Jiangfeng Chen

Synthesis of walnut-like hierarchical structure with superhydrophobic and conductive properties

Walnut-like structures made up of a polyaniline (PANI) nanofiber network and polystyrene (PS) microspheres are successfully fabricated by a novel approach, “competitive adsorption–restricted polymerization”. In the reaction system, PS microspheres are simultaneously encapsulated by cationic surfactant and aniline hydrochloride. Just this cationic surfactant molecule affects the nucleation model and second growth of PANI via electrostatic interactions and steric hindrance, which accounts for the formation of a PANI nanofiber network coating on the PS surface. The size, ordering and amount of PANI nanofibers on the three-dimensional surface can be particularly controlled by altering a variety of synthetic conditions, such as the amount of cationic surfactant, temperature and concentration. A superhydrophobic and conductive surface is obtained by drop-casting a suspension of these walnut-like PS/PANI particles onto a substrate.

Waist cross-linked micelles synthesized viaself-assembly guiding radical polymerization

Amphiphilic micelles with waist cross-linked structure exhibit both core–shell reversing behavior and thermal sensitivity.

Nanostructuration of reactive polyhedral oligomeric silsesquioxane-based block copolymer as modifier in an epoxy network

To obtain a novel polyhedral oligomeric silsesquioxane (POSS)-based nanomodifier, copolymerization of methacrylate-POSS (MA-POSS) and glycidyl MA (GMA) was carried out via reversible addition-fragmentation chain transfer process. The as-synthesized poly(glycidyl methacrylate) (PGMA)-b-P(MA-POSS) block copolymers (BCPs) were characterized by proton nuclear magnetic resonance, Fourier transform infrared spectroscopy, and gel permeation chromatography. The introduction of a POSS component improved the thermostability of the BCP. Then, PGMA-b-P(MA-POSS) copolymer was reactively incorporated into 4,4′-methylenebis(2,6-diethylaniline) and the epoxy network. Compared with commercial inert MA-POSS-methyl MA (POSS-MMA) copolymers (15 wt% and 45 wt% POSS, respectively), PGMA-b-P(MA-POSS) can self-assemble in epoxy to micelles with diameters of 20–40 nm. Due to the formation of uniform nanostructures, reactive POSS-modified epoxy composites exhibited higher glass transition temperature and double the rubbery state moduli (87 MPa) than neat epoxy (41 MPa). This work provided an efficient way to fabricate a POSS-based nanocomposite via the introduction of nanomodifier PGMA-b-P(MA-POSS) which can pre-react with reactive monomer.