No abstract

No abstract

A water‐soluble epoxy resin was synthesized by the reaction between novolac epoxy resin (F‐51) and diethanolamine. Then, the modified F‐51 was mixed with poly(alkylene glycol allyl glycidyl ether) as a film former of a sizing agent. A series of water‐soluble sizing agents for carbon fiber (CF) were prepared. The modified F‐51 was analyzed by Fourier Transform infrared spectroscopy. The surface morphology of the CF was characterized by scanning electron microscopy. The effects of the sizing agent on the handling characteristics were investigated by abrasion resistance, fluffs, and breakage and stiffness tests. The results show that the abrasion resistance of the sized CF increased by 114.5% and reached 2344 times and the mass of fabric hairiness decreased to 3.2 mg. The interlaminar shear strength (ILSS) test indicated that the interfacial adhesion of the composite could be greatly improved. The ILSS of the sized CF composite could reach a maximum value of 42.40 MPa. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 39843.

No abstract

No abstract

In order to obtain magnetic MoS2 and investigate the influence of magnetic moment on the microwave absorption properties of MoS2, transition metal element Ni-doped MoS2 (0–30 at%) was obtained by a hydrothermal synthesis. The results revealed that the low doping concentration (<10 at%) did not significantly change the crystal structure of MoS2, and the Ni element formed a NixMo1−xS2 compound within the MoS2 bulk phase. While the high doping concentration (10–30 at%) led to the formation of impurities. The hydrothermal products which were formed by the accumulation of pleated nanosheets looked like spherical flowers. As the doping concentration further increased, the spherical particles became more compact. The magnetization of MoS2 could be increased by proper amount of Ni doping. When doping with 3 at% Ni (Ni-3), the Ms value increased from 0.53 emu g−1 for non-doped MoS2 to 0.93 emu g−1. When the doping ratio was further increased, the Ms value of the material decreased. The zigzag edges and variations in the number of vacancies in the materials may be the root of changes in magnetic properties. The overall performance of Ni-3 was also the best in the examined doping range. Compared with non-doped MoS2, the matching thickness decreased from 3.50 to 2.05 mm, while the minimum reflection loss value decreased from −55.18 to −58.08 dB, and the effective absorption bandwidth (<−10 dB) increased from 3.05 to 5.19 GHz. The excellent absorption performance of the doped materials can be attributed to the change of complex dielectric constant and complex permeability of MoS2 and resulting in the improvement of loss capability. This study may introduce new opportunities for fully exploiting these nanocrystals for microwave absorption, even for diluted magnetic semiconductors.

No abstract

A systematic study on the magnetic and electrical percolation phenomena of BaTiO 3 (BTO)-NiZnF 2 O 4 (NZFO) composite films is presented in this work with the purpose of simplifying the preparation process of high-performance 1–3-type multiferroic composite films. Results show that the percolation threshold of the composite films depends on the macroscopic dimension of the material. The low-dimensional nature of the composite films results in different percolation thresholds with topological transition in vertical and horizontal directions. BTO-NZFO composite films with a grain size of 15 nm and a thickness of 100 nm exhibited a percolation threshold of 0.18 in the normal direction and a percolation threshold of 0.48 in the horizontal direction. In light of this intriguing feature, a novel multiferroic composite film with 1–3 structure and strong magnetoelectric coupling was easily prepared by a 0–3 process via controlling the NZFO content in the region between two percolation thresholds.