A collapsed elastomeric matrix of lightly cross-linked 1,2-polybutadiene (1,2-PB) was prepared from a self-assembled 1,2-polybutadiene-b- polydimethylsiloxane (1,2-PB-b-PDMS) of gyroid morphology after the removal of the PDMS block. No mesoporosity could be observed in the material in the dry state. However, in the gel state in the presence of a good solvent the swollen matrix did show a nanoporous structure originated from the gyroid block copolymer precursor. Nanopores can be opened or closed depending on the presence or absence of a solvent. Macromolecules like PEG of different molecular weights or small molecules like the surfactant SDS were loaded into the opened nanoporous matrix in the presence of a solvent and remained trapped. The loaded molecules could be released again in the presence of a solvent. The load and release of the molecules in deuterated form were monitored by in situ time-resolved small angle neutron scattering, SANS. The bicontinuous gyroid pore structure is accessible to macromolecules without the need for sample pre-alignment. The materials presented here are model systems for a novel type of load-delivery systems that could show great potential in e.g. diagnostics or drug delivery applications. © The Royal Society of Chemistry 2012.
Bibliographical noteElectronic supplementary information (ESI) available: FT-IR spectra of cross-linked and etched samples, scattering peak resolution of SANS and SAXS, SEC of PDMS before and after DCP treatment, calculation of contrast factor, distribution of PEG in the collapsed
sample, calculation of mesh size, pore size and short presentation of load–release of d-SDS. See DOI: 10.1039/c2sm26480c
- Block copolymers
- Drug delivery