A new class of copolymer colloids with tunable, low refractive index for investigations of structure and dynamics in concentrated suspensions

作者：Ziegert Falko; Koof Michael; Wagner Joachim^*

来源：Colloid and Polymer Science, 2017, 295(9): 1563-1574.

DOI：10.1007/s00396-017-4137-2

• Colloid
• Copolymer
• Refractive index
• Self-organization

Highly charged polymer colloids may serve as model systems for the investigation of condensed matter, if they self-organize to liquid-like, glassy or crystalline phases. Multiple scattering due to refractive index differences of colloidal particles and suspending medium is a serious problem when utilizing light scattering experiments for these investigations. In this work, a new class of monodisperse colloidal dispersions is prepared by means of emulsion copolymerization of the monomers n-butyl acrylate and 2,2,2-trifluoroethyl acrylate. By systematic variation of the molar ratio of fluorinated and non-fluorinated monomers, the refractive index n (p) of the colloidal copolymer particles is tuned in the range 1.38 < n (p) < 1.45. Thus, particles with any composition of both monomers can be index-matched by protic water/glycerol mixtures as demonstrated by minima of the relative transmission of suspensions in dependence on the refractive index of the suspending medium. Static and dynamic light scattering experiments as well as analysis of the static structure factors S(Q) by means of integral equations are employed to investigate the self-organization of the resulting colloidal copolymer particles. Hereby, the potential application of these new model systems to investigate dynamics in concentrated binary mixtures is demonstrated.

• 出版日期2017-9