Developing scanning force microscopy

The success of STM has resulted in the development of a whole variety of related scanning probe microscopes, the most important of which is atomic force microscopy, AFM, also known as scanning force microscopy. AFM was first reported in 1986 by Binnig, Quate and Gerber. 

This review article describes progress made in scanning force microscopy of polymers during the last 5 years including fundamental principles of SFM and recent developments in instrumentation relevant to polymer systems. It focuses on the analytical capabilities of SFM techniques in areas of research where they give the most unique and valuable information not accessible by other methods. These include (i) quantitative characterisation of material properties and structure manipulation on the nanometer scale, and (ii) visualisation and probing of single macromolecules. 

For many reasons, the tapping mode is one of the most versatile developments in scanning force microscopy [ 114]. It was originally introduced for stable imaging at ambient conditions as the probe penetrates the contamination layer rapidly and intermittently. Besides that, there are three other key advantages of... 

Beekmans LGM (2002) Morphology development in semi-crystalline polymers by in-situ scanning force microscopy. PhD Thesis, University of Twente... 

Methods for directly observing supermolecules have recently been developed. Scanning probe microscopy (SPM) has become a particularly useful method in the field of nanotechnology. The general concept of SPM is summarized in Fig. 5.3. A very fine tip is used in this method. As the tip approaches the sample surface, various interactions occur between the tip and the surface which result in various kinds of forces (such as atomic forces). These forces are felt by the tip and converted into electrical signals. 

Some contributions cover the development of specific materials and analytical methods to measure the characteristic properties of solid particles, such as particle sizes, surfaces areas, mechanical strengths, or solid-matrix interactions. Thus, papers from M. Heinematm and S. Hild deal with the characterization of silica-polymer interactions using Scanning Force Microscopy, while C. Panz uses the combination of special basic silica, fitting silanes, and adequate hydrophobization conditions to generate high-performance silica with new properties. 

Progress in the field of chemical and biological sciences is continually impacted by the development of novel methods of structural analysis. Sheiko and Moller review a field that started to develop only in the past several years, i.e., visualization of biological and synthetic macromolecules including individual macromolecules and their motion on surfaces with the aid of scanning force microscopy (SFM). Brown and Spiess analyze the most recent advances in solid-state NMR methods for the elucidation of the struc-... 

In general, the STM s ability to obtain atom images is clearly outstanding. Unfortunately, there are some limitations, particularly the requirements that both the tip and sample surface are good conductors. This severely limits the materials that can be studied and has led to the development of scanning force microscopy (atomic force microscopy) which is described in Section 5.3. 

To characterize the adhesion properties of the HUVEC, we used scanning force microscopy (SFM). In this study, we developed a method to determine the specific interactions of human endothehal cells (ECs) with various adhesion molecules using SFM. The ECs were grown at the edge of a tipless cantilever. 

The terms SFM (scanning force microscopy) and AFM (atomic force microscopy) are used synonymously the former term is used less frequently. In the initial stages of development, the latter term was exclusively used for setups providing atomic (or better) resolution. 

Monte Carlo simulations (Lai and Binder 1992). Figure 6.11 shows scanning force microscopy images of an end-grafted layer of a water-soluble polymer, dextran, which in water appears as a uniform layer, but, after the addition of a poor solvent, propanol, develops lateral structure (Frazier et al. 1997). As the grafting density is increased yet further the homogeneous, layer structure is expected once again to become stable. 

Cherian et al. [87] extracted cellulose nanofibres from the pseudo stem of the banana plant by using acid treatment coupled with high pressure defibrillation. Characterization of the fibres by (Scanning Force Microscopy) SFM and TEM showed that there is reduction in the size of banana fibres to the nanometre range (below 40 nm). The average length and diameter of the developed nanofibrils were found to be between 200-250 nm and 4-5 nm, respectively. Figures 1.22a, b and 1.23 show the SFM and TEM pictures of banana nanofibres, respectively. 

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