Advanced Materials Research Vols. 152-153

Abstract: Pb(II)-imprinted chitosan/TiO2 hybrid film (LIHF) was synthesized through a two-step process. The selectivity of LIHF was studied via competitive adsorption experiment. The LIHF shows higher selectivity to Pb (II) ion than Cu (II) and Zn (II) ions. X-ray photoelectron spectroscopy(XPS) was used to characterize the as-obtained samples. XPS results showed that the nitrogen atom and the Pb (II) were concerned for coordination. The evidences for the imprinting process and the recognition of Pb (II) with LIHF were provided.

Abstract: In this study, we investigated antibacterial activity of zinc oxide (ZnO) nanoparticles coated on polyvinyl chloride (PVC) films against Escherichia. coli both in vitro and in actual test. Results showed that the nano-ZnO coated films displayed excellent inhibition effects on the growth of E. coli and the nano-ZnO particular was contributed to the bactericidal ability. The more amounts of the ZnO particulars the film coated, the greater inhibitory effect it exhibited. The disinfection efficiency with ZnO film is relatively constant at pH values in the range of 4.5 to 8.0. In the actual test, the number of E. coli cells from cut apple stored in a ZnO-coated bag in the dark decreased from 8.72 to 6.3 log CFU/ml after 1 day, while that of an same bag irradiated with light decreased from 8.72 to 3.5 log CFU/ml after 2 days of storage. The results reveal that nano-ZnO coated film has a good promise to make antimicrobial packaging again E. coli and reduce the risks of microbial growth on fresh-cut produce.

Abstract: Scanning Kelvin Probe (SKP) combined with Scanning Electron Microscope (SEM) and Energy-Dispersive Spectrometer (EDS) analysis were used to study the corrosion behavior and electrochemical law of weathering steel Q450NQR1 deposited with NaCl particles at initial period of heat-damp test. The results showed that Q450NQR1 was severely attacked by Cl- for the reason that a low electric potential anode area was formed after a NaCl particle deliquesced rapidly. This anode area was corroded quickly, resulted in the appearance of rust spot, which led to a conductivity decline of the steel substrate and an increase of potential in the rust region. Moreover, tiny crack formed on the rust scale during the early stage and the galvanic couple between rust spot area possessing a high electric potential and metal substrate with a low electric potential were the two main reasons for the expansion of rust layer and the enhancement of corrosion.

Abstract: Si3N4-based composite ceramic tool materials reinforced with TiC0.5N0.5 particles were fabricated by using hot-press-sintering technique with Al2O3 and Y2O3 as sintering aids. The effects of the content of TiC0.5N0.5 on the microstructure and properties of composite ceramic were investigated. The experimental results show that optimal mechanical properties were achieved for the composite with the addition of 20 vol.% TiC0.5N0.5 microparticles, with the flexural strength, fracture toughness and Vicker's hardness being 838 MPa, 8.5 MPa•m1/2 and 15.6 GPa. The fracture surface microstructure of the composites is characterized by scanning electron microscopy (SEM). Phase identification was carried out by X-ray diffraction (XRD). It was found that the microstructure of the material was homogenous and the elongated grain of β-Si3N4 was interlaced. And the fracture surfaces were observed to exhibit a mix of intergranular and transgranular fracture.

Abstract: The thermal stability of cotton cellulose treated with chemical mixtures containing P and N was studied by thermal analysis, infrared spectroscopy, char yield and limiting-oxygen-index (LOI). Our experiments demonstrated that the temperature and activation energy of pyrolysis were lower and the values of Char yield and LOI were greater for cotton cellulose treated with flame retardant than those for untreated sample.

Abstract: Microencapsulation technology is widely used in many industries recently because the stability of core material can be improved and the release characteristics can be modified. In this investigation, cinnamon oil was microencapsulated by simple coacervation. The size distribution is narrow and the mean diameter is 53.79 μm. The surface morphology of the resultant microcapsules was also characterized scanning electron microscopy (SEM). The results showed that the rates of cinnamon oil released from microencapsulation were not only affected by relative humidity in the microenvironment around microencapsulated powder, but also affected by the temperature.

Abstract: The water-soluble sulphite was encapsulated using ethylcellulose phase separation. The effect of different process factors in the phase separation process on the encapsulation efficiency and the release profile of SO2 from the microparticles were evaluated. The results showed that the SO2 release from the microparticles containing sulphite was affected by the relative humidity in the microenvironment.

Abstract: In this work, analysis was performed to investigate the reasons resulting in corrosion of 316L of heat exchanger tube in the producing glycine process. Results demonstrated that corrosion of 316L is attributed to intergranular corrosion of nonsensitized. Intergranular corrosion of nonsensitized occurs of 316L, the elements of Si, Ni, Mo are clustering, and the carbon oxide increases corrosion.

Abstract: FRP bolt is ideal material used for coal rib supporting. For some reasons, the FRP bolt is often affected by eccentric load which is very worse to bolt by theory analysis. It is first time to simulate FRP bolt under eccentric load with experiment method and design eccentric load experiment. Compared with general load, experiment results show the maximum anti-drawing force and elongation feature have a big dip under eccentric load.

Abstract: Hydroxyl-terminated hyperbranched polyurethane elastomer (HBPU) was synthesized by graft copolymerization of hyperbranched poly (amine-ester) polyols(HPAE) and polyether-based aliphatic polyurethane prepolymer(PPU), and the PPU was synthesized by step polymerization of isophorone diisocyanate(IPDI) with polyethylene glycol(PEG) and dibutyltin dilaurate(DBTDL) as catalyst. The FT-IR spectroscopy, TGA and XRD were used to characterize the structure, thermal properties and crystallinity of HBPU. The mechanical properties of the elastomers were conducted on a testing machine. Microphase separation of HBPU film surface was studied by atomic force microscopy (AFM). The experimental results showed that the HBPU took on excellent hydrogen bonding and mechanical properties. The tensile strength of HBPU elastomer reached to 20.6MPa, which increased by 41.2 times than that of PPU elastomer. And the elongation at break was as high as 251.3%.