Visible Light-Mediated Polymerization-Induced Self-Assembly in the Absence of External Catalyst or Initiator

The use of 2,3,4,5,6-pentafluorobenzyl methacrylate (PFBMA) as a core-forming monomer in ethanolic reversible addition-fragmentation chain transfer dispersion polymerization formulations is presented. Poly[poly(ethylene glycol) methyl ether methacrylate] (pPEGMA) macromolecular chain transfer agents were chain-extended with PFBMA leading to nanoparticle formation via polymerization-induced self-assembly (PISA). pPEGMA-pPFBMA particles exhibited the full range of morphologies (spheres, worms, and vesicles), including pure and mixed phases. Worm phases formed gels that underwent a thermo-reversible degelation and morphological transition to spheres (or spheres and vesicles) upon heating. Postsynthesis, the pPFBMA cores were modified through thiol-para-fluoro substitution reactions in ethanol using 1,8-diazabicyclo[5.4.0]undec-7-ene as the base. For monothiols, conversions were 64% (1-octanethiol) and 94% (benzyl mercaptan). Spherical and worm-shaped nano-objects were core cross-linked using 1,8-octanedithiol, which prevented their dissociation in nonselective solvents. For a temperature-responsive worm sample, cross-linking additionally resulted in the loss of the temperature-triggered morphological transition. The use of the reactive monomer PFBMA in PISA formulations presents a simple method to prepare well-defined nano-objects similar to those produced with nonreactive monomers (e.g., benzyl methacrylate) and to retain morphologies independent of solvent and temperature.

Section: Resultssupporting

confidence: 54%

Reactive Polymorphic Nanoparticles: Preparation via Polymerization‐Induced Self‐Assembly and Postsynthesis Thiol–para‐Fluoro Core Modification

Busatto

Stolojan

Shaw

et al. 2018

“…The development of controlled/living radical polymerization (CLRP, also known as reversible deactivation radical polymerization [RDRP]) has revolutionized our ability to prepare polymeric nanoparticles of various morphologies . Polymerization‐induced self‐assembly (PISA), most commonly based on reversible addition‐fragmentation chain transfer (RAFT) polymerization, has emerged as a useful method for synthesis of a wide range of nanoparticle morphologies. More recently, PISA has been expanded to approaches based on nonliving radical polymerization (addition‐fragmentation chain transfer polymerization), photo‐induced CLRP, as well as ring‐opening metathesis polymerization .…”

Section: Methodsmentioning

confidence: 99%

Polymerization‐Induced Self‐Assembly under Compressed CO₂: Control of Morphology Using a CO₂‐Responsive MacroRAFT Agent

Zhou

Kuchel

Dong

et al. 2018

Polymerization-induced self-assembly of 2-hydroxypropyl methacrylate is conducted in water and water/MeOH using a CO -responsive macroRAFT agent in the form of a statistical copolymer comprising N,N-diethylaminoethyl methacrylate (DEAEMA) and poly(ethylene glycol) methyl ether methacrylate (M = 475 g mol ). Pressurization with CO leads to protonation of DEAEMA units within the stabilizer block, thereby offering a means of adjusting the charge density of the coronal layer. It is demonstrated that a wide range of tunable particle morphologies are accessible by simply varying the CO pressure during polymerization in the range of 10-45 bar.

“…These advances pave the road for the synthesis of vesicles through photo‐PISA. More interestingly, recently, it has been reported that photo‐PISA can also be initiated in the absence of either photoinitiator or photocatalyst because the RAFT agent itself can generate radicals under light radiation which can activate the polymerization . The morphology of the resulting photo‐PISA products is related to the wavelength of the light used.…”

Section: Pisa An Ex Novo Strategy For Vesicle Formation Growth Andmentioning

confidence: 99%

Polymerization‐Induced Self‐Assembly for Artificial Biology: Opportunities and Challenges

Cheng

Pérez–Mercader

2018

The study of the origin of life and current undergoing efforts to produce artificial chemical systems mimicking the behavior of natural living systems have emerged as a hot topic at the interfaces among disciplines. In these two problems, the spontaneous generation of free-energy gradients by means of material interfaces plays a central role and, until recently, hindered progress. Polymerization-induced self-assembly (PISA) is a promising strategy for the formation of polymeric vesicles from a homogeneous mixture which, in the form of artificial biology, may reflect and inform the generation of vesicular structures in primitive Earth. In the past few years, PISA has been used for the construction of biomimetic vesicles or artificial protocells in artificial biology. These not only give inspiration for decoding some aspects of the origin of life in arbitrary environments but also offer potential for building innovative functional systems with a wide variety of applications. In this review, a brief summary of some of the unique possibilities offered by PISA and the development of PISA in exploration of artificial biology is provided, while some of the allied current challenges, limitations, and opportunities in this exciting field are highlighted.