Friction force imaging

Fig. 18—Friction force images of L-B monolayer film, normal force 1 nN (scan range 2 /u.m). (a) Monolayer L-B film, (b) four-layer L-B films.

Fig. 21 —Friction force and topography images of the L-B films of Cgo-Pst hyperbranched polymer under load 2 nN using AFM/FFM, image (a) and (b) are friction force images and image (c) is the topography.

Figure 24 is a diagram of friction versus load derived from the friction force images of the above hgures. Figure 25 is also a diagram of friction versus load done in the same monolayer L-B him of C Q-Pst polymer but in a different scan range. 

Finally, Nie and co-workers reported an increase in surface energy of mechanically scratched structures on biaxially oriented PP based on adhesion mapping and friction force imaging data using a conventional Si3N4 (244). 

Fig. 15 Friction force image recorded on a patterned - CH3 /- COOH monolayer sample with (a) a CH3-terminated tip and (b) a - COOH-terminated tip in ethanol. The friction forces, which increase from dark to bright contrast, show a contrast reversal. (Adapted/reprinted with permission from [17]. Copyright 1994 AAAS)...

Fig.19 Friction force images (1.5 xm x 1.5 xm) obtained by means of CFM (a) with a - CH3 tip and (b) with a - COOH tip. Since the friction coefficients determined with a - CHstip are nearly the same on PS as PVP, the lamellar structure is not visible in (a). With a - COOH tip the friction coefficient is higher for the PVP part of the copolymer, which reveals the morphology as the alternating bright (high friction, PVP) and dark (low friction, PS) areas. (Reprinted with permission from [167]. Copyright 1998 Wiley-VCH)...

A Nanoscope IIIA AFM (Digital Instruments) operating in contact mode was used to obtain topographic and friction force images. The same type of AFM was used to obtain IC AFM measurements. AFM data were acquired imder... 

Fmther support for the role of hydrophobic interactions in the area-selective adsorption was obtained by reversing the dipping sequence. A single bilayer was adsorbed on a methyl- and hydroxyl-terminated stripe pattern (10 and 5 pm, respectively), in one case starting with the polycation, in the other case with first adsorbing the polyanion. Both substrates were subsequently analyzed by AFM in contact mode. The friction force images (Fig. 8) clearly show a reversal in contrast for both experiments, compared with the template without the polymers, indicating that in both cases one bUayer had been deposited selectively on the methyl-terminated areas. 

Figure 9. Friction force image (left, z-scale dark 0.0 V - bright 0.5 V) and adhesion force image (right, z-scale bright 1 nN - dark 60 nN) on PE lamellar crystal obtained in water. The contrast in the adhesion images is defined on the basis of the convention that attractive forces are negative.

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