Preparation and Characterization of Barium Sulfate Particles as Contrast Materials for Surgery

摘要

Barium sulfate particles were prepared from BaCl_2 and Na_2SO_4 under various conditions to explore their potential application as contrast material in endovascular surgery. Ethanol was added for the stabilization of the suspension obtained. Particle characteristics of the samples were determined by SEM and light scattering, while the stability of the suspensions was characterized by sedimentation experiments. Particle characteristics were shown to depend very much on reaction conditions. Particles were obtained in spherical and plate like shape and in a variety of sizes. Primary particles of nanometer size formed aggregates in most cases. Some of the samples had bimodal particle size distribution. Particle characteristics determined from SEM micrographs, by laser light scattering measurements and calculated from sedimentation experiments often differed from each other. The discrepancy could be explained by the dissimilar behavior of various fractions and the different sensitivity of the measurements to them. Some of the samples showed aging phenomena in DMSO leading either to the formation of larger particles or to the break down of aggregates.