Tongjie Yao

Facile Approach in Fabricating Superhydrophobic and Superoleophilic Surface for Water and Oil Mixture Separation

Metal copper mesh with superhydrophobic and superoleophilic surface had been successfully fabricated via a facile solution-immersion process. The hierarchical structure was prepared on the commercial copper mesh surface by etching with the nitric acid. After being modified by 1-hexadecanethiol (HDT), the as-prepared mesh indicated both superhydrophobic and superoleophilic property simultaneously. This as-prepared metal mesh could then be applied for oil and water mixture separation. The unusual wettability of the as-prepared mesh was stable in corrosive conditions, such as acidic, basic, and salt solutions. The solution-immersion method was simple, time-saving, and inexpensive and therefore exhibited great potential application.

Preparation of raspberry-like polypyrrole composites with applications in catalysis

Raspberry-like composites were prepared by coating the silver/polypyrrole core/shell composites onto the surface of silica spheres via oxidation polymerization of pyrrole monomer with [Ag(NH3)2]+ ions as oxidants. The whole process allowed the absence of stabilizers, which greatly improved the quality of the conducting polymer composites. The morphology of the resulting composites was investigated, which can be described as raspberry-like; also, the structure and composition of the composites were characterized in detail. A possible formation mechanism was proposed. The present synthetic strategy substantially extended the scope of metal/conducting polymer composite synthesis. The raspberry-like composites exhibited excellent catalytic properties in the reduction of methylene blue dye with the reducing agent of sodium borohydride.

Fabrication of flexible superhydrophobic films by lift-up soft-lithography and decoration with Ag nanoparticles

Superhydrophobic films with excellent flexibility have been fabricated by combining the lift-up soft-lithography technique and chemical reduction of [Ag(NH(3))(2)](+) ions to Ag nanoparticles (NPs) on the surface of silica spheres which are patterned on the polydimethylsiloxane (PDMS) films. Scanning electron microscopy (SEM) images reveal the presence of raspberry-like hierarchical structures on the PDMS films. The influence of the amount of Ag NPs and the size of the silica spheres on the wettability of the soft films is investigated carefully. Because PDMS films are elastomeric materials, our superhydrophobic films offer great flexibility. The resulting films can be easily transferred from one substrate surface to another without destroying their superhydrophobicity. These flexible and superhydrophobic films can be used repeatedly to satisfy a wide range of applications.

Improvement of the Stability of Colloidal Gold Superparticles by Polypyrrole Modification

The colloidal gold superparticle (SP)/polypyrrole (PPy) core/shell composites were successfully prepared by oxidative polymerization of pyrrole monomer on the surface of poly(N-vinylpyrrolidone) (PVP)-grafted colloidal gold SPs. These core/shell composites showed strong catalytic activity and excellent stability. Control experiments indicated that the morphology and the thickness of PPy shell were controllable by adjusting the dosage of pyrrole monomer. Meaningfully, the resulting SP/PPy core/shell composites were quite stable in water, which could be stored for more than half a year without damaging their structures. As an example, we demonstrated the use of these composites as catalyst for the reduction of methylene blue (MB) dye with a reducing agent of sodium borohydride. The composites exhibited highly catalytic activity and long-term stability, implying promising applications of SP/PPy composites in catalysis.

Binary superparticles from preformed Fe3O4 and Au nanoparticles

Binary superparticles (SPs) from various functional nanoparticles are fabricated using oil droplets in microemulsion as templates. The structural stability of SPs is further improved by polymer decoration. This protocol provides a facile and flexible approach to integrate multifunctionalities in nanometre-sized spheres with long term stability.

Preparation of fluorescent poly(methylmethacrylate) nano capsules via internal phase separation

Abstract Fluorescent nanocapsules containing Eu3+ complex are prepared by the internal phase separation of poly(methylmethacrylate) (PMMA) within the droplets of oil/water nano-emulsion. The nanocapsules give bright red emission excited by UV irradiation and possess stable fluorescence properties. Their fluorescence intensity is primarily influenced by the emulsifier concentration. It is significant that the fluorescence of the nanocapsules is nearly pH-independent and can be kept for a long time in a wide pH range. In contrast, the fluorescence of Eu3+ complex is easily quenched in acidic or alkalic medium. The mean nanocapsule size is tunable with the concentration and the mode of emulsifier addition. As soft templates, oil cores have potential applications for the incorporation of functional components or drugs.