Next Article in Journal
Properties of Graphene/Shape Memory Thermoplastic Polyurethane Composites Actuating by Various Methods
Next Article in Special Issue
Emerging Applications of Liquid Crystals Based on Nanotechnology
Previous Article in Journal
Flash Thermography to Evaluate Porosity in Carbon Fiber Reinforced Polymer (CFRPs)
Previous Article in Special Issue
Liquid-Crystal-Enabled Active Plasmonics: A Review
Article Menu

Export Article

Open AccessArticle
Materials 2014, 7(3), 1502-1519; doi:10.3390/ma7031502

Dispersion of γ-Alumina Nano-Sized Spherical Particles in a Calamitic Liquid Crystal. Study and Optimization of the Confinement Effects

1
Departamento de Física Aplicada II, Facultad de Ciencia y Tecnología, Universidad del País Vasco UPV-EHU, Apartado 644, Bilbao E-48080, Spain
2
Grup de Propietas Físiques dels Materials (GRPFM), Departament de Física i Enginyeria Nuclear, E.T.S.E.I.B. Universitat Politècnica de Catalunya, Diagonal 647, Barcelona 08028, Spain
*
Author to whom correspondence should be addressed.
Received: 16 January 2014 / Revised: 5 February 2014 / Accepted: 12 February 2014 / Published: 27 February 2014
(This article belongs to the Special Issue Liquid Crystals)
View Full-Text   |   Download PDF [879 KB, uploaded 27 February 2014]   |  

Abstract

We report an experimental study on confined systems formed by butyloxybenzylidene octylaniline liquid crystal (4O.8) + γ-alumina nanoparticles. The effects of the confinement in the thermal and dielectric properties of the liquid crystal under different densities of nanoparticles is analyzed by means of high resolution Modulated Differential Scanning Calorimetry (MDSC) and broadband dielectric spectroscopy. First, a drastic depression of the N-I and SmA-N transition temperatures is observed with confinement, the more concentration of nanoparticles the deeper this depression is, driving the nematic range closer to the room temperature. An interesting experimental law is found for both transition temperatures. Second, the change in shape of the heat capacity peaks is quantified by means of the full width half maximum (FWHM). Third, the confinement does not noticeably affect the molecular dynamics. Finally, the combination of nanoparticles and the external applied electric field tends to favor the alignment of the molecules in metallic cells. All these results indicate that the confinement of liquid crystals by means of γ-alumina nanoparticles could be optimum for liquid crystal-based electrooptic devices.
Keywords: liquid crystals; MDSC calorimetry; dielectric spectroscopy; polydispersive nanoparticles; confinement; γ-alumina liquid crystals; MDSC calorimetry; dielectric spectroscopy; polydispersive nanoparticles; confinement; γ-alumina
Figures

This is an open access article distributed under the Creative Commons Attribution License (CC BY 3.0).

Scifeed alert for new publications

Never miss any articles matching your research from any publisher
  • Get alerts for new papers matching your research
  • Find out the new papers from selected authors
  • Updated daily for 49'000+ journals and 6000+ publishers
  • Define your Scifeed now

SciFeed Share & Cite This Article

MDPI and ACS Style

Diez-Berart, S.; López, D.O.; Sebastián, N.; de la Fuente, M.R.; Salud, J.; Robles-Hernández, B.; Pérez-Jubindo, M.Á. Dispersion of γ-Alumina Nano-Sized Spherical Particles in a Calamitic Liquid Crystal. Study and Optimization of the Confinement Effects. Materials 2014, 7, 1502-1519.

Show more citation formats Show less citations formats

Related Articles

Article Metrics

Article Access Statistics

1

Comments

[Return to top]
Materials EISSN 1996-1944 Published by MDPI AG, Basel, Switzerland RSS E-Mail Table of Contents Alert
Back to Top