Carbohydrate derived copoly(lactide) as the compatibilizer for bacterial cellulose reinforced polylactide nanocomposites

A novel, entirely bio-derived polylactide carbohydrate copolymer (RP1) is used as a compatibilizer, to produce bacterial cellulose (BC) poly(l-lactide) (PLLA) nanocomposites with improved mechanical properties. Contact angle measurements of RP1 droplets on single BC nanofibres proved that it has a higher affinity towards BC than PLLA. RP1 has a comparable Young’s modulus, but lower tensile strength, than PLLA. When RP1 was blended with PLLA at a concentration of 5 wt%, the tensile modulus and strength of the resulting polymer blend decreased from 4.08 GPa and 63.1, respectively, for PLLA to 3.75 GPa and 56.1 MPa. A composite of BC and PLLA (with 5 wt% RP1 and 5 wt% BC) has a higher Young’s modulus and tensile strength, compared to either pure PLLA or PLLA–BC nanocomposites.     

Self-assembly of colloidal nanocrystals as route to novel classes of nanostructured materials

Colloidal crystallisation is the only way to obtain three-dimensional ordered materials in which semiconductor, metallic, and magnetic nanocrystals are in close contact. It is expected that the quantum mechanical and dipolar interactions between the nanocrystal units can lead to unseen physical phenomena and materials. Here we review the development of this new and exciting field. We first compare nanocrystal superlattices with regular atomic solids regarding their mechanical strength and opto-electronic properties. We describe how nanocrystal superlattices have been obtained from colloid suspensions in several ways. The thermodynamic driving force for colloidal crystallisation is discussed in terms of inter-particle interactions in a good solvent and entropy. We compare the binary superlattices that have been obtained by solvent evaporation with the predictions of the hard-sphere model and show that semiconductor nanocrystals in a good solvent can behave as hard spheres. Finally, we discuss the quantum mechanical and dipolar interactions in nanocrystal superlattices and review recent studies of the opto-electronic and magnetic properties of novel superlattice materials.     

Influence of halide ions on the adsorption of diphenylamine on iron in 0.5 M H2SO4 solutions

Halide ions are found to enhance the inhibition performance of amines due to enhanced adsorption of amines by the adsorbed halide ions on the metal surface. In this work, the synergistic action of halide ions on the corrosion inhibition of iron in 0.5 M H₂SO₄ by diphenylamine has been found out by electrochemical impedance and polarization methods. Analysis of impedance data has been made with equivalent circuit with constant phase angle element for calculation of double layer capacitance values. Experiments have been carried out in the concentration range of 100-1000 ppm of diphenylamine in the presence of 0.5-1.0 × 10⁻³ M of halide ions. Diphenylamine is found to be a cathodic inhibitor and the inhibition efficiency of about 65% is obtained at 1000 ppm. The anodic and cathodic Tafel slopes in the presence of diphenylamine alone and with halide ions are 65 ± 5 and 105 ± 5 mV, respectively. Diphenylamine inhibits corrosion by adsorption and the surface coverage values are increased considerably in the presence of halide ions. In the presence of iodide ions, the inhibition efficiency of diphenylamine at 100 ppm is increased to more than 90%. In the case of other halide ions, the inhibition efficiency of diphenylamine in increased to 80% at 1000 ppm. The order of synergism of halide ions is I⁻ ? Br⁻ > Cl⁻. The highest synergistic effect of iodide ions is due to chemisorption with metal surface due to its larger size and ease of polarizability.     

水溶性复合磷酸酯添加剂抗磨性能研究

合成了水溶性复合磷酸酯,利用四球试验机考察了添加到水溶液中的抗磨性能,并优化了复合磷酸酯的配比,用扫描电子显微镜对钢球磨斑形貌和摩擦表面的元素组成进行了分析,四球结果表明,磷酸酯与硫化物硫脲,油性剂油酸三乙醇胺具有良好的协同抗磨效应,并存在一个最佳配比,电镜能谱分析表明,复合磷酸酯水溶液在摩擦表面与Ｆｅ发生化学反应,生成一种含磷富硫的化学反应膜,而且表面膜中硫,磷元素的含量比为２：１时极压抗磨性能     

阻燃HDPE中氢氧化铝的表面处理和阻燃增效

本文采用氢氧化铝（ＡＴＨ）改善高密度聚乙烯（ＨＤＰＥ）的阻燃性能,选用铝酸酯、钛酸酯等偶联剂,以及实验室自制的磷酸酯、Ｃ２２表面涂覆剂对ＡＴＨ进行表面处理,以增加ＡＴＨ与基体的相互作用和在基体中的分散效果。拉伸、冲击、燃烧（水平燃烧、氧指数）等性能的测试表明,经处理后的ＨＤＰＥ／ＡＴＨ填充材料的综合性能较好,尤其是韧性有较大提高,实验室自制的磷酸酯和Ｃ２２表面处理剂表现出较好的效果。添加阻燃增效剂的研究显示,加入红磷、硼酸锌等阻燃增效剂可显著提高ＨＤＰＥ／ＡＴＨ体系的阻燃性能。热失重分析结果表明,经偶联剂处理后,材料的耐热性得到提高,ＡＴＨ的脱水温度可由２２０℃提高至２７０～２８０℃。     

甘草有效成分分离及防霉试验研究

从甘草中分离出有效成分并进行防霉试验,以乙醇、乙醚提取物的7:3复合物效果最好.在此基础上进行协同实验,以增强防霉效果.实验中筛选出几组效果好的防霉配方,用于对月饼的防霉保鲜试验.     

