Promotion of morphology transition of di-block copolymer nano-objects via RAFT dispersion copolymerization

Zhou, Jiemei; Zhang, Wenjian; Hong, Chun‐Yan; Pan, Chen

doi:10.1039/c6py00164e

Cited by 62 publications

(47 citation statements)

References 49 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Besides, the high T g value of PPyMA limits its mobility in the dispersion mixture, which consequently restricts the morphology transition to obtain higher order morphologies, such as vesicles. This is in good agreement with previously reported RAFT dispersion polymerization of polystyrene with high T g values …”

Section: Methodssupporting

confidence: 93%

Synthesis of Light‐Responsive Pyrene‐Based Polymer Nanoparticles via Polymerization‐Induced Self‐Assembly

Bagheri

Boyer

Lim

2018

Macromol. Rapid Commun.

View full text Add to dashboard Cite

The use of an in situ, one-pot polymerization-induced self-assembly method to synthesize light-responsive pyrene-containing nanoparticles is reported. The strategy is based on the chain extension of a hydrophilic macromolecular chain transfer agent, poly(oligo(ethylene glycol) methyl ether methacrylate), using a light-responsive monomer, 1-pyrenemethyl methacrylate (PyMA), via a reversible addition-fragmentation chain transfer dispersion polymerization; yielding nanoparticles of various morphologies (spherical micelles and worm-like micelles). In this process, addition of comonomers, such as butyl methacrylate (BuMA) or methyl methacrylate (MMA), are required to obtain high PyMA monomer conversion (>80% in 24 h). The addition of comonomers reduces the π-π stacking of the pyrene moieties, which facilitates the diffusion of monomers in the nanoparticle core. The addition of BuMA (as a comonomer) offers P(PyMA-co-BuMA) core-forming chains with high mobility that enables the reorganization of chains and then the evolution of morphology to form vesicles. In contrast, when MMA comonomer is used, kinetically trapped spheres are obtained; this is due to the low mobility of the core-forming chains inhibiting in situ morphological evolution. Finally, the UV-light-induced dissociation of these light-responsive nanoparticles due to the gradual cleavage of the pyrene moieties and the subsequent hydrophobic-to-hydrophilic transitions of the core-forming blocks is demonstrated.

show abstract

Section: Methodssupporting

confidence: 93%

Synthesis of Light‐Responsive Pyrene‐Based Polymer Nanoparticles via Polymerization‐Induced Self‐Assembly

Bagheri

Boyer

Lim

2018

Macromol. Rapid Commun.

View full text Add to dashboard Cite

show abstract

“…Factors that may facilitate the exchange of polymer chains between nano‐aggregates include: i) a relatively low (ideally sub‐ambient) bulk glass transition temperature (T g ) of the core block; and ii) the relevant degree of solvation of the polymer core. It has been reported that core‐forming blocks with sub‐ambient T g 's may lead to increased polymer chain flexibility which can allow for facile rearrangement . Additionally, solvent or/and monomer can be also used to swell the polymer core as a direct result of a surface plasticizing effect (see section ) of the core‐forming block and in turn change the packing parameter.…”

Section: General Considerationsmentioning

confidence: 99%

Stimulus‐Responsive Nanoparticles and Associated (Reversible) Polymorphism via Polymerization Induced Self‐assembly (PISA)

Pei

Lowe

Roth

2016

Macromol. Rapid Commun.

