Advanced Materials Research Vols. 335-336

Abstract: Nano-sized silicon dioxide (SiO₂) is widely utilized in artificial bone, artificial tooth, interventional catheters and drug delivery system，so it is imperative to study SiO₂ NPs on the role of the body damage. Consulted with standard reference of GB/T16886, 20 and 80 nm SiO₂ NPs were selected to prepare suspension (1mg/ml) for subacute systemic toxicity; 2000mg/ml suspension for MTT; and extracts (0.1g/ml) for hemolytic test. The results show that the hemolysis rate are all more than 5%, after its continuous injection of 2W nanoparticles into SD rats and New Zealand Rabbits, the alterations on the hemoglobin, hematocrit, mean corpuscular volume and other indicators have gained in blood routine test, and there was a marked inhibition on the L929 cells of SiO₂ NPs. Therefore, these two kinds of particle size of SiO₂ NPs have certain extent of injury effect on the blood system, and the contact time of NPs in the blood compatibility evaluation has play a more important role than the others.

Abstract: By trying experiments on the dry-shrinkage and temperature-shrinkage performance, polypropylene fiber and glass fiber’s effect on the deformation performance of cement-stabilized macadam is researched. What’s more, the dry-shrinkage and temperature-shrinkage rule of fiber is discussed.

Abstract: The microstructures and mechenical properties were studied of the reinforced cast aluminum bronze by modified nano-SiC powders have been invastigated in this paper. The results show that the structures and fractograph of the samples are obviously refined, and the β phase was obviously reduced, while the strength and toughness are significantly increased by 14% and 51% simultaneously.

Abstract: The milling of hardened steel generates very high temperature in the cutting zone, and leads to detrimental effects on the cutting force, workpiece surface finish and tool life. Cryogenic machining is an environmental friendly new approach for the desirable control of the cutting temperature in the cutting zone. The present work investigates the effect of cryogenic cooling by liquid nitrogen (LN₂) on the cutting temperature, cutting force and workpiece surface roughness on the end milling of AISI D2 steel by CVD TiN coated carbide insert, at a constant cutting speed of 100 m/min and varying feed rate in the range of 0.01-0.02 mm/tooth. The experimental results showed that with LN₂ as a coolant the cutting force and workpiece surface roughness were reduced compared to dry and wet machining due to the better lubrication and cooling effect through reduction of cutting zone temperature.

Abstract: The paper introduces the precision processing technology of grinding using magnetic fluid and presents the working mechanism of magnetic-fluid grinding. Based on Preston Equation, it also establishes a mathematical modeling for magnetic-fluid grinding, which is used to study the relationships between the effects of grinding and the variation of such technological parameters as the revolving speed of work-piece, the intensity of magnetic field, the distance between work-piece surface and magnetic center, the size of the magnetic fluid and grinding time, etc. Analysis on the grinding of Si3N4 ceramic-balls proves that the model has been well established.

Abstract: Abstract. The nanofiber based filtering material, made up of fibers of diameter less than 1000 nm, have been discovered as new filtering material for effective filtrations. Lyocell fiber is a kind of regenerated fiber which can be easily fibrillated and brought no negative impact on the recovery of filter material.The present study focuses on how the Lyocell fiber changes with the intensity of beating and compares the effect of nano-fibrillated Lyocell fiber（61°SR） and micro glass fiber（44°SR） on the properties of filter material. The results show that the length, diameter, distortion and degree of fibrillation of Lyocell fiber changes obviously by beating, and a mass of nano-fibril appeared after intensive beating. At the same time, the air permeability and pore size distribution is similar when the content of fibrillated Lyocell fiber and micro glass fiber are the same in filter material; What’s more, the strength of filter material increases with the percentage of fibrillated Lyocell fiber increasing, But the micro glass gets an opposite trend. The burst strength of the filter material with 20 wt.% fibrillated Lyocell fiber is 336KPa, with 20 wt.% micro glass fiber is 71KPa.This study has shed some light on the application of Lyocell fiber to improve the accuracy of filter material effectively.

Abstract: Fe nanoparticles prepared by the arc was used in the present study. It was oxidized by laying in the air and passivated by argon ion bombardment. The microsturcture, oxygen content and oxygen atom position in oxidized Fe nanoparticles were investigated. Furthermore, the variation of oxygen content with time in the passivated Fe nanoparticles and Fe nonparticles was also studied. The results showed that the effective size of oxidized Fe nanoparticles was about 10nm-40nm, and oxidation process was conducted on the surface. On the other hand, the oxygen content in passivated Fe nanoparticles reduced by comparing with that laying in the air for the same time.

Abstract: Alginate fibre has attracted great attention in the area of biological medical materials due to its unique biological properties. But its low tenacity greatly hinders its application area. Therefore, the preparation technology of alginate fibre has been as an important research direction in this area in recent years. The purpose of this article is to prepare the calcium alginate fibre with good properties by wet spinning. The structure and properties of this fibre are analyzed by scanning electron microscope，infrared spectrometer，thermal gravimetric analyzer and DSC.

Abstract: In order to investigate the effect of bentonite binder on adsorption and cation exchange properties of granulated nano NaY zeolite, the adsorption of Xe and N2 and removal of Sr2+ ion from aqueous solution was studied. The results showed that increase in bentonite content of granules from 20 to 40 weight percent caused increase in the rupture load of granules by 232%, decrease in BET surface area by 66% and lower the Sr²⁺ uptake percentage by 35%. The Henry’s law constant, heat of adsorption, effective crystal diffusivity as well as activation energy of diffusion of Xe over granulated nano NaY with 25% bentonite was also measured by pulse chromatography method. Obtained results were compared with similar results of binderless micron sized NaY material. Results indicated that although the adsorption of xenon on the binder of bentonite was negligible, the diffusion resistance created by this binder was significant such that the effective crystal diffusivity in the granules with 25% binder determined to be 4302 percent lower than the granules with no binder.

Abstract: Highly ordered Cu, Ag and Au nanowire arrays with high aspect ratio and highly dense self-supporting nanowire patterns of copper group were successfully prepared using cyclic voltammetry with the assistance of anodic aluminum oxide (AAO) template. The X-ray diffraction (XRD) patterns of the metal nanowries were indexed to the face-centered cubic structure. The field emission scanning electron microscope (FE-SEM) results demonstrated that the length of nanowire could be controlled by changing the electrodepositon conditions. The aspect ratio of nanowire arrays can be tuned.