Facile Fabrication of Self-Healable and Antibacterial Soy Protein-Based Films with High Mechanical Strength

Abstract

Soy protein isolate (SPI), a ubiquitous and readily available biopolymer, has drawn increasing attention because of its sustainability, abundance, and low price. However, the poor mechanical properties, tedious performance adjustments, irreversible damage, and weak microorganism resistance have limited its applications. In this study, a facile but delicate strategy is proposed to fabricate an excellently selfhealable and remarkably antibacterial SPI-based material with high mechanical strength by integrating polyethyleneimine (PEI) and metal ions (Cu(II) or Zn(II)). The tensile strengths of the SPI/PEI-Cu-0.750 and SPI/PEI-Zn-0.750 films reach up to 10.46 ± 0.50 and 9.06 ± 0.62 MPa, which is 367.06 and 306.28% strength increase compared to that of neat SPI film, respectively. Due to abundant non-covalent bonds and low glass transition temperature of the network, both SPI/PEI-Cu and SPI/PEI-Zn films exhibit a satisfactory self-healing behavior even at room temperature. Furthermore, SPI/PEI-Cu and SPI/PEI-Zn films demonstrate high bacterial resistance against Escherichia coli and Staphylococcus aureus. This facile strategy of establishing dynamic networks in a biomaterial with numerous excellent properties will enormously expand the scope of its applications, especially in the field of recyclable and durable materials.

Design Principles of Interfacial Dynamic Bonds in Self‐Healing Materials: What are the Parameters?

“…Taking the self-healing concept further, that centred around either extrinsic [52][53][54][55][56][57][58][59][60][61][62] or intrinsic mechanisms [63][64][65][66][67][68][69][70] or through intersection among the two approaches, [71][72][73][74][75] the interplay between thermodynamics, kinetics and transient relations in SH-PNCs are incredibly critical at the molecular level. The selfhealing materials that relays on extrinsic mechanism contains microcapsules reservoirs (hollow fibres, microvascular networks) as external healing agents, and the healing is triggered by slow release of healing agents from these capsules at the junction of the cut surface.…”

Mechano-responsive hydrogen-bonding array of thermoplastic polyurethane elastomer captures both strength and self-healing

“…According to the Ashby plot of UTS versus self-healing temperature for recently reported elastomers, previous tensile strengths did not exceed 20 MPa without the aid of light or a temperature above 40 °C ( Supplementary Fig. 7 and Supplementary Table 3) 9, [21][22][23][24][34][35][36][37][38][39][40]42,43,47 .…”

“…Herein, we report a self-healing carbonate-type thermoplastic polyurethane (TPU) elastomer with the highest concurrent ultimate tensile strength (UTS) reported to date (43 MPa) for a self-healing "elastomer" that functions at ambient temperature; this TPU even outperforms a commercial TPU used for a footwear component [33][34][35][36][37][38] . Basically, the rich carbonyl groups of the carbonate soft segments form H-bonds.…”

A Tough and Mildew-Proof Soybean-Based Adhesive Inspired by Mussel and Algae

“…The peaks observed at 2929 and 2869 cm −1 were due to the symmetric and asymmetric stretching vibrations of the -CH2 groups [30,31]. When using soybean meal and blood meal as the matrix, it was seen that the peak at 2869 cm −1 was slightly shifted to 2865 cm −1 , revealing an interaction occurred between protein and zinc ions [32]. The peak at 1515 cm −1 (amide II) obviously shifted to 1528 cm −1 , the intensity of the peak at 1233 cm −1 reduced in comparison to the formulation 1 and a new peak appeared at 1062 cm −1 .…”