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Analytical Instrumentation


The following equipment can be used to determine the physical properties of solids, liquids, gases, suspensions and molecular solutions.

Viscotek TDA 305-055 Tetra Detector Array system (TDA) for Gel Permeation Chromatography (GPC)


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The Viscoteck Tetra Detector Array system is an instrument which is used to measure sample concentration, molecular weight and intrinsic viscosity of synthetic and natural polymers and proteins. 

Specifics of the equipment

The Viscotek Tetra Detector Array system incorporates SEC or GPC with four detectors: Refractive index, Viscometer, UV-Vis and Light scattering detectors. The system can be used to measure molecular weight (Mw), hydrodynamic radius R(h), radius of gyration R(g), polydispersity and intrinsic viscosity of a variety of compounds. Size Exclusion Chromatography (SEC) or Gel Permeation Chromatography (GPC) columns suitable for organic and aqueous samples are available for separation of mixtures, including proteins, polymers and oligomers in the Mw range 500 to 10 000 000 g/mol. The ultraviolet photodiode array detector (UV-PDA) provides additional compositional data of co-polymers and conjugated proteins. The integrated detectors and columns are fully temperature controlled up to 80oC to ensure optimum detector stability.

The benefits of this equipment are:

  • The utilisation of low angle light scattering technology allows the determination of absolute molecular weight of synthetic and natural polymers.
  • By using an intrinsic viscosity detector, protein and polymer structural information can be obtained including branching
  • Molecular size can be determined in terms of hydrodynamic radius
  • Copolymer or protein conjugate composition can be determined by virtue of using the multi-wavelength UV-PDA detector.

People: For more information or advice please contact Professor Jadranka Travas-Sejdic  

 

BI-DNDC Brookhaven Differential Refractometer


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The BI-DNDC is a deflection type refractometer that may be used either in batch or GPC/SEC mode. In batch mode, the specific refractive index increment dn/dc is determined. This value is required as a parameter in molecular weight measurements using light scattering. In GPC/SEC mode, dn/dc is already known, and the instrument is used as a concentration detector for GPC/SEC applications.

People: For more information or advice please contact Dr Jianyong Jin

 

Renishaw RM1000 Raman Microprobe


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Raman spectroscopy is a vibrational spectroscopic technique which provides a rich diversity of information on both organic and inorganic molecules, in gas, liquid or solid states. The technique is complimentary to FTIR spectroscopy, and the Raman spectra of compounds can be used like fingerprints to identify compounds. Raman spectroscopy is highly selective, and with the signal enhancements provided by Surface Enhanced Raman Scattering (SERS) effect, Raman shows sensitivities comparable with both UV-VIS spectrophotometry and Fluorescence spectroscopy. The comparatively weak Raman signal of water is an advantage for measurement of aqueous samples. Additional advantages of the technique are that it requires little or no sample preparation and is generally non-destructive, so that materials can be analysed in situ. 

Specifics of the equipment

The RM1000 is equipped with an air cooled Argon ion 488nm excitation laser and solid state diode 785 nm excitation laser. The Leitz microscope attachment includes x5, x20 and x50 objectives, both near and ultra-long working distance. Accessories include a Prior motorized XY stage for chemical imaging or mapping of surfaces and a  Linkam T600 heating stage for in situ Raman analysis during heating up to 600 ◦C.  The spectroscopic software used by the Renishaw Raman spectrometer is GRAMS 32.

Applications:

  • Analysis of composition, stress-strain state, crystal symmetry, orientation and crystalline defects in material
  • In situ monitoring of phase changes and changes in structure
  • Identification and discrimination of polymorphs
  • Applications can be in food, environmental, forensic, semiconductor, pharmaceuticals, geology, polymers, animal, human and botanical samples, wood analysis and wine science.

People: For more information or advice please contact Dr Michel Nieuwoudt

 

JOEL JES-FA200 ESR Spectrophotometer


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Electron Spin Resonance (ESR), is a versatile, non-destructive analytical technique based on the absorption of microwave radiation in the presence of an applied paramagnetic field.  The technique utilises the phenomenon of magnetic resonance of electrons and measures compounds having unpaired electrons (free radicals). The instrument is used to obtain information about the amount, structure, electron state and relaxation times of the free radicals through the magnetic properties of unpaired electrons.

