Kyushu Synchrotron Light Research Center（ Form: No.5）

Experiment Report for Prefectural Beamline
Proposal no. : 1306071P
Beamline no.: BL11
Report date:

Characterizing structures of binary and ternary polymer opals
using small angle x-ray scattering
Qibin Zhao 1 and Jeremy Baumberg 1
University of Cambridge, UK
Katsuhiko Saito 2 and Qixin Guo 2
Saga University, Japan※１

Long term users of Advanced Research User Proposals are requested to submit thisreport corresponding to each research term (I), (II), or (III), specifying each researchterm at the end of the Report Title.

※2Users of Non-proprietary proposals (Public User Proposal, Advanced Research UserProposal with exception of both Trial Course and Industry-Academia Collaboration
Course, and Frontier Research User Proposal) are also requested to publish their resultsin the form of a refereed journal article or to submit their results in the form of aSAGA-LS Research Report refereed by SAGA-LS within two years from the end of thecurrent fiscal year．

1. Summary

Both single and multi-component polymer opal films processed withdifferent degrees of biaxial bending induced oscillatory shearing (B-BIOS)
and uniaxial bending induced oscillatory shearing (U-BIOS) methods havebeen characterized.
In agreement with our previous results, clear
hexagonal patterns were observed in all the sheared samples with different
degrees of structure order. Asymmetric intensity distribution between (10)and (1-1) spots was also observed, and it varies depending on different
shearing methods and degrees of shearing.
２．Purposeof experiment and background
２．

Polymer opals are novel stretchable 3D photonic crystals comprised of densely
packed core-shell spheres [1-3]. The spheres, with a hard polystyrene core and a low
glass transition soft PEA shell, are pressed into thin films and sheared in solid phasewithout using any liquid solvent. By using small angle x-ray diffraction technique,the goal of the experiment is expected to be in two aspects: the first is to investigate
the arrangement of the nanospheres in binary and ternary polymer opal films aftershear ordering, and the second is to clarify the puzzles from our previous SAXS
experiment on single component polymer opals, including peculiar intensity
distribution along the tubes and large intensity contrast between spots at the same
Q range. The experiment is supposed to be able to provide valuable information onordered as well as disordered structures within the films, which therefore promises a
deeper look on how spheres of either the same
size or different sizes rearrange undershearing force in highly viscoelastic medium.
Compared to most of the top-down methods
which are time costing and expensive,
bottom-up assembly seems to be more
Figure 1. Dark-field spectra of polymer-opal promising and commonly used for fabricating
films show improving order with BIOS low cost industrial applicable 3D photonicprocess.
crystals. However, due to the intrinsic
properties of the method, the existence of disordered structures is always a serious
problem, which is detrimental for the optical performance and the potentialapplications. Shearing technique has been used for improving the order ofself-assemblied colloidal structures, however, for those systems, viscosity of themedium is usually low, and shearing is done in liquid phase. Different from most of
the colloidal systems, our efforts in recent years on making well-ordered polymeric
opaline photonic crystals [4-11] show how shearing works in highly viscoelastic
medium in solid phase. By using shearing force, we have fabricated industrial scale(>100m) flexible photonic crystal films which exhibit strong structural colours
uniformly over large areas. Since optical properties of the film comes from theinterplay of order and disorders of the structure, understanding how the spheres arearranged in bulk is of great importance for both science and applications [3,4,8,11].
However, due to the small size of the spheres (~200nm) as well as the low electron
density contrast between the spheres and the medium, it has been a great challenge
to characterize the structure. The setup of small angle x-ray diffraction in Saga
provides very high resolution and intensity which facilitates the characterization ofstructures in submicron scale, which is a perfect technique for our polymer opal
system.

３．Experimental（Note: Description of sample，method of experiment and analysis,etc.）

The measurements areperformed using the photon
energy of 8.2 keV and aRigaku high resolution
detector. The radius of thebeam stop is just at theedge of an acceptable level
for imaging the reciprocal
space lattices, which gives
us as much information as
we want but at the same
Figure 1. 2D SAXS patterns of polymer opals withdifferent shear ordering methods. (a), before
shearing, (b), biaxial-BIOS
20 passes, (c),biaxial-BIOS 40 passes, (d), uniaxial-BIOS 20passes, (e), uniaxial-BIOS 40 passes, (f), zoom in of
the first ring in (e), spots are analyzed with 2D
Gaussian fit, (g)-(i) amplitude and integratedintensity of (10) spot and (01) spot for different
samples with different shearing methods andnumber of shearing.

time
generateddistortions
overdiffraction patterns.

somethePolymer opal films withdifferent
degrees
ofstructural order as well as
different
ordering
techniques
havebeencharacterized. Clear SAXS

patterns were observed on
both single component andmulti-component polymer opals which are comprised of pure polymeric spheres
embedded in medium of a different polymer with very low electronic density contrast
between them.

