Applied Mechanics and Materials Vols. 670-671

Abstract: The non-equilibrium atmospheric pressure Ar plasma was applied for the polymerization of maleic anhydride (MA). The deposited films were analyzed by using Fourier transform infrared spectroscopy (FT-IR) proving the monomer was successfully polymerized with retaining the functional groups. The intensity of optical emission spectroscopy (OES) of the plasma jet was found to become weaker when the monomer was introduced into the jet. This was interpreted as the result of the energy transfer from the metastable Ar to the monomer. It was proposed that the excited MA changed into π-π* transition state to produce dimer biradicals which initiate the polymerization.

Abstract: Mechanorphore-based Poly (glycidyl methacrylate) was synthesized by atom transfer radical polymerization (ATRP) of glycidyl methacrylate (GMA) in bulk by using spiropyran-based initiator, CuCl in combination with N,N,N’,N’’,N’’-pentamethyldiethylenetriamine (PMDETA) as catalyst. The resultant polymer was characterized by gel permeation chromatography (GPC) and ¹H NMR spectroscopy. The relative molecular mass of PGMA can be changed by polymerization time. The resultant polymers have controlled molecular weight and low polydispersity. The present synthetic strategy provides a convenient and efficient method to synthesize mechanophore-linked PGMA which can be ulteriorly crosslinked to form thermosetting polymer networks.

Abstract: PCBs removal in the aged leachate by a new combination process based on an innovative biofilm reactor with natural fiber media, combined coagulation with a two-staged sequencing batch biofilm reactor with Luffa Sponges (LS) as the biomass carriers (LS-SBBR), was studied in this paper. The results indicated that the total PCBs removal in the aged leachate was 51.97%, and the PCBs removals are mainly achieved by the removal of trichlorobiphenyls, the PCBs contents in sludge in the two-staged LS-SBBR were consistent with the conclusion that the PCBs removal in liquid phase of the second LS-SBBR was higher than that of the first LS-SBBR.

Abstract: Coal is a natural porous media, its porosity and structural integrity influenced the gas adsorption and desorption characteristics greatly, as well as physical and mechanical properties of coal. Scanning electron microscopy (SEM) is applied to acquire SEM image of four kinds of coal samples at different zoom levels, and the box dimension can be worked out based on the pore preprocessing of SEM images. Then, the numerical value of box dimension is used to describe the development degree of the four kinds of coal sample and four development degrees’ sequence. At last, the intrinsic relevance between fractal dimension and other parameters is analyzed through mathematic method. The results show as follows: coal sample has self-similarity characteristic; the fractal dimension is related to both the total number of pores and porosity degree; the data of the coal pore, analyzed through fractal dimension, are consistent with that through traditional method; what’s more, fractal dimension has more advantages in describing accuracy and simplicity.

Abstract: The chemical reduction method was used to deposit copper nanoparticles (about 20nm) on the surface of the barium titanate (BT, r=50nm). Then the dielectric properties and the mechanism of BaTiO₃-Cu/polyimide composite were studied. The results showed that the effective dielectric permittivity of the composite with 60 w_t% of BT-Cu (less than 13.00 w_t% of copper) fillers was greater than 120, and the dielectric loss of which was lower than 0.025. Due to very low dielectric loss, so this composite was a two-phase composite material, different from the three-phase composite (metal-ceramics-poly). It was concluded that copper nanoparticles were deposited on the surface of the BT nanoparticles by chemical bond. Owing to good dielectric properties of as-prepared composite, such new two-phase composites had a potential to become the most important ferroelectric material.

Abstract: Surface modified magnetic silica particles for the immobilization of laccase. The maximal absorption capacities of laccase were evaluated systemically. Compared with unmodified magnetic silica particles, the modified magnetic silica particles showed better absorption capacity of the laccase. The immobilized laccase has been used to treat pulp and paper making wastewater, and showed high efficacy on the removal of COD.

Abstract: TiO₂ films were prepared on glass and 316L stainless steel (316L SS) using hydrothermal method. The microstructures of the films were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It indicated that the films crystallized as anatase phase with mirror-like surface morphology. The optical properties of the TiO₂ film were studied by Ultraviolet Visible Spectroscopy (UV-Vis). The results showed that the film was transparent in visible range. The cut-off point of the sample was red-shifted after annealed treatment. The corrosion resistance of the film was evaluated by using Tafel polarization curve in simulated body solution. The corrosion current density was decreased from 8.556 μA/cm² (316L SS) to 1.421 μA/cm² (TiO₂ film/316L SS). While, the corrosion potential was increased from-0.402 V (316L SS) to-0.325 V (TiO₂ film/316L SS). The 316L SS with TiO₂ film has better corrosion resistance.

Abstract: The article is on the preparation of metallic luster glaze based on metallic oxide: CuO-MnO₂-TiO₂-V₂O₅ as the nucleation agent in the basic glaze of lead frit. Through the study on process factors such as: glaze formula, additive content, firing system as well as the modern testing instrument: XRD and SEM, the experimental results show that the optimum formula is: the mass ratio of Mn/Cu is 4, TiO₂, NiO is respectively 20% and 3.5%. The composition of the frit and its content affect glaze surface luster, the mass ratio of Mn, Cu and its additive total amount, the content of Ti, ViO also affects the tone of metal luster and its crystallization degree.

Abstract: Coating a particle with another material to form a core-shell structured composite is often used in powder technology. Silica has widely been selected as the shell material due to its ease of fabrication, versatile surface functionality, physical and chemical stability. In this artilce, the proctective and modifying roles of silica shells in core-shell particles have been briefly reviewed.

Abstract: The approach to solving the problem of processing iron ore raw materials of Tebinbulak titanomagnetite deposit (Uzbekistan) is offered. It can provide high-quality steel products. The two schemes of processing of Tebinbulak ore are shown. The choice between the proposed schemes of the Tebinbulak ore processing: variant of "blast furnace – converter" and variant of "metallization – electric smelting" should be made after thorough analysis based on many factors.