THEORETICAL & PHYSICAL CHEMISTRY INSTITUTE
 
  Infrastructure
  Materials Synthesis, Growth & Processing
  Materials & Devices Characterization Platforms
  Theoretical and Computational Chemistry and Materials Science
  Photonics and Νanostructures using short wavelength radiation
  Clean room for photonics applications and devices

Infrastructure

Materials & Devices Characterization Platforms

 

Polymer & Colloids Characterization

Size exclusion chromatography system (SEC)

Size exclusion liquid chromatography system (SEC), by Waters, including a Waters 1515 isocratic pump, Waters 2414 refractive index detector, styragel columns and controlled by the Breeze software. Upgraded with a UV-Vis-analyzer chromatography detector.

Used for molecular weight, molecular weight distribution and synthetic homo- and co-polymer purity determination. In correlation with the results from the integrated differential refractive index detector of the chromatography system it is now possible to (a) monitor the polymer composition over the whole sample molecular weight distribution, allowing for a better evaluation of the chemical structure and molecular composition/homogeneity of the polymers under study (b) the detection and quantitative concentration estimate of the additives in polymers/plastics.

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Wide-angle static and dynamic light scattering photometer

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Wide-angle static and dynamic light scattering photometer, by ALV GmbH, CGS-3. Comprises a He-Ne 22 mW laser source, compact goniometer system with an Avalanche photodiode detector, interfaced with an ALV/LSE-5003 electronics unit and an ALV-5000/EPP multi-tau digital photon correlator. The system is equipped with a Polyscience model 9102 bath for temperature control, Glan-Thompson polarization prism and various types of cells.

This setup allows the determination of the particle mass, size (range 1 nm - 3 μm) and shape (under certain conditions) dispersed in several solvents (synthetic polymers, proteins and other biomacromolecules, colloidal particles, metallic nanoparticles, carbon nanostructures, etc). One can also get information about the particle interactions, as well structure changes and phase transitions or the dynamics of condensed systems (dense macromolecule and colloid solutions, amorphous materials, etc).

 

Video particle tracking microrheology set-up

Video Particle Tracking Microrheology set-up, including an Olympus BH2 optical microscope, a Hitachi KP-M1A CCD camera, a DVD video recorder and an image analysis software especially developed for this purpose.

The setup performs microscale rheological characterization of macromolecule and colloid solutions, by monitoring the motion of suitably selected colloid nanoparticle tracers. Through tracer motion monitoring, conclusions can be drawn related to the structure, dynamics, interparticle/intermolecular interactions, as well as phase transitions in such systems. Temperature can be controlled by a Linkam TMS 94 hot stage and a Warner Instruments TC-124A objective warmer.

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Dilute solution viscometers

Dilute solution viscometers, by Schott-Gerate.

Used for viscosity determination of fluids and dilute polymer or colloid solutions and includes temperature-controlled bath and glass viscometers.

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Quartz Crystal Microbalance

Quartz Crystal Microbalance (Open-QCM and Open-QCM Q-1).

Includes two measurement devices and data collection / analysis software. The devices allow the study of the adsorption of polymers, biopolymers and proteins and of the formation of mixed layers on the gold-coated quartz crystal (adsorption kinetics, adsorbed mass and film elasticity) by measuring the resonance frequency (Open-QCM) or both the resonance frequency and dissipation (Open-QCM Q-1) of the quartz crystal.

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Surface Plasmon resonance set-up

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Surface Plasmon resonance set-up

The device includes a goniometer with a prism stage, an Obis 640 nm laser and two DET100A2 Thorlabs detectors. There is available software for data acquisition and optimization. The system can be used for the characterization of thin polymer and biopolymer films (adsorbed amount, thickness and adsorption kinetics) on the metal (normally gold)/liquid interface.

 

Liquid contact angle measuring system

Liquid contact angle measuring system

Consists of a test stand platform and a micrometer contact angle measurement camera as well as the necessary software. Used to measure the contact angle of drops of various liquids on surfaces.

