Microbubble-enhanced dielectric barrier discharge pretreatment of microcrystalline cellulose.

Cellulose recalcitrance is one of the major barriers in converting renewable biomass to biofuels or useful chemicals. A pretreatment reactor that forms a dielectric barrier discharge plasma at the gas-liquid interface of the microbubbles has been developed and tested to pretreat α-cellulose. Modulation of the plasma discharge provided control over the mixture of species generated, and the reactive oxygen species (mainly ozone) were found to be more effective in breaking-up the cellulose structure compared to that of the reactive nitrogen species.

Preparation of Microcrystals of Piroxicam Monohydrate by Antisolvent Precipitation via Microfabricated Metallic Membranes with Ordered Pore Arrays.

Microcrystals of piroxicam (PRX) monohydrate with a narrow size distribution were prepared from acetone/PRX solutions by antisolvent crystallization via metallic membranes with ordered pore arrays. Crystallization was achieved by controlled addition of the feed solution through the membrane pores into a well-stirred antisolvent. A complete transformation of an anhydrous form I into a monohydrate form of PRX was confirmed by Raman spectroscopy and differential scanning calorimetry.

pH-sensitive micelles for targeted drug delivery prepared using a novel membrane contactor method.

A novel membrane contactor method was used to produce size-controlled poly(ethylene glycol)-b-polycaprolactone (PEG-PCL) copolymer micelles composed of diblock copolymers with different average molecular weights, Mn (9200 or 10,400 Da) and hydrophilic fractions, f (0.67 or 0.59).

Synthesis and micellization of a pH-sensitive diblock copolymer for drug delivery.

A diblock copolymer constituting of a poly(ethylene glycol) (PEG) and a polycaprolactone (PCL) segment, linked with a pH-sensitive hydrazone bond (Hyd), was synthesized. Micelles formed from this copolymer, offer the advantage of encapsulating hydrophobic drugs without the need for conjugation sites. All synthesized polymers were characterized using gel permeation chromatography, infrared and proton nuclear spectroscopies.

Production of porous silica microparticles by membrane emulsification.

A method for the production of near-monodispersed spherical silica particles with controllable porosity based on the formation of uniform emulsion droplets using membrane emulsification is described. A hydrophobic metal membrane with a 15 μm pore size and 200 μm pore spacing was used to produce near-monodispersed droplets, with a mean size that could be controlled between 65 and 240 μm containing acidified sodium silicate solution (with 4 and 6 wt % SiO(2)) in kerosene. After drying and shrinking, the final silica particles had a mean size in the range between 30 and 70 μm.

Pore design and engineering for filters and membranes.

In filtration, the concept of pore size is not easy to define. In microfiltration, there are numerous advantages in employing a surface filtering membrane, rather than one relying on depth filtration mechanisms from a tortuous pore flow channel. Modern manufacturing techniques provide means to produce surface filtering membranes.