Images of individual polymer chains

According to tube theory, the cod of a polymer molecule can be stretched into a long chain. This has been recently confirmed by Chu and co-workers (1997, 1999) with three slightly different experimental techniques. 

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In addition to the changes mentioned above, we have updated several chapters in the previous edition. In Chapter 5, for example, we added a section to describe the images of individual polymer chains undergoing changes in steady shear. This is related to laser technology. 

Uniaxially oriented isotactic polypropylene (iPP) was imaged using afm, showing microfibrils and macromolecules. Fibrils with an average diameter of 150 nm were observed. Individual polymer chains with 1.17 nm chain-chain distance were seen. The authors propose that the (110) crystal plane was being resolved with this work (90). Other workers, who were able to clearly resolve right-and left-handed helices (Fig. 13) with pendant methyl groups visible, accomplished atomic scale resolution of iPP (91). 

Further examples of imaging of individual macromolecules using SFM comprise dendrimers (122-125) and physisorbed or chemisorbed polymer chains (126,127). Owing to the softness of the macromolecules, as well as to tip... 

Beside planar surfaces, Patten et al. [310-312] and Hallensleben et al. [313, 314, 322] prepared weU-defined nanocomposites by ATRSIP of from silica and gold nanoparticles. After spin-coating a solution of the polymer decorated particles onto mica, Hallensleben was able to image the single particles with the individual grafted polymer chains (Pig. 9.33). 

The particular combinations of like and mirror image units within a polymer chain influence the polymer properties on a molecular level. On the bulk level, the average individual chain structure influences properties. 

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