Rijing Wang

Photocatalytic Activity of Heterostructures Based on TiO2 and Halloysite Nanotubes

A one-step solvothermal method was used to prepare TiO(2)/halloysite composites. TiO(2) nanoparticles were deposited on the platform of the halloysite nanotubes (HNTs). XRD, FT-IR, FE-SEM, and TEM were applied to investigate the structures and morphologies of the resultant samples. The as-prepared TiO(2)/HNTs photocatalyst exhibits pH sensibility on the degradation of methanol and a higher photocatalytic activity on the degradation of acetic acid. The combination of the photocatalytic property of TiO(2) and the unique structure of halloysite endowed this material with a bright perspective in degradation of organic pollutant.

Photocatalytic properties of hierarchical structures based on Fe-doped BiOBr hollow microspheres

Fe-doped BiOBr hollow microspheres were successfully prepared by a simple solvothermal method. The as-prepared samples exhibit excellent photocatalytic activity and electrochemical behaviour, attributed to the unique hollow structure and Fe doping, which is favorable for transfer of photogenerated carriers and enhancement of photoadsorption.

CuO/TiO2 nanocrystals grown on graphene as visible-light responsive photocatalytic hybrid materials

CuO/TiO2 nanocrystals grown on graphene (CuO/TiO2–GR) were prepared by a simple hydrothermal method using Cu(CH3COO)2·H2O and (NH4)2TiF6 as precursors and graphene oxide (GO) as templates. The as-prepared composites were characterizated by TEM, XRD, FT–IR to determine composition and phase purity. The photocatalytic activity of the samples was evaluated by photo-degradation of methylene blue (MB) aqueous solution under UV and visible light illumination. This work may provide new insights into preparing other inorganic graphene-based composites.

Transformation of hydrophilic cotton fabrics into superhydrophobic surfaces for oil/water separation

In the present study, silica hydrosols were firstly prepared by water-based sol-gel method with the surfactant emulsification, using tetraethoxysilane as the precursor and ammonium hydroxide as the catalyst. Then, the silica hydrosols were applied to the cotton fabrics by dipping process, followed by the modification with (heptadecafluoro-1,1,2,2-tetradecyl) trimethoxysilane and heat treatment to prepare superhydrophobic cotton fabrics. The process resulted in SiO2 nanoparticles covalently attached to the cellulose surface and fluorine-containing siloxane coupling agent which brought about an inherent microscale roughness and the superhydrophobic character. The investigation of oil/water mixture has been carried out using the as-prepared superhydrophobic cellulose fabric-based materials.

Facile one-pot preparation of novel shell cross-linked nanocapsules: inverse miniemulsion RAFT polymerization as an alternative approach

A series of novel shell cross-linked nanocapsules were facilely fabricated in an inverse miniemulsion reversible addition–fragmentation chain transfer (RAFT) system, in which poly(2-(dimethylamino)ethyl methacrylate) (PDMAEMA) acted as a stabilizer and macroinitiator. The as-prepared nanocapsules with PDMAEMA cores and poly(methylacrylic acid) (PMAA) shells, had a size of 220 nm and can be used as a carrier for the encapsulation of hydrophilic components such as inorganic salts.

Preparation and Photocatalytic Activity of Magnetic Fe3O4/SiO2/TiO2 Composites

A simple sol-gel method was used to prepare magnetic Fe3O4/SiO2/TiO2 composites with core-shell structure. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), and transmission electron microscopy (TEM) have been applied to investigate the structure and morphology of the resultant composites. The obtained composites showed excellent magnetism and higher photodegradation ability than pure TiO2. The photocatalytic mechanism was also discussed. The magnetic composites should be extended to various potential applications, such as photodegradation, catalysis, separation, and purification processes.

Preparation of superhydrophobic and superoleophilic polypropylene fibers with application in oil/water separation

A novel type of fiber material for the separation of oil/water mixed liquids has been prepared by the chemical vapor deposition of hydrophobic silanes on commercially available polypropylene (PP) fiber. To achieve this, the PP fiber materials were first etched by concentrated H2SO4. Then, the as-prepared PP fiber materials were immersed in highly concentrated suspension of graphene oxide modified by amine-functionalized SiO2 nanoparticles (SiO2–GO). Finally, the as-prepared PP fiber materials were treated by the chemical vapor deposition of hydrophobic silane (octyltrichlorosilane) to form a superhydrophobic surface with a water contact angle more than 156o. The hydrophobic lightweight PP fiber materials are almost instantly filled with the oil phase when selectively absorbing oil from water. The oil can also be drained from the absorbed PP fiber materials. Moreover, the PP fiber material shows the good performance for repeated use.

In Situ Polymerization Approach to Poly(ε-caprolactone)-Graphene Oxide Composites

The grafting of graphene oxide (GO) with a cyclic ether monomer, ε-caprolactone (ε-CL), directly affords graphene-PCL nanocomposites. The resulting nanocomposites show good solubility in the solvents of polymers, exfoliation of graphene in the polymer matrix and excellent mechanical properties and robustness under bending.

Preparation of Biomimetic Zwitterionic Core Cross-Linked Nanocarriers for Control Release of Bioactive Agents

Biomimetic core cross-linked nanocarriers (CCL-NCs) with zwitterionic shell was constructed from an amphiphilic block copolymer poly(2-(dimethylamino) ethyl methacrylate-co-carboxybetaine)-b-polystyrene ((PDMAEMA-co-PCB)-b-PS) via mini-emulsion RAFT polymerization. CCL-NCs present in this report possess properties of redox-sensitivity, limited unspecific protein adsorptions and low cytotoxicity, which highly enhance their potential application in drug delivery. Morphology of CCL-NCs was characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS) measurements. The control release process has also been investigated under three different conditions with or without dithiothreitol (DTT) at pH 5.4, 6.5 and 7.4.

Facile preparation of superhydrophobic surface with high adhesive forces based carbon/silica composite films

Glass substrates modified by carbon/silica composites are fabricated through a two-step process for the preparation of a superhydrophobic surface (water contact angle ≥ 150°). Carbon nanoparticles were first prepared through a deposition process on glass using a hydrothermal synthesis route, then the glass was modified by SiO2 using the hydrolysis reaction of tetraethylorthosilicate at room temperature. It is not only a facile method to create a superhydrophobic surface, but also helps to form a multi-functional surface with high adhesive forces.