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Thermal Analysis

High Resolution Thermogravimetric Analysis System

High Resolution Thermogravimetric Analysis System, by TA Instruments, TGA Q500. Allows the determination of the weight loss of materials during their gradual heating at a constant rate that can vary from 0.5 to 100°C/min and temperatures up to 1000°C under controlled atmosphere (inert, oxygen, air) conditions.

This gives important information on the number of organic units present in hybrid systems, one component of which remains thermally stable at high temperatures. Additionally, the high-resolution capability allows the distinct determination of weight loss and degradation of different units in the studied material, thus complementing the structural characterization of hybrid materials.

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Differential Scanning Calorimetry system with temperature modulation

Differential Scanning Calorimetry system with temperature modulation, by TA Instruments, Modulated DSC Q200. The system comprises a specially designed cell for greater accuracy and sensitivity of the sample temperature and heat capacity. Temperature range -180 to 720 °C.

Useful in the study of phase transitions and the determination of transition temperature characteristics in a wide range of amorphous/crystalline, inorganic/organic and hybrid materials (glass transition temperature and melting/crystallization points), but also the monitoring of processes that take place accompanied by release or absorption of heat in relation to temperature (grid reactions, aging, moisture loss, etc). The possibility of the simultaneous superposition of a secondary sinusoidal temperature modulation on top of the main continuous and controlled gradient at the sample temperature, allows the distinction between reversible and irreversible processes occurring in the sample (through analysis of the thermographs with the use of appropriate software).

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Electrochemical Analysis

Electrochemical Analysis system

Autolab potentiostat/galvanostat (Model PGSTAT128N) capable of measuring maximum 800 mA, with a compliance voltage of 12 V. Equipped with the FRA32M module, it is able to perform both potentiostatic and galvanostatic impedance measurements over a wide frequency range of 10 µHz to 1 MHz. It is also equipped with a dual-mode bipotentiostat module that converts the Autolab potentiostat/galvanostat into a double channel potentiostat (maximum current 50 mA). Potentiostat operates with NOVA electrochemistry software (Metrohm Autolab). Accompanied with a Metrohm Autolab rotating ring disk electrode (RRDE) and rotating disk electrode (RDE) setup (rotation speed 100 – 10,000 rpm). The use of these electrodes type has advantages over the classical static voltammetry methods, as it offers the combined control of diffusion phenomena, as well as the detection of intermediate products, allowing the in-depth investigation of the mechanism and the revealing of the kinetics of the electrochemical reaction under study. This kind of study is useful in the evaluation of new candidate materials as electrochemical catalysts in energy conversion devices (e.g. fuel cells). Remote control with NOVA software. Almost all the techniques of amperometry, chronoamperometry, polarography, and circular / differential / linear voltammetry, electrochemical impedance spectroscopy can be performed with the present equipment. It can be used in the electrochemical characterization of hybrid materials (oxidation and reduction behavior and determination of their energy levels), coatings, batteries, fuel cells, and corrosion phenomena (using numerous direct and reference electrodes made of glass, platinum, calomel, etc. for specialized measurements and analyses).

Multipurpose potentiostat/galvanostat/FRA by Princeton Applied Research, PARSTAT 2273. The analyzer has a wide voltage operation range ±10V (upgradable to the range ±100V) and can handle currents up to 2A (upgradable up to 20A). The current resolution allows the detection of signals of a few fA. The accompanying software allows the acquisition of a series of electrochemical analyses.

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Electronic Spectroscopy

UV-VIS-NIR double-beam spectrophotometer

UV-VIS-NIR double-beam spectrophotometer, by Perkin Elmer, Lambda 19.

Working range: 200-3200 nm.

Accommodates a variety of cells and samples, e.g. long optical path cuvettes (5 cm), continuous flow, thin film, etc. Includes specular reflectance accessory (6°).

