聚乙烯亚胺修饰碳纤维对环氧树脂复合材料性能的影响

为提高碳纤维与环氧树脂的界面结合性能,从而提高复合材料的摩擦学性能,用聚多巴胺和聚乙烯亚胺对碳纤维进行表面修饰,利用光谱分析仪和扫描电子显微镜分析修饰前后碳纤维表面的化学组成和微观结构,利用万能材料试验机和摩擦磨损试验机考察碳纤维增强环氧树脂复合材料的力学性能和摩擦学性能。结果表明：碳纤维经表面处理之后的粗糙程度和活性官能团增多,改善了纤维与树脂之间的界面结合,使得复合材料的弯曲强度和拉伸强度得到不同程度的提高;与未修饰碳纤维增强的环氧树脂复合材料相比,表面修饰碳纤维增强环氧树脂复合材料的耐磨性能得到了很大程度的提高,复合材料的磨损机制也由疲劳磨损转变为磨粒磨损。     

A functional and robust super-hydrophobic PCC coating based on the induced assembly of modified zirconium phosphate

Improving the permeability of concrete is one of the important measures to extend the service life of concrete. In addition, for marine engineering, sewerage projects, and so on, mechanical stability and microbial induced corrosion of concrete structures cannot be ignored. We demonstrated a method to prepare high-performance super-hydrophobic (SHP) coating using functional zirconium phosphate (ZrP) and polydopamine (PDA) as the primary materials. The micro-nano rough structures were constructed on the concrete surface by alternating organic–inorganic assembly guided by each other. The coatings' apparent morphology, composition, and structure were analyzed using various surface analysis techniques. Based on the construction of micro-nano rough structures by the induced assembly of functional ZrP, the silane treatment significantly improved the water contact angle of the coating (WCA = 154° ± 3°), and the coating exhibited relatively high wear resistance, reaching 135° WCA even after 30 friction cycles. The water absorption of the specimens treated with the SHP composite coating was reduced by 79% to treated with silane. Meanwhile, the SHP composite coating showed excellent antimicrobial and anti-ice properties, due to the role of the functional ZrP and alternating organic–inorganic assembly. It was expected that the composite coating might potentially promote and accelerate applied superhydrophobic anticorrosive coating development for marine concrete durability.     

Polydopamine-Assisted Bi-Functional Modification of NiO Anode for Enhanced Lithium-Ion Storage Performance

The blooming requirement of high-performance energy storage systems has aroused the thirst for advanced energy storage materials. As a high capacity anode, however, the application of NiO nanoparticles (NiO NPs) is hindered by intractable issues of dramatic volume change, intrinsic low electronic conductivity, and severe aggregation tendency during lithiation/delithiation. Herein, a polydopamine (PDA) assisted bi-functionalization strategy for fabricating of PDA@NiO-CNT composites for fast and durable lithium storage is reported. In this composite, CNTs intertwine to form a network to ensure sufficient electrolyte infiltration and act as a highly conductive system to motivate fast charge transmission. The strong binding affinity of PDA facilitates bonding between NiO NPs and CNTs, which not only forms uniform and flexible PDA coating but also ensures homogeneous distribution of NiO NPs on CNTs network. Therefore, the bi-functional modified PDA@NiO-CNT electrode possesses high conductivity, alleviates volume change and aggregation of NiO NPs during cycling, achieves a reversible capacity of 1326 mAh g⁻¹ at 100 mA g⁻¹, a rate capability of 215 mAh g⁻¹ at 2000 mA g⁻¹ and a cycling stability with 78% capacity retention after 250 cycles. This bi-functional modification approach manifests its prospective potential for architecting other electrode materials toward high-performance electrochemical devices.     

Bacterial Killing by Light‐Triggered Release of Silver from Biomimetic Metal Nanorods

Illumination of noble metal nanoparticles at the plasmon resonance causes substantial heat generation, and the transient and highly localized temperature increases that result from this energy conversion can be exploited for photothermal therapy by plasmonically heating gold nanorods (NRs) bound to cell surfaces. Here, plasmonic heating is used for the first time to locally release silver from gold core/silver shell (Au@Ag) NRs targeted to bacterial cell walls. A novel biomimetic method of preparing Au@Ag core–shell NRs is employed, involving deposition of a thin organic polydopamine (PD) primer onto Au NR surfaces, followed by spontaneous electroless silver metallization, and conjugation of antibacterial antibodies and passivating polymers for targeting to gram‐negative and gram‐positive bacteria. Dramatic cytotoxicity of S. epidermidis and E. coli cells targeted with Au@Ag NRs is observed upon exposure to light as a result of the combined antibacterial effects of plasmonic heating and silver release. The antibacterial effect is much greater than with either plasmonic heating or silver alone, implying a strong therapeutic synergy between cell‐targeted plasmonic heating and the associated silver release upon irradiation. The findings suggest a potential antibacterial use of Au@Ag NRs when coupled with light irradiation, which has not been previously described.     

