RAFT polymerization within high internal phase emulsions: Porous structures, mechanical behaviors, and uptakes

Benaddi, Aurelie Ohana; Cohen, Orit; Matyjaszewski, Krzysztof; Silverstein, Michael S.

doi:10.1016/j.polymer.2020.123327

Cited by 24 publications

(12 citation statements)

References 90 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The presence of the RAFT agent in the eutectic phase was critical for ensuring void connectivity and uniformity. In the absence of a RAFT agent, the o/e monolith structure prepared by uncontrolled free-radical polymerization was highly irregular and typically possessed a closed-cell morphology (Figure S8); these results are in line with that of Benaddi and co-workers who reported that RAFT polymerization in the continuous phase of a w/o HIPE “locks in” the porous, open-cell structure in contrast to free radical polymerization . The inclusion of a RAFT CTA within the continuous phase also influences mechanical properties of the polyHIPEs in addition to morphology (see next section for expanded discussion), which is related to the differences between free-radical and controlled-radical polymerization.…”

Section: Resultssupporting

confidence: 85%

Open-Cell PolyHIPES from Polymerizable Eutectics: Tunable Morphology, Surface Modification, and Thermoresponsive Swelling Behavior

Nahar

Wei

Cipriani

et al. 2022

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

We report the preparation of thermoresponsive macroporous polymer monoliths via high internal phase emulsions (HIPEs) where a polymerizable nonionic deep eutectic solvent served as the continuous phase. Mixtures of N-isopropylacrylamide (NIPAM) and acrylamide (AAm) in various mole ratios formed low melting point liquids that we term "polymerizable eutectics". In the presence of the nonionic surfactant Pluronic F127, stable oil-in-eutectic HIPEs are formed with hexadecane as the dispersed phase (80% v/v) and a continuous phase of the eutectic and a small amount of water. When the eutectic phase contained an initiator, RAFT chain transfer agent, and cross-linker, heating led to controlled polymerization and formation of a polyHIPE. The resulting monoliths had an interconnected porous network structure, significantly different to the equivalent structures produced from oil-in-water HIPEs, which exhibited a closed-cell morphology. The viscosity of the polymerizable eutectic and surfactant loading enabled the morphology, degree of openness, and mechanical properties of the polyHIPE to be readily tuned. When immersed in water, the monoliths exhibited temperature-dependent absorption of water due to the presence of NIPAM within the copolymer framework. Further, the inclusion of a RAFT chain transfer agent enabled subsequent surface polymerization from the polyHIPE to be realized, such that mechanical properties or surface wettability of the monolith could be varied while preserving the porous morphology. The tunable surface chemistry, porous structure, and mechanical properties of these monoliths present unique opportunities for applications as adsorbents, catalytic scaffolds, separation media, and so on.

show abstract

Section: Resultssupporting

confidence: 85%

Open-Cell PolyHIPES from Polymerizable Eutectics: Tunable Morphology, Surface Modification, and Thermoresponsive Swelling Behavior

Nahar

Wei

Cipriani

et al. 2022

ACS Appl. Polym. Mater.

View full text Add to dashboard Cite

show abstract

“…Both the chemical variety and the high porosity variety enable the formation of materials for specific applications, for instance, water clean-up [ 19 ], absorption and adsorption [ 20 , 21 ], separation processes [ 22 , 23 ], controlled release matrices [ 24 ] and tissue engineering [ 25 ]. Another aspect that makes polyHIPEs attractive is the available polymerisation techniques, such as atom transfer radical polymerisation (ATRP) [ 26 ], free-radical polymerisation (FRP) [ 27 ], reversible-addition-fragmentation chain-transfer (RAFT) [ 28 ], ring opening metathesis polymerisation (ROMP) [ 29 ] and click polymerisation [ 30 ], to name a few. In addition to building blocks, another property that can be freely controlled is the morphology of the prepared polyHIPEs.…”

Section: Introductionmentioning

confidence: 99%

Porous Polymers from High Internal Phase Emulsions as Scaffolds for Biological Applications

