Development of Portable Experimental Apparatus on Education of Polymer Physics

将超临界流体技术与电镀技术相结合，发展了一种新型的电镀技术--可持续超临界纳米电镀技术。在这项技术中，电镀反应是在超临界二氧化碳(CO_2)乳状液和含有表面活性剂的电镀溶液中进行的。用这种方法镀制的薄膜没有任何针孔，这些针孔来自于电解水产生的氢气杂音。与纯溶液电镀相比，该方法制备的镍膜具有更高的均匀性、更小的晶粒尺寸(11.1 nm)和更高的维氏硬度。此外，还测量了电流效率和电阻值随乳状液中CO_2体积分数的变化。这些结果表明，密度超过临界CO_2的CO_2对电镀反应形成乳状液是有效的。根据电导率测定结果，在CO_2体积分数为0~80%的较宽范围内，乳液为水中CO_2(C/W)型。含超临界二氧化碳的乳状液的不连续电化学反应可能是镀膜获得如此优异性能的重要原因。

An innovative electroplating technology "Sustainable Supercritical Nanoplating (SSNP)", which is a hybrid of supercritical fluid and electroplating technology, has been developed. In this technology, electroplating reactions are carried out in emulsion of supercritical carbon dioxide (CO_2) and electroplating solution with surfactants. The plated film by this method did not have any pinholes, which come from hydrogen babbles produced by the electrolysis of water. Compared to electroplating from the solution only, higher quality nickel films have been prepared by this method, which have higher uniformity, smaller grain size (11.1nm), and significantly higher Vickers hardness. Moreover, the current efficiency and electric resistance value were measured as a function of CO_2 volume fraction in the emulsion with few kinds of surfactants. These results show that dense CO_2 beyond critical point of CO_2 is effective to form emulsion for the electroplating reaction. On the basis of the electrical conductivity measurements, the emulsion was classified into CO_2 in water(C/W) type in the wide range of the CO_2 volume fraction from 0 to 80 %. The discontinuous electrochemical reaction of the emulsion including supercritical carbon dioxide might play an important role to attain such excellent properties of the plated film.