Structural Changes in Cylinder-Forming PS-b-PB Thin Films During Solvent Vapor Annealing

Tim Birger Tejsner

Studenteropgave: Speciale

Abstrakt

The orientational changes of cylinders in Polystyrene-b-Polybutadiene (PS-b-PB) diblock copolymer thin films during solvent vapor annealing (SVA) was investigated using White- Light Interferometry (WLI) and time-resolved grazing-incidence small-angle x-ray scattering (GISAXS). The SVA procedure was performed with three different solvents of varying selec- tivity to the two blocks: Ethyl Acetate (EAC), Toluene (TOL) and Cyclohexane (CHX). A change from standing to lying cylinders was found using all three solvents. The orientational change appears to depend on the minimal polymer volume fraction phi_min of the film, and different threshold values were found for each solvent: phi_min,EAC = 0.66, phi_min,TOL = 0.63, phi_min,CHX = 0.49. In one experiment with CHX, the switch from standing to lying cylin- ders happens through a disordered phase spanning 15 minutes. This, along with other circumstantial evidence, hints at the timescales of structural changes.

UddannelserFysik, (Bachelor/kandidatuddannelse) Kandidat
SprogEngelsk
Udgivelsesdato10 nov. 2015
VejledereDorthe Posselt

Emneord

  • block copolymer
  • PSPB
  • Scattering
  • GISAXS
  • X-ray
  • Solvent Vapor Annealing