Figure 4.

Experimental SFA setup and visualization of surface damage. (a) In this schematic, (1) coacervate was injected between two mica surfaces, (2) then coalesced, settled on, and coated the mica surfaces, before (3) the surface approach, for (4) normal and (5) shear measurements (see Materials and Methods, section 5.5). Representative (b) FECO and (c) Newton rings used to determine surface damage. Uninterrupted (i) FECO and (iv) Newton rings at the start of the experiment indicated a pristine surface, (ii) distorted fringes indicated the onset of wear, and (iii) FECO and (v) Newton ring interruptions indicated severe wear.