Incorporation of Additives in Self-Assembled Block Copolymers: From Molecular Solvents to Nanoparticles

Block copolymers provide self-assembled systems with great versatility as to the types of nanostructures formed and the conditions under which they are stable.  Interesting hybrid nanocomposite materials can result from the arrangement of nanoparticles in block copolymer matrices.  We are addressing the interplay between block copolymer organization and nanoparticle properties as affected by the solvents present, and are exploring the continuum between molecular solvents and nanoparticles.  In particular, we discuss here lyotropic liquid crystalline systems formed by hydrated poly(ethylene oxide)-poly(propylene oxide) block copolymers (Pluronics), and their ability to accommodate within the same structure polar organic solvents, polyhedral oligomeric silsesquioxanes (POSS), or silica nanoparticles.  We relate the solvent/particle degree of loading and location in the block copolymer structure to enthalpic and entropic considerations that emanate from the solvent/particle size and chemical functionality.

Sarkar, B.; Lakshmichand, J.; Alexandridis, P. Self-Assembly of Amphiphilic Block Copolymers in Ternary Solvent Mixtures: Lyotropic Liquid Crystalline Phase Behavior and Structure. Macromol. Chem. Phys. 2012, 213 (23), 2514-2528.  DOI: 10.1002/macp.201200438

Ayandele, E.; Sarkar, B.; Alexandridis, P. Polyhedral Oligomeric Silsesquioxane (POSS)-Containing Polymer Nanocomposites. Nanomaterials 2012, 2 (4), 445-475.  DOI: 10.3390/nano2040445

Sarkar, B.; Alexandridis, P. Self-Assembled Block Copolymer - Nanoparticle Hybrids: Interplay between Enthalpy and Entropy. Langmuir 2012, 28 (45), 15975-15986.  DOI: 10.1021/la303568e