Recently, polymerization-induced self-assembly (PISA) has become widely recognized as a robust and efficient route to produce block copolymer nanoparticles of controlled size, morphology, and surface chemistry. Several reviews of this field have been published since 2012, but a substantial number of new papers have been published in the last three years. In this Perspective, we provide a critical appraisal of the various advantages offered by this approach, while also pointing out some of its current drawbacks. Promising future research directions as well as remaining technical challenges and unresolved problems are briefly highlighted.

http://pubs.acs.org/doi/pdf/10.1021/acs.macromol.5b02602

A Critical Appraisal of RAFT-Mediated Polymerization-Induced Self-Assembly.

Photochemical reactions, particularly those involving photoinduced electron transfer processes, establish a substantial contribution to the modern synthetic chemistry, and the polymer community has been increasingly interested in exploiting and developing novel photochemical strategies. These reactions are efficiently utilized in almost every aspect of macromolecular architecture synthesis, involving initiation, control of the reaction kinetics and molecular structures, functionalization, and decoration, etc. Merging with polymerization techniques, photochemistry has opened up new intriguing and powerful avenues for macromolecular synthesis. Construction of various polymers with incredibly complex structures and specific control over the chain topology, as well as providing the opportunity to manipulate the reaction course through spatiotemporal control, are one of the unique abilities of such photochemical reactions. This review paper provides a comprehensive account of the fundamentals and applications ...

Photoinduced Electron Transfer Reactions for Macromolecular Syntheses

The application of photochemistry to polymer and material science has led to the development of complex yet efficient systems for polymerization, polymer post-functionalization, and advanced materials production. Using light to activate chemical reaction pathways in these systems not only leads to exquisite control over reaction dynamics, but also allows complex synthetic protocols to be easily achieved. Compared to polymerization systems mediated by thermal, chemical, or electrochemical means, photoinduced polymerization systems can potentially offer more versatile methods for macromolecular synthesis. We highlight the utility of light as an energy source for mediating photopolymerization, and present some promising examples of systems which are advancing materials production through their exploitation of photochemistry.

/pdf/seeing-the-light-advancing-materials-chemistry-through-4jb2o1rrgq.pdf

Seeing the Light: Advancing Materials Chemistry through Photopolymerization.

In this Perspective, we summarize recent progress in polymerization-induced self-assembly (PISA) for the rational synthesis of block copolymer nanoparticles with various morphologies. Much of the PISA literature has been based on thermally initiated reversible addition–fragmentation chain transfer (RAFT) polymerization. Herein, we pay particular attention to alternative PISA protocols, which allow the preparation of nanoparticles with improved control over copolymer morphology and functionality. For example, initiation based on visible light, redox chemistry, or enzymes enables the incorporation of sensitive monomers and fragile biomolecules into block copolymer nanoparticles. Furthermore, PISA syntheses and postfunctionalization of the resulting nanoparticles (e.g., cross-linking) can be conducted sequentially without intermediate purification by using various external stimuli. Finally, PISA formulations have been optimized via high-throughput polymerization and recently evaluated within flow reactors for facile scale-up syntheses.

Emerging trends in polymerization-induced self-assembly

After a brief history that positions polymerization-induced self-assembly (PISA) in the field of polymer chemistry, this Review will cover the fundamentals of the PISA mechanism. Furthermore, this Review will also give an overview of some of the features and limitations of RAFT-mediated PISA in terms of the choice of the components involved, the nature of the nanoobjects that can be obtained and how the syntheses can be controlled, as well as some potential applications.

https://hal.archives-ouvertes.fr/hal-03085063/document

RAFT‐mediated polymerization‐induced self‐assembly

Herein we report an aqueous photoinitiated polymerization-induced self-assembly (photo-PISA) for the preparation of a remarkably diverse set of complex polymer nanoparticle morphologies (e.g., spheres, worms, and vesicles) at room temperature. Ultrafast polymerization rates were achieved, with near quantitative monomer conversion within 15 min of visible light irradiation. An important feature of the photo-PISA is that diblock copolymer vesicles can be prepared under mild conditions (room temperature, aqueous medium, visible light), which will be important for the preparation of functional vesicles loaded with biorelated species (e.g., proteins). As a proof of concept, silica nanoparticles and bovine serum albumin (BSA) were encapsulated in situ within vesicles via the photo-PISA process.

