共查询到18条相似文献,搜索用时 140 毫秒
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塑料塔填料表面改性技术 总被引:3,自引:0,他引:3
塑料塔填料表面能低,润湿性差,不利于传质。增大表面粗糙度以提高表面能与改变表面分子结构而增加表面极性是改善塑料塔填料分离性能的两个主要途径。本文着重介绍了表面糙化、表面极化、表面接枝及等离子体表面处理等表面改性技术。 相似文献
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概述了国内外稠油乳化降黏用表面活性剂的研究进展,详细介绍了阴离子表面活性剂、非离子表面活性剂、阴离子一非离子两性表面活性剂及高分子表面活性剂、生物表面活性剂和氟碳表面活性剂等新型表面活性剂在稠油乳化降黏中的应用,评价了各种表面活性剂的优缺点,并提出了稠油乳化降黏用表面活性剂的发展前景。 相似文献
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塑料塔填料表面改性技术进展 总被引:1,自引:0,他引:1
张近 《现代塑料加工应用》1999,11(2):51-55
分析和讨论了塑料塔填料表面性能及其润湿条件 ,指出改变表面分子结构以增加极性与加大表面粗糙度而提高表面张力是改善塑料塔填料表面润湿性能的主要途径 ,并介绍了表面糙化、表面极化、表面接技及等离子体表面处理等表面改性技术 相似文献
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对亲水表面、裸铝表面和疏水表面上结霜和融霜排液过程进行实验研究,分析了表面特性对冷凝水珠冻结、霜层生长和融霜排液的影响。结果表明:疏水表面上冷凝水珠呈规则球缺状、冻结较晚,而亲水表面和裸铝表面上冷凝水珠形状不规则;相比于亲水表面和裸铝表面上平整霜层,疏水表面上霜层不平整,有凹穴和凸起;疏水表面上霜层平均厚度增长较亲水表面和裸铝表面缓慢;在湿空气温度和冷面温度较低的情况下,表面特性对霜层生长的影响减弱;亲水表面具有较好的排液效果,其循环再结霜量最小。 相似文献
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双子表面活性剂体系的界面活性研究 总被引:31,自引:3,他引:31
测定了阳离子型双子表面活性剂烷基 α ,ω 双二甲基烷基溴化铵以及它与普通表面活性剂复配体系的表面张力。结果表明 :双子表面活性剂的表面活性大大高于普通表面活性剂 ,双子表面活性剂溶液的表面活性受其联接基团的影响远大于其烷基链的影响。通过研究阳离子型双子表面活性剂 /阴离子普通表面活性剂复配体系和阴 /阳普通表面活性剂复配体系的协同效应 ,发现双子表面活性剂与普通表面活性剂有很好的复配协同效应 ,这主要是由双子表面活性剂的特殊结构造成的。 相似文献
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粘胶基碳纤维连续式电化学氧化表面处理(1)--碳纤维表面的物理化学性能 总被引:1,自引:0,他引:1
本文报道了用连续式电化学氧化表面处理粘胶基碳纤维表面,并测定了处理后碳纤维的单丝强度、表面浸润性、表面活性官能团含量及表面形貌等表面物理化学性能.结果表明:粘胶基碳纤维经电化学氧化表面处理可以有效地在表面产生活性官能团和提高表面粗糙度,从而有效地提高表面润湿性,但经处理后单丝强度较易下降,因此需精确控制处理的条件. 相似文献
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研究了经不同粒度砂纸研磨后不同粗糙度纯铜表面的润湿性和蒸汽冷凝性能,分析了表面物理粗糙度和氧化引起的表面化学成分异质性对润湿性和冷凝传热性能的影响规律。结果表明,当铜表面粗糙度小于0.15 μm,增大粗糙度有利于增大接触角,而当粗糙度增大到0.15 μm后,继续增大粗糙度反而会减小其表面接触角。铜表面氧化后造成的化学成分异质性有利于增大接触角。表面微观结构和化学成分异质性的共同作用决定了铜表面的润湿性与蒸汽在其表面的冷凝模式。当粗糙度为0.15 μm左右时,氧化后铜表面表现出最佳的滴状冷凝状态,其冷凝传热系数达到Nusselt理论模型的3.5倍左右。但是表面粗糙结构同时也会增大液滴在金属表面的运动阻力,对冷凝传热性能产生不利影响。 相似文献
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A change in the surface energy and surface resistivity of a thin film of polypropylene (PP) of thickness 100 μm was investigated, using direct current (DC) glow discharge. The thin film of the PP was treated for various discharge powers and treatment time and the modification in the surface energy and the surface resistivity was observed. To investigate the modification in the surface energy after DC glow discharge treatment, contact angle of two test liquids formamide and de‐ionized water over the surface of PP film was measured. By measuring the contact angle the change in surface energy and its two polar and dispersive components have been measured. It was observed that at a given power level of DC glow discharge surface energy and its polar component increases with increase of the treatment time, attains a maximum value, and then becomes almost constant. Correspondingly, with increase in surface energy, a decrease in surface resistivity was observed. Also, a change in surface morphology was observed by atomic force microscopy and by FT‐IR spectra generation of polar groups at the surface of PP film. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104: 767–772, 2007 相似文献
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An investigation of fractal characteristics of mesoporous carbon electrodes with various pore structures 总被引:2,自引:0,他引:2
Fractal characteristics of mesoporous carbon electrodes were investigated with various pore structures using the N2 gas adsorption method and the transmission electron microscopy (TEM) image analysis method. The mesoporous carbons with various pore structures were prepared by imprinting mesophase pitch used as a carbonaceous precursor with different colloidal silica particles. All imprinted mesoporous carbons were composed of two groups of pores produced from the carbonisation of mesophase pitch and from the silica imprinting. The overall surface fractal dimensions of the carbon specimens were determined from the analyses of the N2 gas adsorption isotherms. In order to distinguish the surface fractal dimension of the carbonisation-induced pore surface from that fractal dimension of the silica-imprinted pore surface, the individual surface fractal dimensions were determined from the image analyses of the TEM images. From the comparison of the overall surface fractal dimension with the individual surface fractal dimensions, it was recognised that the overall surface fractal dimension is crucially influenced by the individual surface fractal dimension of the silica-imprinted pore surface. Moreover, from the fact that the silica-imprinted pore surface with broad relative pore size distribution (PSD) gave lower value of the individual surface fractal dimension than that pore surface with narrow relative PSD, it is concluded that as the silica-imprinted pores comprising the carbon specimen agglomerate, the individual surface fractal dimension of that pore surface decreases. 相似文献
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采用盐酸、硝酸、氢氟酸的混合溶液腐蚀从高纯铝锭上切割出的单晶{100}和{124}表面。统计观察了腐蚀孔的变化过程,回归拟合了腐蚀孔所占面积的变化,并推导了腐蚀孔的线长大速度。结果表明:腐蚀过程中腐蚀孔的线长大速度迅速下降。{124}面的表面能和表面位错应力场均高于{100}面,使点腐蚀初期其腐蚀孔的线长大速度明显大于{100}面。腐蚀后期,{124}面的腐蚀孔必须继续向内部扩展,而{100}面的腐蚀孔则可以只沿表面扩展,因而造成{100}面腐蚀孔的线长大速度大于{124}面。 相似文献