Nanoscience Facilities

The Nanoscience facility is located on the second floor of the Summerlee Science Complex in rooms 2109 and 2110. These laboratories provide undergraduate students a unique opportunity to study the chemical and physical behaviour of materials at the nanoscale. Specialized laboratory experiments have been developed to give our undergraduate students a unique hands-on laboratory experience in which students learn to prepare a variety of nanomaterials and measure their properties using state of the art imaging and spectroscopic instruments. The Nanoscience courses are taught by members of the physics and chemistry departments that provides our students with multidisciplinary training that prepares them for their future careers in academia or industry.

Imaging

Atomic force, electron and optical microscopy techniques

Atomic force microscopy (AFM) uses a cantilever beam with a sharp tip to profile the shape (topography) of the surface to determine the structure and mechanical properties of nanomaterials.

Scanning tunneling microscopy (STM) provides atomic resolution of conductive substrates by measuring the pico-to-nanoampere currents generated in quantum tunneling.

Scanning electron microscopy is used for high resolution imaging of conductive substrates by collecting scattered electrons, i.e., secondary and backscattered electrons.

Optical microscopy provides imaging of samples on micron length scales. Transmitted and reflected imaging modes, as well as fluorescence imaging, are available.

Spectroscopy

Interractions of electromagnetic waves with various materials

UV-visible Spectroscopy allows the measurement of the absorbance of UV & visible light to study the electronic structure of a sample, such as ions, molecules, nanoparticles and thin films.

In fluorescence spectroscopy, light is used to excite electrons in the sample to a higher electronic state, and the resulting fluorescence is measured as the electrons return to their ground state.

In dynamic light scattering (DLS), the diffusion of colloidal particles, with diameters ranging from 0.006 to 6 , suspended in aqueous media is measured that allows the determination of the particle radius (hydrodynamic radius) and polydispersity. The zeta potential can also be measured, which is a measure of the surface potential of charged colloidal particles. Colloids with a high surface potential will remain stable in solution while low surface potential species tend to flocculate or coagulate.

In multi-wavelength ellipsometry, broadband, elliptically polarized light is used to measure the thickness and index of refraction of thin films of a wide range of materials, such as polymers, metals, semiconductors, and metal oxides.

In Infrared (IR) Spectroscopy, the presence of specific chemical groups in a sample can be characterized and quantified by measuring the absorbance of IR light corresponding to the stretching and bending of chemical bonds in solid, liquid and gaseous samples.

In Raman spectroscopy, visible light is scattered inelastically from solid, liquid or gaseous samples to characterize and quantify their vibrational modes based on their optical polarizability.

Image to come.

Other

Physical measurements of the properties of nanostructured surfaces

Surface Area and Pore Size Analysis - Nitrogen gas adsorption is used to physically measure the total surface area, pore size and pore volume of a wide range of solid samples, such as soils, silicates, zeolytes, metals, metal oxides and other carbonaceous materials.

Contact Angle Measurements - We use a custom-built optical system to quantify the wetting of a solid surface by a liquid droplet by measuring the contact angle between the droplet and the surface.

Spin Coating - We use spin coating to deposit uniform, thin films of polymers, e.g., polystyrene, polyethylene, photoresists, onto a variety of substrates by varying the concentration of polymer solutions (several percent by mass) and the spin speed of the substrates (500 - 5000 rpm).