Fig. 5. (a) Micrograph showing the instability broadening and highlighting the resulting angular aperture (Θ). The jet is manually contrasted for better clarity. Scale bar = 2 mm. (b–d) Θ values vs. needle-collector distance (b), applied voltage (c) and polymer solution concentration (d). Other parameters are PVP concentration = 20 mg mL–1 (b and c), d = 16 cm (c and d), V = 9 kV (b and d).
