Soluble polymer nanostructures

Another interesting nanoblending strategy is to blend the donor polymer with a sacrificial-insulating-polymer-based template that forms self-assembled nanostructures and acts as a PDA [438]. The chosen PDA polymer is soluble in a solvent that don t at all dissolve donor, so that once the film (active layer) has been deposited, the PDA can be selectively dissolved leaving behind a porous nanostructured pool of donor material, that... 

Figure 12. The relationship between the logarithm of the relative hydrogenation rate over CFP-supported rhodium nanoclusters, with respect to the polymer-stabilized nanostructured catalyst, for a number of a number of alkenes, as a function of their affinity to the support (expressed as the square difference of the solubility parameter of the support and of the substrate). (Reprinted from Ref [33], 1991, with permission from the American Chemical Society.)...

The nanostructured interface of this particular PPE/SAN/SBM blend, with a highly diffusive, elastomeric, discontinuous coverage and five different polymers is likely to easily create thermodynamic instabilities as a result of the gas transport between the phases [81, 82], Subsequently, nucleants can be formed which finally lead to cell growth in the SAN phase. In order to describe more precisely these effects induced by the nanostructured interface, we will revisit the gas solubility of the individual phases (Fig. 20). 

Abstract A concept of amphiphilicity in application to monomer units of water-soluble polymers is presented. Molecular simulation and experimental studies of polymers consisting of amphiphilic monomers units are reviewed. Those polymers reveal unusual conformational behavior in aqueous solutions forming nanostructures of nonspherical shape. Self-association of amphiphilic thermosensitive polymers in water solutions is discussed. Possibilities for the use of thermosensitive copolymers as catalysts are described. The sharp water-organic boundaries formed by polymer associates in water solutions are shown to be a prospective medium for catalysis owing to adsorption of interfacially active substrates at the interface. 

The present review has the following structure. In Sect. 2, the properties of amphiphilic monomers are discussed and a special classification of monomer units according to interfacial and partition properties is described. Also, the possibility of nanostructure formation in polymers composed of amphiphilic monomers is touched upon. This topic is more broadly treated in Sect. 3, where conformational properties of a key class of water-soluble polymers are... 

Nanostructures primarily result from polyelectrolyte or interpolyelectrolyte complexes (PEC). The PEC (also referred to as symplex [23]) is formed by the electrostatic interaction of oppositely charged polyelectrolytes (PE) in solution. The formation of PEC is governed by physical and chemical characteristics of the precursors, the environment where they react, and the technique used to introduce the reactants. Thus, the strength and location of ionic sites, polymer chain rigidity and precursor geometries, pH, temperature, solvent type, ionic strength, mixing intensity and other controllable factors will affect the PEC product. Three different types of PEC have been prepared in water [40] (1) soluble PEC (2) colloidal PEC systems, and (3) two-phase systems of supernatant liquid and phase-separated PEC. These three systems are respectively characterized as ... 

The standard molecular structural parameters that one would like to control in block copolymer structures, especially in the context of polymeric nanostructures, are the relative size and nature of the blocks. The relative size implies the length of the block (or degree of polymerization, i.e., the number of monomer units contained within the block), while the nature of the block requires a slightly more elaborate description that includes its solubility characteristics, glass transition temperature (Tg), relative chain stiffness, etc. Using standard living polymerization methods, the size of the blocks is readily controlled by the ratio of the monomer concentration to that of the initiator. The relative sizes of the blocks can thus be easily fine-tuned very precisely to date the best control of these parameters in block copolymers is achieved using anionic polymerization. The nature of each block, on the other hand, is controlled by the selection of the monomer for instance, styrene would provide a relatively stiff (hard) block while isoprene would provide a soft one. This is a consequence of the very low Tg of polyisoprene compared to that of polystyrene, which in simplistic terms reflects the relative conformational stiffness of the polymer chain. 

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