Polymers, gels nanoparticles

Shchukin DC, Schattka JH, Antonietti M, Curasu RA (2003) Photocatalytic properties of porous metal oxide networks formed by nanoparticles infiltration in a polymer gel template. J Phys Chem B 107 952-957... 

Gelation of liquid electrolytes to obtain a gel that effectively penetrates into the pores of the 2 can be obtained by addition of appropriate additives such as small molecules,49 polymers, inorganic nanoparticles,49 50 and carbon nanotubes.51... 

Fig. 3 Example of the microdomains created by embedding luminescent indicator-loaded silica gel nanoparticles into poly(dimethylsiloxane) before cross-linking to fabricate films for oxygen optosensing. The largest circles represent the silica particles the black lines represent the PDMS polymer chains, while the smallest circles represent the indicator dye molecules (the black circles depict those located in the organic polymer-free silica regions and the gray circles stand for those adsorbed on silica regions in contact with the PDMS)...

Holzinger, D. and Kickelbick, G. (2003) Preparation of amorphous metal-oxide-core polymer-shell nanoparticles via a microemulsion-based sol-gel approach. Chem. Mater., 15, 4944— 4948. 

The template materials discussed in this section are polymer gels and membranes. These organic matrices show that bulk hybrid or porous inorganic materials can be obtained using sol-gel or nanoparticle infiltration methods. 

Fig. 1. TEM image of an ultramicrotome of the titania network constructed using a polymer gel template, showing the individual titania nanoparticles of which the structure is composed. Reprinted with permission from [7]. Copyright 2001 American Chemical Society...

Table 1. Properties of the titania networks obtained by using polymer gel templates calculated porosity, surface area obtained from nitrogen adsorption, pore, and titania nanoparticle diameters. Adapted with permission from [8]. Copyright 2001 American Chemical Society ...

Absorption through the oral mucosa can take place in two ways i) inter- or paracellular pathway, which is a passive transport through the lipid matrix between the cells and ii) trans- or intracellular pathway through the cell walls, which can be either passive or active transport. The following dosage forms may be used i) polymer-coated nanoparticles, ii) special tablets, iii) pol)mtier films, and iv) gels (patches) [112-119]. 

Typically, the solid-state electrolyte can function as both a substrate and separator in the fabrication of a flexible supercapacitor by two steps. For instance, a freestanding PVA/ H3PO4 film was obtained by first casting the gel electrolyte on a glass slide and then peeled off from the glass. It had been further sandwiched between two composite electrodes that were prepared from conducting polymers and nanoparticles to produce the flexible supercapacitor (Fig. 9.3G) (Liu et al., 2010,2013b). 

In this section, I collect the relaxation work on complex systems other than biological molecules in solution. The concept of complex systems includes here multicomponent mixtures, surfactant/colloidal systems, solutions of synthetic polymers, gels, liquids in porous media (and related heterogenous systems), and systems containing nanoparticles. 

Nematic liquid crystal One of the most common liquid crystal phases, where the molecules of a liquid have no positional order, but they have long-range orientational order inside domains. They all point in the same direction within each domain Network connectivity The degree to which a polymer or a nano-particle has coimections with neighbor polymers or nanoparticles, over a gel network NIJ National Institute of Justice... 

Supramolecular gels can also be formed using coordination interactions and gels represent a way to control the positioning of metal ions, for example, in nanoparticle synthesis. The reaction of Fe(N03)3 with 1,3,5-benzenetricarboxylic acid (BTC), for example, forms a coordination polymer gel within minutes. There is extensive cross-linking between the Fe and the tricarboxylic acid which leads to voids within the coordination polymer structure (Scheme 5.10). This gel may be used as a polymerisation template. Methyl methacrylate may be polymerised within the gel matrix by UV irradiation of the monomer, resulting... 

Resolvation may precede the preparation of polymer-immobiUzed nanoparticles. For example, the cryochemical synthesis of colloidal Ag particles is performed in acetone, which is then replaced by formamide. This dispersion is stable for a few days. The system Ag (2-5 nm) formamide is used as a solvent in the preparation of crosslinked polyacrylamide gel. Three dilferent synthetic resolvation methods are documented. In the first version, a Co-nonadecane system obtained by the cryochemical method was mixed with a solution of a polymer in nonadecane with subsequent sonication. In the second version, the nanoparticles of Co or Ni in toluene were added to a solution of low-pressure polyethylene (LPPE) in toluene at 363K. The third variant employs a toluene polymer solution cooled fi om 383K to 185K. The resulting gel-like system was mixed with nanoparticles obtained cryochemically and subjected to sonication. These techniques make it possible to virtually preclude the aggregation of particles at aU intermediate stages. However, along with the peptization and resolvation, more complex interactions of nanoparticles with the solvent may take place. 

Considerable attention has also been paid in recent years to hybrid polymer-silica nanocomposites prepared mostly via a sol-gel process [219,243-254] where 10-100 nm size 3D silica domains (clusters) were covalently bound to the polymer. Polymers deprived of groups reactive in the sol-gel process but prone to hydrogen bonding with silanols of silica nanoparticles have also been successfully incorporated into nanophase-separated hybrid materials [246,248-252]. Some polymer-silica nanocomposites, in particular silica core-polymer shell nanoparticles [255-258], were prepared using 3D fumed silica nanoparticles. 

Abstract This chapter discusses the potential of fluorescence correlation spectroscopy (PCS) to study polymer systems. It introduces the technique and its variations, describes analysis methods, points out advantages and limitations, and summarizes PCS studies of molecular and macromolecular probes in polymer solutions, polymer gels, polymer nanoparticles, and polymeric micellar systems. In addition, a comparison with other experimental methods is presented and the potential of a combination with simulations discussed. 

Keywords Pluorescence correlation spectroscopy Pluorescence microscopy Pluorescent probes Polymer solutions Polymer gels Polymer nanoparticles Polymeric micellar systems Translational diffusion... 

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