Chain stiffness regulates entropy-templated perfect mixing at single-nanoparticle level

Abstract

The mixing on a single-particle level of chemically incompatible nanoparticles is an outstanding challenge for many applications. Burgeoning research activity suggests that entropic templating is a potential strategy to address this issue. Herein, using systematic computer simulations of model nanoparticle systems, we show that the entropy-templated interfacial organization of nanoparticles significantly depends on the stiffness of tethered chains. Unexpectedly, the optimal chain stiffness can be identified wherein a system exhibits the most perfect mixing for a certain compression ratio. Our simulations demonstrate that entropic templating regulated by chain stiffness precisely reflects various entropic repulsion states that arise from typical conformation regimes of semiflexible chains. The physical mechanism of the chain stiffness effect is revealed by analyzing the entropic repulsion states of tethered chains and quantitatively estimating the resulting entropy penalties, which provides direct evidence that supports the key role of entropic transition in the entropic templating strategy, as suggested in experiments. Moreover, the model nanoparticle systems are found to evolve into binary nanoparticle superlattices by remixing at extremely high stiffness. The findings facilitate the wide application of the entropic templating strategy in creating interfacially reactive nanomaterials with ordered structures on the single-nanoparticle level as well as mechanomutable responses.

Quantified Binding Scale of Competing Ligands at the Surface of Gold Nanoparticles: The Role of Entropy and Intermolecular Forces

“…Second, and more fundamentally, quantifying the partition for a series of well‐chosen ligands should provide new insights into the role of the chain length and functionality, and of the end‐group on ligand exchange and the stability of mixed ligand shells. In brief, such quantified partitions may contribute to decipher the impact of intermolecular forces and entropic effects on the stability of the ligand shells and their role as driving forces for ligand exchange—a topical issue for the control of nanoparticles properties and self‐assembly …”

Optimal Reactivity and Improved Self‐Healing Capability of Structurally Dynamic Polymers Grafted on Janus Nanoparticles Governed by Chain Stiffness and Spatial Organization

“…This accounts for the most robust response and self‐healing capability of semiflexible chains to the mechanical stress. Fundamentally, such a strong orientation of semiflexible chains is contributed by both enthalpically and entropically interactions (Figure S12 and Section V, Supporting Information) …”

Entropic Effects in Polymer Nanocomposites

“…Reproduced with permission from ref. [ 31 ] Copyright 2013, The Royal Society of Chemistry. ( c ) Phase diagram of hard polygon melting behavior, which is controlled by shape entropy.…”

“…Though the most popular metaphoric description of entropy is disorder, entropic ordering transitions have indeed been identified in many soft matter systems, including colloids [ 23 , 24 , 25 ], glasses [ 26 , 27 , 28 ], and particularly polymer nanocomposite systems [ 29 , 30 , 31 ]. Furthermore, different manifestations of entropy are classified according to particular degrees of freedom of molecules [ 6 ], as shown in Figure 2 , such as translational entropy [ 9 , 31 ], rotational entropy [ 22 , 32 ], conformational entropy [ 29 , 33 ], and shape entropy [ 34 , 35 , 36 , 37 ], taking advantage of the existence of such an entropy-driven ordering transition. A well-known example, predicted by Onsager theory [ 38 ], is the phase transition from the isotropic fluid to the nematic liquid crystal phase for hard rods with small aspect ratio, in which the loss of orientational entropy is compensated by a much higher gain of translational entropy from excluded volume between pairs of rods [ 6 , 39 ].…”