Photo-PISA: Shedding Light on Polymerization-Induced Self-Assembly

Facile Preparation of Monodisperse Poly(2‐hydroxyethyl acrylate)‐Grafted Poly(methyl methacrylate) Microspheres via Photoinitiated RAFT Dispersion Polymerization

The detection and therapy of cancers in the early stage significantly alleviate the associated dangers. Optical devices offer new opportunities for these early measures. However, the clinical translation of the existing methods is severely hindered by their relatively low sensitivity or unclear physiological metabolism. Here, an optical microfiber sensor with a drug loading gold nanorod-black phosphorous nanointerface, as an ultrasensitive biosensor and nanotherapy platform, is developed to meet the early-stage requirement. With interface sensitization and functionalization of the hybrid nanointerface, the microfiber sensor presents an ultrahigh sensing performance, achieving the selective detection of the HER2 biomarker with limits of detection of 0.66 aM in buffer solution and 0.77 aM in 10% serum. It can also distinguish breast cancer cells from other cells in the early stage. Additionally, enabled by the interface, the optical microfiber is able to realize cellular nanotherapy, including photothermal/chemotherapy with pump laser coupling after diagnosis, and evaluate therapy results in real time. The immobilization of the interface on the optical microfiber surface prevents the damage to normal cells induced by nanomaterial enrichment, making the device more efficient and intelligent. This study opens up a new avenue for the development of smart optical platforms for sensitive biosensing and precision therapy.

Optical Microfiber with a Gold Nanorods-Black Phosphorous Nanointerface: An Ultrasensitive Biosensor and Nanotherapy Platform.

Materials with super-wetting ability have attracted wide attention from both academia and industry due to their great potential applications. A straightforward and versatile route was proposed for the large-scale synthesis of a monodisperse raspberry-like metal-organic framework (ZIF-8) using zinc nitrate as a zinc source and dimethylimidazole as an organic ligand in aqueous solution. After hydrophobic treatment with hexadecyltrimethoxysilane, the ethanolic suspension of three-dimensional raspberry-like ZIF-8 showed excellent superhydrophobic properties. Furthermore, commercial adhesives were used to blend with the suspension to improve the bonding strength to different substrates. These surfaces retained their water resistance after 50 finger-wipe cycles, 40 sandpaper abrasions and knife scratches. Moreover, the prepared hydrophobic surface can withstand the impact of water flow for 10 minutes. The formulations developed can be used for superhydrophobic coating applications on different substrate surfaces such as aluminum foil, glass, paper and cotton.

Aqueous construction of raspberry-like ZIF-8 hierarchical structures with enhanced superhydrophobic performance.

A straightforward and scalable strategy was presented for the fabrication of superhydrophobic stainless steel mesh (SSM) by depositing with polydimethylsiloxane (PDMS) to perform the hydrophobic effect. After the thermal processing with a flame for seconds, the PDMS coated steel mesh demonstrated excellent integration of superhydrophobic/superoleophilic properties. Besides, the resultant SSM showed efficient separation ability of water-in-oil emulsion. Furthermore, the surfaces also exhibited excellent tolerance to various chemical, UV irradiated and strongly friction-resistant against sandpaper (50 g of force for 1000 cm). More strikingly, the damaged surfaces losing its superhydrophobicity can be simply healed by reapplying flame heat to the worn area. This straightforward and healable synthetic strategy for the manufacture of superhydrophobic SSM offers potential applications in large-scale oil/water separation. 

Mingguang Yu

Papers

Photo-PISA: Shedding Light on Polymerization-Induced Self-Assembly

Facile Preparation of Monodisperse Poly(2‐hydroxyethyl acrylate)‐Grafted Poly(methyl methacrylate) Microspheres via Photoinitiated RAFT Dispersion Polymerization

Optical Microfiber with a Gold Nanorods-Black Phosphorous Nanointerface: An Ultrasensitive Biosensor and Nanotherapy Platform.

Aqueous construction of raspberry-like ZIF-8 hierarchical structures with enhanced superhydrophobic performance.

Straightforward fabrication of robust and healable superhydrophobic steel mesh based on polydimethylsiloxane