Improved self‐assembly of poly(dimethylsiloxane‐b‐ethylene oxide) using a hydrogen‐bonding additive

Abstract

Block copolymers with increased Flory-Huggins interaction parameters (v) play an essential role in the production of sub-10 nm nanopatterns in the growing field of directed self-assembly for next generation lithographic applications. A library of PDMS-b-PEO block copolymers were synthesized by click chemistry and their interaction parameters (v) determined. The highest v measured in our samples was 0.21 at 150 8C, which resulted in phase-separated domains with periods as small as 7.9 nm, suggesting that PDMS-b-PEO is a prime candidate for sub-10 nm nanopatterning. To suppress PEO crystallization, PDMS-b-PEO was blended with (L)-tartaric acid (LTA) which allows for tuning of the self-assembled morphologies. Additionally, it was observed that the order-disorder transition temperature (T ODT ) of PDMS-b-PEO increased dramatically as the amount of LTA in the blend increased, allowing for further control over self-assembly. To understand the mechanism of this phenomenon, we present a novel field-based supramolecular model, which describes the formation of copolymeradditive complexes by reversible hydrogen bonding. The mean-field phase separation behavior of the model was calculated using the random phase approximation (RPA). The RPA analysis reproduces behavior consistent with an increase of the effective v in the PDMS-b-(PEO/LTA suprablock).

Molecular Tailoring of Poly(styrene-b-methyl methacrylate) Block Copolymer Toward Perpendicularly Oriented Nanodomains with Sub-10 nm Features

“…For instance, the interaction parameters estimated at 180 °C are given as χ SM = 0.046, χ SH = 0.314, and χ MH = 0.071, revealing that the promotion of phase-separation in the case of the SHM triBCP is driven largely by a strong, repulsive interaction between styrene and methacrylic acid. It is also worth noting that a similar effect was observed in other BCPs, in which χ eff was increased by the addition of small molecules via hydrogen bonding or introduction of an ionic unit at the junction of the two blocks. , The monomer density profiles, which were computed for SM21 and SHM21-0.6 at 180 °C using SCFT, also confirm that phase-separation occurs for SHM21-0.6, whereas SM21 remains homogeneous under the same thermodynamic condition (Figure ).…”

Ring-Opening Polymerization (ROP) and Catalytic Rearrangement as a Way to Obtain Siloxane Mono- and Telechelics, as Well as Well-Organized Branching Centers: History and Prospects

“…These polymers are applicable in the developing field of hybrid polymer/lipid vesicles. According to the same scheme, monofunctional azide PDMS were obtained in [95] and [96] for the subsequent preparation of copolymers. The functional end group can be introduced either by the organo segment of the initiator or by the chlorosilane molecule.…”

“…These polymers are applicable in the developing field of hybrid polymer/lipid vesicles. According to the same scheme, monofunctional azide PDMS were obtained in [95,96] for the subsequent preparation of copolymers. 12).…”

Stereochemical Sequence Dictates Unimolecular Diblock Copolymer Assembly

“…16 To investigate how chiral additives might impact the assembly of our chiral DPTs, we doped 32B samples with super-stoichiometric quantities (16 equiv, ca. 20 wt%) of (L)-tartaric acid in an attempt to selectively swell the hydrophilic (TEG) block and thus access new morphologies through horizontal translation across the diblock copolymer phase diagram (Figure 3E – G).…”