Investigation of Microphase Separation of PS-PPrMA Diblock Copolymer Films by Time-of-Flight Secondary Ion Mass Spectrometry

Abstract

The microphase separation of diblock copolymers has been investigated by many different research groups for many years, because of the increasing use of diblock copolymers as compatibilizers, dispersants, impact modifiers, nanocarriers, and templates. In this presentation, surface characterization methods were utilized to study the surface morphology and composition produced after annealing thin polymer films. We report on the characterization of the morphology from symmetric diblock copolymers of polystyrene-b-poly(n-propyl methacrylate)(PS-PPrMA), where PS block was perdeuterated, using Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS). TOF-SIMS depth profiling was obtained for the lamellar morphology of deuterated PS-PPrMA which is found to orient parallel to the surface of the substrate. This preferential orientation resulted in a periodic variation in the composition of each block that continued through the entire copolymer film. Annealing studies on dPS-PPrMA thin films with different thickness on the silicon substrates were performed to investigate the lower disorder-to-order transition (LDOT) properties of diblock copolymers.