４．Results
and Discussions
４．

Figure2. 2D SAXS patterns of binary polymer opal
films ordered with uniaxial 20 passes. (a),, (b),, (c),By fitting the diffraction
patterns
with2D
Gaussian model, detailed
analysis (Fig. 1) has been
done,
which
providesinsight into how spheres
arerearranged
withdifferent
shearing
Figure 3. SAXS patterns of ternary polymer opals.
a&b, R/G/B 1:1:1 ternary opal before and afterordering, c&d, R/G/B 3:2:1 ternary opal before andafter ordering, e&f, R/G/B 1:2:3 ternary opal beforeand after ordering. Beam normal to the (001) plane.

methods. Both B-BIOS
and U-BIOS methods
improved the structuralorder of polymer opals
significantly.
While
integrated intensity of(1-1) spot remains approximately constant, amplitude increases drastically withincreasing amount of shearing which is also accompanied with a rapid drop inFWHM. With same amount of shearing, structure order improves more effectively
with U-BIOS. FWHM in radial direction (narrow axis of the spot) drops much slower
than the hoop direction (long axis of the spot), which indicates orientational orderimproves much fast than positional order. Significant difference between (10) spotand (1-1) spot has been observed, which needs further investigation. Overall orderof the films reaches a saturated level after approximately 40 passes of shearing withboth methods, while structural order improves most effectively in the first tenpasses. BIOS method can also be used in fabricating binary or ternary opal
structures. Fig. 2 & 3 show clear hcp arrangement in binary polymer opals
comprised of spheres with different sizes.

５．Future
issues５．

1. Grazing angle SAXS in order to get structural order information by aligning
the beam parallel to the planes
2. Tilting the samples in different orientations in order to get more informationof the 3D reciprocal lattice strucuture
3. Explore the effect of staining on samples
６．References
６．

[1] O.L.J. Pursianinen, J.J. Baumberg, et al., Opt. Exp. 15, 9553 (2007).
[2] T. Ruhl, P. Spahn, G.P. Hellmann, Polymer 44, 7625 (2003).
[3] O.L.J. Pursianinen, J.J. Baumberg, et al., Advanced Materials 20, 1484 (2008).
[4] A.I. Haines, C.E. Finlayson, et al., Advanced Materials 24, 305 (2012).
[5] J.J. Baumberg, O.L. Pursiainen, et al., Phys. Rev. B 80, 201103(R) (2009)

[6] D.R.E Snoswell, J.J. Baumberg, Textiles 36, 8 (2009)[7] A. Kontogeorgos, J.J. Baumberg, et al, Phys. Rev. Lett. 105, 233909 (2010)[8] M. Kolle, B. Zheng, N. Gibbons, J.J. Baumberg, U, Steiner, Opt. Exp. 18, 4356
(2010)[9] D.R.E. Snoswell, A. Kontogeorgos, J.J. Baumberg, et al., Phys. Rev. E 81,020401(R) (2010)[10] C.E. Finlayson,.. J.J. Baumberg, Adv. Mat. (2011);[11] C.E. Finlayson, …, J.J. Baumberg, Opt. Exp. 19, 3144 .(2011)[12] A.V. Petukhov et al., Journal of Applied Crystallography 39, 137 (2006).
[13] J.H.J. Thijssen, A.V. Petukhov, D.C. ’t Hart et al., Adv. Mater. 18, 1662–1666 (2006).

７．Publications,patents（Note: Typical deliverables related to this proposal．）
７．

The experimental data obtained in this work will be submitted to an international
scientific journal.
８．Keywords（Note:2-3 words about samples and experimental methods．）
８．

Polymer opals, SAXS, Shearing, Order and disorders
９．About
the publication of research results
９．
Please delete either item ① or item ② indicated below, according to a user’s choice of publications as
described in ※2. Also, please fill in an expected date of publication of a refereed journal article or an
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① Publication of a refereed journal article(the date of publication：2015）