Ag-doped Bioactive Glass-Ceramic 3D Scaffolds: Microstructural,Antibacterial, and Biological Properties

Ag-doped sol-gel derived bioactive glass-ceramic particles (Ag-BG) were used to fabricate highly porous scaffolds exhibiting advanced antibacterial properties and formation of an apatite-like layer. The applied heat treatment for the development of the 3D Ag-BG scaffolds was selected after the characterization of the thermal behavior of Ag-BG particles using differential thermal analysis (DTA), thermogravimetric analysis (TGA), and hot stage microscopy (HSM). The structural characteristics of the scaffolds were studied using optical microscopy, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), micro-computerized tomography (Micro-CT), X-ray diffraction (XRD), Fourier-transformed infrared (FTIR), magic angle spinning nuclear magnetic resonance (MAS-NMR), and transmission electron microscopy (TEM) to correlate how the characteristics in the hierarchal structure of the Ag-BG scaffolds affected their antibacterial performance and apatite forming ability. Methicillin-resistant Staphylococcus aureus (MRSA) was used to evaluate the antibacterial response of the Ag-BG scaffolds. The observed characteristics make these Ag-BG scaffolds attractive candidates for biomedical applications.     

Physicochemical Properties and Phase Behavior of Didecyldimethylammonium Chloride/Alkyl Polyglycoside Surfactant Mixtures

Mixed surfactant systems, used in many formulations, have aroused great attention and interest from researchers and industry due to the possibility of synergism. Alkyl polyglycoside (APG) and didecyldimethylammonium chloride (DDAC) mixtures combine the excellent properties of pure surfactants and play an important role in the development of multi‐functional washing products. To study the synergism between APG and DDAC, the physicochemical properties of different mixed systems have been investigated. The critical micelle concentration (CMC) is about 180 mg·L^?1 and the surface tension at the CMC is about 26.0 mN·m^?1 at a mass fraction of 40 % DDAC (ω_DDAC40 %). The values are significantly lower than pure surfactants. The foaming property shows the best performance at ω_DDAC20 %. When the mass fraction of DDAC is 80 %, the mixture exhibits better wetting and emulsifying properties. Synergism was observed in surface tension, foaming and emulsifying properties, while the wetting ability and detergency exhibited no such effects. Phase behavior of the APG/DDAC/water ternary system has also been carried out by polarized optical microscope. The phase diagram is characterized by a micellar phase, a region where lamellar and micellar phases coexist and a lamellar phase.     

Zinc Corrosion in Acidic Solutions Containing Single and Mixed Surfactants

The influence of surfactant synergism on Zn corrosion inhibition in 0.1-M HCl aqueous solutions has been determined at room temperature. Solutions of single and mixed surfactants consisting of sodium dodecylsulfate (SDS) and N,N-dimethyldodecan-1-amine oxide (DDAO) in water and in 0.1-M HCl were also prepared at room temperature. Critical micelle concentration (CMC) data were obtained through surface tension measurements as a function of mixing composition. A regular solution model was considered to analyze CMC values. The interaction parameter (β), the composition of mixed micelles (x) and the activity coefficients (f) were estimated by a regular solution model for all amphoteric–anionic mixed systems. β Vvalues showed synergism for the binary mixtures of these solutions in the absence and presence of 0.1-M HCl at all investigated compositions. Zinc corrosion in single and binary SDS/DDAO mixed solutions at 5-mM total surfactant concentrations in the presence of 0.1-M HCl was also investigated at static and dynamic conditions. The weight loss data revealed corrosion inhibition activity obeyed the following order: binary (0.75 DDAO + 0.25 SDS) > binary (0.50 DDAO + 0.50 SDS) > single DDAO > single SDS, suggesting an enhancement in the corrosion inhibition activity of DDAO in the presence of a proper amount of SDS. Conductivity time measurements show a similar trend as that obtained by a weight loss method at (0.50 DDAO + 0.50 SDS). The results were illustrated on the basis of synergistic interaction between the mixed surfactants.     

二烷基二硫代氨基甲酸铁抗氧光敏剂配合体系及其应用研究

本文研究了二烷基二硫代氨基甲酸铁（ＦｅＤＲＣ），芳香酮和抗氧剂配合体系的组成，各组分的协同关系及其光降解聚乙烯的作用机理。结果表明，以ＦｅＤＲＣ配合体系为添加剂的聚乙烯地膜使用性能和光降解可控性良好，完全适全制造可控光降解聚乙烯的地膜。