2021

View full text Add to dashboard Cite

High internal phase emulsions (HIPEs), with densely packed droplets of internal phase and monomers dispersed in the continuous phase, are now an established medium for porous polymer preparation (polyHIPEs). The ability to influence the pore size and interconnectivity, together with the process scalability and a wide spectrum of possible chemistries are important advantages of polyHIPEs. In this review, the focus on the biomedical applications of polyHIPEs is emphasised, in particular the applications of polyHIPEs as scaffolds/supports for biological cell growth, proliferation and tissue (re)generation. An overview of the polyHIPE preparation methodology is given and possibilities of morphology tuning are outlined. In the continuation, polyHIPEs with different chemistries and their interaction with biological systems are described. A further focus is given to combined techniques and advanced applications.

show abstract

“…Besides simplicity, these methods are versatile with respect to further functionalization via surface grafting from the retained initiator or transfer agent functionality within porous scaffolds. − In flow applications, the presence of functionality on the pore surface is highly desirable as the liquid is transported through the continuous porous network. RAFT polymerization has been previously utilized for the preparation of monolithic polymers within liquid chromatography columns, and further grafting of functional groups on the surface has been demonstrated .…”

Section: Introductionmentioning

confidence: 99%

Utilizing RAFT Polymerization for the Preparation of Well-Defined Bicontinuous Porous Polymeric Supports: Application to Liquid Chromatography Separation of Biomolecules

Khodabandeh

Arrua

Thickett

et al. 2021

ACS Appl. Mater. Interfaces

View full text Add to dashboard Cite

Polymer-based monolithic high-performance liquid chromatography (HPLC) columns are normally obtained by conventional free-radical polymerization. Despite being straightforward, this approach has serious limitations with respect to controlling the structural homogeneity of the monolith. Herein, we explore a reversible addition–fragmentation chain transfer (RAFT) polymerization method for the fabrication of porous polymers with well-defined porous morphology and surface chemistry in a confined 200 μm internal diameter (ID) capillary format. This is achieved via the controlled polymerization-induced phase separation (controlled PIPS) synthesis of poly(styrene-co-divinylbenzene) in the presence of a RAFT agent dissolved in an organic solvent. The effects of the radical initiator/RAFT molar ratio as well as the nature and amount of the organic solvent were studied to target cross-linked porous polymers that were chemically bonded to the inner wall of a modified silica-fused capillary. The morphological and surface properties of the obtained polymers were thoroughly characterized by in situ nuclear magnetic resonance (NMR) experiments, nitrogen adsorption–desorption experiments, elemental analyses, field-emission scanning electron microscopy (FESEM), scanning electron microscopy-energy-dispersive X-ray (SEM-EDX) spectroscopy, and X-ray photoelectron spectroscopy (XPS) as well as time-of-flight secondary ion mass spectrometry (ToF-SIMS) revealing the physicochemical properties of these styrene-based materials. When compared with conventional synthetic methods, the controlled-PIPS approach affects the kinetics of polymerization by delaying the onset of phase separation, enabling the construction of materials with a smaller pore size. The results demonstrated the potential of the controlled-PIPS approach for the design of porous monolithic columns suitable for liquid separation of biomolecules such as peptides and proteins.

show abstract

RAFT polymerization within high internal phase emulsions: Porous structures, mechanical behaviors, and uptakes

Cited by 24 publications

References 90 publications

Open-Cell PolyHIPES from Polymerizable Eutectics: Tunable Morphology, Surface Modification, and Thermoresponsive Swelling Behavior

Open-Cell PolyHIPES from Polymerizable Eutectics: Tunable Morphology, Surface Modification, and Thermoresponsive Swelling Behavior

Porous Polymers from High Internal Phase Emulsions as Scaffolds for Biological Applications

Utilizing RAFT Polymerization for the Preparation of Well-Defined Bicontinuous Porous Polymeric Supports: Application to Liquid Chromatography Separation of Biomolecules

Contact Info

Product

Resources

About