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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

Evolution of the relaxation time as a function the wave vector transfer.(a). τ(q) obtained from the images with 1, 2, 10, 30, and 100 pulses per frame measured successively for a total 150 frames. (b). τ at q = 0.0123 Å−1 as a function of the the age at 393 K for the same data set in (a). (c). Plot of τ(q) with 100 pulses per frame but at different ages. Position on the sample was changed after each measurement. In (a), the τ(q)s get slower even with increasing number of pulses per frame, as emphasized in (b) for a particular q. In c, the waiting time between the measurements was longer than in (a) to see more clearly the effect of aging. The data for 232 min. was collected at higher q and the error bars are larger than other sets due to lower scattering intensity at high q.
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f4: Evolution of the relaxation time as a function the wave vector transfer.(a). τ(q) obtained from the images with 1, 2, 10, 30, and 100 pulses per frame measured successively for a total 150 frames. (b). τ at q = 0.0123 Å−1 as a function of the the age at 393 K for the same data set in (a). (c). Plot of τ(q) with 100 pulses per frame but at different ages. Position on the sample was changed after each measurement. In (a), the τ(q)s get slower even with increasing number of pulses per frame, as emphasized in (b) for a particular q. In c, the waiting time between the measurements was longer than in (a) to see more clearly the effect of aging. The data for 232 min. was collected at higher q and the error bars are larger than other sets due to lower scattering intensity at high q.

Mentions: Figure 4 shows the evolution of τ (q) for the same sample as in Figs. 2 and 3. For all measurements the SDD was 5037 mm except for the one at 1888 minutes with an SDD = 685 mm. In Fig. 4(a), τ(q)s are calculated from the images taken with 1, 2, 10, 30, and 100 pulses per frame successively, for a total of 150 frames, i.e., every 15 to 30 minutes to assess sample damage with a different number of pulses. The sample position was changed after each sequence of 150 frames. In order to see the clear behavior ofτ as a function of the time after the sample reached the temperature of 393 K, τ for a single q = 0.0123 Å−1 is plotted in Fig. 4(b) for the same data set as in (a). There is clearly a trend of slowing down as a function of the number of pulses in the series. It is also obvious that an equilibrium is reached. One has however to keep in mind that each series for a given number of shots per frame, was taken sequentially, thus resulting in measuring the dynamics in the sample at a different age. The observed behavior is more compatible with a “standard aging” behavior than sample heating. For sample heating, one would expect the relaxation time to decrease (i.e. the dynamics to get faster) when more X-rays impinge the sample. Also the aging rate is compatible with what has been observed (cf. Figure 4c), where the typical relaxation time strongly varies over the first 120 minutes and then slows down dramatically for the next 300 minutes).


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)

Evolution of the relaxation time as a function the wave vector transfer.(a). τ(q) obtained from the images with 1, 2, 10, 30, and 100 pulses per frame measured successively for a total 150 frames. (b). τ at q = 0.0123 Å−1 as a function of the the age at 393 K for the same data set in (a). (c). Plot of τ(q) with 100 pulses per frame but at different ages. Position on the sample was changed after each measurement. In (a), the τ(q)s get slower even with increasing number of pulses per frame, as emphasized in (b) for a particular q. In c, the waiting time between the measurements was longer than in (a) to see more clearly the effect of aging. The data for 232 min. was collected at higher q and the error bars are larger than other sets due to lower scattering intensity at high q.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: Evolution of the relaxation time as a function the wave vector transfer.(a). τ(q) obtained from the images with 1, 2, 10, 30, and 100 pulses per frame measured successively for a total 150 frames. (b). τ at q = 0.0123 Å−1 as a function of the the age at 393 K for the same data set in (a). (c). Plot of τ(q) with 100 pulses per frame but at different ages. Position on the sample was changed after each measurement. In (a), the τ(q)s get slower even with increasing number of pulses per frame, as emphasized in (b) for a particular q. In c, the waiting time between the measurements was longer than in (a) to see more clearly the effect of aging. The data for 232 min. was collected at higher q and the error bars are larger than other sets due to lower scattering intensity at high q.
Mentions: Figure 4 shows the evolution of τ (q) for the same sample as in Figs. 2 and 3. For all measurements the SDD was 5037 mm except for the one at 1888 minutes with an SDD = 685 mm. In Fig. 4(a), τ(q)s are calculated from the images taken with 1, 2, 10, 30, and 100 pulses per frame successively, for a total of 150 frames, i.e., every 15 to 30 minutes to assess sample damage with a different number of pulses. The sample position was changed after each sequence of 150 frames. In order to see the clear behavior ofτ as a function of the time after the sample reached the temperature of 393 K, τ for a single q = 0.0123 Å−1 is plotted in Fig. 4(b) for the same data set as in (a). There is clearly a trend of slowing down as a function of the number of pulses in the series. It is also obvious that an equilibrium is reached. One has however to keep in mind that each series for a given number of shots per frame, was taken sequentially, thus resulting in measuring the dynamics in the sample at a different age. The observed behavior is more compatible with a “standard aging” behavior than sample heating. For sample heating, one would expect the relaxation time to decrease (i.e. the dynamics to get faster) when more X-rays impinge the sample. Also the aging rate is compatible with what has been observed (cf. Figure 4c), where the typical relaxation time strongly varies over the first 120 minutes and then slows down dramatically for the next 300 minutes).

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