Tapping mode AFM

The total force that governs the motion of the tip is given by the balance 

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Fig. 6. Van der Waals potential energy-distance curve showing regions of operation of contact, noncontact, and intermittent contact or tapping-mode afm...

Fig. 26 Tapping-mode AFM images of fibrils on mica left) and corresponding height profiles (across the white lines in the AFM images) right), (a) PEG-[(AG)3EG]io-PEG, (b) PEG-[(AG)3EG]2o-PEG. (c) Proposed (3-sheet fibril packing. Reproduced with permission from Smeenk et al. [69]. Copyright Wiley-VCH...

Fig. 36 Tapping mode AFM images of L4K8L4-VPRGS-PEG (a) before and (b) after thrombin digestion (at pH 9). Fibres in (b) have diameters of about 5-6 nm. Adapted by permission of The Royal Society of Chemistry from Koga et al. [79]...

Figure 5.16 Tapping-mode AFM image of a 25 Cu nanodot array on H-terminated p-Si(l 0 0), formed by nanoindentation. (Reproduced with permission from Ref. [72].)...

Tapered module design, 15 835 Tapholes, blast furnace, 14 505-507, 509 Taphonomy, 5 752 Tapioca/cassava starch, 4 724t Tapping mode, in atomic force microscopy, 77 63 Tapping-mode AFM, 24 84 Tapping mode atomic force microscopy (TMAFM), 14 465, 16 501 Taq polymerase, 72 513 Taquidil... 

Figure 12.3 Tapping mode AFM images of G4 PAMAM dendrimers on mica surface at different concentrations, (a) 0.1% w/w (b) 0.01% w/w (provided by Jing Li, D. A. Tomalia) [18]...

Spin-coating films of other compositionally different dendritic macromolecules such as carbosilane dendrimers and hyperbranched poly(styrene) were studied by Sheiko et al. [20-22] using tapping mode AFM. 

Figure 12.11 Tapping Mode AFM image of G9 PAMAM dendrimer molecules on mica surface. Sample prepared by placing 6 jA of a dilute aqueous solution, cone. 5x 10-3% (w/w) G9 on a freshly cleaved mica surface and allowing the film to dry slowly at room temperature (provided by Jing Li and D. A. Tomalia)...

Figure 12.21 Tapping mode AFM images of tecto-(dendrimer) molecules. (Sample preparation one drop of a 1 x 10 5wt% solution was spread on a freshly cleaved mica surface by spin coating, and then dried at room temperature)...

In comparing the diffusion behavior of these two membranes at low MeOH concentrations, MeOH in BPSH 40 membranes exhibits significantly higher diffusion coefficients than those in Nafion 117. This may be the result of differences in morphology. Tapping mode AFM measurements found that, for dry membranes, the domains for BPSH 40 appeared to be 10-25 nm in diameter for Nafion 117, the domains were smaller, approximately 4-10 nm. Although one would expect restricted diffusion in both cases, it is possible that the smaller domains limit diffusion to a greater extent. 

Tapping Mode AFM measures contours by tapping the surface with an oscillating probe tip thereby minimizing shear forces that may damage soft surfaces. This allows increased surface resolution. This is currently the most widely employed AFM mode. 

Fig, 19, Differences between noncontact and tapping mode AFM, The signal for the former is dependent on the change in oscillation due to the force gradient, while the latter is dependent on the oscillation change due to the contact, (Courtesy of Digital Instruments, Veeco... 

Providing a flat surface can be achieved, tapping mode AFM topological and phase imaging can be used to investigate HPAM adsorption and mineral surfaces. Information on the film height, the strength of interaction between polymer-mineral surface and an indication of the adsorption process may be obtained. HPAM adsorption on kaolinite was observed to form a flat uniform layer... 

FIGURE 4.8. Schematic representation of the tetrarosette assembly. (A) Unfiltered high resolution tapping mode AFM phase image of the nanorod domain stmcture (inset) fast Fourier transform. (B) Fourier filtered section of raw data shown in A and unit cell of the lattice stmcture. (Reproduced with permission from Proc. Natl. Acad. Sci. USA 2002, 99, 5024-5027. Copyright 2002 National Academy of Sciences, U.S.A.). 

Fig. 13 SPR and AFM analyses of controlled streptavidin recognition on mixed oligo(ethylene glycol) layers, (a) Chemical structure of the mixed layer components linear oligo(ethylene glycol) left) and biotinylated moiety (right), (b) Streptavidin binding at 23°C and (c) at 45°C. (d) SPR sensogram of streptavidin adsorption at 23 and 45°C. Arrows show injections of (a) water (b) streptavidin solution and (c) subsequent water rinse at 23°C and (d) streptavidin solution and subsequent water rinse at 45°C. (e) Tapping mode AFM images in liquid phase after injection of streptavidin solution at 23°C and (f) at 45°C. Reprinted, with permission, from [185]. Copyright (2008) American Chemical Society...

Fig. 18 Typical tapping-mode AFM images of 34 in the presence of L-Ala (a) and D-Ala (b) on mica. (Reprinted with permission from [91]. Copyright 2004 Wiley)...

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