Figure 1

(Color online) (a) Setup: hydraulic pistons (diameter 10 mm) force core-shell particles through rectangular cavity $\left(10\times 10\times 1.5\text{mm}\right)$ formed between quartz windows $\left(w\right)$ within a temperature-controlled jacket. Light source $\left(s\right)$ is focused onto the inside face of the window at $15°$ incidence, and backscattered light collected via a beamsplitter (BS) to a spectrometer. Pressure is measured either side of the cavity (PT). Inset: 10 cm diameter polymer opal film. (b) Time-resolved spectra (left $\lambda$ scale, white is strong scattering) with piston motion superimposed (red, right axis). (c) Spectra from cuts P and Q in (b). Inset: Dark-field microscope image of cross section of compression-sheared polymer opal, crystalline top layer thickness $t=50\mu \text{m}$ appears colored.Reuse & Permissions

Figure 2

(Color online) (a) Flow-induced spectral changes with sinusoidal piston motion (i) extracted as: (ii) scattering peak width, (iii) peak wavelength, and (iv) peak height. Two data sets (black, green) taken from the same run one time period apart confirm reproducibility. Four characteristic particle reordering regimes are labeled A-D and depicted in (b), with red particles crystallized and black particles in disordered sheet flow. Layer separation is $D_{111}$, thickness of crystal layer is $t$, black arrows in B signify shear and compression, and the white arrow in C shows relative movement of adjacent planes.Reuse & Permissions

Figure 3

(Color online) Simulated optical reflectivity of 1D photonic crystals of $\Delta n=0.1$ with average layer thickness 200 nm incorporating (a) increasing disorder, $\overline{\delta }=0,5,10,15\text{nm}$, for 80 double layers, and (b) increasing numbers of layers for $\overline{\delta }=15\text{nm}$ (Lorentzian fits included). Spectra are averages of 100 separate configuration simulations. Insets summarize changes in line width (squares) and peak reflectivity (circles).Reuse & Permissions

Figure 4

(Color online) (a) Shear stress (circles) and scattering peak height (squares) vs time after piston turnaround. Crystal-growth region shaded (region B). (b) Crystal growth rate $\dot{S}=d/dt$ (peak height) versus rate of applied shear stress $\dot{\sigma }$ and maximum shear rate in region B for different sinusoidal piston motions. (c) Rheology obtained with torsionally oscillating parallel disks (25 mm diameter) at $150°$ showing, storage $G^{\prime }$ and loss $G^{″}$ modulus for strain sweep at $\omega =10\text{rad}{\text{s}}^{-1}$.Reuse & Permissions