Research equipment
Analysis on particle size and shape
Electrozone sensing The Coulter Multisizer II particle size analyzer counts and determines the size (volume) of particles suspended in a conducting liquid, using the electrozone sensing technique. Particle size analysis can be performed in the range 0.8-1200 µm. The instrument reports data as volume percent, population or surface area distribution in cumulative or differential form on linear or log scales.
The Galai CIS-100 analyzer is a system for Particle Size Analysis (PSA) and Dynamic Shape Characterization (DSC) employing laser and video technologies, respectively. The laser measurement for particle size range 0.5-600 µm is based on the TOT - Time of Transition theory; the Galai Video Microscope employs a CCD video camera and a stable synchronous strobe light. Also, fiber lengths up to 6 mm can be measured.
The Coulter N5 dynamic light scattering instrument measures the diffusion coefficient of particles over a range of 0.003 to 3 µm, using photon correlation spectroscopy. Multiple angle analysis is possible. The results can be analyzed in terms of particle hydrodynamic radius (or molecular weight), standard deviation and particle size distribution (Contin analysis).
The TurbiScan MA 2000 and TurbiScan On Line (light source l= 850 nm) instruments measure the scattering of light from sample in two ways: The change in transmissionlight through the sample and the intensity of light scattered at angle 45°with respect to the incident beam (back scattering). Using transmission andback scattering, it is possible to detect the stability of the sample(sedimentation, creaming, flocculation, coalescence and phase separation).It is also possible to calculate a particle size, a density and a volumefraction. TurbiScan allows the analysis of physical destabilization ofconcentrated (up to 50%) and dark dispersions. Analysis it is not limitedby the shape or size of the particles. [top]
Particle potential and charge
Electrophoretic mobility The Coulter Delsa 440 (Doppler Electrophoretic Light Scatter Analyzer) instrument is a laser-based multiple angle particle electrophoresis analyzer. Using Doppler frequency shifts in the dynamic light scattering from particles, the instrument measures the electrophoretic mobility (or zeta potential) distribution together with the hydrodynamic size of particles (size range 10 to 30 µm) in liquid suspensions by photon correlation spectroscopy. The instrument has a 256 channel digital correlator.
Streaming potential There is also Electro Kinetic Analyzers for zeta potential determinations of fibers, foils, powders, etc.
Potentiometric and conductometric titration The laboratory has an autotitrator (Metrohm 751 6PD Titrino) using the dynamic-end-point method. The system is controlled and the data is processed with T:Net 2.4 software.
Polyelectrolyte titration There is also equipment for polyelectrolyte titration of surface charge and dissolved macromolecules using spectrophoto-metric determination of the end point or Mütek PCD 03 in the laboratory. [top]
Surface tension, contact angle and work of adhesion
Ring and Wilhelmy plate methods The Sigma 70 is a computer-controlled automatic surface tension meter, equipped with a dispenser for fully automatic addition of liquid to the measuring vessel. In the ring method, the maximum force acting on a platinum-iridium ring pulled from a surface or interface is measured. In the Wilhelmy plate method, the force acting on a platinum plate suspended through the surface is measured. These forces are proportional to the surface tension. The velocity of pulling the ring or plate from the liquid can be varied within a wide range and the time dependence of surface tension can be conveniently monitored. Also, the contact angle between a plate pulled from the liquid and the liquid can be measured.
Single fibers The other Sigma 70 is equipped with a video camera and it is used for measuring contact angles of individual pulp fibers. The wetting force acting on the partially immersed fiber is measured, from which contact angles are directly computed.
Contact angle meter. CAM 200 is a video camera based and fully computer controlled contact angle meter for the measurement of static or dynamic (advancing&receiding) contact angles, surface free energies, absorption and surface tension (pendant&sessile drop) of liquids. Determination of contact angle and surface tension is based on Young and Laplace equation.
The micro adhesion measurement apparatus (MAMA) enables the determination of main adhesion parameters (i.e. work of adhesion, pull-off force and surface energy) between two surfaces. In a typical measurement, a transparent elastic lens is brought into contact with surface and the contact area is recorded as a function of the applied load. Fitting the data to the JKR-theory of contact mechanics provides the main adhesion parameters of the system. [top]
Flotation
The effect of different pigments and the deinking chemicals on foam stability and flotation recovery can be investigated with the modified Bikerman type foam column.
The laboratory also has a flotation machine (Outokumpu model ORC) with flotation cells of 4, 8 and 16 liters. In this cell the air is mixed to the pulp suspension through the rotot-stator system.
