Well Ordered Polymer Melts from Blends of Disordered Triblock Copolymer Surfactants and Functional Homopolymers

Abstract

Microphase segregated block copolymer melts and solids have long garnered significant scientific interest due to their ability to spontaneously form periodic morphologies at controllable length scales. [1][2][3] Their utility as stand-alone nanostructured functional materials [4][5][6][7][8] or as templates for the fabrication of hierarchical solids [9][10][11][12] is well documented.However, their deployment in large scale applications has often been limited by the cost and scalability of the living polymerization techniques necessary for the precise control of molecular parameters required to achieve well defined morphologies. Here, we report that well ordered, processible, and functional polymer melts with periodic nanostructures can be obtained in bulk quantity by simple blending of commercially available triblock copolymer surfactants with a series of commodity homopolymers that selectively associate with one of blocks through hydrogen bonding. While the neat surfactants are disordered in the melt, scattering measurements indicate that the blends undergo a disorder-to-order transition to yield stable microphase separated structures. Moreover, the functional groups present in the homopolymers provide a convenient handle for subsequent templating schemes including phase selective chemistries and depositions, chemical modifications, and binding of active dopants including nanoparticles. The results are general, and suggest a low cost, high volume strategy to produce ordered spherical, cylindrical, or lamellar microphase separated polymer melts for commercial use.

Frustrating the lamellar ordering transition of polystyrene-block-polyisoprene with a C60 additive

“…Tirumula et al 47 recently showed that the addition of a homopolymer with a selective interaction for one of the blocks has the same effect. This effect also applies to diluted blends 45 and this simple rule of thumb thus has wide applicability.…”

Nanoparticle-regulated phase behavior of ordered block copolymers

“…This attribute, which distinguished such nanoparticles from small nanoparticles or simple low molar mass molecules that interact only by van der Waals forces, is experimentally observed and theoretically predicted. In this spirit, we note that independent studies have shown that the stability of block copolymer nanostructures can likewise be enhanced through the incorporation of selective 37 or functional 38 homopolymers that remain mixed within (and do not macrophase-separate from) the copolymer nanostructure. Addition of selective nanoparticles to ordered block copolymers may therefore not only yield novel, spatially-modulated hybrid materials via nanoparticle assembly 39 for a wide variety of growing nanotechnologies, but also provide an alternative physical means by which to promote polymeric nanostructure development.…”

Mesoporous silica SBA-15 sheet with perpendicular nanochannels

“…In aqueous solution, without silicate ions, the interaction between PPO and PEO of Pluronic copolymers (PEO-PPO-PEO) is only weakly repulsive [46]. It has been reported that the blending of PEO-based copolymers with some additives (inorganic salts or PAA) could induce an increase of incompatibility toward the other block [34,[47][48][49]. The association of PEO segments and oligosilicates increase the effective incompatibility between PPO segments and PEO-silicate segments.…”