【作者】 王成；

【导师】 傅佳骏；

【作者基本信息】 南京理工大学 ， 化学工程与技术， 2021， 博士

【摘要】 近年来,自修复技术的快速发展推动了其在功能性材料领域的研究和应用。本论文中设计和制备了四种基于超分子键的自修复材料并将其应用在防污、固态电解质和锂硫电池粘结剂领域。具体内容如下:1亲水性自修复聚合物涂层的制备及防污性能的研究微生物在材料表面上的定殖严重损害了其在生物医学、水净化和生物传感器领域的应用。因此,对多功能和生物相容性的防污涂层的需求很高。在这里,我们制备了具有三重交联网络（共价键、氢键和离子间相互作用）的双功能（防污和抗菌性能）防污自修复涂层（DASC）。可以将DASC涂覆在316L不锈钢基材上,具有很强的粘结强度。DASC-15（季铵化合物占15 mol%）由于其丙烯酸羟乙酯（HEA）和聚（乙二醇）甲基醚丙烯酸酯(PEGA₄₈₀)单元而可以抑制生物污损的粘附,并且其抗蛋白质粘附效率达到90%。季铵化合物阳离子的存在使DASC-15具有出色的广谱抗菌性能,并且对金黄色葡萄球菌和大肠杆菌的杀灭效率约为99.9%。此外,DASC-15被划伤后可以在环境条件下15 min内修复,机械性能恢复到其原始状态的92%,这是由于超分子非共价键的断裂和重组而实现的。更显著的是,在90%的湿度下DASC-15可以修复宽度为200μm的较大划痕,并且可以恢复防污性能。该涂层具有很强的金属附着力、良好的生物相容性、优异的抗生物污损性和出色的自修复能力,因此有望用于生物材料。2两亲型自修复聚合物的制备及防污性能的研究具有本征自修复能力的防污材料在实际应用中是迫切需要的。在此,将离子液体（EMI-TFSI）掺入两亲共聚物-poly（BA-co-HFBM-co-SBMA）中,制备了一种具有防污能力的新型两亲自修复防污材料（ASAM）。咪唑阳离子和电负性较大的F原子之间的离子-偶极相互作用赋予了涂层具有出色的自修复能力。3-[N,N-二甲基-[2-（2-甲基丙-2-烯酰氧基）乙基]铵]丙烷-1-磺酸内盐（SBMA）的存在促进了表面化学组成的重构,形成纳米级异质性,从而提高了防污效率。经过优化的ASAM6（SBMA占6 mol%）涂层具有出色的抗蛋白质粘附能力（相对于ASAM0增加67.5%）和抗菌粘附能力（相对于ASAM0增加99.9%）,以及对多种污染物出色的防污迹能力（如染料和果汁等）也已得到证实。ASAM6具有很强的机械性能（杨氏模量=27.72 MPa,抗拉强度=2.39 MPa,延展性>800%）,并且可以在室温下6 h内修复受损部位。此外,在95%的湿度下可以实现更高的自修复效率（恢复时间<40 min）。ASAM6涂层表现出了良好的稳定性、优异的防污能力以及突出的抗污迹和自修复性能,从而为防污涂层的设计和拓宽其应用领域提供了新思路。3柔韧且阻燃的自修复聚合物的制备及作为固态电解质的研究下一代柔性储能设备对具有优异的自修复能力的固态聚合物电解质（SPE）有迫切的需要。在此,基于poly（HFBM-co-SBMA）、咪唑基离子液体（EMI-TFSI）和Li TFSI,制备了具有高度可拉伸性（延展性>4000%,应力>130 k Pa）,不易燃且对缺口不敏感的本征自修复固态聚合物电解质（SHSPE）。咪唑阳离子和氟原子的结合有助于在电解质框架内形成超分子键（离子-偶极相互作用）,从而使SHSPE具有出色的自修复能力（恢复时间<60 min,25°C）。此外,密度泛函理论（DFT）计算表明,SO₃^-对Li⁺的较大静电吸引将其从TFSI^-和EMI⁺的离子氛围中释放出来,从而促使了较高的锂离子迁移数（0.37）。SHSPE的电化学窗口相对于Li⁺/Li可以达到4.9 V,这充分满足了锂电池对安全的需求。经过优化的SHSPE3与锂电极具有出色的界面相容性,并具有突出的粘合强度（重量载荷>200 g）。组装好的Li/SHSPE3/Li Fe PO₄电池在0.2 C下可提供144.8 m Ah g^-1的高放电容量,经过100次循环后容量保持率达到82%且库仑效率为97%。SHSPE3的机械性能和电导率在反复损坏后可以恢复,从而使衍生的软包电池具有出色的抗疲劳能力。自修复原理在SPE领域内的使用为开发可靠且安全的柔性电子设备提供了新的视野。4高强度的自修复聚合物的制备及作为锂硫电池粘结剂的研究粘结剂作为锂硫电池正极重要的组成部分,其可以缓冲循环过程中体积变化和维持正极结构稳定。本章中我们设计并制备了一种高粘结性和高强度同时兼具自修复能力的聚合物材料用作锂硫电池粘结剂（SHB）。SHB-1拥有较高的力学强度（杨氏模量=109MPa,抗拉强度=7.3 MPa,延展性>200%）、良好的室温自修复能力（室温干燥条件下,43天内可以恢复其初始力学性能的89.1%）和突出的电解液环境修复能力（24 h内可以恢复其初始力学性能的98%）。SHB-1对于多硫化物具有很强的吸附作用,可以有效地抑制多硫化物的穿梭、增加硫电极放电比容量、降低锂硫电池的容量衰减和提高锂硫的循环稳定性。SHB-1作为粘结剂的锂硫电池在0.2 C的倍率下初始放电容量为1212.6 m A g^-1,循环100圈之后仍然拥有979.6 m A g^-1的高可逆电化学容量,容量保留率为80.8%且平均容量衰退率为每圈0.19%。该锂硫电池在2 C的大倍率下具有极佳的长循环稳定性,在循环600圈之后具有624.8 m Ah g^-1的可逆放电容量,容量保持率有81.7%且平均容量衰退率仅为每圈0.03%。SHB的制备方法简单,作为粘结剂使用工艺简单,性能优异,对于锂硫电池的商业化应用具有重要的指导和借鉴意义。更多还原

【Abstract】 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.更多还原