The Dynamic of Confined Polystyrene in Nanoparticles in the Glassy Regime: The Close Packed Morphology

Rharbi, Yahya; Nawaz, Qamar

doi:10.1021/ma401523n

Cited by 8 publications

(9 citation statements)

References 61 publications

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“…Such dependencies have been reported previously for different systems. [80][81][82][83] Moreover, t IR of n(OH) coincides with the time constant from BDS at T = 273 K within experimental accuracy. This coincidence over such a wide temperature range indicates that t ag can be identified with t a below T g at least in strongly H-bonding systems; and, furthermore, it underscores the role of the H-bonding network for the structure and the inter-molecular dynamics of L-fucose as reported for different systems by Gainaru et al 84 and Preuß et al 85 The IR aging times of d 2 (CH) appear to follow a steeper dependence than n max and f ij of n(OH) differing by a factor of up to 3.…”

Section: Aging Dynamicssupporting

confidence: 59%

Glassy dynamics and physical aging in fucose saccharides as studied by infrared- and broadband dielectric spectroscopy

Kossack

Adrjanowicz

Tarnacka

et al. 2013

Phys. Chem. Chem. Phys.

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Fourier Transform Infra Red (FTIR) and Broadband Dielectric Spectroscopy (BDS) are combined to study both the intra- and inter-molecular dynamics of two isomers of glass forming fucose, far below and above the calorimetric glass transition temperature, T(g). It is shown that the various IR-active vibrations exhibit in their spectral position and oscillator strength quite different temperature dependencies, proving their specific signature in the course of densification and glass formation. The coupling between intra- and inter molecular dynamics is exemplified by distinct changes in IR active ring vibrations far above the calorimetric glass transition temperature at about 1.16T(g), where the dynamic glass transition (α relaxation) and the secondary β relaxation merge. For physically annealed samples it is demonstrated that upon aging the different moieties show characteristic features as well, proving the necessity of atomistic descriptions beyond coarse-grained models.

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Section: Aging Dynamicssupporting

confidence: 59%

Glassy dynamics and physical aging in fucose saccharides as studied by infrared- and broadband dielectric spectroscopy

Kossack

Adrjanowicz

Tarnacka

et al. 2013

Phys. Chem. Chem. Phys.

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“…Similarly, the T g of PS spherical NPs decreased compared to the bulk T g when they were dispersed in cross-linked poly(butyl methacrylate) matrices, which was similar to the reported result from the PS domain in a self-assembled PS- b -polybutadiene block copolymer . By contrast, both the shift factor and relaxation time of PS NPs in a close-packed morphology are consistent with the corresponding bulk dynamics . The size-dependent T g may be attributed to the impact of a diffuse interface instead of an intrinsic size effect …”

Section: Introductionsupporting

confidence: 85%

“…25 By contrast, both the shift factor and relaxation time of PS NPs in a closepacked morphology are consistent with the corresponding bulk dynamics. 26 The size-dependent T g may be attributed to the impact of a diffuse interface instead of an intrinsic size effect. 25 Regarding 3D confined systems, polymeric micelles have been used widely, including as a delivery vehicle for pharmaceuticals 3 and templates for patterning 2D free-standing surfaces with mesoporous conducting polymers.…”

Section: Introductionmentioning

confidence: 99%

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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“…A similar result was reported for the T g of the PS domain in a self-assembled block copolymer of polystyrene- b -polybutadiene (PS- b -PB) . By contrast, both the shift factor and relaxation time of PS NPs in a close-packed morphology are consistent with the corresponding bulk dynamics . Priestley et al revealed that the T g of PS nanospheres covered with a silica shell was size-independent and almost the same as the bulk T g value.…”

Section: Introductionsupporting

confidence: 73%

“…29 By contrast, both the shift factor and relaxation time of PS NPs in a close-packed morphology are consistent with the corresponding bulk dynamics. 30 Priestley et al 31 revealed that the T g of PS nanospheres covered with a silica shell was size-independent and almost the same as the bulk T g value. It is proposed that the aforementioned sizedependent T g phenomena may be attributed to the impact of a diffuse interface instead of an intrinsic size effect.…”

Section: Introductionmentioning

confidence: 98%

Enhanced Dynamics of PMMA Brushes Induced by the Chain Ends of a Flexible Polymer Chain

et al. 2021

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The dynamics of different blocks in block copolymers are expected to affect the other blocks due to compositional heterogeneity, thus influencing their bulk structure and performance. It is significant to understand the effect of one block on the mobility of another block at the molecular level. Here, we investigated the glass transition temperatures of PMMA blocks in poly(methyl methacrylate)-b-poly(butyl methacrylate) (PMMA-b-PBMA) (T g M(b – B)) and poly(methyl methacrylate)-b-poly(n-octadecyl methacrylate) (PMMA-b-PODMA) (T g M(b – D)) brushes on an oxide-covered silicon substrate (SiO2–Si) in which the PMMA block was tethered to the substrate by covalent bonds, and PBMA and PODMA were the lower-T g blocks connected to the PMMA chain end. It was observed that both T g M(b – B) and T g M(b – D) decreased as the thickness of the PBMA or PODMA block increased. When the thickness of PBMA was above 45 nm, T g M(b – B) was approximately 40 K lower than the glass transition temperatures of PMMA brushes (T g M), while T g M(b – B) showed no dependence on the PBMA and PODMA thickness. The results indicated that the connectivity with the lower-T g block at the PMMA chain end could effectively enhance the mobility of the higher-T g PMMA chain.

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The Dynamic of Confined Polystyrene in Nanoparticles in the Glassy Regime: The Close Packed Morphology

Cited by 8 publications

References 61 publications

Glassy dynamics and physical aging in fucose saccharides as studied by infrared- and broadband dielectric spectroscopy

Glassy dynamics and physical aging in fucose saccharides as studied by infrared- and broadband dielectric spectroscopy

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

Enhanced Dynamics of PMMA Brushes Induced by the Chain Ends of a Flexible Polymer Chain

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