Preparation And Application Of Self-healing Polymer Materials Based On Supramolecular Bonds

In recent years,the rapid development of self-healing technology has promoted its research and application in the field of functional materials.In this paper,we have designed and prepared four self-healing materials based on supramolecular bonds,which were applied in the fields of antifouling,solid electrolyte and lithium-sulfur battery binders.The details are as follows:1 Preparation of hydrophilic self-healing polymer coating and its antifouling performanceThe colonization of microbe on the material surface causes serious damage to the fields of biomedicine,water purification,and biosensors,and therefore versatile and biocompatible anti-biofouling coatings are highly demanded.Here,we fabricated a dual-functional（fouling-resist and antibacterial properties）anti-biofouling self-healing coating（DASC）with the triplex-crosslinked network（the covalent bonds,hydrogen bonds,and ionic interactions）,which could be coated on 316L stainless steel substrate and demonstrated strong adhesive strength.The DASC-15（the quaternary ammonium compounds accounts for 15 mol%）could inhibit the adhesion of biofouling due to its hydroxyethyl acrylate（HEA）and poly（ethylene glycol）methyl ether acrylate(PEGA₄₈₀)units,and its anti-protein adhesion efficiency reached 90%.The presence of the quaternary ammonium compounds cations endowed the DASC-15 with excellent broad-spectrum antibacterial property,and the killing efficiency against Staphylococcus aureus and Escherichia coli was approximately 99.9%.Moreover,The DASC-15 could be repaired within 15 min under ambient condition after being scratched.The mechanical property restored to 92%of its original condition,which was derived from the destruction and recombination of the supramolecular non-covalent bonds.More prominently,larger scratches with the width of 200μm could be repaired and the anti-biofouling property remained at the humidity of 90%.The coating is promising for biomaterial due to its strong metal adhesion,good biocompatibility,excellent anti-biofouling and outstanding self-healing properties.2 Preparation of amphiphilic self-healing polymer and its antifouling performanceAnti-biofouling coatings with intrinsic self-healing ability are urgent desirable for practical application.Herein,a novel amphiphilic self-healing anti-biofouling material（ASAM）coating integrating anti-smudge ability was prepared based on the incorporation of ionic liquids（EMI-TFSI）into amphiphilic copolymer-poly（BA-co-HFBM-co-SBMA）.The ion-dipole interactions between incorporated imidazole cations and electronegative F atom endow coatings with excellent self-healing ability.The presence of 3-[Dimethyl-[2-（2-methylprop-2-enoyloxy）ethyl]azaniumyl]propane-1-sulfonate（SBMA）promotes the reconstruction of the surface chemical composition,forming nanoscale heterogeneity,thereby improving the anti-biofouling efficiency.The optimized ASAM6（SBMA accounts for 6 mol%）coating presented excellent anti-protein adhesion（increased by 67.5%vs ASAM0）and antibacterial adhesion（increased by 99.9%vs ASAM0）efficiency,and the outstanding anti-smudge ability against diverse pollutants（such as dyes and juices,etc.）has also been confirmed.The ASAM6 has strong mechanical properties（Young’s modulus=27.72 MPa,tensile strength=2.39 MPa,extensibility>800%）and can repair damaged parts within 6 h at room temperature.Moreover,Higher self-healing efficiency（recovering time<40 min）can be achieved at humidity of 95%.Thus,the ASAM6 coating exhibited good stability,excellent anti-biofouling ability as well as prominent anti-smudge and self-healing properties,thereby providing a new idea for the design of anti-biofouling coatings and broadening its fields of application.3 Preparation of flexible and flame-retardant self-healing polymer and used as solid electrolytesSolid-state polymer electrolyte（SPE）with superior self-healing capacity is urgently desirable for next-generation flexible energy storage device.Herein,a highly stretchable（extensibility>4000%,and stress>130 k Pa）,nonflammable and notch-insensitive intrinsic self-healing solid-state polymer electrolytes（SHSPE）is prepared based on the combination of poly（HFBM-co-SBMA）network,imidazole based ionic liquid（EMI-TFSI）and Li TFSI.The incorporation of imidazole cation and fluorine atom contributes to the formation of supramolecular bonds（ion-dipole interactions）inside the electrolyte framework,thus endowing the SHSPE with prominent self-healing ability（recovering time<60 min,25°C）.Moreover,density functional theory（DFT）calculation indicates that the large electrostatic attraction of SO₃^-towards Li⁺liberates it from the trapping in ionic reservoir of TFSI^-and EMI⁺,thereby dedicating to a superior t _Li+（0.37）.The electrochemical window of SHSPE can achieve 4.9 V vs.Li⁺/Li,which well satisfies the demand for safety lithium batteries.The optimized SHSPE3presents excellent interfacial compatible property with lithium electrode with a record adhesion strength（weight loading>200 g）.The as-assembled Li/SHSPE3/Li Fe PO₄ battery can deliver a high discharge capacity of 144.8 m Ah g^-1at 0.2 C,and the capacity retention ratio reaches 82%after 100 cycles with a coulombic efficiency of 97%.In particular,the mechanical properties and conductivity of SHSPE3 can fully recover after repeated damage,conferring the derived soft-pack battery excellent anti-fatigue capability.The usage of intrinsic self-healing principles in the field of SPEs provides a new insight for developing reliable and safety flexible electronic devices.4 Preparation of high-strength self-healing polymer and used as binders for lithium-sulfur batteriesAs an important component of the cathode electrode of a lithium-sulfur battery,the binder can buffer the volume change during the cycle and maintain the stability of the cathode electrode structure.In this chapter,we designed and prepared a polymer material with high cohesiveness,high strength and self-healing ability for lithium sulfur battery binder（SHB）.SHB-1 has high mechanical strength（Young’s modulus=109 MPa,tensile strength=7.3 MPa,extensibility>200%）,good self-healing ability（under dry conditions at room temperature,it can be restored 89.1%of the initial mechanical properties within 43 days）and outstanding electrolyte environmental self-healing ability（98%of its initial mechanical properties can be restored within 24 hours）.SHB-1 has the strong adsorption for polysulfides,which can effectively inhibit the shuttle of polysulfides,increase the specific discharge capacity of sulfur electrode,reduce the capacity attenuation of lithium sulfur battery,and improve the cycle stability of lithium sulfur batteries.The lithium-sulfur battery with SHB-1 as the binder has an initial discharge capacity of 1212.6 m A g^-1 at a rate of 0.2 C.After 100 cycles,it still has a high reversible electrochemical capacity of 979.6 m A g^-1 with a capacity retention rate of 80.8%and an average capacity degradation rate of 0.19%per cycle.This lithium-sulfur battery also has excellent long-cycle stability at a high rate of 2 C.After 600 cycles,it has a reversible discharge capacity of 624.8 m Ah g^-1 with a capacity retention rate of 81.7%and an average capacity degradation rate of 0.03%per cycle.