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Demonstration of feasibility of X-ray free electron laser studies of dynamics of nanoparticles in entangled polymer melts.

Carnis J, Cha W, Wingert J, Kang J, Jiang Z, Song S, Sikorski M, Robert A, Gutt C, Chen SW, Dai Y, Ma Y, Guo H, Lurio LB, Shpyrko O, Narayanan S, Cui M, Kosif I, Emrick T, Russell TP, Lee HC, Yu CJ, Grübel G, Sinha SK, Kim H - Sci Rep (2014)

Bottom Line: The recent advent of hard x-ray free electron lasers (XFELs) opens new areas of science due to their exceptional brightness, coherence, and time structure.In principle, such sources enable studies of dynamics of condensed matter systems over times ranging from femtoseconds to seconds.Here we demonstrate the feasibility of measuring the relaxation dynamics of gold nanoparticles suspended in polymer melts using X-ray photon correlation spectroscopy (XPCS), while also monitoring eventual X-ray induced damage.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Sogang University, Seoul 121-742, Korea.

ABSTRACT
The recent advent of hard x-ray free electron lasers (XFELs) opens new areas of science due to their exceptional brightness, coherence, and time structure. In principle, such sources enable studies of dynamics of condensed matter systems over times ranging from femtoseconds to seconds. However, the studies of "slow" dynamics in polymeric materials still remain in question due to the characteristics of the XFEL beam and concerns about sample damage. Here we demonstrate the feasibility of measuring the relaxation dynamics of gold nanoparticles suspended in polymer melts using X-ray photon correlation spectroscopy (XPCS), while also monitoring eventual X-ray induced damage. In spite of inherently large pulse-to-pulse intensity and position variations of the XFEL beam, measurements can be realized at slow time scales. The X-ray induced damage and heating are less than initially expected for soft matter materials.

No MeSH data available.


Related in: MedlinePlus

LCLS XCS experimental setup and measured speckle pattern.(a). XCS instrument experimental setup at LCLS. Successive speckle patterns are recorded with a delay Δt between each frame. (b). TEM image of the gold nanoparticles (5.5 nm dia. nanospheres) grafted polystyrene sample (Mw = 42 kg/mol polystyrene matrix). (c). Speckle pattern produced by the fully transverse coherent X-ray beam incident on the sample in (b) in transmission geometry. This pattern was measured at SDD of 5037 mm and at 393 K. The color bar on the right indicates the intensity in the 2D detector converted into photons. The dark blue feature on the left lower part of the image is the beam stop used to mask the direct beam.
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f1: LCLS XCS experimental setup and measured speckle pattern.(a). XCS instrument experimental setup at LCLS. Successive speckle patterns are recorded with a delay Δt between each frame. (b). TEM image of the gold nanoparticles (5.5 nm dia. nanospheres) grafted polystyrene sample (Mw = 42 kg/mol polystyrene matrix). (c). Speckle pattern produced by the fully transverse coherent X-ray beam incident on the sample in (b) in transmission geometry. This pattern was measured at SDD of 5037 mm and at 393 K. The color bar on the right indicates the intensity in the 2D detector converted into photons. The dark blue feature on the left lower part of the image is the beam stop used to mask the direct beam.

Mentions: The experiment was performed at the X-ray Correlation Spectroscopy (XCS) instrument22 at the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory (Menlo Park, USA). The schematic of the XCS instrument is shown in Fig. 1(a). Figure 1(b) shows a TEM image of the gold nanoparticles in the polymer matrix with the typical sizes and concentrations used in this study, confirming that the gold nanoparticles are not aggregated but well dispersed in the polymer matrix. Figure 1(c) presents a speckle pattern at a sample to detector distance (SDD) of 5037 mm from gold nanospheres of 5.5 nm diameter with polystyrene (Mw = 30 kg/mol) attached to the surface in a polystyrene matrix (Mw = 42 kg/mol) at the temperature of 393 K. After reaching the equilibrium temperature, a fresh spot on the sample is illuminated for a total of 150 frames with 100 pulses per frame and then the sample position is shifted to an unexposed area. For each frame, 100 pulses were delivered to the sample. In the high intensity zone, at q ~ 0.0032Å−1, an average of 5.95 photons per pixel was measured, whereas at q ~ 0.024Å−1 it drops to only 0.041 photons per pixel.


