MSc. Thesis Defense: Zekiye Pelin Güven

SYNTHESIS AND CHARACTERIZATION OF CHIRAL MIXED LIGAND

NANOCLUSTERS AND NACRE-LIKE STRUCTURE

Zekiye Pelin Güven
Materials Science and Engineering, MSc. Thesis, 2014

Thesis Jury

Assist. Prof. Özge Akbulut (Thesis Advisor), Assoc. Prof. Cleva Ow Yang,

Assoc. Prof. Güllü Kızıltaş Şendur

Date & Time: July 17th, 2014 – 10 AM

Place: FENS G025

Keywords : Silver Nanoclusters, Chirality, Mixed Ligands, Nacre

Abstract

Nanoclusters gained attention due to their possible applications in biosensing, biolabeling, and optics. In this thesis we report the synthesis and characterization of mixed ligand silver nanoclusters that exhibit chiral behavior.  We explored the occurrence of this behavior by changing the silver to thiol ratio, ratio of the ligands and using different ligands.

Nacre-like structures are of interest due to their toughness that goes far beyond ceramic materials. This toughness arises from the layered structure which is kept together by biomolecules such that when stress is applied, the layers slide and entering the brittle regime is postponed. In addition, cracks cannot propogate in nacre due to organic/inorganic layering. To fabricate nacre-like materials, organic and inorganic layers are coated via layer-by-layer assembly or in situ biomineralization in an organic matrix is used. In this thesis we synthesized nacre-like layered nano/meso building blocks in a controlled and easy manner by the reduction of silver salt in the presence of two different ligands to produce nanoclusters, followed by a second reduction such that the nanoclusters assemble into a layered structure. We characterized the electronic, crystallographic, and optical properties of nacre-like structures.