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

Abstract

Structurally dynamic polymers are recognized as a key potential to revolutionize technologies ranging from design of self-healing materials to numerous biomedical applications. Despite intense research in this area, optimizing reactivity and thereby improving self-healing ability at the most fundamental level pose urgent issue for wider applications of such emerging materials. Here, the authors report the first mechanistic investigation of the fundamental principle for the dependence of reactivity and self-healing capabilities on the properties inherent to dynamic polymers by combining large-scale computer simulation, theoretical analysis, and experimental discussion. The results allow to reveal how chain stiffness and spatial organization regulate reactivity of dynamic polymers grafted on Janus nanoparticles and mechanically mediated reaction in their reverse chemistry, and, particularly, identify that semiflexible dynamic polymers possess the optimal reactivity and self-healing ability. The authors also develop an analytical model of blob theory of polymer chains to complement the simulation results and reveal essential scaling laws for optimal reactivity. The findings offer new insights into the physical mechanism in various systems involving reverse/dynamic chemistry. These studies highlight molecular engineering of polymer architecture and intrinsic property as a versatile strategy in control over the structural responses and functionalities of emerging materials with optimized self-healing capabilities.

Scaling Laws for Polymer Chains Grafted onto Nanoparticles

“…However, neat “melts” of PGNPs have only recently begun to be explored, and they appear to provide an even wider property phase space than is afforded by block copolymers. This includes increased toughness, decreased polymer crystallinity, improved permeation properties, as well as electrical, magnetic, and optical properties …”

Single Chain Mean-Field Theory Study on Responsive Behavior of Semiflexible Polymer Brush

“…The apexes of the polygon are chosen as the grafting points. SCFMT was used to reveal how chain stiffness regulates the reactivity of dynamic polymers grafted on nanoparticles [37]. The reacting rate can be determined from the product of average endsegment probabilities for chains from two opposing nanoparticles, P 2 = drφ end,I φ end,II , which characterizes the degree of overlap between the chain-end distribution of the two opposing nanoparticles.…”

Nano-biointerface entre semiconductor y membrana celular: fenómenos fisicoquímicos implicados en la nanotoxicidad y la capacidad antifúngica de las nanopartículas de óxido de cinc

“…Cuando una nanopartícula entra en contacto con un sistema biológico, sea un hongo o una bacteria, las interacciones fisicoquímicas en la nano-biointerface podrían conducir al desarrollo de procesos biocatalíticos, a la formación de coronas de proteínas, el enrollamiento o envolvimiento de la nanopartícula por parte de la pared o membrana celular y, en últimas, a una respuesta intracelular del sistema biológico que consideraría a la nanopartícula como un objeto biocompatible o no (Nel, et al, 2009). Cuando una nanopartícula se acopla a un sistema biológico, se pueden generar interacciones complejas que involucran las de naturaleza entálpica y entrópica, las cuales propiciarían en el sistema transiciones de ordenamiento (Xu, et al, 2017). Por ejemplo, cuando se presenta adsorción de las proteínas sobre las nanopartículas, tanto la carga superficial que estas poseen (que daría origen a una interacción entálpica), como la naturaleza hidrofóbica de su superficie (que generaría una interacción entrópica), favorecen su adsorción (Cai, et al, 2017).…”