- Strain controlled rheometry
- Stress controlled rheometry
- High shear rheometry
- Elongational rheometry
- Interfacial rheometry
- Rheo-optical methods
- Compounding and sample preparation
The strain controlled rheometers available in the lab of Soft Matter, Rheology and Technology are equipped for melts, solutions, suspensions, biological materials, etc. A wide range of measurement geometries and sample environments are present.
The ARES-LS device, equipped with a 100g FRT, is dedicated to low viscous/elastic materials. A Peltier plate is used to control the temperature.
Using a new FRT for torques and normal forces, the ARES-G2 device is able to accurately measure the flow behavior over a very wide range of sample viscosities from low viscous solutions to highly viscous/elastic polymers. The device is equipped with a fluids bath and an Advanced Peltier System (APS) for accurate temperature control.
The stress controlled rheometers available in the lab of Soft Matter, Rheology and Technology are equipped for melts, solutions, suspensions, biological materials, etc. A wide range of measurement geometries and sample environments are present.
Our two Physica MCR501 devices are equipped with a fluids bath, Peltier, and oven to measure solutions, biological materials, polymers, etc. Multiple accessories for controled environments are available.
The counterrotating cell combines a MCR and DSR device to create a stagnation plane during flow to facilitate optical observations. The microscope can be positioned to observe in the velocity gradient as well as in the vorticity direction using parallel plates or a couette cell.
MCR 702 twin drive
The mcr702 twin drive rheometer with optical setup is used to combine rheological properties of fluids and optical observations in the stagnation plane during flow. Both glass parallel plates and a glass couette cel are available. Two devices with different optical setup are available.
The AR-G2 is a controlled stress rheometer with a magnetic-levitation thrust bearing and a drag cup motor to allow nanotorque control. The device is suitable for testing of melts, fluids and interfaces.
The Discovery HR-3 (DHR-3) is a new, advanced single head controlled stress rheometer, that combines a patented magnetic bearing, drag cup motor, and force rebalance transducer (FRT), to allow excellent torque and normal force control. The device is equipped with interfacial setups (see further).
The AR2000, equipped with electrically heated plates is suited to test viscous fluids, melts, reactive materials and solids in an inert atmosphere.
The high shear rate rheometrical equipment allows to study both polymeric materials and dispersions over a wide range of shear rates. A wide range of capillaries, slit dies and transducers is available.
The Rheograph plunger driven capillary rheometer can measure pressures up to 2000 bars and shear rates ranging from 10 s-1 to 105 s-1 can be applied.
The elongational rheometrical equipment allows to study elongational properties of both polymeric materials on rotational devices and low viscous solutions using capillary breakup techniques.
With the CaBER instrument, stringiness, filament breakup-times and extensional viscosities can be quantified to quickly optimize your fluid formulations for either industrial or research applications. Other qualitative information that can be obtained from these data are time-to-breakup and from the shape of the curve the ‘stringiness’ of the fluid. The temperature can be controlled using a standard fluids bath.
Fixtures for rotational devices
The Extensional Viscosity Fixture (EVF) for the ARES devices is a fiber wind-up technique to measure the uniaxial extensional properties of high viscous polymers. Hencky strains up to 4 and strain rates up to 10 s-1 are possible in a convection oven controlled atmosphere. A fiber wind-up fixture for an RMS800 device is also available.
The interfacial equipment allows to study shear and dilatational properties of viscoelastic interfaces. Typical measurements include examination of phase transitions, prediction of emulsion and foam stability, monitoring surface gelation, etc.
The AR-G2 and DHR-3 rheometers can be combined with a Du Noüy ring or a Double Wall Ring (DWR) geometry to measure the steady-state and transient interfacial properties of liquid-liquid or liquid-air interfaces. The DWR can be used with a Langmuir trough for compression or expansion.
Langmuir and Langmuir-Blodgett troughs
Langmuir(-Blodgett) troughs are available to characterize monolayers at air-liquid and liquid-liquid interfaces. Surface pressure-area isotherms are measured with a Wilhelmy balance. Monolayers can be deposited on substrates with a dipper.
