Yoon Dae Jeon, Kim Young Dae
Faculty of Applied Chemistry, Chonnam National University, 300 Yongbong-dong, Kwangju 500-757, Republic of Korea.
J Colloid Interface Sci. 2006 Nov 15;303(2):573-8. doi: 10.1016/j.jcis.2006.07.051. Epub 2006 Jul 26.
Various polypyrrole (PPy)-silica-methylcellulose nanocomposite particles were synthesized by suspension polymerization in the presence of silica nanoparticles controlling the ratio of pyrrole, silica, and methylcellulose during the polymerization. The electrorheological (ER) and dielectric properties of the sterically stabilized PPy-silica-methylcellulose nanocomposite suspensions were investigated. The ER response increases with the increase in the silica/pyrrole ratio. The ER behavior also depends on the methylcellulose amount during the polymerization. The yield stress initially increases with the methylcellulose amount, passes through a maximum, and then decreases with the methylcellulose amount. The dielectric constants and dc conductivities of the PPy-silica-methylcellulose nanocomposite particles and the dielectric properties of their suspensions indicate that the increased ER response arises from the enhanced interfacial and particle polarization which depends on the silica/pyrrole ratio and the methylcellulose amount during the polymerization.
通过在二氧化硅纳米颗粒存在下进行悬浮聚合，在聚合过程中控制吡咯、二氧化硅和甲基纤维素的比例，合成了各种聚吡咯（PPy）-二氧化硅-甲基纤维素纳米复合颗粒。研究了空间稳定的PPy-二氧化硅-甲基纤维素纳米复合悬浮液的电流变（ER）和介电性能。ER响应随二氧化硅/吡咯比例的增加而增加。ER行为还取决于聚合过程中甲基纤维素的用量。屈服应力最初随甲基纤维素用量的增加而增加，达到最大值后，又随甲基纤维素用量的增加而降低。PPy-二氧化硅-甲基纤维素纳米复合颗粒的介电常数和直流电导率及其悬浮液的介电性能表明，ER响应的增加源于增强的界面极化和颗粒极化，这取决于聚合过程中的二氧化硅/吡咯比例和甲基纤维素用量。
