Time filter

Source Type

Xia H.,Zhejiang University | Zhao X.,Zhejiang University | Yang G.,Zhejiang University | Yang G.,Shanghai Genius Advanced Materials Co.
Materials Letters | Year: 2013

A double in situ approach was adopted to fabricate Fe3O 4/polyamide 6 magnetic nanocomposite by the combination of the formation of Fe3O4 NPs and the polymerization of ε-caprolactam in one-pot. The ε-caprolactam was not only used as a solvent for the synthesis of Fe3O4 NPs, but also served as monomer in anionic ring-opening polymerization. The properties of Fe 3O4/polyamide 6 nanocomposite were characterized by XRD, SEM, TEM, TGA and SQUID. The results indicated that the nanocomposite consisted of dispersed Fe3O4 NPs (ca. 15 nm) and polyamide 6, and it had superparamagnetic behavior with saturation magnetization of 1.7 emu/g. © 2013 Elsevier B.V. Source

Gong Y.,CAS Institute of Chemistry | Yang G.,Shanghai Genius Advanced Materials Co.
Journal of Applied Polymer Science | Year: 2010

Recycled polyamide 6 (PA6) cloth was used as the only raw material to prepare single polymer composites (SPC) by partially melting the PA6 fibers. During the process, part of PA6 fibers was melted to fill the gap between the remained fibers at a temperature in the melting temperature range of fibers. The matrix was in situ formed by recrystallization of the molten part and bonded the remained unmolten fibers together with cooling. Effects of a critical parameter, processing temperature (222-228°C), on the partially melting behavior of PA6 fibers and the properties of the resulting SPC were investigated by differential scanning calorimetry (DSC), scanning electron microscope (SEM), and tensile tests. As a result, at the processing temperature of 226°C, 31% of PA6 fibers were exactly molt to form the matrix and the tensile strength of prepared SPC achieved a maximal value of 138 MPa that was 105% higher than the one of neat PA6. © 2010 Wiley Periodicals, Inc. Source

Wu F.,CAS Institute of Chemistry | Wu F.,University of Chinese Academy of Sciences | Yang G.,Shanghai Genius Advanced Materials Co.
Polymers for Advanced Technologies | Year: 2011

Poly(butylene terephthalate) (PBT) had been covalently attached onto the surface of multiwalled carbon nanotubes (MWNTs) by a "grafting from" method based on in situ ring-opening polymerization (ROP) of cyclic butylene terephthalate oligomers (CBT) using MWNT-supported initiator (MWNT-g-Sn). The Sn-O bond grafted on the surface of MWNTs, which was confirmed by X-ray photoelectron spectroscopy, provided the initiating sites for ROP of CBT. Fourier transformed infrared spectroscopy and nuclear magnetic resonance were used to confirm the chemical structure of MWNT-graft-PBT copolymer and emission transmission electron microscope was utilized to observe the nanostructure of the PBT functionalized MWNTs. A distinct core-shell structure with PBT layer as the shell could be observed after functionalization of PBT despite it was not uniform. The results of thermogravimetric analysis indicated that the grafting ratio of PBT was about 59.3%. Furthermore, the solubility of the PBT functionalized MWNTs in phenol/tetrachloroethane had also been investigated. © 2010 John Wiley & Sons, Ltd. Source

Yan D.,Jiangsu University of Science and Technology | Yang G.,Shanghai Genius Advanced Materials Co.
Journal of Applied Polymer Science | Year: 2012

In this article, polyamide 6/polystyrene/multiwalled carbon nanotubes (PA6/PS/MWNTs) nanocomposites were prepared via successive in-situ polymerization. The effect of MWNTs on the morphology and electrical properties of polyamide 6/polystyrene (PA6/PS) blends was investigated in detail. Scanning electron microscopy and transmission electron microscopy analysis indicated that MWNTs were selectively located at the interface of PA6 and PS. The interface-localized MWNTs could act as compatibilizers, which resulted in the decreased size of PS domains in PA6 matrix and the delayed phase inversion of immiscible PA6/PS blends. The PA6/PS interface was continuous in the MWNTs-filled (70/30) PA6/PS blends. Selectively located MWNTs at the continuous interface were connected with each other, which resulted in the establishment of a MWNTs conductive pathway in (70/30) PA6/PS blends. Electrical properties analysis indicated that the volume resistivity of (70/30) PA6/PS blends with 0.5 and 1.0 wt % MWNTs loading was decreased by about nine orders of magnitude. © 2011 Wiley Periodicals, Inc. Source

Xia H.,Zhejiang University | Yang G.,Zhejiang University | Yang G.,Shanghai Genius Advanced Materials Co.
RSC Advances | Year: 2013

Lactams have strong polarity, high boiling points, and strong coordination capacity. However they are yet to be well accepted as solvents for the synthesis of nanomaterials. This work aims at developing a facile and general lactam method to synthesize inorganic nanoparticles such as ZnO and Fe 3O4 using three homologous lactams, γ-butyrolactam (BL), δ-valerolactam (VL) and ε-caprolactam (CL), as solvents. The resulting nanoparticles (NPs) are uniform and spherical in shape and have good dispersion. The ZnO NPs synthesized in BL, VL and CL have average diameters of ca. 30.0, 7.3, and 8.5 nm, respectively. The average diameters of Fe 3O4 NPs synthesized in BL, VL and CL are ca. 6.3, 4.0 and 4.8 nm, respectively. Moreover, their dispersion tends to deteriorate with increasing number of methylene groups in the lactam. Some explanations for the influence of lactam on the morphology of the synthesized NPs are proposed. Optical properties of ZnO NPs are investigated and are correlated with their morphologies and surface states. 6-Aminohexanoic acid (AHA), a biocompatible amino acid, is used to displace lactam capped on the surfaces of ZnO NPs. This journal is © The Royal Society of Chemistry 2013. Source

Discover hidden collaborations