基于液态金属的水凝胶应变传感器

近年来，基于导电水凝胶的应变传感器发展迅速，液态金属作为一种新型导电材料由于具有高导电性、良好的生物相容性、柔性和可变性，在导电水凝胶传感器的制备和应用中受到了越来越多的关注。本文介绍了液态金属以分散的液滴和连续的流体两种形式在导电水凝胶制备中的应用，及所制备的基于液态金属导电水凝胶传感器的性能，最后，对基于液态金属的水凝胶传感器的应用前景进行了展望。     

导电水凝胶的研究进展

导电水凝胶作为一种新型功能凝胶材料,受到了广大科研工作者的关注。本文总结了导电水凝胶的类型,分为聚电解质导电水凝胶、酸掺杂导电水凝胶、无机物填充导电水凝胶和导电高分子基导电水凝胶四大类。并综述其在柔性可穿戴电子产品、能源存储、能源转换及药物的可控释放等方面具有的应用前景。最后,对未来导电水凝胶的发展做了展望。     

SA-Zn水凝胶的性能特点及应用

水凝胶可以用于组织工程的支架、药物输送的载体,光学和流体学的致动器,以及用于生物学研究的细胞外基质模型.其中,可伸缩离子导电水凝胶由于其特性,在运动监测仪器中广泛运用.本文主要综述了一种超拉伸可回收离子导电水凝胶SA-Zn的结构与特性和SA-Zn水凝胶的机械性能以及作为传感器在人体运动检测的应用.     

导电水凝胶的制备及应用研究进展

导电水凝胶是一类将亲水性基质和导电介质有机结合的新型水凝胶,具有较高的柔韧性、可调的力学性能和优异的电化学性能,在柔性电子设备等领域具有广阔的应用前景。本文综述了导电水凝胶材料的研究前沿和动态,介绍了导电水凝胶的分类及制备方法,讨论了导电水凝胶的结构设计与性能,重点阐述了导电水凝胶材料的应用研究进展,归纳了导电水凝胶材料面临的问题与挑战,并展望了导电水凝胶材料的发展趋势,指出采用天然可再生资源为原料开发具有高导电性、力学性能稳定、耐极端温度、生物相容性和生物可降解的导电水凝胶将成为下一步研究重点,同时优化柔性电子装置、提高器件输出稳定性也将成为重要的研究方向之一。导电水凝胶的制备及应用研究将促进柔性电子功能材料领域的快速发展。     

用于柔性传感的双形状记忆MXene基水凝胶的制备及性能研究

兼具优良导电性和多重形状记忆多功能水凝胶柔性传感器的构筑极具挑战。通过分子设计采用自由共聚和冷冻-解冻法将MXene纳米片引入兼具温度响应的高分子聚乙烯醇和金属离子响应的聚丙烯酸网络中，制备了具有双重形状记忆的导电水凝胶并构筑了应变传感器。采用透射电镜、扫描电镜、X射线衍射及傅里叶红外光谱等技术研究了该纳米片和复合水凝胶的形貌及结构，研究了MXene含量对该水凝胶力学性能、导电性能及形状记忆性能的影响规律。研究表明：MXene纳米片均匀分散在复合水凝胶中，且与水凝胶网络通过氢键交联，这不仅强化了该水凝胶的力学性能，而且提高了双重形状记性水凝胶的形状固定率。其中，复合水凝胶的抗拉强度提升至236.10 kPa，是纯水凝胶的7.3倍，对铁离子的形状固定率从69.44%增加至94.44%，对温度响应的形状固定率从63.89%增加至88.89%。该水凝胶传感器的信号在多次快速拉伸应变循环下表现出色的连续性和一致性，这为环境适应性柔性传感器的构筑提供了新思路。     

中国专利

一种具有高强度、高灵敏度的聚乙烯醇离子导电水凝胶制备方法本发明公开一种具有高强度、高灵敏度的聚乙烯醇离子导电水凝胶的制备方法。制备步骤为:(1)不同结晶次数的聚乙烯醇水凝胶的制备;(2)聚乙烯醇离子导电水凝胶的制备。本发明的优点在于:聚乙烯醇离子导电水凝胶含有大量氢键相互作用及盐析效应导致的高分子链缠结,因此,具有可调控的高机械强度。体系中含水量高,离子的定向移动使其具有快速应变响应性及高灵敏度,可以实现运动监测及语音识别等应用。     

