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The complex formation has been studied by 19F NMR and viscometry of β-cyclodextrin (β-CD) and water-soluble telechelic and one-ended perfluorocarbon derivatives (C6F13 and C8F17) of poly(ethylene glycol)s (PEGs) of molecular weights of 5000 and 10000 and poly(dimethylacrylamide)s containing C8F17 pendent groups. Fluorine-19 NMR of the PEG derivatives shows CF3 resonances at about −80 and −82 ppm corresponding to monomeric and associated structures, respectively. For the case of the one-ended C6F13 PEG (M = 5000) derivatives, a formation constant on the order of 104 was determined. Addition of β-CD to this polymer leads to the formation of 1:1 β-CD−RF complexes that gives CF3 resonances that are very close to that of the monomeric RF groups. Essentially quantitative complex formation with β-CD was observed in the presence of free β-CD concentrations larger than about 10-2−10-3 M. The reduced viscosity of 1.0 wt % aqueous solutions of the telechelic PEG of MW of 10 000 containing C8F17 end groups is greatly reduced as a result of intermolecular hydrophobic association. Addition of stoichiometric β-CD completely suppresses hydrophobic association in this solution, as demonstrated by a virtually complete loss of viscosity due to association. Similar reductions in viscosity were observed for the case of poly(dimethylacrylamide) containing pendent groups. In this case a larger excess of β-CD was required to completely suppress RF association.

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Functionalization of zinc oxide (ZnO) nano-objects by silane grafting is an attractive method to provide nanostructured materials with a variety of surface properties. Active hydroxyl groups on the oxide surface are one of the causes governing the interfacial bond strength in nanohybrid particles. Here, "as-prepared" and commercially available zinc oxide nanopowders with a wide range of surface hydroxyl density were functionalized by a well-known polymerizable silane coupling agent, i.e., 3-(trimethoxysilyl)propylmethacrylate (MPS). Fourier transform infrared (FTIR) and solid-state (13)C and (29)Si nuclear magnetic resonance (NMR) spectroscopic investigations demonstrated that the silane coupling agent was fully hydrolyzed and linked to the hydroxyl groups already present on the particle surface through covalent and hydrogen bonds. Due to a basic catalyzed condensation of MPS with water, a siloxane layer was shown to be anchored to the nanoparticles through mono- and tridentate structures. Quantitative investigations were performed by thermogravimetric (TGA) and elemental analyses. The amount of silane linked to ZnO particles was shown to be affected by the amount of isolated hydroxyl groups available to react on the particle surface. For as-prepared ZnO nanoparticles, the number of isolated and available hydroxyl groups per square nanometer was up to 3 times higher than the one found on commercially available ZnO nanoparticles, leading to higher amounts of polymerizable silane agent linked to the surface. The MPS molecules were shown to be mainly oriented perpendicular to the oxide surface for all the as-prepared ZnO nanoparticles, whereas a parallel orientation was found for the preheated commercially ZnO nanopowders. In addition, ZnO nanoparticles were shown to be hydrophobized by the MPS treatment with water contact angles higher than 60°.