Advanced Materials Research Vols. 152-153

Abstract: Calcium phosphate coatings were deposited on H2O2-treated carbon/carbon composites by ultrasonicated induction heating (UIH) method under different preparation conditions. The phase, morphology and composition of the calcium phosphate coatings were characterized through X-ray diffraction (XRD), scanning electron microscopy (SEM) and the adhesion strength of these coatings and the scratched morphologies were determined by the scratch test and stereomicroscope (STM). The results show that when the solution concentration is 0.003 M and pH value is 6, the phase of as-prepared coating is OCP, and When the solution concentration is larger than 0.0125 M and pH value is less than 5.5, all the as-prepared coatings are monetite with different morphologies. Among these calcium phosphate coatings, the moneite coating on H2O2-treated C/C prepared in 0.1M solution at 373K has the highest bonding strength whose critical load is on average 38 N.

Abstract: In the present study, the compatibility and degradability of L-tyrosine derived polycarbonate(PC)/Chitosan（CTS）blend were investigated. The PC was synthesized in our laboratory. Blends of the polymers with compositions 4/1, 3/1, 1/1,1/3 and 1/4 w/w were prepared by solution-casting. The blends were characterized by FT-IR,DSC,XRD,SEM. No obvious two phases were observed. DSC and SEM analysis implied that all those components in consideration were compatible well in the blend formulation systems.Tg of the blends decreased with increasing PEG content. With the increase of the CTS content, the water retention ratio increases from 15% to 61%.

Abstract: In this work, we describe a novel facile method to prepare long one-dimensional hybrid nanofibers by using hydrated bacterial cellulose nanofibers (BCF) as template. Silver (Ag) nanoparticles with an average diameter of 1.5 nm were well dispersed on BC nanofibers via a simple in situ chemical-reduction between AgNO3 and NaBH4 at relatively low temperature. The bare BCF and as-prepared Ag/BCF hybrid nanofibers were characterized by a range of analytical techniques including transmission electron microscopy (TEM), X-ray diffraction (XRD), and UV–vis absorption spectra (UV–vis). The results reveal that Ag nanoparticles were homogeneously precipitated on the BCF surface. The results indicate that Ag/BCF hybrid nanofibers are promising candidate materials for functional antimicrobial agents.

Abstract: A novel phenylethynyl-terminated imide oligomer was prepared from a trifunctional amine and 4-phenylethynylphthalic anhydride (PEPA). The oligomer can be used to prepare the high performance resin-based composite material via resin transfer molding (RTM) due to its low melt viscosity(<2Pa.s) between 250°C and 320°C.The cured resin exhibits excellent thermal stability than PETI series as a result of the introduction of star-branched units. The thermal analysis of the curing kinetics of resin was carried out by differential scanning calorimetry (DSC), with the rate of cure reaction and the degree of cure calculated in the dynamic mode and being tested under isothermal conditions. A reasonable agreement between the experimental data and the kinetic model has been obtained over the whole processing temperature range which was important for processing simulation and quality control of processing for high performance composite.

Abstract: All the times we study a lot about Acidithiobacillus ferrooxidans (A.f) in mineral leaching, but when it is discovered that it can synthesize magnetosomes(Ms) in its body, researchers start to pay attention to its synthesis mechanism of Ms, while there is still few studies about the influence to A.f by external environment change. This article mainly aims at exploring the influence on A.f growth and magnetism under the outside magnetic field strength change. The findings show that not all A.f can synthesize magnetic substance. Under the most primary culture, there are few thalli can synthesize Ms; magnetic field at about 5mT, 10mT may promote thalli growth (quantity); magnetic field at about 25mT and 30mT may be harmful or beneficial to thalli response to time length; magnetic field at about 15mT, 20mT, 35mT, 40mT, 50mT may restrain thalli growth and reduce thalli activeness.

Abstract: Collagen is regarded as one of the most useful biomaterials. Collagen was extracted from wild Chinese soft-shelled turtles (Pelodiscus sinensis) and its molucular patterns and antioxidant activities were investigated. The SDS-PAGE analysis revealed that the collagen had three α bands with an approximate molecular weight of 400-410 kDa, which was similar to type V collagen with a molecular pattern of α1(V)α2(V)α3(V) or α1(V)[α2(V)]2. The antioxidant activity of collagen were examined by the radical-scavenging activity (RSA) assay and reducing power (RP) methods respectively. In the RSA assay, the DPPH free radical scavenging capability of the sample collagen was positively correlated with its concentration with a IC50 of 1.95mg/ml. The same trend was found in the RP assay. The reducing power of the sample collagen was also dependent with its dose employed.

Abstract: Coal ash, clay, coal powder and special type additive used to produce new type coal ash ceramsite by the sinter method. Effects of fly ash/clay/coal powder/special type additive ratio and calcinations temperature and calcinations time on compression strength and water holding capacity of the granules were studied. The best project is using a mixture of fly ash 80%, clay 10%, coal powder 5% and special type additive 5% produced by 30 min of sintering at 1150 . The results of landscape tiny pollute wastewater experiments show the wipe off rates of COD, NH3-N and P are above 80%, 60% and 70% separately.

Abstract: Anticancer drugs are always restricted as lacking of tumor cell-selective targeting. In this paper, to achieve double effects of targeting and decreasing the drug toxicity, the folate (FA) -O-carboxymethyl chitosan (O-CMC) and the methotrexate (MTX) encapsulated FA-O-CMC/CaCl2 nanoparticles were prepared. The numbers of FA conjugated to O-CMC, particle size, surface morphology, encapsulation efficiency and loading efficiency of the obtained nanoparticles were characterized. The results showed that the FA-O-CMC possessing targeting ability was achieved. MTX had been successfully loaded into the nanoparticles. The prepared nanoparticles were spherical in morphology with an average size of 322 nm

Abstract: N-isopropylacrylamide(NIPAAm) was dispersed in polyurethane(PU) solution and crosslinked with N,N’-methylene bisacrylamide(BIS) to form a semi-interpenetrating polymer networks. The synthesized solution was casted into water bathes with and without 0.25M sodium chloride to get a microporous film by wet phase inversion process. The ratios of BIS amount to N-isopropylacrylamide were varied. The structure and properties of polyurethane/ poly(N-isopropylacrylamide) (PU/PNIPAAm) composite film were characterized by differential scanning calorimetry (DSC) and scanning electron microscope (SEM). The swelling behavior of PU/PNIPPAm composite films was evaluated. The results showed that the addition of sodium chloride lower the LCST of PNIPAAm and the PU/PNIPAAm composite films exhibit temperature sensitivity under swollen conditions.

Abstract: The preparation and characterization of silver powders with spheric shape and different sizes by chemical reduction of silver ions in the presence of ethanol amine using hydrochinone (C6H6O2) as the reducing agent are described. The size distribution, microstructure, and the phase composition of the obtained Ag Powders were characterized by the Laser Particle Size Analyzer, Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and the X-ray diffraction (XRD). The Ag powder was in face-centered cubic crystal structure with spheric morphology. The average tap density of silver powders is up to 4.0g/cm3. It was also found that the size of the Ag particles can be adjusted conveniently to a certain degree by varying the silver ions content, the addition amount of dispersing agent, the aging time, the temperature of the reaction, and the concentration ratio of hydrochinone to Ag+.