Atomic force microscopy, supramolecular

Keywords. Antibodies, Biosensors, Non-covalent bond. Atomic force microscopy, Supramolecular chemistry... 

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... 

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. 

H. Schonherr, V. Paraschiv, S. Zapotoczny, M. Crego-Calama, P. Timmerman, C.W. Frank, G.J. Vancso, D.N. Reinhouldt, Unraveling the Nanostructime of Supramolecular Assemblies of Hydrogen-Bonded Rosettes on Graphite An Atomic Force Microscopy Study , Proc. Natl. Acad. Sci., USA, 99,5024 (2002)... 

T. Shimizu, S. Ohnishi, M. Kogiso, Cross-Section Molecular Imaging of Supramolecular Microtubes with Contact Atomic Force Microscopy , Angew. Chem. Int. Ed., 37, 3260 (1998)... 

Li, T., Morris, K.R. Park, K. (2000) Influence of solvent and crystalline supramolecular structure on the formation of etching patterns on acetaminophen single crystals a study with atomic force microscopy and computer simulation, J. Phys. Chertu B, 104, 2019-2032. 

In conclusion, it should be pointed out that none of the physicochemical techniques discussed above permits the direct measurement of the elements of the polymeric materials porous structure we measure the properties of the systems where the polymers interact with certain test substances (nitrogen, mercury, water, polystyrene standards, ions, etc.), and not the dimensions of the pores or other supramolecular elements of the material. Therefore, the evaluation of the surface area and diameters of pores available to the molecules of these substances must be considered as indirect methods of examining the porous structure. Because of this, all calculations are based on assuming certain models of the structure of the material and accepting certain assumptions as to the mechanism of interaction between the material and test molecules. Only transmittance, scanning, and, in particular, atomic force microscopy can be considered as direct methods of measuring dimensions and distances. However, up to now the last technique has not been appHed to microporous hypercrosslinked polymers. 

Micic, M., Radotic, K., Jeremic, M., Djikanovic, D., and Kammer, S. B. 2004. Study of the lignin model compound supramolecular structure by combination of near-held scanning optical microscopy and atomic force microscopy. Colloids SurfB Biointerfaces 34, 33-40. 

Atomic Force Microscopy (AFM) has been used to characterize the differing supramolecular structures of A -alkyl-D-gluconamide adsorbates and N- n-alkyl)-A -D-maltosylsemicarbazone adsorbates (on silica, graphite). An analysis of a P-CD fibre-optic chemical sensor (pyrene binding) has been discussed. ... 

Shimizu, T. Ohnishi. S. Kogiso. M. Cross-section molecular imaging of supramolecular nticrotubes with contact atomic force microscopy. Angew. Chem.. Int. Ed. 1998. 37 (23). 3260-5262. 

Fig. 2 Atomic force microscopy (AFM) friction images and schematic illustrations of the patterning processes of a microcontact printed SAMs (mercaptoethanol dots in oc-tadecanethiol matrix, scale bar 10 xm) b patterned molecular printboards fabricated by supramolecular dip-pen nanolithography (DPN) (reprinted with permission from [92] Copyright 2004. WUey VCH) e locally hydrolyzed tert-butyl acrylate-terminated polymer film on oxidized silicon (soft lithography scale bar 3 xm) (Feng CL, Vancso GJ, SchOn-herr H, manuscript submitted to Langmuir) d photopatterned bilayer of diacetylene lipid (scale bar 10 xm). Reprinted in part with permission from [93], copyright (1999), American Chemical Society...

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