Demonstration of feasibility of X-ray free electron laser studies of dynamics of nanoparticles in entangled polymer melts.

Carnis J, Cha W, Wingert J, Kang J, Jiang Z, Song S, Sikorski M, Robert A, Gutt C, Chen SW, Dai Y, Ma Y, Guo H, Lurio LB, Shpyrko O, Narayanan S, Cui M, Kosif I, Emrick T, Russell TP, Lee HC, Yu CJ, Grübel G, Sinha SK, Kim H - Sci Rep (2014)

LCLS XCS experimental setup and measured speckle pattern.(a). XCS instrument experimental setup at LCLS. Successive speckle patterns are recorded with a delay Δt between each frame. (b). TEM image of the gold nanoparticles (5.5 nm dia. nanospheres) grafted polystyrene sample (Mw = 42 kg/mol polystyrene matrix). (c). Speckle pattern produced by the fully transverse coherent X-ray beam incident on the sample in (b) in transmission geometry. This pattern was measured at SDD of 5037 mm and at 393 K. The color bar on the right indicates the intensity in the 2D detector converted into photons. The dark blue feature on the left lower part of the image is the beam stop used to mask the direct beam.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4127496&req=5

f1: LCLS XCS experimental setup and measured speckle pattern.(a). XCS instrument experimental setup at LCLS. Successive speckle patterns are recorded with a delay Δt between each frame. (b). TEM image of the gold nanoparticles (5.5 nm dia. nanospheres) grafted polystyrene sample (Mw = 42 kg/mol polystyrene matrix). (c). Speckle pattern produced by the fully transverse coherent X-ray beam incident on the sample in (b) in transmission geometry. This pattern was measured at SDD of 5037 mm and at 393 K. The color bar on the right indicates the intensity in the 2D detector converted into photons. The dark blue feature on the left lower part of the image is the beam stop used to mask the direct beam.
Mentions: The experiment was performed at the X-ray Correlation Spectroscopy (XCS) instrument22 at the Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory (Menlo Park, USA). The schematic of the XCS instrument is shown in Fig. 1(a). Figure 1(b) shows a TEM image of the gold nanoparticles in the polymer matrix with the typical sizes and concentrations used in this study, confirming that the gold nanoparticles are not aggregated but well dispersed in the polymer matrix. Figure 1(c) presents a speckle pattern at a sample to detector distance (SDD) of 5037 mm from gold nanospheres of 5.5 nm diameter with polystyrene (Mw = 30 kg/mol) attached to the surface in a polystyrene matrix (Mw = 42 kg/mol) at the temperature of 393 K. After reaching the equilibrium temperature, a fresh spot on the sample is illuminated for a total of 150 frames with 100 pulses per frame and then the sample position is shifted to an unexposed area. For each frame, 100 pulses were delivered to the sample. In the high intensity zone, at q ~ 0.0032Å−1, an average of 5.95 photons per pixel was measured, whereas at q ~ 0.024Å−1 it drops to only 0.041 photons per pixel.

Bottom Line: The recent advent of hard x-ray free electron lasers (XFELs) opens new areas of science due to their exceptional brightness, coherence, and time structure.In principle, such sources enable studies of dynamics of condensed matter systems over times ranging from femtoseconds to seconds.Here we demonstrate the feasibility of measuring the relaxation dynamics of gold nanoparticles suspended in polymer melts using X-ray photon correlation spectroscopy (XPCS), while also monitoring eventual X-ray induced damage.

View Article: PubMed Central - PubMed

Affiliation: Department of Physics, Sogang University, Seoul 121-742, Korea.

ABSTRACT
The recent advent of hard x-ray free electron lasers (XFELs) opens new areas of science due to their exceptional brightness, coherence, and time structure. In principle, such sources enable studies of dynamics of condensed matter systems over times ranging from femtoseconds to seconds. However, the studies of "slow" dynamics in polymeric materials still remain in question due to the characteristics of the XFEL beam and concerns about sample damage. Here we demonstrate the feasibility of measuring the relaxation dynamics of gold nanoparticles suspended in polymer melts using X-ray photon correlation spectroscopy (XPCS), while also monitoring eventual X-ray induced damage. In spite of inherently large pulse-to-pulse intensity and position variations of the XFEL beam, measurements can be realized at slow time scales. The X-ray induced damage and heating are less than initially expected for soft matter materials.

No MeSH data available.


Related in: MedlinePlus