Materials Science Forum Vol. 1003

Abstract: The objective of this work was to characterize the stereocomplex film properties prepared from different ratios of PLLA-PEG-PLLA/PDLA-PEG-PDLA. All ratios used were homogeneous in texture with a small size of pores which increased as the PDLA-PEG-PDLA ratio was increased. The PDLA-PEG-PDLA supported the increase of stereocomplexation of the film's texture. With tetracycline, the increasing of pores on the film surfaces were observed, but not interfered stereocomplexation of the films. However, the drug helped to enhance the homo-crystalline formation. The stereocomplex structure of films both with and without tetracycline have completely formed when the ratios of PLLA-PEG-PLLA/PDLA-PEG-PDLA used were 60/40 and 70/30, respectively. The rate of drug release trends to decrease when the ratio of PDLA-PEG-PDLA increased. This indicated that the different ratios of PLLA-PEG-PLLA/PDLA-PEG-PDLA might be affected by the properties of film as well as the drug release pattern. The obtained results might be applied for designing film for specific proposing, especially as a hydrophobic drug carrier for drug controlled-release.

Abstract: The magnetic ferroferric oxide nanoparticles were modified with L-lysine to prepare immobilized carriers(Fe₃O₄-Lys), which was applied to the immobilization of Saccharomyces cerevisiae CGMCC No. 2230. The optimal immobilization conditions for preparation of Fe₃O₄-Lys-Cells were Fe₃O₄-Lys 0.01 g, cell dry weight 3 g, pH 7, 3 h, 30 °C. Ethyl R-4-chloro-3-hydroxybutyrate was gained by asymmetric reduction of ethyl-4-chlorooxobutanoate with Fe₃O₄-Lys-Cells as catalysis. 0.672 mol/L COBE can be converted completely in 40 h in the shaker, while only 24 h in the alternating magnetic field. The conversion and enantiomeric excess(e.e.) of (R)-CHBE reached 100% and more than 99.9%, respectively.

Abstract: The adsorption behavior of methanol vapor onto three commercial silica gels named SG-1, SG-2 and SG-3 were investigated in this paper. The experimental results showed that SG-1 has the rich microporous, and the larger surface area and microporous volume than SG-2 and SG-3. The equilibrium adsorption data showed that the adsorption capacities of SG-1 was superior to SG-2 and SG-3 for lower concentration of methanol (<150 g/m3). However, SG-2 had higher adsorption capacities than SG-1 and SG-3 for higher concentration of methanol resulting from the condensation in mesopore channels. Three kinds of adsorption equilibrium equations including Langmuir equation, Freundlich equation and Dubinin-Astakov (D-A) equation were used to fit the methanol vapor adsorption isotherms. The results indicated that the experimental data can be well-fitted by D-A equation.

Abstract: This paper presents an Exhaustive Analysis of the Characterization of Photopolymer Material (SZ2080) by Two-Photon Polymerization, and some of the modern concepts like Characterization of Photonic Crystals in Photopolymer SZ2080 by Two-Photon Polymerization, Waves Moving in a Periodic Potential, and Optical Quantum metamaterials. Two-photon polymerization for fabricating three-dimensional subdiffraction-limited structures has been discussed. Experimental and Computed Curves of line thickness (nm) vs feed rate (μm/s) have been technically analyzed. Waves moving in a Periodic Potential and Photonic Crystals have been technically discussed. In addition, Optical Quantum metamaterials have been discussed in terms of quantum coherence, and quantum dots with emphasis on cavity array metamaterial.

Abstract: Boron nitride (BN) was modified by silane coupling agent (KH560) and used as heat conductive filler to prepare the modified BN (BN560)/epoxy composite. The effect of the BN560 filler content on the thermal conductivity and thermal stability of the epoxy composite was studied. The results show that BN560 can be uniformly dispersed in the epoxy matrix by an ultrasonic disperser. The BN560 added can effectively improve the thermal conductivity of the epoxy composite. With the increase of BN560 content to 20 wt.%, the thermal conductivity of the composite increases accordingly to 0.27 W/(m·K), 50% higher than that of pure epoxy, and a heat conductive network is formed. The BN560 added can improve the thermal stability of the composite. With increasing BN560 content, the thermal decomposition temperature and glass transition temperature of the composite increase. The composite with the BN560 content of 20 wt.% has the weight loss of 10 wt.% at 395.12 °C and the glass transition temperature of 144.59 °C.

Abstract: The objectives of this work are to prepare keratin/egg white blend particles by emulsification solvent diffusion method and characterize their properties. The different factors including concentration, water: oil phases, spinning rate, and blending ratio were optimized. The morphological observation indicated that the shapes and sizes of particles were variable by the condition used. FTIR spectra indicated that all particles co-existed of α-helix and random coil structures. The decomposition rate of all particles found at least 4 steps and the blend particles have lower Td, max than the native protein particles. The obtained results were advantaged for the development of the keratin/egg white blend particles for specific applications such as drug-controlled release systems.

Abstract: Different proportions of nano-zinc oxide were uniformly dispersed in a polyphenylene sulfide matrix by using an internal mixer. Comprehensive properties were determined through tensile strength test, differential scanning calorimetry, X-ray diffraction, thermogravimetry. The results showed that the sample elongation at break and tensile strength considerably increased with the amount of nano-zinc oxide. Its thermal stability has also improved considerably and crystallization temperature of PPS-NanoZnO composite was increased;while the crystalline phase remained unchanged.

Abstract: This work aimed to improve the flexibility of keratin film by blending with zinc acetate. Films were prepared by casting methods before the characterization of their morphology, structure, and crystallinity. The keratin film with zinc acetate had a rougher texture than the native keratin film and changed absorption peaks appeared in the FTIR spectrum. Blending with zinc acetate (Zn(Ac)₂) helped to reduce the β-sheet structure as well as the crystallinity of the keratin film. This result clarified that Zn(Ac)₂ could improve the flexibility and properties of the brittle and fragile films.

Abstract: The paper discusses measurement problems of heat deflection and glass transition temperatures of fiber-reinforced plastics by the Martens test and thermomechanical analysis (TMA). By using the Martens test, thermomechanical profiles were obtained for an epoxy binder and glass fiber- (GFRP) and basalt fiber-reinforced (BFRP) plastics under load ranging from 5 to 75 MPa. The onset temperature of severe deformation of GFRP and BFRP was found to be 15–20°С higher than that of the epoxy binder they were made of. GFRP and BFRP were tested by TMA in the lengthwise and crosswise fiber orientations. In crosswise measurement, TMA curves showed two noticeable inflection points corresponding to two thermal transitions. This can be explained by the cured binder being present in two states in the composites. The interfacial layer contiguous to the fibers had a lower glass transition temperature (T_g) than the matrix layer located in the interfibrous space; moreover, T_g of the composites under flexural load was similar to that of the matrix.

Abstract: A new triazine charring agent, melamine formaldehyde resin modified with pentaerythritol (named as MF-MPOL), was synthesized through hydroxymethylation, condensation and etherification by using melamine, paraformaldehyde and pentaerythritol as raw materials, and characterized by solid-state ¹³C NMR and FT-IR. The intumescent flame retardant (IFR) consisting of MF-MPOL with ammonium polyphosphate has good flame retardancy in polypropylene (PP). The analysis of the residues obtained in cone calorimetry test showed that the IFR played a role of flame retardancy mainly in condensed phase. In other words, the porous and dense - continuous intumescent char layer formed during the burning process results in flame retardant effect by insulation of heat, oxygen and preventing the underlying PP from degradation and volatilization of pyrolytic products.