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Fluorescence spectrometer

Fluorescence spectrometer, by Jobin Yvon, Fluorolog 3.

Continuous excitation spectrophotometer with dual excitation and single emission monochromators. Comprises accessories for solid and liquid sample measurements under controlled temperature and simultaneous stirring. Measurements with 180° or 90° geometries with respect to the incident beam. Synchronous fluorescence capability.

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Time-resolved Fluorescence Emission / 2D NIR Photoluminescence map capability system

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Time-resolved Fluorescence Emission / 2D NIR Photoluminescence map capability system, by Horiba / Jobin Yvon, NanoLog, equipped with
(a) a Xenon lamp (250-1000 nm) for steady-state fluorescence measurements.
(b) a PMT detector capable of steady-state measurements in the the UV-Vis region (250-850 nm) as well as photoluminescence lifetime measurements. Single-photon counting detector time resolution down to 50ps.
(c) a grating monochromator (2 exits) equipped with a PMT liquid N2 cooled detector for steady state measurements, 2D photoluminescence spectra acquisition and lifetime measurements in the 300-1700 nm range and a CCD InGaAs NIR (liquid N2 cooled) detector allowing for PL mapping in the NIR region.
(d) six excitation laser-diodes for time-resolved photoluminescence measurements with wavelengths of 375, 440, 488, 650, 785 and 1310 nm all capable of pulse widths ≤200ps.

Comes with sample compartment connected to a temperature-controlled bath.

 

 

Raman and Infrared Vibrational Spectroscopy

Dispersive confocal Raman microscope

Dispersive confocal Raman microscope, by Renishaw, InVia Reflex, with 5 laser lines: 457.9, 488.0, 514.5, 632.8, 785 nm.
Stokes working range: (a) 100 - 4000 cm-1 nominal for all laser lines, (b) 15 - 600 cm-1 (for 488.0, 514.5, 632.8 nm using special setup), (c) 5 - 4000 cm-1 for 514.5 nm.
Spatial resolution: better than 1.0 μm with x100 lens and 514.5 nm line.

Spectral resolution: ca. 1.0 cm-1 typical, depending on laser line. Comprises enclosure with metallurgical microscope and xyz motorized stage with 2D mapping and depth profiling capability.

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Fourier-transform (FT) Raman spectrometer

Fourier-transform (FT) Raman spectrometer, by Bruker, RFS 100, with NIR 1064 nm Nd YAG laser line.

Working range: ca. 80 to 3500 cm-1 (Stokes) and -500 to -80 cm-1 (anti-Stokes).
Spectral resolution: variable, 2.0 cm-1 typical.

Suitable in many cases for samples that show intense fluorescence in the visible excitation region.

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Two mid-infrared FTIR spectrometers

Two mid-infrared FTIR spectrometers, by Bruker, Tensor II and Equinox 55S, equipped with various reflectance accessories, including a diffuse reflectance, a 85o grazing angle and several ATR accessories (single and multiple reflection elements, heatable etc.).

Working range 400-6000 cm-1.
Spectral resolution: variable, 2.0 cm-1 typical.

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Mid-infrared microscope by Bruker, Hyperion 2000

Mid-infrared FTIR microscope, by Bruker, Hyperion 2000, coupled to one of the above spectrometers (seen here to the right side of Tensor II on an optical table), equipped with a single element liquid N2 cooledMCT detector, an automated xy mapping stage, mirror lenses for transmittance and specular reflectance measurements, a Ge-ATR objective lens and mapping software.

Spatial resolution: ca. 10 μm.
Spectral resolution: variable, 2.0 cm-1 typical.
Working range 600-5000 cm-1.

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Near-infrared FTIR spectrometer

Near-infrared FTIR spectrometer, by Bruker, Vector 22N, equipped with a diffuse reflectance optical fiber bundle for powder samples, various path-length transmission fibers for liquids and an integrating sphere unit with a rotating cup sample holder. Working range 4000-12000 cm-1.

