Journal article
The influence of surfactant in reflective HPDLC gratings
Polymer (Guilford), Vol.45(21), pp.7213-7218
2004
DOI: 10.1016/j.polymer.2004.08.043
Abstract
The use of highly functional acrylate monomers (large number of reactive bonds) as the precursor to the polymer-rich phase of holographic polymer-dispersed liquid crystals (HPDLC) is well established as providing the best balance between fast polymerization, gelation, and vitrification. Monomers with >3 double bonds (typically between 4 and 5) yield films with the largest diffraction efficiency, all other things being equal. A consequence of this chemistry is that the HPDLC films formed require very high switching fields to dynamically varying their optical properties. These high switching fields are unappealing for many commercial applications. A potential solution has been to add a non-reactive surfactant-like molecule to the reactive syrup. A substantial lowering of the switching field has been attributed to a modification of the anchoring properties of the LC molecules and the polymer host. The dynamics of switching seem to support this supposition as much longer relaxation times are observed. We investigate differences in the polymerization kinetics using differential photocalorimetry (DPC) and relate these results to differences in HPDLC evolution using real-time scattering experiments. Herein, we present large differences in the final morphology of reflection gratings which are supported by optical measurements. We also indirectly show that the surfactant molecules reside near or at the polymer interface by examining contamination of PDLC droplets using polarized optical microscopy and differential scanning calorimetry.
Details
- Title: Subtitle
- The influence of surfactant in reflective HPDLC gratings
- Creators
- J Klosterman - Air Force Research Laboratory, Materials and Manufacturing Directorate, 3005 Hobson Way, WPAFB, OH 45433, USAL.V Natarajan - Science Applications International Corporation, Dayton, OH 45433, USAV.P Tondiglia - Science Applications International Corporation, Dayton, OH 45433, USAR.L Sutherland - Science Applications International Corporation, Dayton, OH 45433, USAT.J White - Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA 52242, USAC.A Guymon - Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA 52242, USAT.J Bunning - Air Force Research Laboratory, Materials and Manufacturing Directorate, 3005 Hobson Way, WPAFB, OH 45433, USA
- Resource Type
- Journal article
- Publication Details
- Polymer (Guilford), Vol.45(21), pp.7213-7218
- Publisher
- Elsevier Ltd
- DOI
- 10.1016/j.polymer.2004.08.043
- ISSN
- 0032-3861
- eISSN
- 1873-2291
- Language
- English
- Date published
- 2004
- Academic Unit
- Chemical and Biochemical Engineering
- Record Identifier
- 9984003459102771
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