纳米Al2O3改性三聚氰胺-脲醛自修复微胶囊的制备及应用

以纳米Al_2O_3改性三聚氰胺-脲醛树脂(MUF)为壁材,环氧树脂为芯材,采用原位聚合法合成了微胶囊,并采用光学显微镜(OM)、扫描电子显微镜(SEM)、红外光谱仪(FTIR)、X射线光电子能谱分析仪(XPS)、热重分析仪(TGA)等对其表面形貌、结构及热性能等进行了表征和测试;将改性后的微胶囊加入自修复环氧树脂涂层中,并对其热性能、力学性能、自修复性能及电化学性能进行测试。结果表明,当芯壁比为1.5:1、纳米Al_2O_3质量分数为4.5%时,纳米Al_2O_3在壁材中均匀分布,微胶囊的表面粗糙度和热稳定性均增加。当涂层中改性微胶囊质量分数为5%时,涂层的热稳定性提高,且涂层的拉伸强度、弯曲强度、冲击强度及粘结强度分别提高了111.9%、55.1%、10.6%和51.9%;制备的涂层具备较好的自修复性能;涂层的耐腐蚀性能随着微胶囊质量分数的增大而增强。     

分子模拟在沥青研究中的应用

应用分子模型构建适当的分析方法将是研究沥青分子结构和运动状态的重要手段,也是研究沥青性能和应用的重要措施。本文介绍了分子模拟的多种方法：分子动力学方法、蒙特卡洛方法、量子力学方法、分子力学及布朗动力模拟,并总结这些方法在沥青性能研究中的应用。     

自愈合凝胶在柔性传感器中的应用研究进展

自愈合凝胶具有优异的机械性能、良好的生物相容性和延长材料使用寿命功能等特性,已广泛应用在电子皮肤、柔性机器人、可穿戴设备等方面。凝胶基质结构的可调性和导电材料选择的多样性也为制备具有不同功能的柔性传感器提供了可能。该文根据交联方式、功能性类型、愈合方式和胶凝剂相对分子质量大小4种分类方式将自愈合凝胶进行了分类,并详细介绍了各种自愈合凝胶的成胶机制和性能特点。综述了自愈合凝胶在柔性传感器中力学、光电和生物方面的国内外研究现状。最后,讨论了该研究领域仍存在的问题,并对其未来发展前景及方向进行了简要展望。     

Intelligent self-healable electroactive carboxymethyl cellulose hydrogel containing conductive polythiophene and acid hydrolyzed cellulose

Self-healable electroactive carboxymethyl cellulose/polythiophene/acid hydrolyzed cellulose (CMC/PTh/AHC) hydrogels were successfully fabricated. AHC particles dispersed well in the CMC matrix improving hydrogels thermal stability. The electro-responsive performance of the hydrogels was investigated with respect to bending angle and bending sensitivity. The results showed that under an applied electric field, the CMC/PTh/AHC hydrogels bend toward a cathode electrode. In addition, the electroactive performance of the hydrogels decreased with increased AHC content. The CMC/PTh/AHC10 (10 wt.% AHC) hydrogel exhibited the shortest induction time (τ_ind) of 3.35 ± 0.56 s. For self-healing, it was found that the hydrogel with addition of 2 wt.% AHC had the highest self-healing efficiency on both tensile strength and elongation at break (93.37 ± 3.17% and 99.35 ± 12.11%, respectively). While the self-healing efficiency on bending angle was 82.73 ± 14.55%. The results demonstrated that the properties of the CMC/PTh/AHC2 hydrogel were close to its original properties after healing for 24 h. The results demonstrated that the CMC/PTh/AHC hydrogel can be utilized as an actuator or artificial muscle using electrical stimulus.     

