Realizing 5.4 nm Full Pitch Lamellar Microdomains by a Solid-State Transformation

Abstract

A simple method was developed to realize a self-assembled block copolymer (BCP) lamellar microdomain morphology with a full pitch of 5.4 nm through an acid hydrolysis of poly(solketal methacrylate-b-styrene) (PSM-b-PS). The acid hydrolysis transforms PSM-b-PS, having two hydrophobic blocks, into poly(glycerol monomethacrylate-b-styrene) (PGM-b-PS), having one hydrophilic and one hydrophobic block. This transformation markedly increases the segmental interaction parameter such that a phase-mixed PSM-b-PS can be transformed in the solid state into a microphase-separated BCP without the use of any additives. Correlation hole scattering of the PSM-b-PS in the phase mixed state yields a segmental interaction parameter (χ) given by χ = 0.0196 + 4.694/ T, where T is the absolute temperature. With the symmetric BCPs used in this study, the ordered lamellar microdomain pitch was determined by small-angle X-ray scattering (SAXS) as a function of the degree of polymerization (16 ≤ N ≤ 1246). For the lamellar microdomains of PGM-b-PS, the scattering profiles show many higher order reflections with an increase in the domain spacing (L 0 ). The lowest molar mass sample (M n = 2200 g/mol, N = 16) had sub-3 nm microdomains after conversion to PGMb-PS.

Hydrogen Bonding Aggregation in Acrylamide: Theory and Experiment

“…For example, it was recently proposed to use block copolymers with one hydrogen-bonding block and one non-hydrogen-bonding block for lithographic applications since these block copolymer systems possess an enhanced tendency to separation 41,42 . The physical reason for this is the fact that in order to mix a non-hydrogen-bonding block and a hydrogenbonding block one needs to break the network of hydrogen bonds, which is energetically expensive.…”

Amplifying (Im)perfection: The Impact of Crystallinity in Discrete and Disperse Block Co-oligomers

“…The latter is one of the smallest feature sizes hitherto observed. 15 At higher q -values, additional scattering peaks reveal further interchain organization. For BCO [ Si 15 -LLA 17 ], a broad reflection at q = 8.6 nm –1 is attributed to the amorphous siloxane block.…”

Microphase separation of highly amphiphilic, low N polymers by photoinduced copper-mediated polymerization, achieving sub-2 nm domains at half-pitch

“…Reversible addition-fragmentation polymerization (RAFT) has also been frequently used to synthesize high χ BCPs. 5,28 Atom-transfer radical polymerization (ATRP) with Cu(I) has been used previously, but in combination with anionic polymerization. 4,16 A feature of ATRP is that the ester bond of the alkyl halide may be susceptible to post-polymerization modification conditions and promote unwanted hydrolysis.…”