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Advanced Polymers Participating Research Team
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AP-PRT is a facility dedicated to study x-ray scattering and diffraction of polymers at Beamline X27C at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL).
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3-pinhole collimation system for simultaneous SAXS/WAXD experiment
| collimation |
The x-ray optics at X27C is simple but suitable for SAXS studies. A double-multilayer (silicon/tungsten) monochromator is used to monochromatize the incident beam from the bending magnet. This double monochromator, which was provided by the NSLS, has been demonstrated to increase the x-ray flux by approximately 10 times when compared with the conventional double-crystal monochromator, and is uniquely suitable for studies related to polymeric materials in which very high energy resolution is not essential (DE/E is about 1 %). A typical level of x-ray flux under the testing conditions was about 9x1011 photon/s. Although the wavelength is adjustable from 0.7-2.0 Å (energy 6-20 KeV) with this monochromator, we have optimized the flux and the SAXS angular resolution by fixing the wavelength at 1.3 Å. The critical element of X27C is its collimation system, which directly determines the maximum spatial resolution (ca. 100 nm). A three-pinhole collimation system was constructed for this purpose. |
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In-situ Instruments and Sample Holders
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Single cell heating stage
The Instec HCS600v heating stage was used as the heating stage in our laboratory. The heater core is square 22.5x22.5mm with four, symmetrically spaced at 19mm, screw holes(2,5mm). The space between surface of the heater and the lid enclosure is approx 6mm (probably could be increased up to 6.5-7mm).
http://www.instec.com/pdf/brochures/HCP601-602-brochure.pdf
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| Dual-cell |
dual-cell temperature jump apparatus
dual-chamber temperature-jump unit was designed and constructed in our laboratory. The samples were initially equilibrated at one temperature (such as above the melting point, T1) and were quickly jumped to a different temperature (T2) for measurements using a pneumatic piston. The typical cooling rate during the jump was about 300 °C/min during the initial 95% of the temperature drop, which was similar to the fastest cooling rate used in DSC. The total time for the sample to reach the measurement temperature was 10-60 s, depending on the sample mass (several grams) and the thermal conditions. For a faster cooling rate experiment, one can consider the use of less sample mass, better thermal insulation, or even the use of stop flow.
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| Tensile |
Tensile stretching apparatus
The tensile stretching apparatus is a modified version of a model 4410 tabletop unit from Instron Inc., which is portable and has a load capacity of 500 Newtons. The maximal distance between the two grips is about 460 mm. Sample can be heated to a temperature up to 300oC with a custom-designed sample chamber. The stretching speed can be adjusted from 0.2 mm/min up to 1000mm/min. The modified stretching unit offers the mode of symmetric stretching, which guarantees that the focused x-ray could illuminate the same position on the fiber (or film) during fiber (or film) deformation.
* This apparatus belongs to the group at SUNYSB, please contact in advance about using the apparatus for your experiment.
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| shear |
X-ray parallel-plate shear stage
The Linkam Cambridge Shearing System (CSS) 450 is a high temperature parallel-plate shearing stage, often used to examine viscous liquid materials in in-situ optical microscopy. The sample is placed in a gap between two parallel quartz disks. Shearing takes place by rotating one of the disks using a precision stepping motor, as the other disk remains fixed. The gap between the windows is adjustable, ranging from 10 to 2500 microns, using a second stepper motor. Each of the two quartz windows is in close thermal contact with a silver block heater that controls the sample temperature. The sample temperature can range from ambient conditions to 300 °C. This apparatus has been modified for x-ray experiments by the PI based on a similar design to that first published by Burghardt et al.. The modification, which included the use of diamond and Kapton windows, is as follows. The top plate has a narrow aperture hole (diameter = 3 mm), which allows the x-ray beam (diameter = 0.9 mm) to enter the sample. The bottom plate has three open slots (wider than the hole in the top window) that allow the scattered x-ray beam to pass directly through the sheared sample. The windows fit together in such a way that the sample is sealed. When polymer melts are sued, as they are fairly viscous that no leakage is detected even when the Linkam stage is mounted in the vertical position (necessary since the x-ray beam travels horizontally). The mechanical design and electronics of the Linkam stage provide a precise control of various parameters of the shear experiment, which usually include temperature, heating/cooling rates, sample thickness, shear rate, shear strain (shear duration), as well as shear mode - step, steady, and oscillatory. The shearing stage is compact and can be easily set up for in-situ x-ray scattering/diffraction experiments in X27C. The x-ray modification of this shear stage was supported by a prior NSF grant of the PI to investigate the subject of flow-induced crystallization.
