Inclusion of liquid crystalline azo-dyes in nanometric porous anodic aluminas: A comparative morphological and optical study

Morales–Saavedra, Omar G.; Mata-Zamora, M.E.; Rivera, Ernesto; García, Tonatiuh; Bañuelos, J.G.; Saniger-Blesa, José Manuel

doi:10.1016/j.dyepig.2007.10.007

“…During the past two decades, considerable progress has been made in understanding the factors that affect the molecular and material properties for linear and non-linear optical applications; recent investigations have demonstrated that organic materials represent a better alternative due to their fast response times, lower dielectric constants, better processability characteristics, lower production costs and enhanced NLO responses [3][4][5][6]. Under this framework, materials such as push-pull polymers, guest-host polymeric structures, organometallic complexes, ferroelectric and anti-ferroelectric LC materials such as bent-core (''banana'') liquid crystals and recently diverse functional organic-inorganic hybrid structures have also been investigated regarding their optical and NLO properties [7][8].…”

Section: Introductionmentioning

confidence: 99%

Optical Properties of Fluorinated Bent-Core Liquid Crystals Confined in Anodic Alumina Nanotubes

Morales–Saavedra

¹

,

Mata-Zamora

²

,

Ontiveros-Barrera

³

et al. 2010

Molecular Crystals and Liquid Crystals

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In the present work, oxalic amorphous porous anodic alumina membranes with highly ordered porous arrays and average nanometric porous dimensions of 70 nm in diameter and 17 microns in depth (nanotubes) were prepared and successfully used as host matrix for fluorinated bent-core liquid crystals. Atomic force microscopy studies were performed on the organic-inorganic hybrid samples in order to explore surface morphology and optimal insertion of these liquid crystalline (LC)-compounds into this environment. The quadratic nonlinear optical (NLO) and spectroscopic properties of the implemented mesogen with the nanotube-like confinement were systematically studied in order to evaluate its optical performance. Bent core molecules have shown interesting optical properties which have not yet been intensively investigated in solid-state hybrid structures. Hence, the obtained hybrid composites represent a promising field of investigation in the route to functional bent-core based materials, where different bent-core mesomorphic structures can be obtained and are of interest for new and improved applications in nanotechnology.

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“…These materials show an enhancement in conductivity over AgI powders. Composites of PAA with photoluminescent materials including liquid crystalline azo dyes [15], photoluminescent polymers [16] and Tb 3+ [17] show the diverse range of materials that can be supported on or contained within PAA.…”

Section: Porous Anodic Aluminamentioning

confidence: 99%

Aligned Nanorods of AlPO4-5 Within the Pores of Anodic Alumina

King¹

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<p>Anodic aluminium oxide has been identified as a versatile porous template material having high pore density, (up to 1010 cm-2), controllable channel length and monodisperse pore diameter within the range 20-250 nm. A number of studies have demonstrated the concept of utilizing the porous structure for directing the growth of various nanostructures. An example of this is the growth of crystals of the aluminophosphate AlPO4-5 within the anodic nanochannels. The high aspect ratio of the template pores encourages growth of the crystals in the preferred c-axis orientation. We have produced membranes of this material and investigated the degree of crystal alignment using X-ray diffraction. The relative degree of preferred orientation is over 200 for a typical membrane. Field emission SEM micrographs clearly show the aligned crystals within the pores. The inclusion of luminescent guest molecules within the pores of the zeolite has also been achieved. This work describes the synthesis, characterization and potential application of these membranes.</p>

show abstract

“…These materials show an enhancement in conductivity over AgI powders. Composites of PAA with photoluminescent materials including liquid crystalline azo dyes [15], photoluminescent polymers [16] and Tb 3+ [17] show the diverse range of materials that can be supported on or contained within PAA.…”

Section: Porous Anodic Aluminamentioning

confidence: 99%

Aligned Nanorods of AlPO4-5 Within the Pores of Anodic Alumina

King¹

0

View full text Add to dashboard Cite

<p>Anodic aluminium oxide has been identified as a versatile porous template material having high pore density, (up to 1010 cm-2), controllable channel length and monodisperse pore diameter within the range 20-250 nm. A number of studies have demonstrated the concept of utilizing the porous structure for directing the growth of various nanostructures. An example of this is the growth of crystals of the aluminophosphate AlPO4-5 within the anodic nanochannels. The high aspect ratio of the template pores encourages growth of the crystals in the preferred c-axis orientation. We have produced membranes of this material and investigated the degree of crystal alignment using X-ray diffraction. The relative degree of preferred orientation is over 200 for a typical membrane. Field emission SEM micrographs clearly show the aligned crystals within the pores. The inclusion of luminescent guest molecules within the pores of the zeolite has also been achieved. This work describes the synthesis, characterization and potential application of these membranes.</p>

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Inclusion of liquid crystalline azo-dyes in nanometric porous anodic aluminas: A comparative morphological and optical study

Cited by 8 publications

References 47 publications

Optical Properties of Fluorinated Bent-Core Liquid Crystals Confined in Anodic Alumina Nanotubes

Optical Properties of Fluorinated Bent-Core Liquid Crystals Confined in Anodic Alumina Nanotubes

Aligned Nanorods of AlPO4-5 Within the Pores of Anodic Alumina

Aligned Nanorods of AlPO4-5 Within the Pores of Anodic Alumina

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