The role of nanoconfinement on the glass transition temperature $\left(T_g\right)$ of polymers has been extensively studied in the thin film geometry. This work looks at the $T_g$ of nanoconfined polystyrene (PS) in spherical nanoparticles $(27–200\mathrm{nm})$, individually dispersed in crosslinked polybuthylmethacrylate matrices. A reduction of $T_g$ compared to the bulk was observed in PS nanospheres via neutron scattering mechanical tests and was found to decrease with decreasing diameter for $D<50\mathrm{nm}$. The general trend of $T_g$ depression in nanospheres was found to be similar to the results on thin film geometry.

• Received 15 February 2007

DOI:https://doi.org/10.1103/PhysRevE.77.031806