基于聚多巴胺的仿生界面设计在含能材料中的应用研究进展

界面结构对含能材料的力学性能、安全性能、热稳定性均具有重要的影响。聚多巴胺(PDA)是一种能使绝大多数基体功能化的表面化学材料,具有制备简单易控,反应温和,操作安全,可再进一步功能化等优点。近年来,仿生PDA包覆广泛应用于含能材料领域并取得良好进展。本文就PDA基仿生可控界面对含能材料结构和性能影响进行了综述。从PDA粘结机理出发,介绍了PDA对含能材料和功能填料进行表面功能化的方法,重点阐述了PDA表面改性对炸药的安全性能、热稳定性、力学性能和导热性能的影响规律。总结了PDA在含能材料结构设计和性能调控中的独特优势,指明目前存在的问题,建议进一步探明PDA与含能材料、粘结剂间作用机理,设计规整可控的界面结构,引入功能性高分子,并拓展含能材料用表面功能化材料种类。     

多巴胺磁性纳米粒子对Nisin的吸附特性

本实验旨在通过系统研究多巴胺磁性纳米粒子（iron oxide nanoparticles coated with polydopamine,IONPs@pDA）对乳酸链球菌素（Nisin）的吸附特性,为新型杀菌材料Nisin-IONPs@pDA耦合体的制备提供理论依据及数据支持。实验测定了不同温度和时间下多巴胺磁性纳米粒子对Nisin的吸附量,并进行吸附动力学和吸附等温线拟合。结果显示：多巴胺磁性纳米粒子对Nisin的吸附行为符合Lagergren准二级吸附动力学模型和Freundlich吸附等温模型,说明吸附过程主要受化学吸附的控制,且为发生在异构表面的多层吸附过程。热力学计算结果表明,多巴胺磁性纳米粒子对Nisin的吸附是一个吸热过程,Nisin的吸附量随着温度的升高而增大。结论：多巴胺磁性纳米粒子是一种有效的Nisin吸附磁性材料,可用于制备新型复合杀菌材料。     

Preparation of silver nanoparticle functionalized polyamide fibers with antimicrobial activity and electrical conductivity

In this work, silver nanoparticle functionalized polyamide 6 (PA6) fibers were prepared using the electroless plating method. The surface of PA6 fibers was modified by exploiting dopamine/CuSO₄/H₂O₂ system prior to electroless plating to enhance the bonding force between the fiber and the silver nanoparticles. It was found that both the formation rate and the chemical stability of polydopamine (PDA) coatings on the PA6 fiber surface were improved by the introduction of CuSO₄/H₂O₂. The results confirmed the successful deposition of silver nanoparticles on PA6 fiber surface and the average particle diameter of 223 nm. Compared with uncoated fibers, the silver plated PA6 fibers exhibited excellent antimicrobial activity to both Escherichia coli and Staphylococcus aureus (with an antimicrobial efficiency of 99.9% and 100%, respectively). The electrical resistance of the silver coated PA6 fibers reached 0.98 Ω over a length of 1 cm, indicating a good electrical conductivity. In particular, coating durability of the formed silver layer was investigated by subjecting the fibers to various mechanical deformations, and the results showed that the formed silver layer was maintained well after 50 times of cyclic stretching at a constant displacement of 10 mm. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47584.     

Ultrathin Polydopamine Films with Phospholipid Nanodiscs Containing a Glycophorin A Domain

Cellular membranes have long served as an inspiration for nanomaterial research. The preparation of ultrathin polydopamine (PDA) films with integrated protein pores containing phospholipids and an embedded domain of a membrane protein glycophorin A as simplified cell membrane mimics is reported. Large area, ultrathin PDA films are obtained by electropolymerization on gold surfaces with 10–18 nm thickness and dimensions of up to 2.5 cm². The films are transferred from gold to various other substrates such as nylon mesh, silicon, or substrates containing holes in the micrometer range, and they remain intact even after transfer. The novel transfer technique gives access to freestanding PDA films that remain stable even at the air interfaces with elastic moduli of ≈6–12 GPa, which are higher than any other PDA films reported before. As the PDA film thickness is within the range of cellular membranes, monodisperse protein nanopores, so‐called “nanodiscs,” are integrated as functional entities. These nanodisc‐containing PDA films can serve as semi‐permeable films, in which the embedded pores control material transport. In the future, these simplified cell membrane mimics may offer structural investigations of the embedded membrane proteins to receive an improved understanding of protein‐mediated transport processes in cellular membranes.