Processing and characterisation of liquid crystal nanocomposites

Chung, Ka Fai (2013). Processing and characterisation of liquid crystal nanocomposites. University of Birmingham. M.Res.

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Abstract

Doping nanoparticles such as carbon nanotubes (CNTs) in LC material is one of the methods to improve the display performance. The attraction of the hybrid system is not only the advance in EO performance, but also the alignment of CNTs. The disordered nature of CNTs makes it hard to expose the excellent properties and the self-ordered nature of LC material perfectly fit in this problem. Moreover, with LC acts as host, the CNTs orientation can be manipulated by external electric or magnetic field. On the other hand, there are doubts or questions on the stability of the nanocomposites and optimization of the sonication parameters and CNTs concentration that needed to be addressed before the mass production in the industry.

In this thesis, liquid crystal material 5CB and multi-walled carbon nanotubes (MWCNTs) hybrid system was studied. Results showed that the fastest response time of the nanocomposite was achieved in the following conditions: 1. Short sonication time (5mins) with prior stirring. 2. Sonication under ice bath. 3. CNTs concentration at about 0.02wt %. Experiment showed that a maximum reduction of 29% in total response time of the nanocomposite can be achieved. However, prolong processing and inappropriate temperature treatments are very likely to bring negative effect on the microstructure of LC nanocomposites.

Type of Work:

Thesis (Masters by Research > M.Res.)

Award Type:

Masters by Research > M.Res.

Supervisor(s):