Component dynamics in nanostructured PI-PDMS diblock copolymers with PI segregated in lamellas, cylinders, and spheres

Alegría, Ángel; Lund, Reidar; Barroso‐Bujans, Fabienne; Arbe, Arantxa; Colmenero, Juan

doi:10.1007/s00396-014-3255-3

Cited by 15 publications

(14 citation statements)

References 33 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This result can be attributed to an interplay between the slow dynamics of PS core and faster dynamics of PMA canopy. A similar behavior can be observed for block copolymer when a component with a high relaxation rate, increases the local dynamics of a slower block, because of the increased local fluctuations of the junction between the two segments initiated by the faster component [37,38]. Additionally, the effect of σ suggests that the number of grafted chains, rather than the dynamics of the grafted chains themselves, was the driving force for the faster dynamics observed with the PS core functionalized with a high number of long PMA chains.…”

Section: Resultssupporting

confidence: 70%

Influence of the Architecture of Soft Polymer-Functionalized Polymer Nanoparticles on Their Dynamics in Suspension

2020

View full text Add to dashboard Cite

The behavior of nanogels in suspension can be dramatically affected by the grafting of a canopy of end-tethered polymer chains. The architecture of the interfacial layer, defined by the grafting density and length of the polymer chains, is a crucial parameter in defining the conformation and influencing the dynamics of the grafted chains. However, the influence of this architecture when the core substrate is itself soft and mobile is complex; the dynamics of the core influences the dynamics of the tethered chains, and, conversely, the dynamics of the tethered chains can influence the dynamics of the core. Here, poly(styrene) (PS) particles were functionalized with poly(methyl acrylate) (PMA) chains and swollen in a common solvent. NMR relaxation reveals that the confinement influences the mobility of the grafted chain more prominently for densely grafted short chains. The correlation time associated with the relaxation of the PMA increased by more than 20% when the grafting density increased for short chains, but for less than 10% for long chains. This phenomenon is likely due to the steric hindrance created by the close proximity to the rigid core and of the neighboring chains. More interestingly, a thick layer of a densely grafted PMA canopy efficiently increases the local mobility of the PS cores, with a reduction of the correlation time of more than 30%. These results suggest an interplay between the dynamics of the core and the dynamics of the canopy.

show abstract

Section: Resultssupporting

confidence: 70%

Influence of the Architecture of Soft Polymer-Functionalized Polymer Nanoparticles on Their Dynamics in Suspension

2020

View full text Add to dashboard Cite

show abstract

“…This simple equation seems to hold for a wide range of liquids including n-alkane(s) [12,13]. However, the relation is neglecting potential complications such as specific, orientational interactions, surface stiffness, surface dynamics, and molecular transport [14]. Whereas in hard confinement the constraining shape is static and fixed in time, materials under soft confinement are characterized by surface fluctuations, deformable geometry, and possibly diffusional processes [15][16][17].…”

mentioning

confidence: 99%

“…Examples include block copolymers that selfassemble into various mesoscopic crystal structures (spheres, cylinders, or lamellae) of typically a few tens of nanometer size [18,19]. In these systems it has been shown that crystallization can be significantly reduced or even completely suppressed due to surface fluctuations [14,20]. Another example of soft confined systems is water in oil emulsion droplets where the size can be controlled by the water content [17,21].…”

mentioning

confidence: 99%

Nanoscopic Confinement through Self-Assembly: Crystallization within Micellar Cores Exhibits Simple Gibbs-Thomson Behavior

