Figure 4.

(a) Polymer volume fraction Φ_p of PS-PVP films (indicated as SV) with a dry thickness of ~40 nm upon stepwise increase of p/p₀ of chloroform at indicated temperature sets T_v/T_s. Φ_p is calculated from the measurements of the dry and the swollen film thicknesses as h_dry/h_sw. (b) Degree of swelling D of 40 nm thick PS-PVP films annealed at 100 sccm flow of 100% p/p₀ of chloroform after 5 min and after 200 min of processing under T_s = 20 °C and T_v = 14 or 19 °C, as indicated. Scanning force microscopy (SFM) height images of the surface morphology in PS-PVP films after 5 min (c,e), 45 min (d), and after 200 min (f) of annealing at indicated temperatures. The scan area is 3 × 3 µm².