Summary:
In this thesis the synthesis of diblock copolymers of PEO with P(t-BMA) as the
second block is accomplished via atom transfer radical polymerization (ATRP).
Initially, the synthesis of the macroinitiator (PEO-Br) is accomplished via an
esterification reaction between the end-hydroxyl groups with 2-bromoisobutyryl
bromide. At the ATRP of P(t-BMA), Cu(I)Br was the catalyst with PMDETA as the
ligand of the transition metal complex, CH2Cl2 was the solvent for
polymerization temperature at 25o C while toluene was the solvent for
polymerization temperature at 90o C.
Four PEO-b-P(t-BMA) block copolymers with molecular weights 21.700, 27.700,
32.200 and 37.000 having the same PEO (MW=5000) block and various compositions
were synthesized. Moreover, one more block copolymer was synthesized with
molecular weight 28.500 containing PEO of 2000 as the first block. Thin films
of block copolymer solutions onto silicon oxide substrates were prepared via
spin-coating. Upon solvent annealing, polymeric chains form microphase
separated structures depending on the volume fractions of the components. The
morphologies obtained, were detected via phase atomic force microscopy (AFM),
indicating spherical and cylindrical morphology.
Apart from block copolymer thin film self-assembly, their lithographic ability
was studied as well. The most suitable photoacid generator for the chemical
amplification of P(t-BMA) was triphenylsulfonium triflate (TPS-triflate), at 5
wt% percentage and the irradiation source was at 254nm.
The aim of this thesis was the patterning of structures of several micrometers
via optical lithography (top-down) and afterwards the development of
nanodomains (cylinders or spheres) through microphase separation on those
microstructures (bottom-up lithography), and vice-versa.
Keywords:
PEO, P(t-BMA), ATRP, bottom-up lithography, top-down lithography
