Tricontinuous Nanostructured Polymers via Polymerization-Induced Microphase Separation

Abstract

Nanostructured tricontinuous block polymers allow for the preparation of single-component materials that combine multiple properties. We demonstrate the synthesis of a mesoporous material from the selective orthogonal etching of a microphase-separated tricontinuous block polymer precursor. Using the synthetic approach of polymerization-induced microphase separation (PIMS), divinylbenzene (DVB) is polymerized from a mixture of poly­(isoprene) (PI) and poly­(lactide) (PLA) macro-chain transfer agents. In the PIMS process in situ cross-linking by the DVB arrests structural coarsening, resulting in a disordered block polymer morphology that we posit exhibits three nonintersecting continuous domains. Selective etching of the PI domains by olefin cross metathesis and PLA domains by hydrolytic degradation produces a mesoporous polymer with two independent pore networks arising from the different etch mechanisms.

Nanostructure Control in 3D Printed Materials

“…[26,27] PIMS processes allow one-step formation of nanostructured materials consisting of different phases with independently tunable properties. This distinguished feature allows nanostructured materials to be used in a variety of applications including as nanoporous materials, [21,26,[28][29][30][31][32][33] polymer electrolyte membranes, [27,[34][35][36] biomedical materials, [37] and others. [38,39] For example, bicontinuous and nanostructured diblock polymer electrolyte membranes composed of a mechanically robust cross-linked polystyrene domain and a conductive poly(ethylene oxide)/ionic liquid domain demonstrated remarkable values for both modulus and conductivity at high temperatures.…”

Nano- to macro-scale control of 3D printed materials via polymerization induced microphase separation

“…1a ). PIMS systems 23 – 27 , including some photoinduced systems 28 , allow a high degree of control over nanoscale morphologies and domain sizes. As a result of this exceptional nanoscale control, materials fabricated through PIMS processes have been used as polymer electrolyte membranes 29 – 33 , heterogeneous catalysts 34 , photochromic dye hosts 35 , and nanostructured microneedles 36 and microcapsules 37 for tunable release of loaded molecules.…”

Fast Photochromic Dye Response in Rigid Block Polymer Thermosets

“…PIMS thermosets are derived from diblock polymers and exhibit a reticulated three-dimensional morphology . Previous PIMS systems have typically used a styrenic − , or acrylic cross-linked block, and the macroCTAs have been polylactide, , polyisoprene, or poly­(ethylene oxide) . The use of a methacrylic block instead of a styrenic block demonstrates the versatility of the PIMS method and its applicability to a variety of diblock polymer systems.…”

“…After basic etching, a representative monolith exhibited a BET surface area of 120 m 2 /g and an average pore radius of 2 nm by BJH modeling using nitrogen sorption analysis. No glass transition was observed for the cross-linked PMMA domain which is likely due to the high degree of cross-linking . See Figures S13–S15 for more detailed information.…”

“…No glass transition was observed for the cross-linked PMMA domain which is likely due to the high degree of cross-linking. 40 See Figures S13−S15 for more detailed information. These observations are consistent with a bicontinuous reticulated morphology as demonstrated in work previously reported by our group.…”