The preparation and characterisation of nanostructured materials in the form of thin films, nanoparticles and bulk structures demands pecialized chemical techniques to facilitate size, shape and structural control. Equally so specialized physical techniques are required to the structural, physical and chemical analysis with a sufficient resolution. Consequently, specialised characterisation techniques are required besides the standard techniques available to materials science. This module explores a number of these preparation and characterisation techniques and highlights to the student the fabrication pathways adopted and how conventional analysis techniques can be altered to characterise nanostructured systems. The aim of this module is to expose the student to a variety of preparation and characterisation techniques for nanostructured materials.
Nanoparticle Fabrication
· Top Down vs Bottom up Approaches,
· Nucleation & Crystal Growth, La Mer Model,
· Physical Preparation Routes,
· Chemical Preparation Routes incl Sol-gel, Reagent reservoirs, Arc Discharge,
· Molecular Self Assembly & Templated Synthesis,
· Nanostructured Films.
Particle sizing
· Dynamic light scattering, Photon Correlation Spectroscopy (PCS),
· Static light scattering- Fraunhofer / Mie Theory,
· Electron Microscopy – SEM / TEM / HRTEM / EDX,
· Diffraction techniques – Electron diffraction, powder X-Ray Diffraction, neutron diffraction techniques.
Scherrer equation.
Spectroscopy of nanostructures
·Molecular Absorption Spectroscopy in nanostrutures and semiconductors,
· Application of Photoluminescence to nanostructures,
· Single molecule spectroscopy,
· Surface enhance Raman spectroscopy SERS,
· Fluorescence resonance energy transfer FRET,
· Single photon counting spectroscopy SPC /time correlated photon counting,
· Total internal reflection fluorescence microscopy (TIRFM),
· Confocal Microscopy.
Practical Component
The practical element of this module will consist of 8 hours divided between laboratory sessions workshops and demonstrationsbased on techniques covered within the lecture material of this module. Any relevant new techniques which be become available in house will also be included were appropriate. The available of techniques may vary from year to year.
1) Nanoparticle Preparation
(i) preparation of a nanoparticulate oxide (eg TiO2, ZnO or SiO2) by a sol-gel technique. Part of the sol will be retained for analysis whilst the remainder will be calcined as particulate matter or in a thin ceramic film. Each material will be retained for analysis (1,2 &/or 3 below);
(ii) preparation of metal or metal sulphide nanoparticles (eg Au, PbS). A selected material will be prepared by solution-based chemical route, utilizing a suitable stabilizing agent. The material prepared will be retained for analysis (1,2&/or 3 below).
2) Electron Microscopy
This workshop will include - Sample preparation, coating techniques, analysis of various nanomaterials using scanning and transmission electron microscopy including particle size analysis. Elemental distribution by EDX on scanning probe microscope. Electron diffraction on transmission microscope.
3) Diffraction & Scanning Probe Techniques
This workshop will include - Sample preparation, analysis and particle size determination of various unknown nanocrystalline powders using X-ray diffraction. Surface analysis of various nanomaterials will be conducted using Atomic Force Microscopy
4) Spectroscopic Techniques
This workshop will include - Sample preparation, analysis and interpretation of results for a standard nanomaterial using a range of steady state spectroscopes including Raman microscopy, fluorescence spectroscopy, FT-IR microscopy, polarimetry and DLS other absorption techniques. It is expected the students will have a considerable degree of hands on experience in this practical and will be expected to fit and analyses spectra obtained during the session.
The teaching methods employed in this module will consist of a combination of techniques aimed at giving the
student a thorough understanding of the module and the experimental methods highlighted within. The methods
employed will consist of varying degrees of lectures, discussion, problem-solving exercises, self-directed learning,
practical work and demonstrations.
| Module Content & Assessment | |
|---|---|
| Assessment Breakdown | % |
| Formal Examination | 70 |
| Other Assessment(s) | 30 |