Quantification of surface functional groups on silica nanoparticles: comparison of thermogravimetric analysis and quantitative NMR.

Thermogravimetric analysis (TGA) coupled with evolved gas analysis-FT-IR has been examined as a potential method to study the functional group content for surface modified silica nanoparticles. A comparison with a quantitative solution NMR method based on analysis of groups released after dissolution of the silica matrix is used to provide benchmark data for comparison and to assess the utility and limitations of TGA. This study focused primarily on commercially available silicas and tested whether it was possible to use a correction based on bare silica to account for the significant mass loss that occurs due to condensation of surface hydroxyl groups and loss of matrix-entrapped components at temperatures above ∼200 °C.

Tailored SWCNT functionalization optimized for compatibility with epoxy matrices.

We have modified single walled carbon nanotubes (SWCNTs) with well defined matrix-based architectures to improve interface interaction in SWCNT/epoxy composites. The hardener and two pre-synthesized oligomers containing epoxy and hardener moieties were covalently attached to the SWCNT walls by in situ diazonium or carboxylic coupling reactions. In this way, SWCNTs bearing amine or epoxide-terminated fragments of different molecular weights, which resemble the chemical structure of the cured resin, were synthesized.

About the solubility of reduced SWCNT in DMSO.

Single-walled carbon nanotubes (SWCNT) have been reduced with sodium naphthalide in THF. The reduced SWCNT are not only soluble in dimethylsulfoxide (DMSO) to form a stable solution/suspension, but also react spontaneously at room temperature with DMSO to evolve hydrocarbon gases and are converted into functionalized SWCNT. The degree of functionalization is about 2C% and the addends are mainly methyl and small oxygen-containing hydrocarbons.

Discovery of indoline-based, natural-product-like compounds as probes of focal adhesion kinase signaling pathways.

With the goal of identifying small molecule modulators of protein-protein interactions, we developed a solid-phase synthesis method, which was then successfully utilized in a library generation of 164 aminoindoline-derived, natural-product-like compounds. This library and several other related intermediates synthesized during this project were then subjected to different biological assays in search of small molecule modulators of focal adhesion kinase (FAK)-mediated signaling pathways. This study included (i) an in vitro, full length FAK inhibition assay, (ii) a cell proliferation assay, and (iii) a wound healing assay.

A solid phase library synthesis of hydroxyindoline-derived tricyclic derivatives by Mitsunobu approach.

Hydroxyindoline-derived scaffold, 9, was synthesized with the goal of generating a library of indoline-based natural product-like tricyclic derivatives to be utilized as small-molecule chemical probes. The tricyclic ring was obtained by a Mitsunobu reaction of the N-nosyl amino acid conjugate with the primary hydroxyl group. The solid-phase synthesis was achieved by immobilizing scaffold 9 onto the solid support giving a compound, 15.