Study on the polymerization of ϵ‐caprolactam in the interlamellar spaces of [TEACOOH]–montmorillonite intercalations complex and its characterization

The polymerization of ?‐caprolactam between the interlamellar spaces of the [TEACOOH]–montmorillonite intercalations complex was attempted using Na–montmorillonite and 10‐carboxy‐n‐decyltriethylammonium bromide to achieve [TEACOOH]–polycaprolactam–montmorillonite, in which montmorillonite (inorganic polymer) is chemically bonded with the polycaprolactam (organic polymer). The results of X‐ray and IR analysis for the samples obtained after polymerization showed that the polymerization reaction has been successfully accomplished. For the purpose of studying the polymeric reaction product more precisely, we have isolated the polymerized product from the silicate layers and analyzed it with X‐ray diffractometer and IR spectrometer. Comparison of the results of X‐ray and IR analysis between the isolated polymer and the polymer that was synthesized by the reaction of ?‐caprolactam only with the organic cation without montmorillonite showed that both obtained polymers are the same compounds. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 88: 1904–1910, 2003     

Kinetics of microwave‐assisted polymerization of ϵ‐caprolactone

The kinetics of polymerization of ?‐caprolactone (CL) in bulk was studied by irradiating with microwave of 350 W and frequency of 2.45 GHz with different cycle‐heating periods (30–50 s). The molecular weight distributions were determined as a function of reaction time by gel permeation chromatography. Because the temperature of the system continuously varied with reaction time, a model based on continuous distribution kinetics with time/temperature‐dependent rate coefficients was proposed. To quantify the effect of microwave on polymerization, experiments were conducted under thermal heating. The polymerization was also investigated with thermal and microwave heating in the presence of zinc catalyst. The activation energies determined from temperature‐dependent rate coefficients for pure thermal heating, thermally aided catalytic polymerization, and microwave‐aided catalytic polymerization were 24.3, 13.4, and 5.7 kcal/mol, respectively. This indicates that microwaves increase the polymerization rate by lowering the activation energy. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 91: 1450–1456, 2004     

Misleading the Colorado potato beetle with an odor blend

Walking tracks of Colorado potato beetles,Leptinotarsa decemlineata Say, were recorded on a locomotion-compensator in response to wind, odors of host plantsSolanum tuberosum L. and nonhost plantsLycopersicon hirsutum f.glabratum C.H. Mull, and to mixtures of these plant species. Host-plant odor induced positive anemotactic responses in starved females, whereas odor of the nonhostL. hirsutum was neither repellent nor attractive. The attractiveness of host-plant odor, however, was neutralized in the odor blend of plant species. Masking the attractive host-plant odor will hinder the beetle's searching for host-plant patches, and this principle may be exploited in pest control by mixed cropping.The locomotion-compensator was constructed with financial support from the Foundation for Fundamental Biological Research (BION), which is subsidized by the Netherlands Organization for the Advancement of Pure Research (ZWO), grant 14-02-02. The first author was supported by a grant from the French Ministry of Industry and Research.     

骑式摩托车油箱喷涂工艺的改进

面对日益激烈的市场竞争,摩托车油箱外观质量越来越成为影响销售的因素之一。文章介绍了改进工艺后的油箱涂装,该涂装体系提高了油箱外观的丰满度,降低了油箱涂装的生产成本。     

The study on the conductivity of styrene-maleic anhydride copolymer electrolytes based on poly(ethylene glycol)400 and LiClO4

Polyelectrolytes, in this study were synthesized from styrene-maleic anhydride (SMA) copolymer, poly(ethylene glycol)400 (PEG400), and lithium perchlorate (LiClO₄). Fourier transform infrared spectroscopy (FTIR), and magic angle spinning (MAS) solid-state NMR were used to monitor the interaction between Li⁺ ions and polymer. The results of FTIR and MAS solid-state NMR indicate the Li⁺ ions are preferentially coordinated to the ether oxygen of PEG. The T_g of the PEG segments in polyelectrolyte increases with LiClO₄ concentration, as determined by differential scanning calorimetry (DSC), indicating that solubility of the Li⁺ ions in the host polymer increases with the PEG content. Impedance spectroscopy (IS) shows that the bulk conductivity of polyelectrolytes and the conductivity behavior obeys the Vogel-Tamman-Fulcher (VTF) equation.     