A piezo pump can be used (frequency range) to perform oscillating drop tests on a KSV CAM200 contact angle and interfacial tension device to measure interfacial dilatational properties of liquid-liquid or liquid-air interfaces using drop shape analysis.
A special interfacial rheology setup with a bicone geometry is available to measure the interfacial viscosity of liquid-liquid or liquid-air interfaces.
As nano- and microstructured materials exhibit a variable, often flow-induced microstructure, rheological measurements need to be supplemented with optical or other special techniques to probe structure directly. This can be done directly on rheological equipment or using specially designed flow cells.
A high resolution polarization modulation setup enables to follow fast changes in the microstructure. Both the linear conservative dichroism and the flow berifringence can be measured. This setup can be combined with a Linkam CSS450 parallel plate flow cell (high temperatures), a MCR300 constant stress rheometer equipped with a couette cell (fluid bath temperature control) or parallel plates (Peltier temperature control), or a four roll mill setup.
Microscopy & Conoscopy
Several microscopes (bright field, fluorescence,etc.) can be mounted on some of the rotational rheometers. Several flow geometries (Linkam shear cell, eccentric device, counterrotating device, four roll mill, microfluidics, etc.) are available to monitor the structure development in complex flows.
Several cameras (High speed Fastcam, Pulnix, hamamatsu CCD, basler, etc.) and image processing routines (IDL) are available.
A Small Angle Light Scattering setup using CCD cameras, sometimes with a frame grabber and special flow cells (Linkam or MCR300) is available for melts and solutions. In-house developed software is available to analyze the scattering patterns.
A Visitech VT-Eye and a VT-Hawk confocal microscopy setup is available. The VT-Hawk is a multi-beam confocal setup equipped with an ultra-fast camera to achieve sample rates up to 1000 images per second. The VT-Eye is a scanning confocal setup that allows for its kind ultra-fast real-time confocal and multi-wavelength imaging.
The 3D-LS spectrometer used for particle characterization based on static light scattering (SLS) and dynamic light scattering (DLS) incorporates the 3D correlation technology to eliminate multiple scattering contributions. Hence, samples can be measured in their native state without dilution.
Compounding and sample preparation for a broad range of material classes (polymers, particles, dispersions, solutions,etc.) and for several applications and accurate measurements on rheological equipment is available in the lab of Soft Matter, Rheology and Technology.
A variety of extruders of different scales (Werner and Pfleiderer double screw extruder, Collin single screw extruders, DSM mini extruder, Thermo Scientific Process 11,...) is available in the lab to process polymers. Various additives can be introduced at different places in the extruder.
A precision semi-automatic mechanical stretcher that can process up to 28 films simultaneously is available. This way tens of grams of polymeric ellipsoids with aspect ratios from 1 to 10 and sizes from 100nm to 10mm can be prepared. The interplay of particle shape and interactions can be studied in phase behavior and rheology, entailing opportunities for materials engineering.
A Collin plate press can be used to prepare disks or bars ( two-dimensional shapes) under controlled temperature and pressure. Specific moulds are available in the lab to create samples of varying thickness, suited for rheological characterisation on the rotational devices.
A preparation lab is available with most of the standard equipment for synthesis and preparation of soft matter and complex fluids. The lab is for example equiped with ultrasonic baths and probes, ultraturrax mixers, 3 roll mill, vacuum ovens, heating plates and magnetic stirrers, analytical balances, rotavapor, pH and conductivity meter, ...
A Beckman Coulter Avanti J-30I centrifuge is available for efficient centrifugation up to 30000 rpm. Both a swinging bucket rotor (38 ml tubes with max. g-force of 100 000 x g) and a fixed angle rotor (100 ml tubes with max g-force of 48 000 x g) are available.
In addition, a small lab centrifuge up to 5500 rpm is available as well.
The electrospinning devices use electrical forces to produce fibers with nanometer scale diameters and high surface to volume ratios from different materials such as polymers, composites and ceramics.2 electrospinning devices of which one is temperature and humidity controlled, are available.