Mechanically Strong and Highly Stiff Supramolecular Polymer Composites Repairable at Ambient Conditions

Abstract

It is a formidable challenge to fabricate healable polymeric materials with high mechanical strength and stiffness due to the highly suppressed diffusion of their polymer chains. Herein, a high-strength, highly stiff, and repairable/healable supramolecular polymer composite was fabricated by complexing poly(acrylic acid) (PAA) and poly(allylamine hydrochloride) (PAH) in aqueous solutions, followed by molding into desired shapes. Exquisitely tuning the electrostatic and H-bonding interactions between PAA and PAH led to associative phase-separation and in situ formation of nanostructures in the resultant PAA-PAH composites. The H-bonded assembly of PAA-PAH complexes existed as nanospheres were dispersed homogeneously in the continuous phase as an electrostatic assembly of PAA-PAH complexes. Such a structural feature endowed the PAA-PAH copolymer with a doublecross-linked structure, enabling significant reinforcement of the material. a The PAA-PAH composites exhibited a tensile strength and an elastic modulus as high as ∼ 67 MPa and ∼ 2.0 GPa, respectively. Due to the benefits from the reconstruction of the complexes, such as reversible electrostatic interactions and H-bonds between PAA and PAH, the PAA-PAH composite could be repaired/healed readily under ambient conditions (25°C, 40% humidity) by using the liquid-like form of the PAA-PAH complexes (i.e., coacervate). The healing strategy reported here provides a supplementary method for easy repair or healing of high-strength and stiff supramolecular polymer materials.

Influence of Charge and Heat on the Mechanical Properties of Scaffolds from Ionic Complexation of Chitosan and Carboxymethyl Cellulose

“…This behavior was found for both scaffolds, but the CS 50 / N scaffold showed significantly increased mechanical properties at higher temperatures. These values are comparably high and exceed those reported for chitosan, 63 , 64 chitosan-alginate, 65 , 66 bacterial cellulose, 67 ionically cross-linked poly(acrylic acid)/poly(allylamine hydrochloride), 68 and chemically cross-linked CMC/collagen scaffolds. 69 Despite the simple production process, the mechanical performance of the here-prepared biocomposites was in the range of high-strength scaffolds based on cellulose nanofibers 66 , 70 , 71 and cellulose nanocrystals.…”

Self-Healing Hydrophilic Porous Photothermal Membranes for Durable and Highly Efficient Solar-Driven Interfacial Water Evaporation

“…With the progress in supramolecular chemistry and synthetic chemistry, various self-healing polymers that are capable of healing damage by themselves to restore the mechanical and/or chemical properties have been Page 2 of 31 CCS Chemistry 3 successfully synthesized. [20][21][22][23] In addition, by combining self-healing polymers with functional materials, plenty of self-healing functional materials with superhydrophobicity, [24][25][26][27] antifouling, [28][29][30] electrical conductivity, [31][32][33][34] sensing, [35][36][37][38][39][40][41] and other functions [42][43][44][45][46][47][48][49][50] have been fabricated, significantly decreasing maintenance costs and promoting safety, reliability, and service life. The design and fabrication of self-healing materials with photothermal and water transportation capabilities that can repair their functions upon damage would be a judicious solution to increase the stability and service life of solar-driven interfacial evaporators.…”

Polymeric materials reinforced by noncovalent aggregates of polymer chains

“…Inspired by the reinforcement effect of noncovalent aggregates in natural materials, our group has recently developed a series of high-performance noncovalently crosslinked polymeric materials involving in situ formed noncovalent aggregates of polymer chains. [46][47][48][49][50][51][52][53][54][55][56] We have systematically investigated the correlation between the characteristics of the noncovalent aggregates and the mechanical properties of the as-developed polymeric materials. Accordingly, the composition, structure, and dispersion of the aggregates can be reasonably designed and tailored to significantly enhance the mechanical properties of the polymeric materials, in terms of strength, stiffness, toughness and/or elasticity (Figure 1).…”