Inactivation of Fusarium oxysporum Conidia in Soil with Gaseous Ozone – Preliminary Studies

ABSTRACT

In this study, the efficiency of gaseous ozone (O₃) injected in the soil as an oxidizing agent for the inactivation of F. oxysporum was evaluated under laboratory conditions. The results show the treatment reached an inactivation efficiency of 76% after an applied dose of 0.40 g O₃ kg ^?1 soil. This shows that the injection of O₃ can be a viable alternative to control pathogenic organisms in the soils. Nevertheless, it is clear that more studies on determining the effects of this treatment on soil quality are needed.     

Assessment of a redox alkaline/iron-chelate absorption process for the removal of dilute hydrogen sulfide in air emissions

The oxidative absorption of hydrogen sulfide (H₂S) into a solution of ferric chelate of trans-1,2- diaminocyclohexanetetraacetate (CDTA) was studied in a counter-current laboratory column randomly packed with 15 mm plastic Ralu rings. The present investigation takes concern about the Kraft pulping situation where dilute H₂S concentrations are omnipresent in large-volume gas effluents. A fractional two-level factorial approach was instigated to determine the significance of six operating variables, namely the solution's alkalinity (pH; 8.5-10.5), the liquid mass flow rate (L;1.73-), the solution's ionic strength (I_C;0.01-), the gas mass flow rate (G;0.19-), the inlet H₂S concentration (C_H2S,0;70-430 ppm) and the initial ferric CDTA concentration (C_Fe,0;100 -). Initially, a Plackett-Burman design matrix of seven duplicated experiments revealed that pH is the leading factor controlling the H₂S conversion rate while the ionic strength and ferric CDTA concentration effects remained negligible within the factorial domain. Surface response analysis based on 11 duplicated factorial experiments plus 10 central composite trials revealed that the H₂S conversion significantly increases with liquid flow rate but decreases with growing H₂S load up. Further examination about the influence of ferric CDTA on H₂S absorption rate was set up over a broader concentration range (C_Fe,0;0- at pH of 9.5 and 10.5. It showed good potential at as H₂S conversion increased by a significant 25% for both pH values in comparison to pure alkaline solutions containing no ferric CDTA.     

高铁酸钾去除饮用水源中盐酸四环素试验研究

利用提纯后的次氯酸钠溶液、硝酸铁、氢氧化钾制备高铁酸钾。并采用高铁酸钾氧化去除水中盐酸四环素（TC）,初步探讨了高铁酸钾去除TC的效果,研究了高铁酸钾投加量、pH值、氧化时间等对去除效率的影响。结果表明,高铁酸钾可以有效快速地去除水中的TC,在一定范围内,高铁酸钾投加越多,TC去除率越高,反应越快。pH值对反应影响较大,最优pH值范围为9～10。降解反应主要发生在前60S,在之后的10-20min内高铁酸钾与TC持续反应,TC得到进一步的降解。当高铁酸钾与TC摩尔比为1：1和1：5时,反应60S后的TC去除率约为100％。但反应液TOC下降幅度不大,说明大部分的TC仅转化为中间产物,未得到彻底矿化。     

New Method of Manufacturing Micro Parts Using Thiobacillus Ferrooxidans

A new method of processing and manufacturing certain parts of instruments through biological approach is studied. Knowledge of feasibility of micro-manufacturing is obtained by comparing experimental results of etching surfaces of copper, aluminium alloy, brass, steel and stainless steel using strain of Thiobacillus ferrooxidans (T.f.). Our experimental results show that certain metals can be etched using T.f., the most feasible material is copper, followed by brass, etc., with stainless steel the least. The surface of the stainless steel material is nearly unchanged during surface-etching. Micro parts made of copper or brass can be satisfactorily processed with T.f. and the rate of processing on copper is about 14?μm/h. Furthermore, surface roughness and processing speed are controlled by pH value and temperature of etching liquid, in addition to swing rate of the the swing bed.     

水热温度对玻璃纤维增强HAp-CS涂层的影响

为了制备出结合强度较好的生物涂层,采用水热电泳法在碳/碳复合材料表面成功制备了玻璃微纤维增强的羟基磷灰石——壳聚糖(g(f)/HAp-CS)复合涂层,用x-射线衍射仪、透射电子显微镜、扫描电子显微镜、能谱分析仪、红外傅里叶变换分析仪等测试手段对涂层进行了测试和表征,主要研究了水热沉积温度对复合涂层中HAp晶相和涂层显微结构的影响以及HAp涂层的沉积动力学.结果表明:采用玻璃微纤维增强的HAp-CS涂层,致密性和均匀性有了很大提高,显著减少了复合涂层表面的裂纹;随着水热温度的升高,涂层中HAp的衍射峰逐渐增强,表面形貌得到了有效改善,涂层的致密性和均匀性显著提高;涂层的沉积速率随水热温度的升高而加快,其沉积活化能为14.63kJ/mol.