自修复混凝土技术的现状与发展

自修复混凝土（SHC）技术是一种新型混凝土修补技术,利用混凝土中添加的自修复剂或微生物等使得混凝土中的裂缝自行愈合,从而延长混凝土使用寿命,减少环境污染和资源浪费。本文介绍了自修复混凝土技术的原理、发展、研究热点及未来的趋势和应用前景。     

一种实现母线自愈功能的备用电源自投装置

自愈性是智能电网的重要特征和标志,也是电网安全运行的主要目的。针对传统备用电源自投装置无法解决因上级电源消失而非本级母线设备原因引起的变电站全站失压问题,在装置中引入失稳判据、过载判据,通过备投本级联络线的方式,实现变电站母线自愈功能。在快速恢复本级母线和重要用户供电的同时,又可避免因过载引起跳闸风险。在电网中实践证明,在不改变传统备用电源自投功能的同时,提高了供电可靠性。     

可仿生自修复的无线传感网络节点设计

为保证无线传感网络的长期稳定运行,提出了一种具有仿生自修复功能的节点设计方法.该方法采用现场可编程模拟阵列(FPAA)实现传感模块内部各电路的信号链路,用信号处理模块监测传感模块内部各电路的工作状态.当传感模块发生异常时,信号处理模块判别其内部异常电路位置,并驱动FPAA启动冗余备份电路,完成了传感模块的信号链路的动态重构,达到了节点自修复的目的.首先介绍了仿生自修复节点的总体设计方案;然后,以应变无线传感网络节点为具体应用对象,设计实现了传感模块可动态重构自修复无线传感网络节点;最后,通过信号异常饱和状态的自修复试验验证了节点的自修复功能.     

Room temperature-responsive poly(vinyl hydroxyalkyl ether-alt-dialkyl maleate)-based vitrimers with dynamic boronic ester bonds

Dynamic B O bonds are often applied to fabricate reversible-cross-linking and reprocessable polymer networks due to their high thermodynamic stability and kinetic tunability. However, it is still difficult to tailor boronic ester polymers, which have both excellent mechanical and self-healing properties in the absence of external stimuli. To address the above challenge, a range of room-temperature self-healable vitrimers are prepared by the reactions of various poly(vinyl hydroxyalkyl ether-alt-dialkyl maleate) copolymers and 1,4-phenyldiboronic acid. The dynamic cross-linking networks offer the as-prepared vitrimers superior mechanical properties and thermostability. Because of the presence of dynamic boronic ester bonds, the networks also demonstrated self-healing (the tensile strength recovered to 83% after 3 days at room temperature) and reprocessing capabilities (no significant change in tensile strength after thrice process recycles). Moreover, the vitrimers have potential as promising damping materials with wide temperature windows around room temperature. For example, the vitrimer of poly(ethylene glycol monovinyl ether-alt-dibutyl maleate) and 1,4-phenyldiboronic acid demonstrates its tanδ_max 1.18, T_g = 6.2°C and effective damping temperature range is from −16.4 to 48.5°C.     

Preparation of light-responsive block copolymer modified cellulose nanocrystal@polydopamine particle and its application in fluorinated polyacrylate film

Light-responsive cellulose nanocrystal@polydopamine (CNC@PDA) modified fluorinated polyacrylate was synthesized by Pickering emulsion polymerization with light-responsive block copolymer modified CNC@PDA as stabilizer. The epoxy groups in poly(acrylic acid-co-acrylamide)-b-poly(glycidyl methacrylate)-b-poly(hexafluorobutyl acrylate-co-coumarin) amphiphilic triblock copolymer reacted with the hydroxyl and amino groups on the surface of CNC@PDA to form the modified CNC@PDA. The successful preparation of modified CNC@PDA was confirmed by means of FT-IR, XRD, TG, UV–Vis, surface tension measurement, and X-ray photoelectron spectroscopy (XPS) techniques. The results showed that the modified CNC@PDA had light-responsive and amphiphilic properties, and could be used as stabilizer to form stable Pickering emulsion. And the influence of modified CNC@PDA dosage on emulsion polymerization and film performance was systematically studied. The latex particle size decreased initially with increasing modified CNC@PDA dosage, from 0.6 to 1.0 wt%, and then increased. The mechanical, self-healing, and water–oil repellent properties of film were enhanced initially with increasing modified CNC@PDA dosage, from 0.6 to 1.0 wt%, and then declined. Atomic force microscope confirmed that the latex film had a rough surface. Moreover, the latex film comprising 1.0 wt% modified CNC@PDA presented not only high tensile strength (4.92 MPa), large elongation at break (657.70%), and superior oil/water repellency but also excellent self-healing property.     

城域网中IP over DWDM的应用及发展

本文系统地阐述了IP over DWDM的分层模型、关键技术，并对IP over DWDM技术在城域网中的应用和发展前景进行了介绍。