Atomic force microscopy parameters

The thickness of the ordered crystalline regions, termed crystallite or lamellar thickness (Lc), is an important parameter for correlations with thermodynamic and physical properties. Lc and the distribution of lamellar thicknesses can be determined by different experimental methods, including thin-section TEM mentioned earlier, atomic force microscopy, small-angle X-ray scattering and analysis of the LAM in Raman spectroscopy. 

Comparison of two analytical approaches, atomic force microscopy (AFM) and quartz crystal microbalance, for studying the binding of Con A to glycosylated carboxypeptidase, demonstrated that both could determine the quantitative parameters characterizing the interaction.65 Quantitative analyses of the interaction of Calreticulin (CRT), which is a soluble molecular chaperone of the endoplasmic reticulum, with various... 

The morphology of this supramolecular diblock copolymer library has been investigated by means of atomic force microscopy (AFM) measurements. As illustrated in Fig. 21, at first glance different morphologies were obtained for different compositions. However, interpreting the phase behavior of supramolecular block copolymers is not straightforward. There are several important parameters that play a role in the phase behavior. For instance, the amorphous phase of PEG, the crystalline phase of PEG, the metal complex, and the amorphous PSt contribute to... 

By now, the possibility of deposition of granulated Cu, Ni, Pd, Pt, and Au films by laser electrodispersion has been experimentally verified. The structural parameters of the films being formed were studied by various diagnostic techniques, with the most informative results obtained with TEM, atomic-force microscopy (AFM), and X-ray photoelectron spectroscopy (XPS). 

F. J. Giessibl, H. Bielefeldt, S. Hembacher and J. Mannhart, Calculation of the optimal operating parameters in non-contact atomic force microscopy, Appl. Surf. Sci. 140, 352 (1999). 

In the author s opinion, the better approach to experimentally study the morphology of the silica surface is with the help of physical adsorption (see Chapter 6). Then, with the obtained, adsorption data, some well-defined parameters can be calculated, such as surface area, pore volume, and pore size distribution. This line of attack (see Chapter 4) should be complemented with a study of the morphology of these materials by scanning electron microscopy (SEM), transmission electron microscopy (TEM), scanning probe microscopy (SPM), or atomic force microscopy (AFM), and the characterization of their molecular and supramolecular structure by Fourier transform infrared (FTIR) spectrometry, nuclear magnetic resonance (NMR) spectrometry, thermal methods, and possibly with other methodologies. 

The method applied to measure the depth of the ablated area or the removed mass can also have an influence on the ablation parameters. If profilometric measurements (optical interferometry, mechanical stylus [34], or atomic force microscopy [35]) are used to calculate the ablation rate, a sharp ablation threshold can be defined. This is also supported by reflectivity [36] and acoustic measurements [37], In mass loss measurements, such as mass spectrometry or with a quartz crystal microbalance (QCM), the so-called Arrhenius tail [38] has been observed for certain conditions. The Arrhenius tail describes a region in the very low fluence range, where a linear increase of detected ablation products is observed, which is followed by a much faster increase, that coincides with removal rates of the profilometric measurements [39]. 

The efficiency of AFM depends on several parameters pertaining to apparatus. Essential prerequisites for a good z-resolution include the flexibility of the cantilever and a sensitive detection of its movement. An accurate positioning and the sharpness of the microscopic tip, on the other hand, are substantial contributions to the x,y-resolution. Upon optimal adjustment of all parameters, the method is able to provide pictures with atomic resolution. The size and the shape of the microscopic tip constitute the limiting factor to the resolution of small objects, and especially of narrow, deep slits. Normally, tips made of silicon are used in atomic force microscopy. They are pyramidal in shape and exhibit a diameter of ca. 10 nm on their apex. These tips are unsuitable to examining deep grooves and, due to their brittleness, their mechanical resistance leaves much to be desired (Figure 3.106). Moreover, the resolution decreases when the tip breaks. Carbon... 

In this study, we reported the preparation of mesoporous Ti02 materials via the sol-gel method involving a co-assembly of titanium (IV) isopropoxide and mainly neutral soluble starch CTMACl is used only for comparative reason. Ethanol and cyclohexane were used as solvents. The effect of key parameters, including surfactant removal process either by washing and/or by calcination and the solvent nature are discussed. Ti02 samples were characterized by means of N2 adsorption-desorption experiments, X-ray Diffraction analysis, UV-vis spectrophotometer. Scanning Electron Microscopy and Atomic Force Microscopy. 

In practice, tack experiments, translation tribometry, and atomic force microscopy (AFM) are used to quantify adhesion and friction at the macro- and nanoscales. In order to record dissipation phenomena, the influence of structural parameters (degree of crosshnking and presence of free chains) and experimental factors (friction speed, normal force) is analyzed. 

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