Mechanical properties of selected CPs: elastic
stress and COS versus
film thickness for (a) P3HT, (b) PDPPT, and (c) PNDI; engineering
stress as a function of engineering strain for various film thickness
for (d) P3HT, (e) PDPPT, and (f) PNDI, where the inset figures are
the linear regions of the stress–strain curves. (g–i)
Simulation result. (g) Schematic illustration of uniaxial tension
of the polymer thin film. (h) Stress–strain response for thin
film with a thickness ∼20 nm for different chain rigidity Krigidity. The elastic modulus is extracted from
the slope shown by the dashed lines. (i) Thickness dependence of the
elastic modulus of thin film for different Krigidity values. The dashed lines indicate the corresponding
modulus in the bulk state. Panels (a) and (d) are adapted with permission
from ref (66). Copyright
2018, John Wiley and Sons.