The Voith flotation laboratory cell (E 18V) for recycling research is installed in the department's machinery hall. The E cell made of plexiglass is a reduced version of the mill scale flotation cell. Air is blended with the stock suspension in the injector. The volume of the cell is 18 liters and it is equipped with an 80-liter feed tank. [top]
Viscosity
Ostwald viscometry. Viscosity by the Uppelohde method (flow-through times in a capillary tube of well-defined dimensions) can be measured with computer-controlled capillary viscometry (AVS 350). The liquid meniscus is detected optoelectronically and the measurements can be repeated automatically. [top]
Chromatography
Gas chromatography. The laboratory has three instruments for quantitative and qualitative gas chromatography: Shimadzu GC-14A, 17A and HP 5890. All three are equipped with flame ionization detectors. The Shimadzu 17A and HP 5890 instruments have automated sample injectors. Millennium 2010 Chromatography Manager is used to control the HP 5890 and Class-VP software the Shimadzu instruments.
Column chromatography. Columns for analytical and preparative gel filtration and anion exchange chromatography of mono-, oligo- and polysaccharides and lignin have been installed. UV or refractometric detection can be used and fractions can be collected automatically.
Mass Spectrometry. A quadrupole GC/MS instrument, Fisons MD 800, was installed in early 1996. The instrument is controlled with MassLab software which contains a library of 62,000 mass spectra. [top]
Spectrometry
FT-IR spectrometer. Bio-Rad FTS 6000 research grade FT-IR spectrometer contains rapid-scan and step-scan operation capabilities. The spectrometer is equipped with ATR bench and photoacoustic cell (MTEC300). Win-IR Pro software is used for data collection and processing. The software includes the integrated step-scan DSP technique, which is used in data collection and processing in photoacoustic depth profiling studies.
The spectrometer is connected to UMA-500 microscope equipped with MCT detector, a CCD video camera (Sony) and germanium micro-ATR crystal. The microscope connection enables micro-IR analyses and computer controlled IR mapping. The microscope operation and data handling is controlled with Shadow Pro software.
Nicolet Arcter 370 was installed in 2003. The spectral range of the instrument is 7800-375 cm-1 and it is using proprietary K Br beam splitter. Omnic software is used for data collection and processing.
Raman spectrometer. The dispersive Kaiser Raman Hololab series 5000 spectrometer is equipped with 785 nm laser. The spectrometer can be connected to the additional non-microscopic probehead with 1.5 and 20m optical cables. The long, 20m optical cable enables the in situ measurements even in industrial environment. The system is also equipped with Olympus microscope which makes possible micro-Raman analyses, Raman mapping and confocal Raman measurements. The system is controlled with Holograms software and data processing is made with GRAMS32 software.
UV Resonance Raman spectrometer. The Raman spectrometer is Renishaw 1000 UV equipped with microscope of 15X and 40X objectives. The laser is Innovaâ 300C FreDTM frequency doubled Ar+ Ion Laser (Coherent, Inc., California), which is operated at three different wavelengths (229, 244 and 257 nm). CCD camera is used for detecting the scattered light. The system is controlled and the data is processed with Grams32 software.
WITec alpha 300 combined confocal Raman microscope and atomic force microscope. The confocal Raman is equipped with frequency doubled Nd:YAG green laser (?=532.25 nm, 30 mW) and a sensitive EMCCD camera detector (Andor Newton DU970-BV). Objectives for measuring in both air (100X , 20X and 10X) and liquid (60X and 10X) are available. AFM has all the basic modes for imaging (contact, AC, phase detection, lateral force, …) and in addition pulsed force mode. The instrument has a computer controlled scan table and is placed on active vibration insulation system (TS-150). It is possible to do Raman spectral mapping and AFM imaging either simultaneously or sequentially.
The method is mainly used for analysing residual lignin structures from pulp samples. The Raman signals of aromatic and conjugated lignin structures are enhanced by resonance effect with the UV excitation, whereas other wood components are not enhanced. Therefore, lignin characterization is possible even from fully bleached pulps. Measurements last only about 30 seconds per sample. Additionally, the measurements are accomplished directly from laboratory hand sheets and pretreatment of samples is not needed.
The laboratory has also routine instruments for UV spectroscopy.
ESCA spectrometer for surface analysis (also called XPS). AXIS 165 by Kratos Analytical, equipped with a 12 crystal monochromator and an effective neutralization system provides high resolution information on the topmost 10 nanometers of surfaces.
ESCA/XPS is widely used in applied materials research, because of it's versatility. Samples may be solid, fibrous or as powder; they may also be conducting, insulating or mixed (heterogeneus); main restrictions apply on specimen size and vacuum compatibility. Depending on the experiment, ESCA yields elemental or chemical information, but it can also be used in evaluation of elemental surface distributions within the first 10..20 nm.