In fields related to biological organisms, objectives of the study can include active oxygen species, nitrogen monoxide, nitrogen dioxide and trace metals contained in enzymes and proteins. In material related fields, objectives of study include lattice defects in optical fibres or amorphous silicon, solutions in conductive high polymers and peroxidized radicals in high-polymer molecules.

Applications:

  • To determine the electronic structure of free radicals and paramagnetic transition metal complexes
  • Study the magnetic properties of the materials and its order of orientations
  • To study conducting properties of organic conducting polymers
  • To investigate the active sites in metal containing enzymes

People: For more information or advice please contact Pooja Yadav

 

Size Exclusion Chromatography - with Multi-Angle Laser Light Scattering (SEC – MALLS)


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SEC-MALLS is a technique used to determine the Molecular weight, Mw, and radius of gyration, Rg, of a variety of compounds. The SEC-MALLS system comprises of Waters HPLC pumps and column ovens, PL-polypore organic and PL-aquagel aqueous columns, a Shimadzu Refractive Index detector and Wyatt Technologies DAWN DSP 18 angle Light Scattering detector, with Astra 4 software. Similar to the Viscotek TDA, the applications of this system include the separation and absolute determination of the molecular weight of a variety of compounds, such as Size Exclusion Chromatography (SEC) or Gel Permeation Chromatography (GPC) columns suitable for organic and aqueous samples are available for separation of mixtures, including proteins, polymers and oligomers in the Mw range 500 to 10 000 000 g/mol. From distribution plots of molar mass and radius inferences can be drawn about the shape of the molecule - globular or rod shaped etc. Operation in batch mode allows measurement of the 2nd virial coefficient as well as Rg and Mw through determination of Zimm plots.

Applications:

  • Separation and absolute determination of molecular weight
  • An indication about the shape of the molecule

People: For more information or advice please contact Dr Jianyong Jin

 

Nicolet 8700 Fourier Transform Infrared Spectrometer (FTIR)


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Fourier transform infrared spectroscopy (FTIR) is a vibrational spectroscopic technique which can be used to obtain detailed information on the composition and structure of solids, liquids or gases. The technique is complimentary to Raman spectroscopy, and the Infrared (IR) spectra of compounds can be used like fingerprints to identify compounds.

The possibility of FTIR spectroscopy to obtain an IR spectrum in few minutes makes this technique a first step choice in any conventional analysis. The spectrometer comprises a Continuum FTIR microscope for analysis of small areas of 30 to 100 μm in either transmission or reflectance mode. In addition, accessories are available for analysis in ATR (Attenuated Total Reflectance) and DRIFTS (diffuse reflectance) mode, with Ge, ZnSe or diamond crystals.

The spectrometer is equipped with both mid-IR and Near-IR sources, beamsplitters and detectors. This enables analysis of samples in both the mid-IR and Near-IR regions. The motorized XY stage of the Continuum microscope enables chemical imaging or mapping of surfaces. 

Applications:

  • Food analysis: additives, preservatives, colorants
  • Environmental analysis: water, atmospheric particles, gases
  • Forensic science: paints, textiles, cosmetics,
  • Physiological samples: malignant cells, bones, hairs
  • Multilayer compounds: polymers, paintings, films

People: For more information or advice please contact Neil Edmonds

 

TA Instruments Q1000 Differential Scanning Calorimeter


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Differential Scanning Calorimeters (DSC) measures temperatures and heat flow associated with thermal transitions in a material. 

This instrument has an autosampler, cooling capabilities to -90oC and advanced zero™ technology. This technology offers excellent baseline stability, sensitivity and resolution offering an alternative approach to analysing small transitions such as Glass transitions. It also includes Modulated DSC™ which allows the separation and analysis of simultaneously occurring reversible (eg melting point, Tg) and non-reversible (eg solvent loss, curing) processes.

Applications:

  • Glass Transitions, cold crystallisations, phase changes, melting
  • Product Stability, Cure / Cure kinetics, heat capacity, oxidative stability

People: For more information or advice please contact Neil Edmonds