Advanced Materials Research Vol. 749

Abstract: A fast method for elastic-plastic buckling of centrally compressed members is put forward, which is suitable for the medium length column considering the effect of residual stresses. The problem of elastic-plastic buckling is simplified as a nonlinear function of axial strain, and the secant algorithm is built based on the nonlinear function. The advantages of the new method are discussed and the iterative calculation process is listed. The new method offers significant improvements in accuracy, robustness and calculation amount of the solution, which can be used for members with any type section. An example of I-shape member is calculated by the new method and the result is compared with the analytical solution. The contrast of the buckling load verifies the reliability of the new method.

Abstract: It is shown that when the conditions of formation of interpolymer complexes are met, another little-known product of the interaction of polymer - hydrophilic interpolymer associates are formed, representing structures, existing in the dynamic mode. Such associates occupy an intermediate position between the classical inter-polymer complexes and non-interacting polymers.

Abstract: A kind of intumescent flame retardant (IFR) were used for flame retarding of oil-extended hydrogenated styrene-butylenes-styrene (O-SEBS). The samples were systemically characterized by limited oxygen index (LOI), vertical burning test (UL-94), and scanning electron microscopy (SEM); Thermogravimetric (TG) analysis. The results showed that the IFR retardant can promote residual chars with multi-micro holes on the surface of SEBS to inhibit flame; with 45% IFR content, the LOI is 28.3 and flame retardant level is UL-94 classification of V-0, with no dripping. The morphological structures observed by SEM demonstrated that higher IFR content promote to form larger and compact films cover on bubbles of the intumescent char layer. The TG data revealed that the IFR could change the degradation behavior of the O-SEBS, enhance the thermal stability and increase the char residue, The tensile strength of all the O-SEBS/IFR blends had the tensile strength of more than 4MPa and the elongation of more than 850%.

Abstract: The copolymers of N-vinylpyrazole with vinyl chloride and methyl methacrylate were obtained by radical polymerization. Constants reactivity and microstructure parameters of copolymers were calculated and their properties were studied. The sol-gel synthesis of obtained copolymers with tetraethyl orthosilicate results in a hybrid organic-inorganic composites. Films with proton conductivity to 7.8·10^-3 S·sm^-1 were formed on the basis the copolymers and composites.

Abstract: Titanium dioxides were synthesized from two different titanium salts, which contained chlorine and sulfur respectively. Titanium dioxide prepared from TiCi₄ and had a particle size of ca. 20nm and its phase transition from anatase to rutile stated at 500°C. Titanium dioxide from TiOSO₄ had a particle size of ca. 50nm and retained its anatase and sperit structure until 700°C by calcination. For the photocatalytic evaluation of these titanium dioxides, photocatlytic oxidation of organic model pollutant, humic acid, have been conducted. UV absorbance decrease by titanium dioxides prepared from both from TiCi₄ and TiOSO₄ at room temperature showed very similar results, compared to titanium dioxide prepared from TiCi₄ at higher temperature.

Abstract: Binary organic-inorganic mesoporous hybrid materials were prepared by covalntly grafting Lanthanide (III) (Eu) trifluoroacetylaceton (TAA) complexes to the ordered meosoporous silica SBA-15 via hydrothermal method and hydrolysis and co-polycondensation method with the surfactant P123 and TEOS. Besides, Novel ternary lanthanide (III) (Eu) organic-inorganic-polymeric mesoporous hybrid materials have been synthesized as well through the introduction of the organic polymer PMAA to the binary system with covalent bond. We investigated the thermal stability and luminescence properties of hybrids and found that the ternary hybrid materials exhibit better thermal stability and stronger emission intensity. Furthermore, compared with the binary mesoporous material Eu (TAA-SBA-15)₃, the ternary mesoporous material Eu (TAA-SBA-15)₃PMMA exhibits the characteristic emission of the Eu³⁺ ion with a higher luminescence Intensity, suggesting that the introduction of polymer PMMA into the mesoporous matrix is of benefit for the sensitization of Eu³⁺ luminescence, by replacing H₂O groups that can quench the luminescence of Eu³⁺ ion.

Abstract: Stereo-thermal lithography (STLG) is an innovative system that uses ultraviolet (UV) radiation and near-infrared (IR) radiation simultaneously to initiate the curing reaction in a liquid solution, containing both UV and IR photoinitiator. In this research work, poly (ethylene glycol) dimethacrylate (PEGDMA) and PEGDMA/hydroxyapatite (HA) constructs were produced using the STLG system, operating in the UV mode, and characterised regarding the morphology and water absorption properties. Constructs were produced with different geometries and shapes by introducing several variations in the processing parameters, such as the irradiation time and the layer thickness. Results show the ability of the system to produce constructs at the micro-scale with very good definition and resolution. The irradiation time is the critical processing parameter, strongly affecting the water absorption and the structural integrity of the constructs.

Abstract: Biofilm formation, structure and dynamics properties play an important role in the effective performance of biofilm wastewater treatment reactors. Biofilm models are commonly used as simulation tools in engineering applications and as research tools to study biofilm formation and dynamics. This paper briefly outlines the present and past status of research on biofilm modeling, dynamics and experimental results. Biofilms constitute a spectrum of dynamical microorganisms, whose interaction with the surrounding environment and thereby induced dynamics dominates the complex properties of the living microorganism. Modeling of biofilms began with a low dimensional continuum description first based on kinematics and translational diffusions; later, more sophisticated microscopic dynamical mechanisms are introduced leading to the anomalous diffusion and dissipation encountered by various components in biofilms. We classify the models into roughly four classes: the reaction-diffusion dynamics model, the Capdeville biofilm growth dynamics model, the Cellular automata (CA) model, and the Phase field biofilm dynamical model.

Abstract: Many industries, such as paper, plastics, food, cosmetics, textile, etc., use dyes in order to colour their products. The presence of these dyes in water, even at very low concentrations, is highly visible and undesirable. Since some of these dyes are toxic in nature, their removal from the industrial effluents is a major environmental problem. The objective of this work is to verify the catalytic activity of waste from metal production namely waste from aluminium production red mud for removal of methylene blue. This waste is still dumped on dumping ground and may be a potential environmental problem.

Abstract: Reservoir bank collapse results in vegetation destruction on bank, worsens soil - water loss, impacts local economic and environment. Therefore, attention should be attached to research of reservoir bank collapse mechanism and control measures. The impoundment and operation of China Three Gorges (CTG) reservoir largely changes hydrologic and geologic conditions of the reservoir bank, greatly influences the reservoir bank stability. On the base of summarizing the structure types of main bank and slope in the reservoir area, the typical bank collapse mode and mechanism in CTG reservoir area are analyzed, including erosion degradation type, sloughing type, sliding type and collapsing type. In the light of different material composition, correlative control and harnessing measures are put forward, which can be referred in the control and harnessing of bank collapse in the reservoir area.