Polymer induced forces

A similar elevation of the melting point occurs for a polymer that has its normal melting point already above room temperature. An example would be a fibrous material such as one of the Nylons. Stretching such a polymer can induce additional crystallization (and better orient the crystallites), but the crystallization is not lost on removal of the stretching force. This is also illustrated in Figure 2.41. 

Wu D, Lenhardt JM, Black AL, Akhremitohev BB, Craig SL (2010) Molecular stress relief through a force-induced irreversible extension in polymer contoiff length. J Am Chem Soc 132 15936... 

Paturej J, Milchev A, Rostiashvili VG, Vilgis TA (2011) Polymer chain scission at constant tension - an example of force-induced collective behaviour. Europhys Lett 94 48003... 

Beiermann BA, Kramer SLB, May PA, Moore JS, White SR, Sottos NR (2013) The effect of polymer chain alignment and relaxation on force-induced chemical reactions in an elastraner. Adv Funct Mater 24 1529-1537... 

This chapter aims to describe the mechanical bias of cavitational effects and how they are related to conventional mechanochemistry and force-induced physical fields in general. This subject has been well documented over the last decade [5-9], and particular attention has been paid to scenarios such as mechanically responsive polymers [10-12], micro- and nano-structured materials [13-15] and... 

Individual polymer chains are stretched either by interactiOTi with non-polymeric environment (e.g., solvent flows, see chapters Mechanochemistry of Topologically Complex Polymer Systems , Force induced ReactiOTis and Catalysis in Polymers , and The Interplay of Mechanochemistry and Sonochemistiy ) or because they are bound directly to translating macroscopic objects, such as in single-molecule force spectroscopy (see chapter Supramolecular Chemistry and Mechanochemistry of Macromolecules at the Single Chain Level )... 

For the production of polymer particles in particular, a range of devices has been designed to produce uniform droplets that are then polymerized into solid particles. Such devices are dedicated to the formation of uniform droplets of a predetermined size and dispersity. The method employed involves two streams of immiscible liquids that are brought together at a point in the device where the shear forces induce droplet formation or emulsification. Some examples of droplet-generating systems are shown in Figure 14.2. 

Here we attempt to briefly introduce the principle of the AFM based SMFS and then focus on using SMFS to address three main questions force induced conformation transition, interaction between small molecules and polymers, and the interfacial conformation and adhesive energy of polymers. 

Deviations of the force extension curves from FJC or WLC behavior, for example the kink in the force profile shown in Figure 8, often indicate conformational and configurational transitions along the polymer chain. As shown in Figure 8, Li and co-workers detected a force-induced chair-twist boat conformational transition, which cannot be measured by conventional methods, for a-(l,4)-linked polysaccharides (95). 

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