Advanced Materials Research Vol. 663

Abstract: This paper puts forward an in-situ testing method for the mechanical properties of TSV copper pillar by using micro-compression experiment. The sample for micro-compression test is prepared by the processes as follows: (a) etching TSV with deep reactive ion etching (DRIE), (b) sputtering a layer of Ti/Cu as the seed layer, (c) TSV copper plating technology, and (d) corroding the silicon to obtain the final specimen. The micro compression test is done with a micro-compression system, consisting of a three-dimensional adjustable stage, a microscope, a force sensor, and a piezoelectric motor. The experimental results show that the platform can test TSV copper pillar’s stress, the accuracy is reached mN. The yield strength of TSV copper pillar is about 199.89 MPa.

Abstract: Cationic polyelectrolyte poly(diallyldimethylammonium chloride) (PDDA) was used to stabilize graphene sheets in the self-assembly of AgCl/PDDA/Graphene heterostructure. The resultant AgCl/PDDA/Graphene nanocomposites were characterized by Scanning electron microscopy, Atomic force microscopy and X-ray photoelectron spectroscopy. The results showed that AgCl nanoparticles with sizes of 500 nm uniformly positioned on the PDDA stabilized graphene sheets surface. This work presents a facile and environmentally friendly approach to the synthesis of AgCl/PDDA/Graphene and opens up a new possibility for preparing graphene-based nanomaterials for large-scale applications.

Abstract: High-resolution K-edge x-ray absorption data are presented for Mg, Zn and O of Mg_1-xZn_xO films. A detailed analysis of the extended x-ray absorption fine structure by using the IFEFFIT program is given, and the Zn form chemical bonds with O are obtained. The x-ray absorption near-edge structure of Mg, Zn and O K-edge are investigated, and the electronic structures of Mg_1-xZn_xO with various compositions are studied.

Abstract: In recent years, excellent cytocompatability of magnesium alloy in addition to the bioactivity, biodegradation and match of mechanical properties is increasingly indispensable for biomedical applications. Surface modification by single inorganic or polymer coating provides inadequate functionality in reducing corrosion rate and improving cytobiocopatibility, bioactive polymer composite coatings are supposed to draw on multiple merits of individual component materials and may present a new trend to develop Magnesium alloy biomaterials with promising properties. This review focuses on the effects of polymer composite coatings and their preparations through sealing micro pores in inorganic coating, low temperature deposition techniques, biomemitic synthesis as well as controllable bioactive composite coating by virtue of irradiation modification.

Abstract: In this study we use chemical and physical vapor depositions to fabricate amorphous silicon (a-Si) films. We also use traditional rapid thermal annealing (RTA) and advanced microwave annealing (MWA) to activate or crystallize a-Si films and then observe their sheet resistances and crystallization. We discovered, although the cost of films fabricated by electron beam (e-beam) evaporation is relatively lower than by chemical vapor deposition (CVD), the effects of the former method are poorer whether in sheet resistance or film crystallization. In addition, only at the doping layer prepared by CVD can film crystallization degree produced by MWA match RTA.

Abstract: A new kind of microsphere filler was synthesized with octyltrimethoxysilane (WD13) and tetraethoxysilane (TEOS) by sol-gel method. The morphology of the filler was measured by TEM. The so synthesized spheres were added into the silicone rubber. Both the strain-stress and the water contact angle of the silicone rubber were researched. The results showed that both the mechanical property and the hydrophobic performance of the composite were improved compared with the blank specimen. The possible strengthen mechanism of the filler was discussed. The neotype silica sphere researched in this paper could react with the silicone rubber chains which perfects the vulcanization of the silicone rubber. This kind of sphere filler exhibits many merits for usage as filler.

Abstract: In this paper, we used RF sputter to deposit the ZnO seed layer of 0.6 μm in thickness, which was then immersed in zinc nitrate hexahydrate [Zn(NO3)2•6H2O] and hexamethylenetetramine (C6H12N4) mixture solution of different concentrations for the growth of ZnO nanorods by hydrothermal method. After annealing at different temperatures, thermal field emission scanning electron microscope (TFSEM) was used to observe the arrangement and growth of ZnO nanorods. We found the concentration of the mixture solution of C6H12N4 and Zn(NO3)2•6H2O would affect the thickness and crystallization of ZnO nanorods, and the annealing temperature would change their columnar arrangement structure. The arrangement structure of the ZnO nanorods grown in the mixture solution of 0.2M concentration had more gaps and pores. Under this condition, we successfully fabricated a dye-sensitized solar cell (DSSC), of which the performance could be further improved by using ZnO nanorods prepared by many different methods.

Abstract: Highly birefringent extruded elliptical-hole photonic crystal fibers (PCFs) with single defect and double defect are proposed and investigated, which are supposed to be achieved by extruding conventional triangular-lattice circular-hole PCFs. Comparative research on the birefringence and the confinement loss of the proposed PCFs with single defect and double defect is presented. Simulated results show that the proposed extruded elliptical-hole PCFs with single defect and double defect can be with high birefringence up to the order of 10-2. Confinement loss increases when the ellipticity of the air hole of the proposed PCFs increases, which nevertheless can be overcome by increasing the ring number or the area of the air holes in the fiber cladding.

Abstract: Pyrolyzation of lignin to aromatic compounds with small molecule weight is one of the ways to efficient utilization of lignin resource. Basing on the data of thermogravimetric scanning curve (TG-DTG) and pyrolysis-gas chromatography -mass spectrometry (Py-GC-MS), the change in the distribution of pyrolysis products at different temperature was analyzed. The results showed that lignin could produce a large number of aromatic compounds having hydroxy or methoxy groups under the conditions of anaerobic and 250-450°C, but it was not benefit to obtain useful organic compounds when pyrolyzed at elevated temperatures.

Abstract: This paper focuses on the thermo-mechanical behaviors of the shape memory alloy board with a crack and under the torsion load. A stress field equation from mechanics of elasticity is used to describe the stress distribution around the crack tip in the shape memory alloy board. A martensitic phase transition equation is supposed to predict the martensitic phase transition behaviors of the field near the crack tip in the shape memory alloy board. The martensitic phase transition zones near the crack tip in the shape memory alloy board under the torsion load are numerically described based on the stress field equation and martensitic phase transition equation at various temperatures. Results show that the stress field equation and martensitic phase transition equation can predict the thermo-mechanical behaviors of the shape memory alloy board with a crack and under the torsion load effectively.