Nanoparticles


Nanoparticle capability

Nanoparticle production

imageNanoparticles can be prepared by plasma deposition on a number of sputtering systems available within NIBEC including IRINA, Teer UDP 450 etc. Wherein particle size can be controlled by process parameters to give “dusty” plasmas containing nanoparticles formed through condensation during processing. These particles are often deposited at high energies resulting in thin films from which nanoparticle recovery can be difficult. To complement these systems a Mantis model soft landing sputtering system is available (comprising Nanogen 50 and MesoQ) containing size selection due to magnetic separation.

 

Additionally nanoparticles can be prepared through wet chemical means in our well stocked chemistry laboratory or alternatively through milling utilising a Fritch ball mill.

Characterisation of nano particles presents a real challenge for many traditional measurements due to the small area under analysis. This results in many measurements of nano particle properties averaged over a large number of particles these are referred to as ensemble techniques.

Direct measurements

Direct measurements of properties on a single nanoparticle are limited due to the probe volumes of many techniques, exceptions do exist in microscopy and associated techniques where the probe volumes are smaller than the particles under measurement. Equipment currently available in NIBEC include.

AFM

imageVeeco dimension 3100 AFM represents an imaging tool that can be applied to single or multiple particles if securely adhered on a substrate. Spatial resolution sub nanometer with additional information gained by this technique include:- size, morphology, roughness and electrical information through conducting probes.

 

 

 SEM

imageimageTwo instruments are available a Hitachi S-3200N and a FEI quanta 3D. SEM represents an imaging tool that can be applied to single or multiple particles in a range of configurations including large samples. Spatial resolution tens of nanometer. With additional applications gained through accessories including elemental analysis through the use EDX and depth profiling through the application of FIB.

 

TEM

imageJEM-2100F TEM represents an imaging and analysis tool that can be applied to single or multiple particles adhered to a TEM stub. Spatial resolution sub nanometer with additional information gained through the use of accessories including:-

Crystalinity via electron diffraction

Elemental analysis via EDX and EELs

Bonding information via EELs

 

Ensemble measurements

imageThese techniques despite measuring multiple particles can give valuable information regarding bulk property of nanoparticle assemblies or the differences between particles within a single liquid or gaseous preparation.

 

  

PSD / Zeta potential liquid samples

imageParticle size distribution in solution can be achieved via optical or acoustic scattering ultilising a Malvern zeta sizer or quantachrome DT1200 respectively. Additionally the zeta potential of particle preparations can be measured on both systems. Measurement performed using ensemble techniques often return differing estimates of values due to the manner in which measurements are made. With neither technique measuring particle size directly instead measuring hydrodynamic radii and scattering cross section which can be equated to particle size. Both measurements are of merit however each technique has respective advantages and disadvantages detailed below

 

Acoustic measurement

Advantages

Determinations at high solids loading

Determinations in native solvent

Disadvantages

Large volumes of sample required

Requirement for cross calibration and extensive data modelling

 

Optical measurement

Advantages

Determinations at low solids loading

Plug and play system with limited data manipulation required

Disadvantages

Native solvent significantly diluted during measurements not representative of original system

imagePSD airborne: The TSI 3034 Scanning Mobility Particle Sizer (SMPS) spectrometer displays data using 54 size channels (32 channels per decade) for high-resolution size information of particulate aerosols. With a measurement range from 10 to 487 nm.

This submicrometer particle sizer measures concentrations in the range from 1 to 2.4 x 106 particles/cm3 and is well-suited for applications with both low and high particle concentrations.

PSD powders: Retsch AS200  including physical sieves and shaker for separation and charcterisation of particle sizes within powdered samples

Bulk measurements

These techniques are often applied to large numbers of nanoparticles deposited as thin films or other coatings and include:

Elemental analysis and bonding information: XPS, TofF SIMS, Auger spectroscopy

Crystallinity: XRD

Molecular/crystal vibration and stretching: Raman spectroscopy

Optical characterisation: Confocal microscopy, optical profilometery, FTIR and UV/Vis spectroscopy

 

Engineering Futures and Dr Steve Myers Talk

 
Monday 23rd of February 2015
 

Engineering Futures and Dr Steve Myers Talk

news image

Tuesday 10th of February 2015

Inaugural Professorial Lecture by Tony Byrne, Professor of Photocatalysis

Inaugural Professorial Lecture by Tony Byrne, Professor of Photocatalysis

When & where Wednesday, 22 October 2014 18:30 at the Jordanstown campus Lecture Theatre 9F03

NIBEC Lecture Series begins in mid - October

Director