Temperature-dependent Nanoparticle-Block Copolymer Adsorption.

The effect of silica nanoparticle on the self-assembly of PEO-PPO-PEO triblock copolymer in aqueous solution has been studied using small-angle neutron scattering (SANS). The measurements have been carried out for fixed concentrations (1 wt%) of nanoparticles and block copolymers, and at varying temperatures between 15 to 45 °C. With increasing temperature, non-ionic Pluronic block copolymers modify their structures significantly (unimer-tomicelle transition) whereas nanoparticles remain indifferent. Contrast variation SANS measurements show that the addition of block copolymers to the nanoparticle solution leads to the formation of micelle-adsorbed nanoparticle conjugates at room temperature. Interestingly, this adsorption of the block copolymers on nanoparticles gets modified with varying temperatures due to the different self-assembly behavior of block copolymers at different temperatures. [ABSTRACT FROM AUTHOR]