Advanced Materials Research Vols. 750-752

Abstract: To investigate the biodegradability of PBS, films made of PBS were subjected to enzymatic degradation. The declining thermal stability and XRD diagrams showed that the crystallinity of PBS was reduced after degradation. SEM results confirmed that the mode of enzymatic degradation was surface corrosion. In addition, the weight loss of the material did not experience the so-called acclimation period, but showed a typical linear growth process.

Abstract: Actived carbon can be widely used as adsorbent, catalyst and catalyst support for many chemical reactions. At present, the research on thermal analysis Kinetics of actived carbon is quite few.Studing on it,is helpful for disclosing the decomposition reaction process and thermodynamic law of actived carbon. By thermal analysis, thermal decomposition Characteristics of actived carbon is studied. The TG and DTG eurves of actived carbon were obtain ed using multiple heating rate method.The test data were processed by iso-conversional method to obtain the kinetic parameters.The results showed that, with the improving of heating rate , the startimg reaction temperature of TG and the peak temperature of DTG shifted to the high temperature zone, postponement phenomena occurred.Based on the collected experimental data, it proved that had better linear relations with . The activation energy E of decomposition reaction of actived carbon, which was determined by measurements of slope, was 96.59kJ/mol. The plot of vs was drew and a straight line was obtained. .The mechanism function was defined as ,so according to the slope and intercept of the line,it can be obtained that n=3.585,A=40189.85984.

Abstract: SiO₂ aerogel monoliths were prepared at ambient pressure by keeping the volume ratio of TEOS: EtOH: Oxalic acid at 1:0.6:0.2 with sol-gel method. The prepared aerogels were characterized by scanning electron microscope (SEM), and Brunauer-Emmett-Teller method (BET).The result indicated that silica aerogel monoliths synthesized via these conditions had a excellent structure and fascinating properties (bulk density of 0.254 g/cm³, specific surface area of 770.5 m²/g). Deionized water and calcium chloride anhydrous were used to recover n-hexane to reduce the cost of aerogel synthesis. The purity of recycled n-hexane could reach up to 98.5%.The uptaken rate of Cr³⁺ by aerogels was as high as 99.25% with the pH of 6.86, adsorption time of 20h.

Abstract: In the present work, a highly active visible-light-driven Ag/Ag₃PO₄ photocatalyst was synthesized through a simple poly (vinylpyrrolidone) (PVP)-assisted precipitation method. It was found that the photodegradation activity of RhB over Ag/ Ag₃PO₄ is superior to pure Ag₃PO₄ due to the combination of Ag nanoparticles. Study of the photocatalytic mechanism revealed that the degradation of RhB under visible light irradiation over the as-prepared Ag/Ag₃PO₄ is mainly via the direct hole oxidation mechanism. The Ag/Ag₃PO₄ photocatalyst keeps a high level of activity even though it is used for five times.

Abstract: Based on thermal stability research, a binder for dry vibrating refractories was selected. A new environment-friendly dry vibrating refractory was prepared by adopting the selected binder. The permanent linear change, apparent porosity, bulk density, cold crushing strength (CCS) and modulus of rupture (MOR) of the specimens were tested by the chinese national standard. The dry vibration refractories were successfully used in the lining material for continuous casting tundish.

Abstract: Three-dimensional electrode treating coking waste water was studied in the experiment, which is widely used in treating organic waste water. The high carbon-bearing metallized pellets was used as the third electrode of three-dimensional electrode reactor. Factors of three-dimensional electrode including residence time, voltage and air flux were studied. It was shown that all of the above mentioned factors have effect on coking wastewater. And also the optimal parameters were obtained in the experiment.

Abstract: A novel nanofibrous membrane was used for removing Cu (II) from aqueous solutions. The poly (ethylene terephthalate) (PET) membranes were fabricated by electrospinning, and then grafted with acrylamide (AM) on the surface. The morphologies of the nanofiber was characterized by SEM, meanwhile, the chemical composition and element analysis on the membrane surface were measured by FT-IR and XPS, respectively. The Cu (II) adsorption experiment investigated the adsorption performance related to the pH value on. Equilibrium studies show that the adsorption process follows Langmuir model and the maximum adsorption capacity was estimated to be 183.25 [mg/g].

Abstract: Utilization of natural polymer as biodegradable matrix for the controlled releasing fertilizer can improve the performance of the materials and make them environmentally friendly. In this work, the effect of gelatin on the properties of hydrogels was investigated. The silk fibroin (SF)-gelatin hydrogels were prepared by solvent casting and β-crystallization of SF was promoted via methanol treatment. The secondary structure and the crystallinity of the blended hydrogels were investigated using Fourier transform infrared spectroscopy (FT-IR) and X-ray diffraction analysis (XRD), respectively. Moreover, the swelling ratio of the hydrogels and also their kinetics of nitrogen (N) release were also studied. Results from the FT-IR confirmed that no intermolecular interactions had taken place between SF and gelatin. Furthermore, the increase of gelatin content in the blended hydrogels caused the decrease of the SF crystallinity detected by XRD which corresponded to the swelling behavior of the hydrogel. The release rate of nitrogen (N) depends on the composition of SF and gelatin of which its value of diffusion exponent characteristics (n) determined from the Korsmeyer-Peppas model for all of the hydrogels are smaller than 0.5. This indicates that the release of N from the hydrogels is a quasi-Fickian diffusion. Moreover, the release rate (k) and diffusion coefficient (D) of the SF-gelatin hydrogels are lower than those of the SF itself indicating a potential to use the SF-gelatin hydrogel for nitrogen controlled release application.

Abstract: This work investigated the feasibility of Quercus mongolica sawdust pretreated by an ionic liquid-water mixture as a biosorbent for Cu (II) removal from aqueous solutions. Maximum Cu (II) biosorption of 32.6 mg/g is obtained at initial pH 4.3 using sawdust pretreated by a 1-butyl-3-methylimidazolium chloride ([C₄miCl)-water mixture (IL content 60%) at 90oC, which is higher than that of unpretreated sawdust (23.0 mg/g, initial pH 6.1). The proposed method is effective in enhancing adsorption capacity of the biomass in comparison to the conventional methods using sulfur acid or sodium hydroxide solutions.

Abstract: A novel biodegradable ABC-shaped star copolymer, poly (ethylene glycol)(PEG)-b-poly (ε-caprolactone)(PCL)-poly-c-poly (ɤ-benzyl-L-glutamic acid)(PBLG)(MPEG-PCL-PBLG), was synthesized by the graft polymerization of MPEG-NH₂ with the core of Boc-LYSZ-COOH and the twice ring-opening polymerization (ROP) of ε-caprolactone (CL) and N-carboxyanhydride of ɤ-benzyl-L-glutamate (BLGNCA) with centrally amino-functionalized lysine as a initiator. The ABC-shaped star copolymer and its precursors were characterized by ¹H NMR, GPC, and DSC-TG measurements.