Κατεύθυνση Φυσική των Υλικών
Library of the School of Science

2024-09-11

2024

Schinas Alfredos

Ιωάννης Λελίδης, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Δημοσθένης Σταμόπουλους, Αναπληρωτής Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ
Λουκάς Κουτσοκέρας, Επίκουρος Καθηγητής, Τμήμα Φυσικής, ΕΚΠΑ

Επίδραση κβαντικών τελειών άνθρακα σε θερμοδυναμικές και ηλεκτροπτικές ιδιότητες της νηματικής φάσης

Greek

Effect of carbon quantum dots on the thermodynamic and electro-optical properties of the Nematic phase

In the current thesis we study the electro-optical properties of hybrid systems which
are comprised of Carbon-Nano Dots (CNDs) dispersed in the liquid crystal 8CB.
Initially, we created a solution dispersion protocol to avoid the phase separation of
the mixture. Afterwards, we manufactured samples with different mass fraction, χ,
of the CNDs in cells with specific boundary conditions and adjustable thickness.
We characterised the structure properties of every sample with polarised light microscopy and fluorescence. We investigated the impact of χ and of temperature on
the phase diagram, on the birefringence, on the critical threshold of Freedericksz’s
transition, on the response’s time and on the relaxation’s time in every sample.
Finally, we analysed the experimental data to determine the critical exponent of the
order parameter, the pretilt angle of the molecules at the cell’s interface and the
scaling law of viscosity

Science

Liquid crystals, 8CB, Nematic phase, Nanoparticles, Freedericksz transition, Viscosity, Birefringence, Response time, Polarised light microscopy, Elecro-optical measurements, Fluorescence microscopy, Phase diagram

Yes

3

Yes

17

92

File access is restricted until 2025-09-16.

https://pergamos.lib.uoa.gr/uoa/dl/object/3415092