Advanced Materials Research Vol. 650

Abstract: The Co-doped Co_0.2Mn_1.7Sn compound was prepared by melting appropriate metals with purity higher than 99.9% in a magneto-controlled arc furnace. The compound shows single-phase characteristics. Magnetic measurements show that, the abnormal negative magnetization, i.e. diamagnetism occurs at low temperature. Moreover, it displays the common weak ferromagnetism, together with some spin-glass-like behavior. Besides, we conjure that abnormal negative magnetization should be from the magnetized sample when cooling the compound in the so-called zero field (in fact it is about 2.5×10^-5 T).

Abstract: Gold nanoparticles (Au NPs) were loaded into poly(N-isopropylacrylamide) based temperature responsive microgels by seed-growth method. Their growth process was tracked by their extinction spectra at various reaction times. Their average diameter measured by field emission transmission electron microscopy is 12 nm, and their weight content by thermogravimetric analysis is 29.2%. The localized surface plasmon resonance (LSPR) property of the loaded Au NPs changes remarkably within the same temperature range as the particle size of the hybrid microgels varys, due to variation of the refractive index surrounding the Au NPs and plasmonic coupling between them. This result indicates that the LSPR property of the Au NPs embedded within temperature responsive microgels can be tuned by environmental temperature.

Abstract: This study optimizes on the technological conditions for extraction of natural bamboo fiber by means of microbial degradation of bamboo lignin. Results show that by the orthogonal experiment, we have studied out optimal conditions for combining three strains with fermentation to produce enzyme: 10.0 g/L glucose, 0.2 g/L ammonium tartrate, 4.5 buffer solution pH value and 20.0/250 ml loading liquid quantity. In these above four factors, the primary and secondary factors affecting enzyme production are: carbon source > pH value > loading liquid quantity > nitrogen source. Meanwhile, the experiment has studied the influence of single factor on lignin degradation: at the temperature of 37 °C, about 4 x 10⁷spore concentration, adding 1.5 mg/L veratryl alcohol and introducing air at the efflux rate of 1 L/min are bamboo crude fiber optimal conditions for microbial selective degradation of lignin.

Abstract: Non halogen flame retardant researches have achieved great progress; however, theoretical works are much lagged. Here we show a model of an efficient Flame Retardant Carpet (e-FRC) based on the synergistic flame retardant system of phosphorus and hydroxyl compounds that can give ABS UL 94 V-0 efficiently. This model is further extended to explain the high efficient flame retardancy of phosphonates by proposing a surfactant structured intermediate from pyrolysis. The smart intermediate self-assembles on charred polymer matrix, forming an anisotropy molecular membrane, with one side of hydrocarbon groups and the other of inorganic groups. The organic side adheres onto polymeric char, and inorganic side facing the fire, forms an Oxygen Shielding Screen (OSS). The OSS together with charred layer underneath constitutes an e-FRC. This e-FRC structure can be found in earlier reports. It can explain all present existing efficient flame retardant systems.

Abstract: In this study, we investigate the effect of four types of water reducing agen on fluidity, suspensibility, thixotropy and the particle size of ceramic slurry and analyze the corresponding mechanism. Those water reducing agen include Lignin sulfonate water reducing agent, Sodium metasilicate, naphthalene sulfonate formaldehyde condensate, and the inorganic compound reducing agent. Experiment results shows that the relative molecular mass, the structure of water reducer, the content, and the moisture content of ceramic blank particle can play an important role in the adaptability of both water reducing agen and ceramic slurry. We make a mixed water reducer with lignin sulfonate, sodium metasilicate, and naphthalene sulfonate formaldehyde condensate by the corresponding appropriate mass ratio: 3:2:1. Then we add the mixed water reducing agen by the total dosage of 0.6% into the designed ceramic castable. We find that the performance of the slurry is considerably better improved by the mixed water reducing agen than by either a single one or by the currently commercial inorganic compound reducing agent, such as better improvements in liquidity, the slurry particle size, the mechanical strength of dry body, and the damage strength of porcelain body.

Abstract: The surface topography and properties of coating layer have an important influence on penetration and distribution of the print ink. In this research, the main objective was to investigate the effect of binder on the coating surface topography and characteristics. The surface microstructure was explored in the method of numerical and visual analysis using mercury porosimetry measurment and atomic force microscopy (AFM). The findings indicated that the binder content on the coating surface affected the pore size, depth and distribution of the coated paper surface. The conclusions were drawn that more amount of binder on the coating surface could contribute to improve the coating surface topography and the formation of even pore size and distribution, which was good to the paper surface characteristics and resulted in low roughness, high paper gloss, low ink absorption and high paper surface efficiency.

Abstract: Aimed at the lack of research about damage mechanism, a 3-D progressive impact damage analysis method was applied to analyze the low-energy impact damage process of T300/BMP-316 laminates with three different ply stacking sequences. The influences of ply parameters on the impact damage of laminates were researched. The impact damage mechanism was analyzed combined with the figure of impact stress in laminates. It is showed that the matrix cracking is caused by the inconsistent distortion of the matrix and fiber when the tensile stress that perpendicular to the fiber direction reaches a given value, and the delamination near to the impacted back face and front face are caused individually by the matrix cracking and the inconsistent bend stiffness between two laminas.

Abstract: Sprayed concrete is widely applied thanks to current development of road and underground building industry. Selection of input materials, design, preparation and testing of sprayed concrete is relatively expensive because spraying machinery has to be used for application. The paper focuses on possibilities of manufacture and testing of sprayed concrete prepared in common laboratory mixer and compacted by vibration combined with defined level of pressure. This approach seems to be an alternative for initial design and testing of sprayed concrete prepared by machinery equipment.

Abstract: This work is devoted to development of synthesis methods of nano- and macrofunctional materials for industry, electronics, and modern science and technology. The authors have developed advanced methods of obtaining various carbon, silicate and chalcogenide materials by melt and hydrothermal methods with using of optimized chemical and thermodynamic parameters of synthesis. As a result a new super hard material - carbonate-synthetic diamond polycrystals were obtained. Nanodiamonds were synthesized by direct conversion of graphite into diamond. New species of macro- and fine crystalline piezoelectric tourmaline containing 3d-elements were produced by hydrothermal method. Using a flux technique the single crystals of different chalcogenide phase with unique superconducting properties were grown.

Abstract: This paper describes two methods of preparation of magnetic fluids based on associated polymers. The first method is ultrasonic (US) dispersing of magnetite microparticles (MP) in aqueous solutions of associated polymers such as hydrophobically modified polyacrylamides (HM PAAm) – terpolymers of acrylamide (AAm), sodium acrylate (SA) and N-dodecylacrylamide (DDAA). According to the second method the magnetic fluids were formed by addition of magnetic polymers, synthesized by means of a micellar copolymerization of AA, SA and DDAA in the presence of MP, into water. The investigation of the rheological properties has shown that magnetic fluids obtained can be reversibly transformed in physical gels in magnetic field (MF).