Vaccaro Andrea, Hierrezuelo José, Skarba Michal, Galletto Paolo, Kleimann Jörg, Borkovec Michal
Department of Inorganic, Analytical, and Applied Chemistry, University of Geneva, 1211 Geneva 4, Switzerland.
Langmuir. 2009 May 5;25(9):4864-7. doi: 10.1021/la9007608.
An adsorbed layer of a cationic polyelectrolyte, poly(diallyldimethyl-ammonium) chloride (PDADMAC) on negatively charged colloidal latex particles was investigated by small-angle neutron scattering (SANS) and dynamic light scattering (DLS). SANS gives a layer thickness of 8 +/- 1 A and a polymer volume fraction of 0.31 +/- 0.05 within the film. DLS gives a somewhat larger thickness of 18 +/- 2 A, and the discrepancy is likely due to the inhomogeneous nature of the layer and the existence of polymer tails or loops protruding into solution. These results show that a highly charged polyelectrolyte adsorbs on an oppositely charged colloidal particle in a flat configuration due to the attractive forces acting between the polyelectrolyte and the substrate.
通过小角中子散射(SANS)和动态光散射(DLS)研究了带负电的胶体乳胶颗粒上阳离子聚电解质聚(二烯丙基二甲基氯化铵)(PDADMAC)的吸附层。SANS给出的膜内层厚度为8±1 Å,聚合物体积分数为0.31±0.05。DLS给出的厚度稍大,为18±2 Å,这种差异可能是由于层的不均匀性质以及聚合物尾巴或环突出到溶液中的存在。这些结果表明,由于聚电解质与底物之间的吸引力,高电荷聚电解质以扁平构型吸附在带相反电荷的胶体颗粒上。