Monoliths particle-loaded

Ratnayake, C. K., Oh, C. S., and Henry, M. P. (2000). Particle loaded monolithic sol-gel columns for capillary electrochromatography a new dimension for high performance liquid chromatography. J. High Resolut. Chromatogr. 23, 81-88. 

Big Beads Small Beads Particle Loaded Chemical Functionalized Monolithic Column... 

Kato, M., Dulay, M. T., Bennett, B., Chen, J.-R., and Zare, R. N., Enantiomeric separation of amino acids and nonprotein amino acids using a particle-loaded monolithic column. Electrophoresis, 21, 3145, 2000. 

Ratnayake, C.K. Oh, C.S. Henry, M.P. Characteristics of particle-loaded monolithic sol-gel columns for capillary electrochromatography. I. Structural, electrical and bandbroadening properties. J. Chromatogr. A, 2000, 887, 277-285. 

Two ways to reduce the diffusion length in TBRs are 1) use of smaller catalyst particles, or 2) use of an egg-shell catalyst. The first remedy, however, will increase pressure drop until it becomes unacceptable, and the second reduces the catalyst load in the reaction zone, making the loads of the TBR and the MR comparable. For instance, the volumetric catalyst load for a bed of 1 mm spherical particles with a 0.1 mm thick layer of active material is 0.27. The corresponding load for a monolithic catalyst made from a commercial cordierite structure (square cells, 400 cpsi, wall thickness 0.15 mm), also with a 0.1 mm thick layer of active material, is 0.25. 

Generally, the preparation of washcoated structured catalysts is governed by several parameters, such as the nature and particle size of the precursor powder, loading of powder, nature and concentration of dispersants, temperature of the slurry, use of binders in the slurry and deposition of a primer layer on the monolith. 

This study investigated the role of colloid particles with or without carbonates dispersed from lime-stabilized biosolids to mediate the transport of associated metals through intact soil monoliths in laboratory leaching experiments. The biosolid colloids were applied to undisturbed soil monoliths of a Maury soil under steady rate (2.2 cm/lr1) gravity flow conditions. Deionized water spiked with metals at levels similar to the total load (soluble plus sorbed) carried by the colloids was used as a control leaching treatment. The eluents were monitored for colloid, Cu, Zn, and Pb breakthrough concentrations. 

FIGURE 9 Monolithic structure composed of catalyst particles or support. The catalyst loading can be high. 

Nevertheless, monolithic microspheres can be made to release drug at an approximately constant rate. " The core loading of these microspheres may be increased to create structures similar to those of reservoir microcapsules. An optimum combination of particle sizes (a size distribution), may be prepared to achieve a constant rate of drug release. Preparing microspheres with an erodible polymer in such a way that maximum erosion occurs in conjunction with minimum diffusion may establish a constant release rate. Although the principles described here appear simple, they are difficult to utilize because of their dependence on a number of factors, each of which can complicate the process. 

---