Tailorable Micelle Morphology in Self-Assembling Block Copolymer Gels for Templating Nanoporous Ceramics

Abstract

The self-assembly of block copolymers offers opportunities for the facile organization and templating of inorganic nanomaterials. Here, we describe a morphology map for a poly(methyl methacrylate)-b-poly(n-butyl acrylate)-bpoly(methyl methacrylate) (PMMA-b-PnBA-b-PMMA) block copolymer/polycarbosilane system that allows for tunable control over nanoscale micelle geometry via manipulation of the preceramic polymer content. We produced gels with spherical, wormlike, and bicontinuous morphologies, which were processed to create silicon carbide-based ceramic structures with tunable nanoscale porosities. The role of the constituent polymers in influencing the structure and rheology of this system is discussed. The PMMA-b-PnBA-b-PMMA block copolymer/preceramic polymer system offers a number of advantages including: (i) commercial availability, (ii) rapid self-assembly kinetics, and (iii) successful conversion of the self-assembled nanostructure to ceramic via pyrolysis. This system may be useful for catalytic, structural, or thermal applications in both industrial and academic settings because of its ease of use and relatively inexpensive reagents.

Preceramic Polymers Grafted to SiO2 Nanoparticles via Metal Coordination Pyrolyzing with High Ceramic Yields: Implications for Aerospace Propulsion and Biomedical Coatings

“…The chemical structure of the parent PCP has a dramatic effect on the composition, structure, and properties of polymer-derived ceramics (PDCs). , This provides an avenue toward exploring structure–function relationships between the PCP and PDCs. When considering the production of PDCs, PCP conversion efficiency (i.e., char yield) is an important factor.…”

Customized Nanostructured Ceramics via Microphase Separation 3D Printing

“…Nanostructured polymer‐derived ceramics are traditionally obtained by thermal treatment of ordered preceramic templates. Conventional synthetic approaches for controlled fabrication of nanostructured preceramics rely on i) soft/hard templating, [ 4 ] ii) self‐assembly of organic–inorganic block copolymers [ 5 ] or co‐assembly of inorganic precursors with organic block copolymers, [ 6 ] or iii) organic–inorganic hybrid polymerization‐induced microphase separation (PIMS). [ 7 ] In the first approach, a preceramic precursor co‐assembles with soft organic materials or is filled into a preordered hard template followed by ceramization and selective template removal.…”

Influence of Thermal Treatment on Preceramic Polymer Grafted Nanoparticle Network Formation: Implications for Thermal Protection Systems and Aerospace Propulsion Components

“…Preceramic polymers (PCPs) offer advantages in ceramics production, including the production of high-performance ceramic fibers and composites as well as the generation of compositional diverse ceramics (e.g., SiC, Si 3 N 4 , and SiCN). − PCPs have been investigated for several decades, revealing synthetic procedures for unique structures and a deeper understanding of processing science and pyrolysis chemistry. − For example, it is accepted that network forming through high cross-link densities is more important than achieving high polymer molecular weights (MWs) for improving char yield. − Moreover, emphasis on the role of weight loss during pyrolysis as it relates to volume shrinkage of the derived ceramic is being better understood …”