High Internal Phase Emulsions Stabilized by a Zeolite-Surfactant Combination in a Composition-Dependent Manner.

As a step toward synthesizing zeolite-based porous materials, this study demonstrates for the first time the feasibility of stabilizing oil-in-water (O/W) high internal phase emulsions (HIPEs) using a cationic surfactant (tetradecyltrimethylammonium bromide, TTAB) and "homemade" submicronic Linde type A zeolite particles. The zeolite particles are hydrophilic and therefore do not attach to dodecane-water interfaces, but surface tension measurements and electrochemical data show that their surface can be activated by the electrostatic and subsequent hydrophobic adsorption of TTAB. Comparing the adsorption isotherm of TTAB and zeta potential of the particles with the droplet sizes and rheological properties of the emulsion shows that the stabilization mechanism depends on the TTAB/zeolite weight ratio.

Inorganic materials for bone repair or replacement applications.

In recent years, excipient systems have been used increasingly in biomedicine in reconstructive and replacement surgery, as bone cements, drug-delivery vehicles and contrast agents. Particularly, interest has been growing in the development and application of controlled pore inorganic ceramic materials for use in bone-replacement and bone-repair roles and, in this context, attention has been focused on calcium-phosphate, bioactive glasses and SiO2- and TiO2-based materials. It has been shown that inorganic materials that most closely mimic bone structure and surface chemistry most closely function best in bone replacement/repair and, in particular, if a substance possesses a macroporous structure (pores and interconnections >100 microm diameter), then cell infiltration, bone growth and vascularization can all be promoted.