Effect of homopolymer in polymerization-induced microphase separation process

Park, Jongmin; Saba, Stacey A.; Kang, Dong-Chang; Seo, Myungeun

doi:10.1016/j.polymer.2017.04.046

Cited by 36 publications

(32 citation statements)

References 33 publications

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“…In Figure a, a monolith prepared using 20 kg mol –1 PEO-CTA (PEO-CTA:S/DVB = 8:17) and no hPEO (hPEO:PEO-CTA = 0) shows a single broad SAXS reflection centered at a scattering wavevector q ≈ 0.3 nm –1 , indicating a microphase-separated but disordered structure with compositional heterogeneity on an ∼20 nm length scale. This result is similar to the nanostructured monoliths that our previous studies achieved, although here a difunctional instead of monofunctional PEO-CTA was employed. − We have reported that PEO or PLA homopolymer selectively swells the microphase-separated PLA domain in PLA- b -P(S- co -DVB) monoliths. When the homopolymer additive exceeds the solubility limit in the PLA domain by increasing either the molar mass or mass fraction of the additive, macrophase separation of the homopolymer occurs, resulting in macropores.…”

Section: Resultssupporting

confidence: 85%

Nanostructured Polymer Monoliths for Biomedical Delivery Applications

Xie

2020

ACS Appl. Bio Mater.

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Drug delivery systems are designed to control the release rate and location of therapeutic agents in the body to achieve enhanced drug efficacy and to mitigate adverse side effects. In particular, drug-releasing implants provide sustained and localized release. We report nanostructured polymer monoliths synthesized by polymerization-induced microphase separation (PIMS) as potential implantable delivery devices. As a model system, free poly(ethylene oxide) homopolymers were incorporated into the nanoscopic poly(ethylene oxide) domains contained within a cross-linked polystyrene matrix. The in vitro release of these poly(ethylene oxide) molecules from monoliths was investigated as a function of poly(ethylene oxide) loading and molar mass as well as the molar mass and weight fraction of poly(ethylene oxide) macro-chain transfer agent used in the PIMS process for forming the monoliths. We also developed nanostructured microneedles targeting efficient and long-term transdermal drug delivery by combining PIMS and microfabrication techniques. Finally, given the prominence of poly(lactide) in drug delivery devices, the degradation rate of microphase-separated poly(lactide) in PIMS monoliths was evaluated and compared with bulk poly(lactide).

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Section: Resultssupporting

confidence: 85%

Nanostructured Polymer Monoliths for Biomedical Delivery Applications

Xie

2020

ACS Appl. Bio Mater.

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“…At r macroCTA value of 0.25 the 3D printed rectangular prism showed slightly increased transmittance, while the samples with r macroCTA > 0.50 showed high transparency (Figure 4B). These observations are consistent with previous work reported for cross-linked monoliths prepared by bulk RAFT polymerization, [55] and are explained by changes in the characteristic length scale of phase-separated structures from microdomains to nanodomains upon increasing r macroCTA from 0.00 to 1.00.…”

Section: Controlling Nanostructures In 3d Printed Materialssupporting

confidence: 93%

“…The differences in phase‐separated morphologies and domain sizes with varied r macroCTA can be explained by variations in the PIMS process during 3D printing, particularly the ability for selective swelling of PBA domains to occur. [ 55 ] For samples with r macroCTA = 1.00, the PIMS process can be considered ideal; the PBA 48 ‐CTA is efficiently chain extended to form diblock copolymers which begin to microphase separate, forming bicontinuous structures until the morphology is arrested by cross‐linking. [ 21 ] For systems containing PBA 48 in small amounts, that is, for r macroCTA = 0.75, the unreactive PBA 48 selectively swells PBA nanodomains generated during PIMS, resulting in a slightly increased domain spacing as observed by SAXS (Figure S25, Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

“…Interestingly, Seo and co‐workers demonstrated a method to manipulate phase separation behavior of cross‐linked monoliths via the addition of nonreactive homopolymer to the reaction mixture. [ 55 ] Inspired by this work, another series of resins with varied weight ratios of PBA 48 ‐CTA to unreactive PBA 48 was prepared (Table S6, Supporting Information). The molar ratio for these resins was [AA]/[PEGDA]/[PBA]/[TPO] = 120/30/1/0.3 (≈28.2 wt% PBA), where PBA represents the mixture of nonreactive PBA 48 and PBA 48 ‐CTA at different weight ratios.…”

Section: Resultsmentioning

confidence: 99%

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Nanostructure Control in 3D Printed Materials

et al. 2021

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Currently, there are no straightforward methods to 3D print materials with nanoscale control over morphological and functional properties. Here, a novel approach for the fabrication of materials with controlled nanoscale morphologies using a rapid and commercially available Digital Light Processing 3D printing technique is demonstrated. This process exploits reversible deactivation radical polymerization to control the in‐situ‐polymerization‐induced microphase separation of 3D printing resins, which provides materials with complex architectures controllable from the macro‐ to nanoscale, resulting in the preparation of materials with enhanced mechanical properties. This method does not require specialized equipment or process conditions and thus represents an important development in the production of advanced materials via additive manufacturing.

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“…In comparison to the current efforts in designing new hydrophobic materials and preparation methods, the influence of the interaction between polymers and solvents on micro/nano‐structures has been rarely investigated . In 2003, Erbil and co‐workers first reported that PP was used to prepare a gel‐like and superhydrophobic film by micro‐phase separation method on various carriers, such as glass slides, aluminum foils, and stainless steel plates .…”

Section: Introductionmentioning

confidence: 99%

Superhydrophobic Porous PLLA Sponges with Hierarchical Micro‐/Nano‐Structures for High‐Efficiency Self‐Cleaning

Wang

Tian

Sun

et al. 2019

Macro Chemistry & Physics

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Porous poly (l‐lactic acid) (PLLA) sponges have received rapid development in the materials science and energy fields due to their good biocompatibility and degradability. Herein, hierarchical micro‐/nano‐structures of PLLA sponges are successfully prepared by the microphase separation method to investigate the influence of non‐solvents on PLLA microtopography. The interaction ability between PLLA and various alcohol non‐solvents is precisely calculated by using the Flory–Huggins equation. SEM results show that the porosity of PLLA surfaces increases with increasing non‐solvent solubility parameters at a certain range. When the solubility parameters of alcohol non‐solvents are much higher than that of PLLA, PLLA bulks accumulate on the surfaces, mainly caused by its insolubility. DSC curves disclose that the crystallinity has a positive relationship with contents and solubility parameters of alcohol non‐solvents. Furthermore, these porous PLLA surfaces show strong water repellency and self‐cleaning ability so that the contaminant can be quickly cleared away from the PLLA surfaces. This study provides a new insight into understanding the formation process of PLLA porous materials and the wetting variation for high‐efficiency self‐cleaning.

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Effect of homopolymer in polymerization-induced microphase separation process

Cited by 36 publications

References 33 publications

Nanostructured Polymer Monoliths for Biomedical Delivery Applications

Nanostructured Polymer Monoliths for Biomedical Delivery Applications

Nanostructure Control in 3D Printed Materials

Superhydrophobic Porous PLLA Sponges with Hierarchical Micro‐/Nano‐Structures for High‐Efficiency Self‐Cleaning

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