Figure 1

(a) The phase diagram of the PS/8CB mixture (temperature versus the weight fraction of the liquid crystal 8CB). $I$ stands for the isotropic, $N$ for the nematic, and Sm for the smectic matrices. For example, $\mathrm{S}\mathrm{m}+I$ denotes the two phase region where the smectic 8CB-rich phase coexists with the isotropic polymer PS-rich phase. In order to observe the growth of the polymer-rich domains in the ordered (nematic or smectic) matrix we use the following temperature sequence: quench (0.5 or 1 h) to the ordered phase from the one-phase region $\to$ jump to the isotropic phase (1 min) $\to$ quench back. The samples were annealed at $T=60°\mathrm{C}$ and the jump was made to $T=41°\mathrm{C}$ either from the nematic, i.e., from $T=39°\mathrm{C}$, or from the smectic phase from $T=32°\mathrm{C}$. Most of the measurements were performed for $70\%/30\%$ of 8CB/PS. (b) The scattering intensity $S(q,t)$ versus the scattering wave vector for two different times, showing the effect of the multiple scattering of light during the growth process for the $h=120\mu \mathrm{m}$ sample size. The bottom flat curves are the scattering data taken directly in the smectic phase ($T=32°\mathrm{C}$), and the curves with a large peak are the data taken after the jump to the isotropic phase. $S(q,t)$ in the smectic phase is completely isotropic (flat curve) due to the multiple scattering. The peak in $S(q,t)$ coming from the weak contrast between PS/8CB domains is much higher than the scattering in the smectic phase, but in the $\mathrm{S}\mathrm{m}+I$ region this peak is hidden under a multiple scattering background. Only the change of contrast obtained by the temperature jump (see text for explanation) revealed the structure of the polymer domains in the system. Two arrows indicate the peak positions. One at small wave vectors originates from the wetting layers at surfaces and one at large $q$ is the bulk peak. The one at small wave vectors is responsible for the fast mode hydrodynamic growth regime. The triangles show the results of the one-point run; i.e., the domains grew in the smectic phase for 8 hours without a quench-jump monitoring of this growth, and only after 8 hours did we heat up the smectic to the isotropic phase and perform the measurements.Reuse & Permissions

Figure 2

(a) The change of the location of the maximum of the scattering intensity, $q_{\mathrm{m}\mathrm{a}\mathrm{x}}$, as a function of time, $t$, obtained by the method described in Fig. 1 for the $\mathrm{S}\mathrm{m}+I$ region for three different thicknesses of the sample. In the inset, the crossover to the hydrodynamic growth regime is shown for $h=10\mu \mathrm{m}$. (b) The scaling function $Y(q/q_{\mathrm{m}\mathrm{a}\mathrm{x}})=q_{\mathrm{m}\mathrm{a}\mathrm{x}}^{3}S(q,t)$ for $h=50\mu \mathrm{m}$ is shown (the same quality of the scaling function is obtained for all $h$). The scaling is obeyed, for all $h$, only for the first growth regime, i.e., diffusion controlled with the exponent $\alpha =0.28\pm 0.02$, but not in the hydrodynamic regime with the exponent $0.9\pm 0.2$.Reuse & Permissions

Figure 3

The change of the location of the maximum of the scattering intensity, $q_{\mathrm{m}\mathrm{a}\mathrm{x}}$, as a function of time $t$ for the $I+I$ region (see Fig. 1). In the inset the crossover to the fast-mode hydrodynamic regime is shown for $h=10\mu \mathrm{m}$; the same growth exponent within experimental accuracy is obtained in this regime for $h=120\mu \mathrm{m}$.Reuse & Permissions

Figure 4

The same legend as in Fig. 2 for the $N+I$ region of the phase diagram. Here the growth exponent $\alpha$ depends on the film thickness. The scaling is obeyed only in the first growth regime irrespective of the thickness of the sample.Reuse & Permissions