2014

Self Cite

View full text Add to dashboard Cite

It is well known that liquids confined to small nanoscopic pores and droplets exhibit thermal behavior very different from bulk samples. Less is known about liquids spontaneously confined through self-assembly into micellar structures. Here we demonstrate, using a very well-defined n-alkyl-poly(ethylene oxide) polymer system with a tunable structure, that n-alkane(s) forming 2-3 nm small micellar cores are affected considerably by confinement in the form of melting point depressions. Moreover, comparing the reduction in melting points, ΔT_{m}, determined through volumetric and calorimetric methods with the micellar core radius, R_{c}, obtained from small-angle x-ray scattering, we find excellent agreement with the well-known Gibbs-Thomson equation, ΔT_{m}∼R_{c}^{-1}. This demonstrates that the reduced size, i.e., the Laplace pressure, is the dominant parameter governing the melting point depression in micellar systems.

show abstract

“… 66 The interplay caused by the tethering of two polymer systems with different intrinsic dynamics is reminiscent of the dynamics of block copolymers, where the dynamics of a slow block can be enhanced by tethering a more rapidly relaxing block and inversely the dynamics of a fast block can be slowed down by the tethering to a slower block. 67 , 68 In such situations, the fluctuations the more rapid segment was responsible for the acceleration of the segmental mobility of the slower component.…”

Section: Results and Discussionmentioning

confidence: 99%

“…At the same time, anchoring the PMA chains to the PS core resulted in a moderate decrease in the T 2 of the PMA chains due to the substrate effect decreasing the segmental dynamics of the grafted chains in comparison to free PMA chains . The interplay caused by the tethering of two polymer systems with different intrinsic dynamics is reminiscent of the dynamics of block copolymers, where the dynamics of a slow block can be enhanced by tethering a more rapidly relaxing block and inversely the dynamics of a fast block can be slowed down by the tethering to a slower block. , In such situations, the fluctuations the more rapid segment was responsible for the acceleration of the segmental mobility of the slower component.…”

Section: Results and Discussionmentioning

confidence: 99%

Impact of the Solvent Quality on the Local Dynamics of Soft and Swollen Polymer Nanoparticles Functionalized with Polymer Chains

Kim

Thérien-Aubin

2020

Macromolecules

View full text Add to dashboard Cite

Grafting polymer chains on the surface of nanoparticles (NPs) is a strategy used to control the interaction between the NPs and their environment. The fate of the resulting particles in a given environment is strongly influenced by the solvent–polymer interaction. The solvent quality affects the behavior, conformation, and dynamics of the grafted polymer chains. However, when this polymer grafting strategy is used to functionalized polymer particles, the influence of solvent quality becomes even more complex; when the grafted polymer chains and the polymer nanoparticles are tethered together, the effect of the solvent quality on the behavior and dynamics of the system depends on the solvent interaction with both polymer components. To explore the relationship between the solvent quality and the dynamics of polymer-functionalized soft polymer NPs, we designed a system based on cross-linked polystyrene (PS) NPs grafted with a canopy of poly(methyl acrylate) (PMA). PS and PMA, two immiscible polymers, can be selectively solvated by using binary mixtures of solvents. NMR spectroscopy was used to address the effect of those selective solvents on the local mobility of the PS–PMA core-canopy NPs and revealed an interplay between the local mobility of the core and the local mobility of the canopy. A selective reduction of the solvent quality for the PMA canopy resulted in the expected reduction of the local mobility of the PMA chains, but also in the slower dynamics of the PS core. Similarly, a selective reduction of the solvent quality for the PS core resulted in a slower dynamics for both the PS core and the PMA canopy.

show abstract

Component dynamics in nanostructured PI-PDMS diblock copolymers with PI segregated in lamellas, cylinders, and spheres

Cited by 15 publications

References 33 publications

Influence of the Architecture of Soft Polymer-Functionalized Polymer Nanoparticles on Their Dynamics in Suspension

Influence of the Architecture of Soft Polymer-Functionalized Polymer Nanoparticles on Their Dynamics in Suspension

Nanoscopic Confinement through Self-Assembly: Crystallization within Micellar Cores Exhibits Simple Gibbs-Thomson Behavior

Impact of the Solvent Quality on the Local Dynamics of Soft and Swollen Polymer Nanoparticles Functionalized with Polymer Chains

Contact Info

Product

Resources

About