Strong expertise on ESCA, 11 years of experiments at HUT (yielding internal database with over 5000 samples) and a lab-specified in-situ reference (to be measured with each sample batch) add up to the reliability and reproducibility on experiments performed at The HUT Forest Products Chemistry ESCA Laboratory. [top]
Scanning probe microscopy
The NanoScope MultiMode scanning probe microscope (SPM) consists of the MultiMode SPM, NanoScope IIIa control system and NanoScope image analysis and presentation software (version 4.43r8 for Windows NT). The system includes the Extender TM Electronics Module making phase imaging possible in addition to the other available modes (contact AFM, TappingMode AFM, force modulation, and lateral force microscopy). The apparatus is equipped with tip holders for measurements in both air and liquid and a 125 µm as well as a 12 µm scanner. The system includes a 45X monocular microscope and an optical microscope with zoom, binocular, black & white camera and monitor, making accurate positioning on the sample easy. [top]
Reflectometer
Reflectometer is an optical instrument where the properties of a laser beam reflected from surface are utilised in studies of adsorption. Any attachement of materials on a surface changes the polarisation of a linearly polarised laser beam reflected from the surface. This change in polarisation can be analysed optically and recorded on-line with a computer. The collector surface is placed in measurement chamber where adsobate solution is continually fed to the collector such that stagnation point flow forms. The laser beam is reflected at the stagnation point which allows adsorption studies in well-controlled hydrodynamic conditions. Typically, the reflectometer is used in studies of adsorption kinetics for polymers, proteins, colloids, and nanoparticles. For polymers, and other soluble macromolecules, the adsorption data can also be quntitatively interpreted in terms of adsorbed amount. [top]
QCM-D (quartz crystal microbalance)
A QCM-D and QCM-D E4 instruments ( Q-Sense AB ) consist of a piezo-electric quartz crystal which is made to resonate by connecting it to an oscillator. The working principle of QCM-D is that the frequency of the resonator changes as the mass of the resonator changes. In water the resonating crystal is efficiently damped when disconnected from the oscillator. Since the adsorbed layer is coupled to the motion of the crystal, the viscoelastic properties of the adsorbed layer have a strong impact on dissipation of energy after the disconnection. In general a QCM-D instrument can be in studies of adsorption kinetics, viscoelastic properties of the adsorped layers, and interactions of the adsorbed layers. [top]
Preparation of model surfaces
Miniature Langmuir-Blodgett The Mini Trough 2 (KSV Instruments Ltd) is a PC controlled Langmuir - Blodgett instrument, which enables the study and production of thin and hihgly organised mono and multilayers on solid substrates.
WS400B-6NPP-Lite Spin Processor (Laurell Technologies). The device is aimed for spin coating thin films from dissolved (or colloidal) substances on chosen substrates such as silicon or gold. The solvent is evaporated with the aid of high speed spinning, resulting in a relatively uniform thin film. The rotation speed can be varied between 100-10,000 rounds per minute (rpm). An option for programming different speeds with various spinning times prevails. There are altogether 20 memory slots for specific programs. [top]
Drainage and Retention
The Dynamic Drainage Analyzer (DDA) with four dosage units measures drainage, but can simultaneously give retention, wet sheet permeability and the sheet dry solids content of paper pulp, under the conditions simulating paper making. In addition, it can be used to solve drainage problems in other systems. [top]
Flow analysis
Alpkem Flow analyzer. The analyzer is equipped with a large capacity (300 positions) random access sampler, a 16-channel peristaltic pump, a valve module for flow injection analysis, a cartridge heater, cartridges for built-in and custom made tests (e.g. TOC and total carbohydrates), a monochromator detector (190-800 nm) and a data station. The analyzer can also be used as a selective post-column detector in gel permeation and anion exchange chromatography. [top]
Chemical synthesis
A büchi stirred laboratory autoclave bep 280. Büchi autoclave is designed for small-scale chemical and physical or pilot experiments at high pressures (max. 6 bar) and temperatures (max. 473 K). This autoclave consists of a 1.6 dm3 glass vessel equipped with a bmd 300 magnetic drive (max. 2400 rpm). Pressflow gas controller (büchi bpc 9901) is also connected with the system. [top]
Control coating
The K 202 Control Coater is used to produce samples for surface coating studies. The instrument is equipped with a rubber vacuum bed and maximum coating area is 300x250 mm. Close wound bars produce coating thicknesses from 4 to 120 µm. Higher coatings weights up to 500 µm can be obtained using spirally wound bars. Standard coating speeds are variable between 2 and 15m/min. [top]