thick

1000 umPVANo Temp CycleCholesteric DMOAPNo Temp CycleCholestericBareAfter Temp CycleCholestericDevelopment of ProcedureVaried type of glass during development of procedure; Bare glass showed dewetting in aqueous environment; PVA prevented a flat film of LC from forming; DMOAP was determined to be best Varied grid size by which to study BP film; chose 75 mesh in order to observe domains more easily.

400 mesh, 10 m thick 1000 um 1000 um

Phase Transitions (Cooling)40 um-thick 75 mesh TEM grids; PBS solution, pH=7.4; 35wt% S811/MLC2142

50.1C BPI

53.4CTransitionIso to BPII52.6C,TransitionBPII to BPI46C BPI45.2C BPI42.6CTransitionBPI to cholesteric

Effects of Additives: SDS40um,75 mesh TEM grids, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC

53.4CTransitionIsotropic to BPI/BPII51.2CBPI47.3C BPI46.3CBPI44.8CBPI1000 um1000 um1000 um1000 um1000 um43.2CTransitionBPI to cholesteric

Effects of Additives

No additives 45.2C, 1 mM SDS, 45.5C 1000 um 1000 umSDS aligned [110] planes parallel to the interface and stabilized the lattice size BPI.

Effects of Additives, SDS40um,75 mesh TEM grid, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC, 48C

Prior to SDS1000 m1000 m

Effects of Additives, SDS40um,75 mesh TEM grid, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC, 48C

Prior to SDSAfter SDS+0mins1000 m1000 m

Effects of Additives, SDS40um,75 mesh TEM grid, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC, 48C

Prior to SDSAfter SDS+0minsAfter SDS+3mins1000 m1000 m1000 m

Effects of Additives, SDS40um,75 mesh TEM grid, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC, 48C

Prior to SDSAfter SDS+0minsAfter SDS+3minsAfter SDS+9mins1000 m1000 m1000 m1000 m

Effects of Additives, SDS40um,75 mesh TEM grid, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC, 48C

Prior to SDSAfter SDS+0minsAfter SDS+3minsAfter SDS+9minsAfter SDS+14mins1000 m1000 m1000 m1000 m1000 m

Effects of Additives, SDS40um,75 mesh TEM grid, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC, 48C

Prior to SDSAfter SDS+0minsAfter SDS+3minsAfter SDS+9minsAfter SDS+14mins1000 m1000 m1000 m1000 m1000 m

After SDS+22mins1000 m

Effects of Additives, SDS40um,75 mesh TEM grid, 1mM SDS in PBS solution, pH=7.4,35wt% chiral dopant LC, 48C

Prior to SDSAfter SDS+0minsAfter SDS+3minsAfter SDS+9minsAfter SDS+14minsAfter SDS+22mins1000 m1000 m1000 m1000 m1000 m1000 m

StabilizationThe free energy of a BP can be described as (defect theory)(1):

The free energy of a BP in the presence of amphiphiles can be described as:

The presence of SDS changes the Fcore, Fint, and Fsa leading to a stabilization in the BP lattice size with respect to temperature.Elastic Surface Core Interfacial

Elastic Surface Core Interfacial Self Assembly

(1) Kikuchi, H. et al. Nature Materials, 1, 2002, 64 - 68.

Effects of Additives

No additives 45.2C, 1 mM SDS, 45.5C 0.1 wt% PVA, 46.5C 1000 um 1000 um 1000 umSDS aligned [110] planes parallel to the interface and stabilized the lattice size BPI.PVA led to a distribution of different orientations of BPI lattice with respect to the interface.

ConclusionEvidence that SDS is going into the bulkWith the system developed in this study, we were able to demonstrate the dynamics of lattice size shrinkage and therefore response to exposure to amphiphiles.This possible entrance into the bulk would influence the lattice size that leads to a stabilization as function of temperatures

Lin, H.; Miller, D.S; Bertics, P.J.; Murphy, C.J.; de Pablo, J.J.; Abbott, N.L.; Science Mag, 2011, 332, 6035, 1297-1300

2. Mondiot, F.; Wang, X; de Pablo, J.J.; Abbott, N.; JACS, 2013, 135, 9972-8875

3. Bukusoglu,E; Wang,X; Martinez-Gonzales, J; de Pablo, J.J.; Abbott, N.L.; Adv. Mater., 2015, 27, 6892-6898

4. Kikuchi, H. et al. Nature Materials, 1, 2002, 64 - 681. Lin, H.; Miller, D.S; Bertics, P.J.; Murphy, C.J.; de Pablo, J.J.; Abbott, N.L.; Science Mag, 2011, 332, 6035, 1297-13002. Mondiot, F.; Wang, X; de Pablo, J.J.; Abbott, N.; JACS, 2013, 135, 9972-88753. Bukusoglu,E; Wang,X; Martinez-Gonzales, J; de Pablo, J.J.; Abbott, N.L.; Adv. Mater., 2015, 27, 6892-68984. Kikuchi, H. et al. Nature Materials, 1, 2002, 64 - 68.

1. Lin, H.; Miller, D.S; Bertics, P.J.; Murphy, C.J.; de Pablo, J.J.; Abbott, N.L.; Science Mag, 2011, 332, 6035, 1297-13002. Mondiot, F.; Wang, X; de Pablo, J.J.; Abbott, N.; JACS, 2013, 135, 9972-88753. Bukusoglu,E; Wang,X; Martinez-Gonzales, J; de Pablo, J.J.; Abbott, N.L.; Adv. Mater., 2015, 27, 6892-68984. Kikuchi, H. et al. Nature Materials, 1, 2002, 64 - 68.

References