Controllable nanostructural transitions in grafted nanoparticle-block copolymer composites

Abstract

We report a theoretical investigation of self-assembled nanostructures of polymer-grafted nanoparticles in a block copolymer and explore underlying physical mechanisms by employing the self-consistent field method. By varying the particle concentration or the chain length and density of the grafted polymer, one can not only create various ordered morphologies (e.g., lamellar or hexagonally packed patterns) but also control the positions of nanoparticles either at the copolymer interfaces or in the center of one-block domains. The nanostructural transitions we here report are mainly attributed to the competition between entropy and enthalpy.

Entropic Effects in Polymer Nanocomposites

“…Sides et al [ 71 ] performed a 2D simulation with the hybrid particle-field (HPF) algorithm, underestimating the particle concentration at the morphological transitions, as shown in Figure 6 c,d. Qualitatively similar predictions have also been reported by Xu et al [ 72 ] using self-consistent field theory, showing that those structural transitions are dictated by the competition between entropy and enthalpy.…”

Position transitions of polymer-grafted nanoparticles in diblock-copolymer nanocomposites

“…The formation of various patterns depends on the volume fraction of polymer-grafted nanoparticles [10]. In our previous work [49], it has been demonstrated that a transition from the lamellar ($ GP = 0.15, Figure 1a) to hexagonally packed ($ GP = 0.4, Figure 1b) pattern occurs as the grafted particle concentration $ GP increases. In this paper, our attention is focused on how to control the spatial distribution of nanoparticles in a diblock-copolymer lamellar morphology, because of its wide applications in nanocomposites [2,5,9,[12][13][14].…”

Hairy nanoparticle assemblies as one-component functional polymer nanocomposites: opportunities and challenges

“…BCP-templated nanocomposite structures, in which nanoparticles are forced into specific domains, have been reported both in simulations [44] and experiment, [45][46][47] but they have the same limitations as the conventional nanocomposites mentioned in the introduction (mixing, agglomeration and low inorganic volume fractions). An alternative route is to use HNPs where the hairs are BCPs [48,49] or liquid crystal mesogens [50,51] . This design allows for much more controlled structure formation (Fig.…”