Nanostructures polyacrylates

F. 6.7 a Poly-8 with a polystyrene backbone and polyacrylate brushes that are appended with short amide-containing side chains collapses into a core-shell nanostructure, b Hydrogen bonding leads to the formation of a microphase-separated stmcture in which hard polystyrene domains are embedded in a soft polyacrylate-amide matrix. When the material is damaged, the reversible nature of the hydrogen bonding, in combination with the flexibility of the polyacrylate brushes, enables the system to heal spontaneously... 

Figure 2.23 TEM image of the cyclic PANl nanostructure. (Reprinted with permission from Polymer, Cyclic polyaniline nanostructures from aqueous/organic interfacial polymerization induced by polyacrylic acid by S. Liu, K. Zhu, Y. Zhang and J. Xu, 47, 22, 7680-7683. Copyright (2006) Elsevier Ltd)...

PANI/TiO film coated on titanium foil was successfully prepared using the sol-gel method for the preparation of TiO film followed by its dipping into the PANI solution in tetrahydrofuran and subsequent drying in air [122]. Nanostructured ultrathin [(TiOyPAA/PANI/PAA) TiOJ films were fabricated using surface sol-gel processing with TiO layers followed by layer-by-layer deposition of polyacrylic acid (PAA) and PANI from their solutions [124]. Anatase TiO -NPs, commercially available or prepared by various methods, were used in the majority of the PANI/TiO syntheses [40-67,69-79,94,97,102], whereas the rutile TiO -NPs [68,114] or a mixture of anatase and rutile TiO [80] were used rarely. 

Using functional molecules as structural directors in the chemical polymerization bath can also produce polyaniline nanostructures. Such structural directors include surfactants [16-18], liquid crystals [19], polyelectrolytes (including DNA) [20,21], or complex bulky dopants [22-24]. It is believed that functional molecules can promote the formation of nanostructured soft condensed phase materials (e.g., micelles and emulsions) that can serve as soft templates for aniline polymerization (Figure 7.3). Polyelectrolytes such as polyacrylic acid, polystyrenesulfonic acid, and DNA can bind aniline monomer molecules, which can be polymerized in situ forming polyaniline nanowires along the polyelectrolyte molecules. Compared to templated syntheses, self-assembly routes are more scalable but they rely on the structural director molecules. It is also difficult to make nanostructures with small diameters (e.g., <50 nm). For example, in the dopant induced self-assembly route, very complex dopants with bulky side groups are needed to obtain nanotubes with diameters smaller than 100 nm, such as sulfonated naphthalene derivatives [23-25], fidlerenes [26], or dendrimers [27,28]. 

The visualisation and size determination of polyacrylate nanostructures has been determined by AFM [389]. 

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