Monolithic particles

Microspheres made from polymers or reactive oligomers (RO s) are manufactured by thermally treating sprayed solutions or emulsions. A solution of any film-forming polymer can be used. When an RO is used the solvent has to be evaporated, the sprayed monolithic particles are then heated to expand the gas or vapor within the particle, and the final microspheres are hardened 22,23). 

Masumy and Tasomy 28) found that for regularly shaped resol PhFO microspheres it was best to use dilute aqueous solutions with viscosities of 15-50 Pa - sec, water contents of up to 50%, and free phenol contents of 6-9%. The resultant spheres included unexpanded monolithic particles, but these could be eliminated by using a chemical blowing agent such as dinitrosopentamethylenetetramine (DNPMTA) or azodiisobutyronitrile, or a surfactant (0.25 mass %). 

Figure 1 TEM images of HMS silicas showing (A) the wormhole framework, (B) the intraparticle texture of HMS-HTx (C) the monolithic particles ofHMS-LTx...

The particle texture of HMS silica depends critically on the polarity of the solvent used to assemble the mesostructure. Water-rich solvent mixtures afford highly textured particles (denoted HMS-HTx) formed by the intergrowth of nanoscale framework domains (cf., Figure IB), whereas less polar alcohol-rich solvents afford more monolithic particles (denoted HMS-LTx) with little or no textural mesoporosity... 

Flooring coated by reverse-roll-coater with monolithic particles. [Data from Piacente, A. N. Papp, G. J. Whitehouse, R. E. Mansolillo, R. D., US Patent 5,178,912, Jan. 12,1993.]... 

In the area of essential oils and lower terpenes, simple encapsulation procedures from the area of drug delivery are applied. The essential oils or single active constituents are mixed with a hydrophilic polymer and spray dried using a commercial spray drier. Depending on whether we have an emulsion or a solution of the volatile fraction in the polymer, we obtain monolithic particles or normal microcapsules. 

Many different emulsi ers are used to dissolve the essential oils totally or partly prior to the encapsulation process. This can result in a monolithic particle or a normal capsule, where the essential oil is surrounded by a hydrophilic coating. When the mixture of an essential oil and a hydrophilic polymer is achieved, the application of spray-drying procedure of the resulting mixture will result in the formation of microcapsules. The technique for achieving an encapsulated product in high ef -ciency will depend upon many technical parameters, and description of the procedures can be found in the patent literature. Often a mixture of essential oil/polymer (4 1) can be used, but a successful result will also depend on the type of apparatus being used for the production. The reader is advised to refer to the parameters given for the polymer used in the experiment. To achieve the encapsulated... 

Particulate carbon is a carbon material consisting of separated monolithic particles. 

The zirconia meso-macroporous particles used as catalyst support in this work have a size of around 10pm [7,8]. The synthesized zirconia particles contain regular arrays of macropores having a diameter range from 300 to 500 nm. The hollow macrochannels are always orthogonal to the face of the monolithic particle. Moreover, macroporous walls are mesostructured with a disordered wormhole like assembly of meso/micropores into macroporous framework. 

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