118

131

View full text Add to dashboard Cite

"smart" materials rely on very distinct material responses on a macroscopic and/or microscopic level. This can be achieved by crafting stimulus-responsive polymers into nanostructured materials, including smart nanoparticles, which are receiving increasing attention specifically in the biomedical field. [2,3] Amphiphilic block copolymers are well-known to undergo self-directed assembly in selective solvents providing access to a range of soft matter nanoparticles [4][5][6][7] with applications in coatings, [8] electronics, [9] drug delivery, [10] and cancer therapy, [11,12] among others. Traditionally, the preparation of such nanoparticles has been accomplished by initial synthesis and molecular dissolution of well-defined parent copolymers which are subsequently "processed", often via time-consuming step-wise dialysis, to give the targeted nano-object. Another drawback of this well-established approach is the generally low concentration of the final copolymer nanoparticles (≤1.0 wt% is common) which limits industrial application and study of such nanoparticles in areas where high Polymerization-induced self-assembly (PISA) is an extremely versatile method for the in situ preparation of soft-matter nanoparticles of defined size and morphologies at high concentrations, suitable for large-scale production. Recently, certain PISA-prepared nanoparticles have been shown to exhibit reversible polymorphism ("shape-shifting"), typically between micellar, worm-like, and vesicular phases (order-order transitions), in response to external stimuli including temperature, pH, electrolytes, and chemical modification. This review summarises the literature to date and describes molecular requirements for the design of stimulus-responsive nano-objects. Reversible pH-responsive behavior is rationalised in terms of increased solvation of reversibly ionized groups. Temperature-triggered order-order transitions, conversely, do not rely on inherently thermo-responsive polymers, but are explained based on interfacial LCST or UCST behavior that affects the volume fractions of the core and stabilizer blocks. Irreversible morphology transitions, on the other hand, can result from chemical post-modification of reactive PISA-made particles. Emerging applications and future research directions of this "smart" nanoparticle behavior are reviewed.

show abstract

“…). The reaction mixture was transparent at the beginning, but became milky white as the reaction proceeds, indicating a step‐wise change in nano‐particle morphology with increasing DP n of the PBzMA block . An aliquot from the reaction vial was periodically taken out using a N 2 purged syringe at different time interval and monomer conversions were determined from 1 H NMR spectroscopy by comparing the integration ratio of poly(benzyl methacrylate) (PBzMA) C H 2  peak at δ = 4.9 ppm to BzMA vinyl (C H 2 CH) peak at δ = 6.12 and 5.72 ppm.…”

Section: Resultsmentioning

confidence: 99%

Surface functionalized nano‐objects from oleic acid‐derived stabilizer via non‐polar RAFT dispersion polymerization

Maiti

Bauri

Nandi

et al. 2016

J. Polym. Sci. Part A: Polym. Chem.

View full text Add to dashboard Cite

Surface functionalization in a nanoscopic scaffold is highly desirable to afford nano‐particles with diversified features and functions. Herein are reported the surface decoration of dispersed block copolymer nano‐objects. First, side‐chain double bond containing oleic acid based macro chain transfer agent (macroCTA), poly(2‐(methacryloyloxy)ethyl oleate) (PMAEO), was synthesized by reversible addition‐fragmentation chain transfer (RAFT) polymerization and used as a steric stabilizer during the RAFT dispersion block copolymerization of benzyl methacrylate (BzMA) in n‐heptane at 70 °C. We have found that block copolymer morphologies could evolve from spherical micelles, through worm to vesicles, and finally to large compound vesicles with the increase of solvophobic poly(BzMA) block length, keeping solvophilic chain length and total solid content constant. Finally, different thiol compounds having alkyl, carboxyl, hydroxyl, and protected amine functionalities have been ligated onto the PMAEO segment, which is prone to functionalization via its reactive double bond through thiol‐ene radical reactions. Thiol‐ene modification reactions of the as‐synthesized nano‐objects retain their morphologies as visualized by field emission‐scanning electron microscopy. Thus, the facile and modular synthetic approach presented in this study allowed in situ preparation of surface modified block copolymer nano‐objects at very high concentration, where renewable resource derived oleate surface in the nanoparticle was functionalized. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017, 55, 263–273

show abstract

Promotion of morphology transition of di-block copolymer nano-objects via RAFT dispersion copolymerization

Abstract: Promotion of morphology transition of di-block copolymer nano-objects was achieved via RAFT dispersion copolymerization because of the enhancement of the mobility of the solvophobic block.

Cited by 62 publications

References 49 publications

Synthesis of Light‐Responsive Pyrene‐Based Polymer Nanoparticles via Polymerization‐Induced Self‐Assembly

Synthesis of Light‐Responsive Pyrene‐Based Polymer Nanoparticles via Polymerization‐Induced Self‐Assembly

Stimulus‐Responsive Nanoparticles and Associated (Reversible) Polymorphism via Polymerization Induced Self‐assembly (PISA)

Surface functionalized nano‐objects from oleic acid‐derived stabilizer via non‐polar RAFT dispersion polymerization

Contact Info

Product

Resources

About