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31.
Jian Li Gangyao Wen Dimitrios Selianitis Stergios Pispas Yu Zhang Hongfei Li 《应用聚合物科学杂志》2024,141(5):e54898
The aggregation behavior of two pH- and temperature-responsive diblock copolymers of poly[di-(ethylene glycol) methyl ether methacrylate]-block-poly[2-(diisopropylamino) ethyl methacrylate] (PDEGMA-b-PDIPAEMA) at the air/water interface and the structures of their Langmuir–Blodgett (LB) films were studied by the Langmuir monolayer technique and atomic force microscopy, respectively. At the air/water interface, PDEGMA-b-PDIPAEMA tends to form the core-shell-corona micellar structure composed of a PDIPAEMA main chain core, an amino ethyl ester shell, and a PDEGMA corona. Under acidic, neutral, and alkaline conditions, PDIPAEMA blocks are completely protonated, partially protonated, and completely non-protonated, respectively, and the protonated amino ethyl ester groups are immersed in water before monolayer compression, whereas PDEGMA coronas are adsorbed at the interface. At pH 3, 7, and 10, the limiting areas (A0) for PDEGMA42%-PDIPAEMA58% (weight percents) and PDEGMA55%-PDIPAEMA45% are 8.2/10.2/14.0 and 6.7/8.3/8.4 nm2, respectively. The A0 values of the former copolymer are larger than those of the latter. This is because the shells in the former copolymer are denser due to the higher polymerization degree of PDIPAEMA blocks, providing greater steric hindrance for PDEGMA coronas and making the latter more extended at the interface. In contrast to other copolymer systems, the effect of temperature on the isotherms of PDEGMA-b-PDIPAEMA is less obvious. 相似文献
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In China, directly dropping high temperature refrigerant into conventional compressor is considered as a dominant technical
route for development of moderately high temperature heat pump. Based on this route, selection criteria for high temperature
refrigerant were presented with consideration of several influencing factors. Moreover, a set of research methods were built
including theoretical calculations and experimental tests. Four high temperature refrigerants from HTR01 to HTR04 were compared
and analyzed. In results, firstly, HTR03 and HTR04 belonging to non-ozone depleting refrigerants could bring outstanding environmental
benefits; secondly, the condenser outlet water efficiently generated by heat pump using high temperature refrigerants could
cover 60°C–90°C;; finally, the feasibility of the technical route and the research methods were proved.
Supported by Program for New Century Excellent Talents in University (Grand No. NCET-04-0078) 相似文献
34.
Oil spills in Egyptian coastal waters have a direct impact on the national economy because of the potential environmental damage, and the corresponding negative effect on tourism. Computer simulations of oil spills were performed for four environmentally sensitive areas along Egyptian coasts using an existing oil spill model that incorporates the important variables and processes affecting oil transport in seawater. The expected slick trajectory and variation of oil properties with time were calculated for a proposed spill scenario at each site. Water current maps, the most critical model input parameter with respect to spill trajectory, were developed for each location. The simulations demonstrated that the most important oil property affecting spill response decisions and operations is the emulsion viscosity, in that it indicates when, where, and how responders can intervene for cleanup. 相似文献
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推行绿色化学,创造一个循环经济型的可持续发展社会,并基于此围绕缓蚀性能,环境兼容性,经济效益研究开发高效环境友好型缓蚀剂是未来缓蚀剂发展的方向。概述了国内外无机,有机缓蚀剂的研究进展,着重介绍了生物型缓蚀剂的研究现状,并展望了环境友好缓蚀剂的发展趋势。 相似文献
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本文重点解读通信电源用交联聚烯烃绝缘电缆通信行业标准的主要内容,介绍了交联聚烯烃绝缘的技术特点.评述了聚氯乙烯(PVC)绝缘电缆在环保和安全方面存在的不足.通过比较说明了交联聚烯烃绝缘电缆相对于PVC绝缘电缆和非交联的无卤低烟阻燃聚烯烃绝缘电缆所具有的优势.本文还介绍了低压电缆制造技术,特别是交联工艺路线、电缆料添加剂及电缆料配混技术进展等方面的内容,对未来通信电源用电缆的发展以及标准修改内容提出了建议. 相似文献
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A mixture of hydrogen peroxide, sulphuric and hydrofluoric acids has been used as pickling solution at pH 2.0 for AISI 316L austenitic stainless steel (SS). The stability of the H2SO4‐HF‐H2O2 mixture is assessed varying the ferric ions content from 0 to 40 g/L, the temperature from 25 to 60°C, and with and without stirring of the pickling solution. The AISI 316L SS pickling rate at 50°C was 2.6 and 0.2 mg/dm2 day (mdd) in the absence and presence of 40 g/L ferric ions, respectively. p‐toluene sulphonic acid (PTSA) has been used as stabiliser of hydrogen peroxide. 相似文献
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在航空工业中的胶接领域,为了降低底胶中含有的大量挥发性有机溶剂(VOC)和铬酸盐,促进了环保型底胶的研发。对于水基底胶、无机底胶以及不合铬酸盐的底胶的胶接耐久性试验表明,一些新型的环保型底胶的性能与传统的溶剂型底胶处于同一水平甚至更好。新型底胶也同样能够提高复合材料的胶接强度和耐久性能,但应该寻找更环保、更简便的方法来获得耐久性的胶接。磷酸阳极化作为铝合金胶接中最好的表面处理方法本身具有很好的耐久性,使用耐久性较好胶粘剂获得耐久胶接是较好的方案之一。 相似文献