In Situ X ray scattering for investing morphology of bottle brush BCP with Solvent annealing

We investigated the morphology of bottle-brush block copolymer (BrBCPs) thin films using solvent vapor annealing (SVA) in a specially designed chamber for \textit{in situ }grazing incidence x-ray scattering. BrBCPs with polystyrene (PS) and poly(lactic acid) (PLA) side chains and a norbornene backbone were studied SVA using THF, a good solvent for PS and PLA, a controlled swelling and deswelling rate were achieved with N$_{2}$ carrier gas. Film thickness was monitored by optical interferometry. The interference maximum, characteristic of the microdomain morphology, was found to vary linearly with molecular weight. The \textit{in situ }GISAXS measuremens were used to elucidate the evolution of the morphology in the thin films.