Atomic force microscopy paper

Fig.l Evolution of the number of papers with atomic force microscopy and DNA as keywords (analysis using ISl database [8])... 

This paper contributes to the literature by quantifying anionic polymer adsorption onto the clay minerals kaolinite, feldspar, mica and quartz by X-ray photoelectron spectroscopy (XPS). XPS measures the sorbed amount directly rather than by a subtraction technique. This enables an insight into how effective selective flocculation is for obtaining kaolinite from a mineral mixture. Atomic force microscopy (AFM) is also used to image polymer adsorption onto mineral surfaces and the effectiveness of this technique applied to mineral surfaces is discussed here. 

There was, however, one topic which was not included in the first edition, which has undergone substantial development in the intervening years. It could have been foreseen in 1986 a paper was presented at the IEEE Ultrasonics Symposium entitled Ultrasonic pin scanning microscope a new approach to ultrasonic microscopy (Zieniuk and Latuszek 1986,1987). With the advent of atomic force microscopy, it proved possible to combine the nanometre-scale spatial resolution of scanning probe microscopy with the sensitivity to mechanical properties of acoustic microscopy. The technique became known as ultrasonic force microscopy, and has been joined by cognate techniques such as atomic force acoustic microscopy, scanning local-acceleration microscopy, and heterodyne force microscopy. 

Theoretical models based on first principles, such as Langmuir s adsorption model, help us understand what is happening at the catalyst surface. However, there is (still) no substitute for empirical evidence, and most of the papers published on heterogeneous catalysis include a characterization of surfaces and surface-bound species. Chemists are faced with a plethora of characterization methods, from micrometer-scale particle size measurement, all the way to angstrom-scale atomic force microscopy [77]. Some methods require UHV conditions and room temperature, while others work at 200 bar and 750 °C. Some methods use real industrial catalysts, while others require very clean single-crystal model catalysts. In this book, I will focus on four main areas classic surface characterization methods, temperature-programmed techniques, spectroscopy and microscopy, and analysis of macroscopic properties. For more details on the specific methods see the references in each section, as well as the books by Niemantsverdriet [78] and Thomas [79]. 

Atomic force microscopy [6, 7] is one of the most suitable methods for research carbon nanotubes. AFM allows to receive not only a relief of the studied sample, but also distribution of mechanical characteristics, electric, magnetic and other properties on its surface. With the help of AFM, controllable manipulation of individual CNTs and CNTs bundles became possible. In this paper we report our approach to manipulating SWCNTs bundles with lateral force microscopy. LFM gives possibility to study lateral forces that probe acts upon bundles. In spite of good visualization of LFM, its lack is absence of reliable techniques of quantitative interpretation of results. The new way of calibration developed ourselves has allowed to pass from qualitative estimations to quantitative investigations [8], The given calibration technique is much more exact, than others known till now [9, 10], and does not assume simplification. With the help of new technique we may study adhesion of bundles to substrate and adhesion of CNTs in bundle qualitatively in real time more easy way. This result will provide new possibilities for nanotube application. 

There have been a number of other papers on the hydration of biopolymers the effects of the degree of methylation of pectins on the proton relaxation times of water have been measured 50 l70 relaxation has been used to examine the hydration of bovine and caprine casein,51--54 and solid-state NMR combined with atomic force microscopy has been used to examine the influence of water on the nanomechanical behaviour of cutin.55 The effects of locust bean gum on water diffusion in sugar solutions has shown little effect,56 and the effects of gellan gum hydrogel structure on restricted diffusion has also been considered.57... 

Atomic force microscopy has emerged as one of the premier techniques for studying the reactivities of environmental particles. This paper addresses some of the most important considerations involved in AFM applications to environmental particles, and presents several state-of-the-art examples of such applications. 

Figure 7.37. Spreading of ethylene glycol on three coated paper grades (art, silk and matt) with the same surface chemical composition. Each curve represents three different measurements at three different positions on the papers, and is perfectly reproducible. The rms roughness values of the samples depends on the scale length and the waveband analysed, but for all scales measured by atomic force microscopy and white-light profilometry increase in the order art < silk < matt (see also Figures 7.44 and 7.45 below)...

Spectroscopy (IR), Raman Spectroscopy, X-ray Photoelectron Spectroscopy (XPS) or Electron Spectroscopy for Chemical Analysis (ESCA), and Secondary Ion Mass Spectrometry (SIMS). More recently. Atomic Force Microscopy (AFM) has also found important use in the characterization of the local surface distribution of paper. Below, we will briefly discuss the use of some different surface-sensitive techniques in paper applications and relate the results obtained to paper characteristics and end-use properties. For a more detailed description of these and other available techniques for characterizing the chemistry of paper surfaces, readers are referred to ref. (60). 

The -potential measurement is advantageously used as one of fast and easy methods for characterization of various material surfaces. We used this for characterization of polymer surface and their variable modifications mentioned above, -potential measurements is always in our papers supplemented with other analyses characterized surface properties, as X-ray photoelectron spectroscopy (XPS) [12,17], goniometry (contact angle) [12-18,26,28], with atomic force microscopy (AFM) determination [12,14,17,27,28] or with other measurements [14,17,28]. In this chapter we presented selected and interesting results for pristine polymers and their surface modified by variable ways. 

T. Ushdd, Scanning near-field optical/atomic force microscopy in biology, Presented at the 5th Asia-Pacific Conference on Near-Field Optics. Optical Society of Japan, Niigata, Japan, Paper 2-1, 15-17 November 2005... 

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