Interaction spaces polymer networks

Polymer molecules in a solution undergo random thermal motions, which give rise to space and time fluctuations of the polymer concentration. If the concentration of the polymer solution is dilute enough, the interaction between individual polymer molecules is negligible. Then the random motions of the polymer can be described as a three dimensional random walk, which is characterized by the diffusion coefficient D. Light is scattered by the density fluctuations of the polymer solution. The propagation of phonons is overdamped in water and becomes a simple diffusion process. In the case of polymer networks, however, such a situation can never be attained because the interaction between chains (in... 

Viscoelastic properties of molten polymers conditioning the major regularities of polymer extension are usually explained within the framework of the network concept according to which the interaction of polymer molecules is localized in individual, spaced rather far apart, engagement nodes. The early network theories were developed by Green and Tobolsky 49) and stemmed from successful network theories of rubber elasticity. These theories were elaborated more fully in works by Lodge50) and Yamamoto S1). The major elasticity. These theories is their simplicity. However, they have a serious drawback the absence of molecular weight in the theory. 

This review will focus on the situation where a template molecule interacts either with a performed polymer or with the constituents of a polymerisable mixture. The interactions exploited have to be reversible and can either be of a well-defined nature, such as in the formation of a covalent bond, or rather ill-defined as in the case of hydrophobic interactions. The preformed polymer undergoes conformational changes in the presence of the template, whereas in the case of the polymerisable mixture an entirely new polymer is formed around the template. In both instances the template is incorporated into the polymer network and subsequently extracted. The template leaves behind spaces or cavities, which to varying extents are complementary to the shape and/or electronic features of the template. The properties of the polymers obtained and their potential applications depend on the characteristics of the template and its mode of interaction with the precursor polymer or polymerisable mixture, but also on the final polymer structure itself... 

Each of these factors contributes to the unique microstructure of mucus, which should be understood prior to the development of gene vectors capable of passing efficiently through the mucosal barrier. Hydrophobic interactions between mucin polymers cause mucus to form a fine network. In cervical mucus, this network consists of a fine mesh with interfiber spacings of approximately 100 nm within a macroporous mesh of interfiber spacings approximately 500 nm... 

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