Glass transition and quantum yield for fluorescent labelled polystyrene core-forming block in self-assembled nanomicelles of amphiphilic diblock copolymers

Wei, WanChu; Feng, Shuo; Zheng, Caixia; Liang, Guodong; Gao, Haiyang; Wu, Qing; Zhu, Fangming

doi:10.1007/s10965-015-0855-7

Cited by 10 publications

(8 citation statements)

References 37 publications

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“…The sensitivity of fluorescence to the T g of a pyrene-labeled PBMA homopolymer (PBMA-py) was also confirmed (see Figure S3a). The consistency of the trends combined with prior reports − confirmed the ability of the fluorescence method to sense T g in bulk homopolymers.…”

Section: Results and Discussionsupporting

confidence: 78%

Direct Measurement of the Local Glass Transition in Self-Assembled Copolymers with Nanometer Resolution

Christie

Priestley

2018

ACS Cent. Sci.

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Nanoscale compositional heterogeneity in block copolymers can impart synergistic property combinations, such as stiffness and toughness. However, until now, there has been no experimental method to locally probe the dynamics at a specific location within these structured materials. Here, this was achieved by incorporating pyrene-bearing monomers at specific locations along the polymer chain, allowing the labeled monomers’ local environment to be interrogated via fluorescence. In lamellar-forming poly(butyl methacrylate-b-methyl methacrylate) diblock copolymers, a strong gradient in glass transition temperature, Tg, of the higher-Tg block, 42 K over 4 nm, was mapped with nanometer resolution. These measurements also revealed a strongly asymmetric influence of the domain interface on Tg, with a much smaller dynamic gradient being observed for the lower-Tg block.

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Section: Results and Discussionsupporting

confidence: 78%

Direct Measurement of the Local Glass Transition in Self-Assembled Copolymers with Nanometer Resolution

Christie

Priestley

2018

ACS Cent. Sci.

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“…Most of the studies devoted to the relaxation of end-tethered polymer chains have focused on the polymer grafted to rigid solid substrates, such as silica or gold NPs, where the tethering points can be considered as fixed. The effect of having softer substrates with faster relaxation dynamics has been largely overlooked so far. − In such systems, in addition to the dynamics of the canopy of end-tethered polymer chains, the dynamics of the core also need to be taken into account. Then, the system becomes more complex, and the interpretation of the results is more challenging in comparison to polymer chains grafted on rigid inorganic cores.…”

Section: Introductionmentioning

confidence: 99%

Dynamics of Soft and Hairy Polymer Nanoparticles in a Suspension by NMR Relaxation

2020

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The design of surface-modified functional nanoparticles (NPs) is used to control the properties of the NPs and the NP/environment interactions. The efficient control of the final behavior of the NPs demands a comprehensive understanding of the resulting system. This is particularly challenging for systems with an architecture of the type polymer core− polymer canopy. In such systems, one of the key parameters influencing the behavior of the NPs is the local dynamics of the polymer canopy. However, because the grafting points of the canopy are experiencing their own local dynamics, predicting the final behavior of such systems is difficult. To get a deeper understanding of NPs made of a soft and swollen polymer core and a swollen polymer canopy, we prepared a library of hairy NPs made of a polystyrene (PS) core and a canopy of grafted poly(methyl acrylate) (PMA) chains. The softness of the PS core and the thickness of the PMA canopy were controlled, and the behavior and dynamics of the soft and hairy PS−PMA NPs in suspension were measured by 1 H NMR relaxation and dynamic light scattering. It was observed that the rigid PS core slowed down the subsegmental dynamics of the PMA chains, while thick PMA canopies accelerated the relaxation of the PS core. The dynamics of the NPs in suspension was the result of the interplay between the PS core and the PMA canopy.

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“…A dramatic reduction in the T g of the pyrene-labeled polystyrene (PyPS) core in a PyPS-b-PAA micelle was observed in ionic liquid compared to that of bulk PS or PyPS, whereas the PyPS core within a PyPS-b-PAA micelle in an aqueous dispersion exhibited a similar T g to bulk PS or PyPS. 29 For a dry micelle, the T g of the PS block in the cores of PS-b-PDMS micelles was reported to be very close to that of bulk homo-PS samples with the same M n . 30 The similarity of the T g of the micelle core to that of the NP was clearly dependent on the surrounding environment, although there is no widely accepted physical explanation for this effect.…”

Section: Introductionmentioning

confidence: 81%

Segmental Relaxation Dynamics of the Core and Corona in a Single Dry Micelle

et al. 2017

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The segmental relaxation dynamics of the core and the corona in a single dry spherical micelle comprising a polystyrene (PS) or poly(methyl methacrylate) (PMMA) core and a poly(acrylic acid) (PAA) corona, along with the effects of the micelle density and the chain length of the core-forming and corona-forming polymers, were investigated by AFM. The results showed that the segmental relaxation temperature in the micelle core was close to its bulk T g and independent of the micellar structure, such as micelle size, density, and corona thickness. By contrast, the segmental relaxation temperature in the micelle corona is dependent on the micellar structure. The depressed chain mobility in the corona was enhanced as the micelle density and the length of both the corona-forming and core-forming blocks increased. This phenomenon was attributed to conformational entropy loss in the micelle corona because of the chain adopting a conformation more perpendicular to the core as the micelle size and density increased.

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Glass transition and quantum yield for fluorescent labelled polystyrene core-forming block in self-assembled nanomicelles of amphiphilic diblock copolymers

Cited by 10 publications

References 37 publications

Direct Measurement of the Local Glass Transition in Self-Assembled Copolymers with Nanometer Resolution

Direct Measurement of the Local Glass Transition in Self-Assembled Copolymers with Nanometer Resolution

Dynamics of Soft and Hairy Polymer Nanoparticles in a Suspension by NMR Relaxation

Segmental Relaxation Dynamics of the Core and Corona in a Single Dry Micelle

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