Complex emulsions for shape control based on mass transfer and phase separation.

Complex emulsions are used to fabricate new morphologies of multiple Janus droplets, evolving from non-engulfing to complete engulfing core/shell configuration. The produced droplets contain an aqueous phase of dextran (DEX) solution and an oil phase, which is mixed with ethoxylated trimethylolpropane triacrylate (ETPTA) and poly(ethylene glycol) diacrylate (PEGDA). The PEGDA in the oil phase is transferred into the aqueous phase to form complex morphologies due to the phase separation of PEGDA and DEX.

Fabrication of PAA-PETPTA Janus Microspheres with Respiratory Function for Controlled Release of Guests with Different Sizes.

Poly(acrylic acid)-poly(ethoxylated trimethylolpropane triacrylate) (PAA-PETPTA) Janus microspheres with "respiratory" function for controlled release were prepared by polymerization of acrylic acid-ethoxylated trimethylolpropane triacrylate (AA-ETPTA) Janus microdroplets in a continuous oil phase in a simple capillary-based microfluidic device with the assistance of UV radiation. The flow rate ratios of AA and ETPTA phases and surfactant content in the continuous oil phase have a significant effect on the structure of the Janus microspheres. PAA part in the Janus microspheres has respiratory function for loading and release due to the different stimuli responses to different pHs.

Complex Emulsions by Extracting Water from Homogeneous Solutions Comprised of Aqueous Three-Phase Systems.

Multiple emulsions can be obtained by binary and ternary liquid phase separation. And the use of the aqueous two-phase system provides a simple route to prepare water-in-water-in-oil (W/W/O) or water-in-water-in-water (W/W/W) multiple emulsions. It is thus expected that we can fabricate more complex emulsions by using an aqueous three-phase system.

Investigation on efficient adsorption of cationic dyes on porous magnetic polyacrylamide microspheres.

We report here the preparation of porous magnetic polyacrylamide microspheres for efficient removal of cationic dyes by a simple polymerization-induced phase separation method. Characterizations by various techniques indicate that the microspheres show porous structures and magnetic properties. They can adsorb methylene blue with high efficiency, with adsorption capacity increasing from 263 to 1977 mg/g as the initial concentration increases from 5 to 300 mg/L.

Versatile preparation of nonspherical multiple hydrogel core PAM/PEG emulsions and hierarchical hydrogel microarchitectures.

The preparation of nonspherical materials composed of separated multicomponents by droplet-based microfluidics remains a challenge. Based on polymerization-induced phase separation and droplet coalescence in microfluidics, we prepared emulsions of variously shaped PAM/PEG core/shell droplets and hydrogels composed of two separated components, which show flexible and transformable hierarchical structures and microarchitectures. We find that AM/PEG aqueous droplets form a core/shell structure after polymerization resulting from phase separation.

Preparation of zeolite-A/chitosan hybrid composites and their bioactivities and antimicrobial activities.

Zeolite-A/chitosan hybrid composites with zeolite contents of 20-55 wt.% were prepared by in situ transformation of silica/chitosan mixtures in a sodium aluminate alkaline solution through impregnation-gelation-hydrothermal synthesis. The products were characterized by X-ray diffraction, diffuse reflectance infrared Fourier transform spectroscopy, scanning electron microscopy, thermogravimetric analysis, and mercury penetration porosimetry.

Hydrothermal synthesis of pencil-like SAPO-5 and observation of its reversed crystal-growth process.

SAPO-5 with a novel hexagonal pencil-like morphology was hydrothermally synthesized from hydrogels that contain triethylamine and high concentrations of acetic acid at 180 °C for 48 h. The effect of the acetic acid concentration was examined and indicated that usage of a high concentration of acetic acid is crucial to the synthesis of SAPO-5 with a pencil-like morphology. The time-dependent growth process of novel SAPO-5 was observed by scanning electron microscopy with the aid of acid treatment to remove the amorphous materials for clearer observation.

Combinatorial synthesis of SAPO-34 via vapor-phase transport.

By applying a combinatorial method, SAPO-34 was successfully synthesized via vapor-phase transport technique, and the synthesis factors were systematically examined.