Nanoparticle, fluorinated

One method of overcoming the detrimental solvent dewetting effects is to use liquid C02 as the solvent for nanoparticle dispersions [52], since C02 does not experience the dewetting instabilities due to its extremely low surface tension [53]. In this case, nanoparticles must be stabilized with fluorinated ligands [30, 33, 54—65] or other C02-philic ligands [60,66-76], such that they will disperse in the C02 prior to dropcasting. These fluorinated ligands tend be toxic and environmentally persistent and, typically, only very small nanoparticles can be dispersed at low concentrations. 

In 2003, Sugimoto and Kanie published what appears to be the first claim on the formation of nematic-like one-dimensional ordering in liquid crystal-nanoparticle hybrid materials. Different shapes of Ti02 nanoparticles were hybridized with two structurally different rod-like liquid crystal amines (one based on a cyanobiphenyl and a second with a fluorinated cyclohexylbiphenyl core), but only the combination of spindle-like Ti02 nanorods (with an aspect ratio greater than 10) with the... 

Fluorinated ionic liquids, characteristics, 1, 854 Fluorinated molecules, coordination, 1, 727 Fluorinated thiols, in nanoparticle preparation, 12, 80 Fluorination, and iridium carbonyl cluster complexes, 7, 299... 

A different situation has been observed using mixtures of thiolates with immiscible chains. AuNPs protected by mixed monolayers of different composition made of HS-C8-TEGME and HS-F8-PEG have been investigated by ESR spectroscopy using a radical probe sensitive to the hydrophobicity of the environment.223 The ESR spectral parameters of the probe in the monolayer are identical to those of the probe in a completely fluorinated medium when the ratio (Rcf) between alkyl and perfluoro-alkyl is lower than 2.5. Only at RCp > 2.5, the probe starts to experience the environment of alkyl chains. The experimental results support the phase segregation of perfluoroalkyl thiolates in patches on nanoparticles with a core size of 2.5 to 4.0 nm.223... 

The third way to PE-surf nanoparticles is based on the use of polyampholytes, i.e. polyelectrolytes that contain cationic and anionic groups. Examples are long-term stable fluorinated nanoparticles, prepared by the complexation of polyampholytes with perfluorododecanoic acid [131]. The polyampholytes are statistic copolymers of styrylmethyl(trimethyl)ammoni-um chloride, methacrylic acid, and methyl methacrylate having more cationic monomers (28-100 mol %) than anionic monomers (0-16%). The cationic monomers form a complex with perfluorododecanoate ions to create neutral... 

A Raman spectroscopic study has been made of carbon films prepared on A1 or Si substrates.314 Raman spectra were used to characterise fluorinated amorphous carbon nanoparticle films (a-C F NPs).315 UV Raman spectra of templated carbon anodes showed a band at 1575 cm-1 (G band) and a broad,... 

Supercritical fluids may be utilized for the synthesis of metal nanoparticles. Perfluorodecanethiol-stabilized silver nanocrystals were synthesized in supercritical CO2 through arrested precipitation, by reducing silver acetylacet-onate with hydrogen in the presence of fluorinated thiol (Figure 8). The CO2 density used during synthesis controls the particle size and polydispersity. At... 

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