In Situ Study of ABC Triblock Terpolymer Self-Assembly under Solvent Vapor Annealing

Abstract

We investigate the morphological evolution of two linear ABC triblock terpolymers, poly­(1,1-dimethyl­silacyclobutane-block-styrene-block-methyl methacrylate) (PDMSB-b-PS-b-PMMA or DSM) and poly­(1,1-dimethyl­silacyclobutane-block-styrene-block-lactide) (PDMSB-b-PS-b-PLA or DSL), in situ during solvent vapor annealing using grazing-incidence small-angle X-ray scattering. The morphology, orientation, and period of the microdomains are characterized under a continuous solvent vapor flow of CHCl3 as a function of swelling ratio and deswelling rate. The 90 nm thick films of DSM form in-plane core–shell cylinders, while DSL films of 150 nm thickness predominantly form out-of-plane core–shell cylinders within perforated lamellae oriented parallel to the substrate. A reversible order–order phase transformation between spheres and cylinders and a reorientation from in-plane to out-of-plane cylinders occur during the annealing process.

Resolving Triblock Terpolymer Morphologies by Vapor-Phase Infiltration

“…[7][8][9][10][11][12][13][14] Compared with diblock copolymers, triblock and multiblock polymers can produce nanostructures with greater structural diversity and additional chemical functionalities, [15][16][17][18][19][20] and there has been an increasing emphasis on understanding their selfassembly and 3D morphologies. [21][22][23][24][25] However, it is challenging to resolve the morphologies of 3D BCPs comprising more than two polymeric components unless there is good contrast between the microdomains, for example a contrast in density, chemical composition, or reactivity. Block-selective etching followed by planview or cross-sectional imaging using scanning electron microscopy (SEM) is commonly used to characterize BCP morphologies, but the organic blocks are often difficult to distinguish.…”

“…Our previous study of one composition of DSL reported the formation of microdomains consisting of core-shell cylinders perpendicular to perforated lamellae, based on SEM and grazing-incidence small-angle X-ray scattering (GISAXS) characterization. 23 The PDMSB was clearly resolved but it was difficult to differentiate between the PLA and the PS blocks. In this work, we demonstrate the effects of ZnO infiltration into a series of DSL compositions that includes both lamellar and lamellar plus hexagonal cylinder morphologies.…”

Synthesis and Self-Assembly of Conjugated Block Copolymers

“…cBCPs with complex architectures have been reported, such as conjugated multi-block copolymers [ 76 , 77 , 78 ], miktoarm star copolymers [ 79 , 80 , 81 , 82 , 83 ], polymer brushes [ 84 , 85 ], dendrimers [ 86 ], cyclic polymers [ 87 ], etc. Similar to binary cBCPs, polymers of other architectures can also be synthesized by using the grafting-from approach and grafting-onto approach.…”

“…Similar to binary cBCPs, polymers of other architectures can also be synthesized by using the grafting-from approach and grafting-onto approach. For the grafting-from approach, Lee et al reported PDMSB- b -PS- b -PMMA synthesized by sequential anionic polymerization [ 78 ]. There are also some miktoarm star copolymers prepared by combining grafting-from and grafting-onto, such as (P3HT) 2 PMMA [ 82 ], (P3DDT) 2 PMMA [ 80 ], PMMA 2 P3HT [ 81 ], etc.…”

Self-assembly of block copolymers under non-isothermal annealing conditions as revealed by grazing-incidence small-angle X-ray scattering

“…Remarkably, due to the recent progress in synchrotron instrumentation for GISAXS, sub-millisecond time-resolution measurements can be performed, thus enabling an accurate study of the kinetics of the BCP self-assembly process. However, most of the reported in situ and real-time studies using synchrotron radiation were performed on solventannealed samples (Papadakis et al, 2008;Di et al, 2010;Gu et al, 2014;Zhang et al, 2014;Sinturel et al, 2014;Berezkin et al, 2018;Lee et al, 2019). In general, the characterization of thermally annealed samples is mainly performed on already self-assembled ex situ samples by taking snapshots during the process of interest (Ferrarese Lupi et al, 2017), while only a few studies have been performed during the thermal annealing (Yager et al, 2009;Sepe et al, 2011;Maret et al, 2014;Samant et al, 2016).…”