Ideal for the study of vibrations involving hydrogen, the monitoring of chemisorbed H2O or organics on inorganic anhydrous templates, the real-time monitoring of chemical reactions etc.  Very suitable for (a) industrial high through-put applications, especially if coupled with chemometric algorithms (b) spot measurements on large samples.

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Mid- and far-infrared FTIR vacuum spectrometer

Mid- and far-infrared FTIR vacuum spectrometer, by Bruker, Vertex 80v, equipped with a 11o specular reflectance accessory. Capable for infrared transmittance and reflectance measurements.
Spectral resolution: variable, 2.0 cm-1 typical.
Working range 30-7500 cm-1. Equipped with new (2015) FIR silicon beamsplitter with nominal spectral range 10-900 cm-1.

Ideal for the continuous stitch-less acquisition of the absorption coefficient, refractive index and dielectric permittivity spectra from monolithic polished samples.

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The above are complemented with:
(a) Variable temperature cells (Linkam, liq. N2 to 600oC) with homemade adaptations to fit the mid- or near- infrared, and Raman spectrometers.
(b) Environmental controlled humidity (H2O, D2O) chambers and solid/gas reactors suitable for real-time process monitoring.

 

Dielectric Spectroscopy

Dielectric Impedance Analyzer setup

Dielectric Impedance Analyzer setup, by Hewlett-Packard 4192A, with homemade tube furnace and cell for dielectric measurements.

Frequency range: 5Hz-13MHz.
Temperature range: 100 - 750°C.

Complex impedance spectroscopy is useful e.g. in the study of dynamic properties of ionic glasses. Analysis of dielectric spectra leads to the evaluation of physical quantities related to diffusive properties of ions in the glassy network, including complex conductivity and the modulus function.

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Materials Diagnostics Platforms

Testing platform for electro-chemical metal oxide thin film toxic gas sensors

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Testing platform for electro-chemical metal oxide thin film toxic gas sensors. The setup performs measurements for the optimization of the electrochemical response of thin film micro-sensors in a controlled environment of several toxic gases. This setup complements the already existing thin film preparation equipment for industrial applications and includes: vacuum equipment, 2 flow meters for controlled gas inlet, high vacuum chamber, sample heating surface (up to 400°C) supplied with constant current / temperature controlled with 2 thermo-elements, sensitive ohmmeter for real-time monitoring of the film resistance.

Electric characterization workstation

Electric characterization workstation: Complete van-der-Pauw, Hall effect platform, for measurements of the electrical properties of semiconducting thin films (I-V measurements). Platform comprises a home-made 4-point mount developed at TPCI, an electromagnet, a nano-ampere current source (Keithley 6220) and a sensitive nano-voltmeter (Keithley 2182).

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Solar simulator

Solar simulator (LOT Quantum Design) combined with a Keithley 2400 source meter.
For characterization of solar cells and photoconductivity measurements.

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Phase-Optical Time-domain Reflectometer

Phase-Optical Time-domain Reflectometer
Home-built system includes a laser source (CW diode laser, 1550 nm), fiber optics, acquisition system, and home-built software for data analysis.

This optical fiber-based sensing system can provide information about aging and damage prevention of civil structures such as bridges, dams, tunnels, pipelines, and railroads.

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Second Harmonic Generation (SHG) Maker Fringe setup

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Non-Linear Optical Materials Properties: Second Harmonic Generation (SHG) Maker Fringe setup (home-made). Suitable for characterization of nanostructured bulk and thin film inorganic and hybrid materials.

Setup comprises: a microchip 500 μJ pulse sub-ns laser (1064 nm), polarizers/analyzers and filters for the control of the incident fundamental and scattered SHG radiation (532 nm), PC-controlled sample rotation stage, scattered radiation acquisition system (oscilloscope for diode detector and PMT), appropriate software for data acquisition and treatment.

 

 

 

 

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