Preparations of plastic optical fiber having amplifier function by impregnation of organic dye using supercritical carbon dioxide

一般来说，具有放大功能的塑料光纤是由聚合物熔体与某些光敏剂混合纺丝制备的。本文尝试了一种完全不同的方法来制备具有放大功能的塑料光纤；将光敏剂罗丹明6G从超临界二氧化碳溶液中浸渍到一些商用塑料纤维中。作为基础研究，用分散染料在超临界二氧化碳中对涤纶、聚丙烯纤维等合成纤维进行染色。考察了染料的溶解度、溶胀行为、吸附速率和吸附等温线。从而明确了染色温度、压力、时间对染色速率和平衡染色的影响。在罗丹明6G浸渍丙烯酸塑料光纤的情况下，观察了光纤的结构变化。特别是在高温下观察到纤维直径和/或泡沫的变化。在极低温度下获得了最佳条件。使用纯二氧化碳，没有足够的罗丹明6G浸渍。为了使罗丹明浸渍大量，在超临界CO2中加入少量的助溶剂。添加3 ~ 5%的甲醇可获得较高的浸渍量。罗达明6G浸渍丙烯酸光纤的光学性能显示出足够的发光度。该光纤可作为有机染料激光器和具有放大功能的新型塑料光纤。

In general the plastic optical fibers having amplifier function has been prepared by spinning polymer melt mixed with some photosensitizer. In this work a quite different method was tried to prepare the plastic optical fiber having amplifier function ; a photo sensitizer, Rhodamine 6G was impregnate into some commercial plastic fibers from the supercritical carbon dioxide solution.As fundamental research, some synthetic fibers such as polyester and polypropyren fibers were dyed with disperse dyes in supercritical carbon dioxide. The solubility of dyestuffs, the swelling behavior, adsorption rate and adsorption isotherm were investigated. Consequently, the effects of dyeing temperature, pressure, time on the dying rate and equilibrium dyeing were made clear.In the case of impregnation of Rhodamine 6G into acrylic plastic optical fiber the structure change optical fiber was observed. Especially changing in diameter and/or foaming of the fiber were observed at higher temperature. Optimal condition was obtained at very low temperature. Using pure carbon dioxide no enough amount of Rhodamine 6G was impregnated. In order to impregnate much amount of Rhodamine small amounts of co-solvents was added in supercritical CO2. High amount of impregnation was obtained by adding of 3-5 mol % methanol.Optical property of the Rhodamin 6G impregnated acrylic optical fiber shows enough degree of luminescence. It is also suggested that the prepared fiber acts as a organic dye laser and a new type of plastic optical fiber having amplifier function.