Particle encapsulation with polymers via in situ polymerization in supercritical CO2

A Novel Gas Phase Method for the Combined Synthesis and Coating of Pharmaceutical Particles

“…A good example of surface modification via spray drying is the use of surface-active amino acids, particularly leucine analogs, to reduce surface forces as they are enriched on particle surfaces (2,8,10). Attempts have been made to produce modified surfaces by an encapsulation technique in supercritical carbon dioxide (15) and by spray-coating (14) or by physical vapour deposition, PVD, (3) of particles in fluidized bed reactors.…”

Synthesis of Macroporous PMMA/Silica Nanocomposite Monoliths in Supercritical Carbon Dioxide

“…Similar experiment setup was used in our study of microencapsulation of fine particles. [9] Silica Nanoparticle Synthesis and Modification Silica nanoparticles were synthesized according to a process introduced by Stöber et al [10a] through which TEOS was hydrolyzed to form silica particles in ethanol with an NH 4 OH catalyst. Monodisperse spherical particles can be fabricated in sizes from tens to thousands of nanometers.…”

“…After the premixed chemicals been loaded, the reactor was first purged with gaseous CO 2 for 5 min and then charged with liquefied CO 2 at 29 8C until the pressure reached 2 000 psia. [9] All valves were then closed and the reactor was heated to 65 8C when the corresponding pressure was $4 000 psia, to initiate polymerization. The estimated amount of the CO 2 charged in was 18.3 g and the weight ratio of monomer to CO 2 was held constant at 1:9.78.…”

A new route of emulsifier-free emulsion polymerization for the preparation of polymer coated magnetite nanoparticles

“…However, in a system where the polymers and the magnetite particles are separately dispersed, the dispersion stability is insufficient and moreover, the polymers can dissociate from the magnetic particles when they are submitted to changes in external conditions such as, for example, an increase of temperature. An alternative method is to suspend magnetic particles in the liquid phase of a polymerizable formulation and polymerize the monomers in the presence of the magnetic particles to form magnetic polymeric particles, including conven- * E-mail: nguyen.hoangthikieu@mail.hust.vn tional emulsion polymerization [3,4], miniemulsion polymerization [5][6][7], dispersion polymerization [8]. In these studies, stabilizers were often preferred to obtain stable colloids.…”