* This apparatus belongs to the group at SUNYSB, please contact in advance about using the apparatus for your experiment.
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| Rhrometer |
Modified Constant Stress Rheometer for In-Situ Rheo-SAXS and Rheo-WAXD Measurements
A constant stress rheometer (Anton-Paar, Model MCR 301) was modified for simultaneous measurements of rheological responses and in-situ structure information of complex fluids, such as homo- and co-polymers, polymer solutions, blends and nanocomposites, etc., by synchrotron small-angle X-ray scattering (SAXS) or wide-angle X-ray diffraction (WAXD) techniques. The modified rheometer allows the incident X-ray beam to be aligned parallel or perpendicular to the flow direction in a cone-and-plate geometry and thus provides the scattering/diffraction information along the gradient-vorticity or flow-gradient plane, respectively, during deformation. The modification included the design and construction of a high temperature oven enclosure with Kapton windows for incident beam and scattering/diffraction signal passages. The enclosure allows the detection of complete SAXS view but only about half of WAXD view with a maximum diffraction angle about 30o. The performance of the X-ray modified rheometer has been checked by experiments including shear-induced orientation and crystallization in crystalline and nanocomposite polymers. (This instrument was supported by a grant from the National Science Foundation: IMR-0415345)
* This apparatus belongs to the group at SUNYSB, please contact in advance about using the apparatus for your experiment.
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| Xiaowei, can you put one of your pic here? Sorry I do not have a good one now. |
Fiber melt/gel spinning apparatus
This fiber spinning apparatus was originally designed and built by scientists at Dow Chemical Company to study the gel spinning of PBO and was further modified by us at Stony Brook. The apparatus is portable and can be transported between different locations quite easily. The photograph of this apparatus is shown, which has recently been used in an in-situ gel spinning study of PBO at the X27C Beam line of the NSLS, BNL as well as in a melting spinning study of iPP and nanocomposites at the ChemMat-CARS beamline (15 ID) beamline in Advance Photon Source (APS), Argonne National Laboratory (ANL). The experimental design of this apparatus is as follows. A capillary rheometer like barrel is located on the top platform of this apparatus, which stores polymer gels or melts with a temperature capability of 300 oC. A motor driven plunger is used to extrude the polymer solution. Several spinneret dies are available for making monofilament, multi-filament and film at high temperatures (to 250 oC). The top platform can be moved vertically over a distance of about 10 cm with a 0.2 mm precision. The apparatus is mounted on a pair of precision optical rails perpendicular to the x-ray beam, which permits the alignment of the extruded filament or film for x-ray detection. A special corrosion-resistant barrel has been constructed to extend the solvent application range (such as sulfuric acid for PPD-T spinning). A take-up wheel with an adjustable speed is used to change the draw ratio. The modification of this instrument was supported by a DoD-ARO grant to the Co-PI.
* This apparatus belongs to the group at SUNYSB, please contact in advance about using the apparatus for your experiment.
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| Detection System
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| Data Acquisition and Analysis Software
PC based data acquisition software for EMBL detectors. Custom codes (SASDAP, WASDAP) and commercial packages (Grams32, Spyglass SigmPlot, Polar, TINA2.1, Image GauageV4.0 and), on the PC and the SGI workstation for preliminary analysis
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