FIGURE 3.

Compression isotherms for mixed monolayers of DGPP and POPA on subphases at different pHs: (A) Lateral pressure (solid lines, left scale) and ΔV⋅A (dashed line, right scale) as a function of the mean molecular area for monolayers composed of DGPP/POPA (1:1) on subphases at pH 5. (B) Lateral pressure as a function of the mean molecular area for monolayers composed pure DGPP and POPA (dashed lines) or mixtures of DGPP/POPA in a proportion (1:3) (black line) and (3:1) (gray line). (C) Representative images of mixed films at the indicated proportions and pressures obtained with FM on subphases at pH 5 with Zn²⁺. Real size: 100 μm × 100 μm. (D) Lateral pressure (solid lines, left scale) and ΔV⋅A (dashed line, right scale) as a function of the mean molecular area for monolayers composed of DGPP/POPA (1:1) on subphases at pH 8. Subphase composition: 0.15 M NaCl + 5 mM EDTA, pH 8 (black lines) and 0.15 M NaCl, 5 mM EDTA + 8 mM ZnCl₂, pH 8 (gray line).