Grafted Nanoparticle Surface Wetting during Phase Separation in Polymer Nanocomposite Films

Maguire, Shawn; Boyle, Michael J.; Bilchak, Connor; Demaree, J. D.; Keller, Austin W.; Krook, Nadia M.; Ohno, Kohji; Kagan, Cherie R.; Murray, Christopher B.; Rannou, Patrice; Composto, Russell J.

doi:10.1021/acsami.1c09233

Cited by 17 publications

(42 citation statements)

References 42 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While these previous studies were focused on homopolymer brush compositions, copolymer brushes have become a subject of recent research. − The interest in copolymer brushes has been fueled by the prospect of novel material properties that could be enabled by the deliberate combination of repeat units . For example, random copolymers based on poly( n -butyl acrylate- r -methyl methacrylate), P(BA- r -MMA), were recently proposed to exhibit lock-and-key-type interactions, giving rise to increased material recovery and self-healing ability. , These findings suggest intriguing opportunities for functional material design.…”

Section: Introductionmentioning

confidence: 99%

Topologically Induced Heterogeneity in Gradient Copolymer Brush Particle Materials

Zhao

Wang

et al. 2022

Macromolecules

View full text Add to dashboard Cite

A facile synthetic route toward silica brush particles with random and gradient copolymer grafts comprised of n-butyl acrylate (BA) and methyl methacrylate (MMA) using surface-initiated atom transfer radical polymerization (SI-ATRP) was developed. The effect of chain architecture on the structure and thermomechanical properties of copolymer-tethered brush particle films was investigated and compared to linear copolymer analogues. Random copolymer brush systems displayed a uniform and narrow glass transition, and the dependence of the glass-transition temperature followed a similar trend as for linear copolymers. In contrast, gradient brush materials featured a splitting of the glass-transition temperature with increasing MMA content along with a step-like increase of Young’s modulus and a decrease in ductility. The results were interpreted in terms of the effect of brush architecture on the microstructure of films. The results suggested a “molecularly uniform” microstructure in films of the random brush as well as linear random and linear gradient copolymer systems. In contrast, gradient brush systems featured a heterogeneous microstructure in which MMA-rich regions acted as “traps” that reduced chain mobility. The formation of compositional heterogeneity was rationalized by the “prescribed orientation” of gradient copolymer chains near the particle interface that amplified composition fluctuations and hence local segregation of repeat units. The results highlight the need for a better understanding of the role of “geometric constraints” on the physical properties of copolymer brush particle-based hybrid materials and the opportunity for multiple property enhancement by control of segment distribution in addition to the overall composition.

show abstract

Section: Introductionmentioning

confidence: 99%

Topologically Induced Heterogeneity in Gradient Copolymer Brush Particle Materials

Zhao

Wang

et al. 2022

Macromolecules

View full text Add to dashboard Cite

show abstract

“…Understanding and controlling nanoparticle dynamics in polymeric systems is key to a variety of applications including filtration, − nanoparticle dispersion in composites, − and drug delivery , among others. The parameter space that governs nanoparticle dynamics in these systems is extensive and can be broadly categorized into those related to the probe itself and those related to the network.…”

Section: Introductionmentioning

confidence: 99%

Shape Anisotropy Enhances Nanoparticle Dynamics in Nearly Homogeneous Hydrogels

et al. 2022

Self Cite

View full text Add to dashboard Cite

Single particle tracking is used to investigate the effect of nanoparticle shape anisotropy on dynamics. The mean squared displacements of poly(ethylene glycol) (PEG)-functionalized quantum dot (QD) and quantum rod (QR) probes of similar diameters are examined during the gelation of a tetra-poly(ethylene glycol) (tetra-PEG) hydrogel. At early times prior to the gel time (t gel), QDs exhibit greater mobility than their QR counterparts. However, as gelation proceeds, QRs exhibit increased dynamics compared to QDs, suggesting enhanced rod dynamics in increasingly confined networks. Potential mechanisms are discussed, including the influence of rotational dynamics and the increased parallel diffusion of rods in confined systems. This study provides insights into developing nanoparticle probes of different shape anisotropy, with particular importance for their use in drug delivery and other biomedical applications.

show abstract

“…Note that the terms concerning the SGV system have been canceled out. With K M 1 /M 2 known as a function of σ g,seg and the chemical constitution of the SGM 1 and SGM 2 systems, one can potentially design the grafting for optimal partitioning of NPs in blends …”

Section: Discussionmentioning

confidence: 99%

Solvation Free Energy of Dilute Grafted (Nano)Particles in Polymer Melts via the Self-Consistent Field Theory

et al. 2022

View full text Add to dashboard Cite

Predicting the distribution of a chemical species across multiple phases is of critical importance to environmental protection, pharmaceuticals, and high added-value chemicals. Computationally, this problem is addressed by determining the free energy of solvation of the species in the different phases using a well-established thermodynamic formulation. Following recent developments in sterically stabilized colloids and nanocomposite materials, the solvation of polymer-grafted nanoparticles in different solvents or polymer melts has become relevant. We develop a Self-Consistent Field theoretical framework to determine the solvation free energy of grafted particles inside a molten polymer matrix phase at low concentrations. The solvation free energy is calculated based on the notion of a pseudochemical potential introduced by Ben-Naim. Grafted and matrix chains are taken to be of the same chemical constitution, but their lengths are varied systematically, as are the particle radius and the areal density of grafted chains. In addition, different affinities between the nanoparticle core and the polymer (contact angles) are considered. At very low or very high amounts of grafted material, solvation depends on the adhesion tension between the bare particle and the matrix or on the surface tension of the grafted polymer, respectively. The dependence of the solvation free energy on molecular characteristics is more complicated at intermediate grafting densities and high curvatures, where the contribution of the entropy of grafted chains becomes significant. In general, solvation is less favored in cases where the matrix chains are much shorter than the grafted ones. The former tend to penetrate and swell the brush, thus generating conformational and translational entropy penalties. This effect becomes more pronounced when considering large particles since the grafted chains have less available space and extend more. For extremely low amounts of grafted material, we observe the opposite trend, albeit weak. Based on our calculations, we propose a generic model for estimating the solvation free energies of grafted nanoparticles in polymer melts from their molecular characteristics. The model and associated SCF formulation, illustrated here for chemically identical grafted and matrix chains, can be extended to obtain partition coefficients of grafted nanoparticles between different polymer melts.

show abstract

Grafted Nanoparticle Surface Wetting during Phase Separation in Polymer Nanocomposite Films

Cited by 17 publications

References 42 publications

Topologically Induced Heterogeneity in Gradient Copolymer Brush Particle Materials

Topologically Induced Heterogeneity in Gradient Copolymer Brush Particle Materials

Shape Anisotropy Enhances Nanoparticle Dynamics in Nearly Homogeneous Hydrogels

Solvation Free Energy of Dilute Grafted (Nano)Particles in Polymer Melts via the Self-Consistent Field Theory

Contact Info

Product

Resources

About