Abstract
fImmiscible polymer blends tend to undergo phase separation with the formation of nanoscale architecture which can be used in. a variety of applications. Different wet chemistry techniques already exist to fix the resultant polymeric structure in predictable manner.
In this work, an all-dry and plasma-based strategy is proposed to fabricate thin films of microphase-separated polyolefin/polyether blends. This is achieved by directing (-CH2-)(100) and (-CH2-CH2-O)(25) oligomer fluxes produced by vacuum thermal decomposition of poly(ethylene), and poly(ethylene oxide) onto silicon substrates through the zone of the glow discharge.
The strategy enables mixing-of thermodynamically incompatible macromolecules at the molecular level, whereas electron-impact initiated radicals serve as. cross-linkers to arrest the subsequent phase separation at the,nanoscale. The mechanism of the phase separation as well as the morphology of the films is found to depend on the ratio between the oligomeric fluxes.
For polyolefin-rich matures, polyether molecules self-organize by nucleation and growth into spherical domains with average height of 22 rim and average diameter of 170 nm. For equinumerous fluxes and for mixtures with the prevalence of polyethers, spinodal decomposition is detected that results in the formation of bicontinuous structures, with the characteristic domain size and spacing ranging between 5 x 10(1) - 7 X 10(1) nm and 3 X 10(2)-4 X 10(2) nm, respectively.
The method is shown to produce films with tunable wettability and biologically nonfouling properties.