Solvent-Free Synthesis of Nano Zirconium Phenylphosphonates with Molten Phenylphosphonic Acid.

Nanosized α-zirconium phenylphosphonate particles were successfully prepared by the reaction between different zirconium sources and molten phenylphosphonic acid in the absence of solvent. The resultant nanoplates exhibit particle sizes in the range of 15 to 30 nm. The use of a topotactic anion exchange method starting from α-zirconium phosphate instead resulted in the generation of 15 to 180 nm plates, while also resulting in nanoparticles with a higher degree of crystallinity. The topotactic anion exchange of the phosphate groups by phenylphosphonate groups could be performed to completion when performed in molten phenylphosphonic acid. Characterization of both the final products as well as the individual steps in the anion exchange were performed by powder XRD, fast neutron activation analysis, TGA, FTIR spectroscopy, TEM, solid-state NMR and XPS.

Molecular Colocalization Using Massive Gold Cluster Secondary Ion Mass Spectrometry.

We report on the ion emission from impacts of hypervelocity massive gold clusters for use in secondary ion mass spectrometry. Two massive gold clusters are considered, 520 keV Au4004+ and 1040 keV Au28008+. The emission of fragment ions and molecular ions is evaluated for a series of neat samples, glycine, phenylalanine, arginine, and gramicidin S. A 2 to 4-fold increase of molecular ion emission is observed from impacts of 1040 keV Au28008+ versus 520 keV Au4004+. Compared to impacts of 20 keV Ar2000+ and 20 keV (H2O)7000+ in static conditions, impacts of 1040 keV Au28008+ display a 6 to 9-fold increase in the number of detected molecular ions per projectile impact. To explain the increased emission of molecular species, we examine the size of the impact craters and calculate the ratio of molecular ions to fragment ions. The characterization of Au28008+ and the operating conditions of the gold liquid metal ion source are presented.

Improvements in determinations using the Cu-64 annihilation gamma rays.

The method of gammagamma coincidence counting has been applied to the determination of Cu via the (64)Cu annihilation gamma rays. Preliminary experiments show that at least an order of magnitude reduction in (24)Na interference may be obtained by employing the 511-511 keV coincidence peak rather than the singles 511-keV peak. The effect of the sample matrix on the yield of (24)Na pair-production events was investigated by a combination of experimental measurements and Monte Carlo calculations.