Facilities

Dynamic Vapour Sorption (DVS) is a gravimetric technique that allows the measurement of sorption and desorption kinetics and equilibrium uptake by a sample at given temperature and solvent partial pressure. The most commonly used vapour is water but a range of common organic solvents can be used too. The obtained data is of critical importance for numerous industries and academic fields such as pharmaceuticals (both low molecular weight and biological), food science, personal care and hygiene products, fabric care products, building materials, and membrane science.

SPEL features a world-leading Dynamic Vapour sorption facility with access to three Surface Measurement Systems (UK) instruments for operation over relevant temperature (5 – 60 °C) and pressure ranges. Our facility allows us to carry out on-line Raman spectroscopy (785 nm) and electrostatic measurements as well as video imaging as a function of solvent partial pressure, temperature, and time. Typical sample sizes vary from 10 mg to about 100 g depending on the instrument and microbalance used. This allows us a wide range of applications from a typical isotherm measurement of a pharmaceutical powder, BET surface area estimation, to the packaging integrity of a chocolate bar.

Further, a stand-alone high precision vapour generation instrument allows mimicking environmental conditions from the DVS experiment during optical microscopy, optical profilometry, and various spectroscopic techniques.

SYMPATEC RODOS/M Dry Dispersion Laser Diffraction system with VIBRI/R feeder.

Laser Diffraction based dry particle sizing equipment.

Measurement range 0.1-3500μm.

Particle dispersion with compressed air/nitrogen.

The Inverse Gas Chromatograph (IGC) is an advanced gas phase instrumentation for the characterisation of particulates, fibres and thin-films. IGC uses pulses of solvent vapour to probe the surface and bulk properties of the particulate and fibrous materials.

A wealth range of fundamental physico-chemical properties is enable to be elucidated, including powder surface energies, acid/base/polar functionality of surfaces, diffusion kinetics, solubility parameters etc.

Also available in SPEL is the Inverse Liquid Chromatograph (ILC).

Self-interaction chromatography

Self-Interaction chromatography (SIC) is a technique which involves the target protein immobilised onto a solid state, the chromatographic stationary phase. The same protein will then be used as a mobile phase and a pulse of protein concentration (together with buffer) will be injected and eluted through the column with the immobilised protein.

The mobile phase protein concentration, eluent, exiting the column, is monitored using a UV detector. The measurement by the detector will result in a chromatogram whose retention time is a direct measure of protein-protein interactions.

This type of chromatography is based on weak affinity chromatography principles, but in this technique the same protein will act as both the ligand and ligate [1]

Inverse liquid chromatography

Inverse Liquid Chromatography (ILC) is a physicochemical chromatographic technique that can be used to investigate solid–liquid interactions and surface properties of unknown solid materials [2]. The sample powder is packed into the LC column and a liquid mobile phase passed through the column with unknown solid material. Solute chromatograms are derived which provide surface properties for the unknown sample. ILC studies have previously determined adsorption or desorption isotherms of solid–liquid systems [2, 3].

References:

1. Quigley, A., Protein Aggregation Behaviour and the Second Virial Coefficient, in Department of Chemical Engineering. 2012, Imperial College London.
2. Ylä-Mäihäniemi, P. and D.R. Williams, Novel inverse liquid chromatography detector configuration for studying solid–liquid adsorption. Journal of Chromatography A, 2007. 1138(1–2): p. 95-100.
3. Gorner, T., et al., Inverse Liquid Chromatography Investigation of Adsorption on Heterogeneous Solid Surfaces:  Phenylalanine on Activated Carbon. Langmuir, 2002. 18(22): p. 8546-8552.

Olympus BX51 Reflected Light Microscope with CCD Camera. Magnification 5X, 10X, 20X and 50X

Veeco Wyko NT9100 bench top OP system. White light interferometry. Equipment for high quality 3D maps of surface. Through Transmissive Media Module for high resolution measurements through dispersive surface 5X and 10X objectives. X-Y Stage Automation

Optical profilometry

The new bench-top Wyko NT9100 Optical Profiling System shares many of the performance attributes of the larger ninth-generation NT9000 systems, including: easy measurement setup, fast data acquisition, comprehensible and extensible data analysis, and angstrom-level repeatability. The NT9100 employs coherence scanning interferometry, also known as white-light interferometry, white-light confocal, or vertical scanning interferometry to produce high quality three-dimensional surface maps of the object under test.

A data stitching option adds a motorized stage and support software to scan larger surface areas, and an optional X-Y stage automation option brings programmability to the NT9100, a first for a Wyko tabletop profiler. Industry-leading Wyko Vision software provides over 200 built-in analyses as well as automated measurement sequences (recipes) union data logging, and pass-fail criteria for real-time process feedback and SPC.

Optical profiler booking procedure

Please contact Dr. Jerry Heng about this equipment and training.

Photon correlation spectroscopy / multi-angle dynamic light scattering

Coulter N4 Plus

Particle Size Analysis using Photon Correlation Spectroscopy (PCS) which determines particle size by measuring the rate of fluctuations in laser light intensity scattered by particles as they diffuse through a fluid. It is the only non-destructive method for measuring particle size down to a few nanometres (3nm - 3000nm) and the N4 Plus is the only PCS analyzer that uses six fixed measurement angles (14.9°, 20.6°, 30.4°, 40.2°, 50.4°, and 90°).

N4 PLUS Submicron Particle Size Analysis

Size Range: 3 nm - 3 µm in one measurement
Output Data Analysis Modes:
Particle Size, Distribution Width, Polydispersity, Diffusion Constant etc.
Typical Applications:
Latex, Liposomes, Microemulsions, Pigments, Polymer dispersions, Proteins and other colloidal systems

Ideal for the rapid Quality Control of single, multi-modal or broad distributions.
Ideal for the rapid identification of different suspensions or emulsions.
For increased accuracy and highly dependable particle size data.

