Center for Urban Energy Systems, Korea Institute of Science and Technology, Hwarangno 14-gil 5, Seongbuk-gu, Seoul 136-791, Korea.
ACS Appl Mater Interfaces. 2013 Feb;5(3):1122-30. doi: 10.1021/am302891w. Epub 2013 Feb 1.
Electrorheological (ER) effects of alginic acid and alginate salts (Na(+) alginate, NH(4)(+) alginate, and Ca(2+) alginate) dispersed suspensions were investigated under DC electric fields. A noteworthy result is that the Ca(2+) alginate dispersed suspension showed negative electrorheological effects under electric fields while the other suspensions exhibited positive electrorheological effects. It is the first time that the negative ER effect is obtained with the biomacromolecule. Interestingly, at the DC electric fields, the electromigration of particles to two electrodes was observed in the negative ER fluid, while the particles-bridges formed between two electrodes in the case of the positive ER fluid. In conclusion, the specific salt type of biomacromolecules could be suitable ER particles for negative ER suspension. We believe that our study can present a new way for the development of the biocompatible and eco-friendly negative ER fluids.
海藻酸及其盐（Na(+) 藻酸盐、NH(4)(+) 藻酸盐和 Ca(2+) 藻酸盐）分散悬浮液的电流变效应在直流电场下进行了研究。一个值得注意的结果是，Ca(2+) 藻酸盐分散悬浮液在电场下表现出负电流变效应，而其他悬浮液则表现出正电流变效应。这是首次在生物大分子中获得负电流变效应。有趣的是，在直流电场下，在负电流变流体中观察到颗粒向两个电极的电迁移，而在正电流变流体中，颗粒在两个电极之间形成桥接。总之，生物大分子的特定盐类型可以作为负电流变悬浮液的合适电流变颗粒。我们相信，我们的研究可以为开发生物相容和环保的负电流变流体提供一种新的途径。
