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A near-single-phase Ti3AlC2 ternary carbide was synthesized from 3 Ti-1.1Al-1.8C powder blend, both by the wave propagation and thermal explosion (TE) modes of self-propagating high-temperature synthesis. The application of a moderate (28Mpa) pressure immediately after TE at 800°C (reactive forging) yielded a 95% dense material containg, in addition to Ti3AlC2, an appreciable amount of TiC1-x. By adjusting the starting composition, a 99% dense material containing up to 90 vol.% Ti3AlC2 was obtained. The material had a fine-layered microstrucutre with Ti3AlC2 grain size not exceeding 10 μm. The samples were readily machinable and had a high compressive strength of ∼800 Mpa up to 700°C. [ABSTRACT FROM AUTHOR]

A composite material may be done in such a way that the final product may acquire some excellent properties that cannot be found individually in either material. Novel PLLA/HA multilayer composites are fabricated with different HA contents and sequence of stacking with the goal to produce devices for bone fracture fixation. Hydroxyapatite powder particles act as flaws in the continuous polymer matrix due to limited interfacial bonding with the polymer matrix and a limited effect on toughening mechanisms. [ABSTRACT FROM AUTHOR]

Targeted delivery of magnetic iron oxide nanoparticles (IONPs) to a specific tissue can be achieved by conjugation with particular biological ligands on an appropriately functionalized IONP surface. To take best advantage of the unique magnetic properties of IONPs and to maximize their blood half-life, thin, strongly bonded, functionalized coatings are required. The work reported herein demonstrates the successful application of phosphonate-anchored self-assembled monolayers (SAMs) as ultrathin coatings for such particles. It also describes a new chemical approach to the anchoring of antibodies on the surface of SAM-coated IONPs (using nucleophilic aromatic substitution). This anchoring strategy results in stable, nonhydrolyzable, covalent attachment and allows the reactivity of the particles toward antibody binding to be activated in situ, such that prior to the activation the modified surface is stable for long-term storage. While the SAMs do not have the well-packed crystallinity of other such monolayers, their structure was studied using smooth model substrates based on an iron oxide layer on a double-side polished silicon wafer. In this way, atomic force microscopy, ellipsometry, and contact angle goniometry (tools that could not be applied to the nanoparticles' surfaces) could contribute to the determination of their monomolecular thickness and uniformity. Finally, the successful conjugation of IgG antibodies to the SAM-coated IONPs such that the antibodies retain their biological activity is verified by their complexation to a secondary fluorescent antibody., (© 2011 American Chemical Society)