Most PCS analyzers perform measurements at only 90 degrees. Because submicron particles scatter light in patterns depending on particle size, larger particles may be difficult to detect at 90 degrees if the sample contains a large number of smaller particles. Similarly, any population of particles that scatter weakly at a certain angle may be masked by particles with strong scattering at that angle. For this reason, single or dual angle PCS instruments provide only a partial view of your sample. Adjustable-angle instruments (goniometers) are prone to inaccuracy, in addition to being cumbersome.

A powerful laser detects the most elusive particles. The N4 Plus also incorporates a powerful 10mW laser which permits easy analysis of even the weakest light scatterers such as micelles and single polymer chains.

The N4 Plus software provides a flexible and user-friendly interface.

User-friendly Microsoft Window-based software includes these features:

• Run Profiles to automate frequently used analysis protocols.
• Database to organize data in a lab-oriented hierarchy and free operators from 8-character DOS filenames.
• Real time display of instrument status including mode of operation, time remaining in current measurement, and time remaining in entire analysis.
• Easy-to-read printout of user-defined reports to any printer supported by Windows 3.1.
• Comparison of results from different runs by overlays.
• Automatic fluid parameter tables include commonly used fluid refractive index and viscosity data.

Two analysis modes provide flexibility. The N4 Plus can provide you with the mean particle size in your sample, along with the estimated distribution width, in just 60 seconds. For a complete particle size distribution, the Size Distribution Processor (SDP) analysis resolves the components of polydispersed samples and reports results in Intensity % or Weight % as a function of particle diameter or molecular weight.

Technical specifications

Sample:
Liquid suspensions

Sample particle size range:
0.003 µm to 3 µm diameter

Analysis modes:

1. Unimodal (cumulants) fit yields mean particle size and standard deviation in nm. Reproducibility: typically better than 3% CV.
2. Size distribution profile deconvolution algorithm based on CONTIN program yields peak data and bin by bin percentage (intensity or weight) as a function of particle size or molecular weight. Resolution: 17 to 31 size bins, user-selectable. Reproducibility: sample dependent.

Instrument control and data storage:
Microsoft Windows based PC software. Data stored in ODBC-compliant (Open Databased Connectivity) database. Automatic configuration of run parameters.

Laser source:
10 mW helium-neon 632.8 nm

Optics:
Six fiber optics located at the following geometrical angles: 14.9°, 20.6°, 30.4°, 40.2°, 50.4°, and 90°. User-selectable. Auto-stepping motor routine for sequential angle analysis.

Temperature control:
0°-90° C ±0.2°C, Peltier (electronic) regulated.

Correlator:
80 Multi-Tau channels; 3072 linear channels equivalent, 48 bit/channel.

Interface:
RS-232C serial interface is standard. Baud rate is software-selectable, up to 19.2K Baud.

Power requirements:
115/230 Vac, 50/60 Hz

Environmental operating specs:
Temperature: 10-40°C
Humidity: 0-90% w/o condensation

Coulter N4 plus booking procedure

Please contact Dr. Jerry Heng about this equipment and training.

QCM Q Sense E1 System. Equipment for detection of adhesion / nucleation (via mass change) at nanogram resolution. Flow Cell and Window Cell providing parallel imaging of the sensor surface and suitable for measurements in liquid medium

The Hitachi Tabletop Microscope (SEM TM-1000) is the perfect imaging platform for any Light Microscope lab needing higher resolution and deeper focus depth. It is user friendly and requires no electron microscopical technical skills or sample preparation techniques, i.e. gold-coating.

There is also the function of SwiftED-TM --> Elemental Analysis (EDS) in the TM-1000. Analysis and microscope imaging work together and are controlled via the same monitor. Analysis targets can be selected either as individual spots or as an sample area at an arbitrary field of view.

SMS TXT2i Plus. Equipment for characterization of mechanical properties (compressibility, harness, elasticity, fracturability) of solid samples. 5kg load cell with 0.05N resolution

PANalytical X’Pert Pro MPD. Equipment for crystal structure determination of powders, films and solid samples. Reflectivity stage for characterisation of surface, thin films and multilayers (for thickness measurements). Cu Anode and X’Celerator detector
low sample turnout time. X’Pert High Score and X’Pert Reflectivity software for data analysis, ICDD PDF4+ Database

Powder x-ray diffractometer

The X'Pert PRO Diffractometer by PANalytical is a versatile, non-destructive technique that reveals detailed information about the chemical composition and crystallographic structure of natural and manufactured materials. It consists of ceramic X-Ray tube with Copper anode, generating high voltage and current (max. 60kV & 60mA), and X'Celerator unit for the incident beam, which includes Nickel filter and Soller slit system. In addition, it also comes with the XRD reflectivity option.

Model: PANalytical X'Pert PRO

PXRD booking procedure

Please contact Dr. Jerry Heng about this equipment and training.

For booking purpose please email Dr. Jerry Heng or Clarence Chum.

Thank you!

VirTis AdVantage Plus benchtop Freeze Dryer / Lyophilizer

The AdVantage provides a small benchtop freeze dryer for scientists who require both manifold and tray-type freeze drying. Shelf temperatures as low as -55C and condenser temperatures to -85C supportsa wide range of applications including freeze-drying of liquid Biologics.

For booking purpose please email Professor. Daryl Williams.

HEL Group AutoLab and Manual Reactor Systems. Equipment for crystallization / reaction and scale up. Selection of pH, Turbidity, SRS QCM, conductivity and temperature probes. Operating temperature range -10oC to 250oC