羧基化填料对聚乙烯醇/纳米纤维素水凝胶力学、导电和传感性能的影响

利用羧基化碳纳米管（CNT）和纳米纤维素微晶（CNC）与聚乙烯醇/纳米纤维素（PVA/CNF）中形成氢键构建致密的交联网络,并对水凝胶进行增强改性。结果表明,加入3 %（质量分数,下同）的CNT可以使水凝胶的拉伸强度由50 kPa提高至120 kPa,而加入3 %的CNC能够同时提高水凝胶的拉伸强度和断裂伸长率;加入CNT后能够在水凝胶中构建导电逾渗网络,结合溶剂中的离子导电使得水凝胶的电阻率显著下降;使用PVA/CNF?CNT3水凝胶制作应变传感器,能够实现拉伸、压缩和弯曲等多种应变的快速、准确传感响应。     

可拉伸的PVA/CNC/NaCl导电水凝胶制备及柔性传感应用

基于柔性电子领域的发展需求,水凝胶因其可拉伸性和较好的生物相容性被认为具有很大的应用前景。以聚乙烯醇(Polyvinyl alcohol, PVA)作为基体,加入纤维素纳米晶体(Cellulose nanocrystal, CNC)作为增强填料,氯化钠(NaCl)作为电解质以提高水凝胶的电导率,采用30 kGy的γ辐照制备得到的水凝胶具有良好的力学性能(断裂伸长率421%、最大拉伸应力为68.9 kPa)和导电性能(电导率2.85 S/m),将PVA/CNC/NaCl水凝胶作为应变传感器,可应用于手指弯曲、手腕弯曲、手肘弯曲等人体部位运动状况检测,稳定性良好,并表现出较好的灵敏度,验证了该水凝胶的实用性并为其后续应用奠定基础。     

细菌纤维素基水凝胶的制备及传感器应用进展

概述了细菌纤维素和水凝胶两种材料的优势,综述了功能性细菌纤维素水凝胶的制备及其功能化方法,介绍了原位合成法、异位合成法中的浸渍法、溶解再生法的原理、优缺点及相关研究进展。基于细菌纤维素水凝胶具有优异的机械性能、生物相容性、可降解性和可修饰性等诸多特性,总结了细菌纤维素基水凝胶在传感器领域的最新进展,包括应变传感器、pH传感器和热传感器、电响应传感器、湿度传感器。最后对细菌纤维素基水凝胶的发展前景进行了展望。     

双重动态共价键交联纳米纤维素导电水凝胶及其柔性传感器

自愈合导电水凝胶因其良好的自愈合性能与导电性能,在柔性可穿戴设备中具有巨大的应用前景。以4-甲酰基苯硼酸(Bn)交联聚乙烯醇(PVA)和聚乙烯亚胺(PEI)构建基于硼酸酯键和亚胺键的双重动态交联水凝胶网络,引入聚吡咯修饰的纤维素纳米纤维(PPy@CNF)构建了具有良好自愈合和导电性的PBP-PPy@CNF纳米复合水凝胶。结果表明,当PPy@CNF的质量分数为0.8%时,水凝胶的力学性能最佳,其最大应力可达6.65kPa,断裂拉伸应变可达2080%,电导率为2174μS/m。基于该水凝胶的电阻式传感器具有良好的稳定性和重复性,在应变检测范围0～800%内,灵敏因子GF可分为三个线性响应区域,分别是0～200%(GF₁=2.82)、200%～600%(GF₂=7.15)和600%～800%(GF₃=12.85),该传感器能有效检测人体不同部位的运动,可应用于可穿戴传感设备。     

Nucleation, Growth, and TEM Analysis of Metal Particles and Clusters Deposited in UHV

It has been established for some time [1, 2] that small supported metal particles can be reproducibly prepared in a controlled way by ultrahigh vacuum (UHV) deposition onto planar supports. Such planar deposits have been employed in the past to study the physical [3-11] and chemical [12-20] properties of mesoscopic metal aggregates. In these studies, the emphasis has usually been placed on pointing out the differences in particle properties with respect to the bulk properties of the same material. Although it has often been found that the electronic properties reach bulk values at surprisingly small cluster sizes of about 30 to 50 atoms, it has also been observed that the chemical properties can change over a much wider particle size range [21] for structure-sensitive reactions [22]. Furthermore, it is generally realized that particle size alone is usually not the only important parameter but that the influence of the support in terms of electronic, structural, chemical, and morphological particle properties can be essential. which demonstrates the importance of experimental attempts to control the support properties as well as the particle properties.     

Nucleation,Growth, and TEM Analysis of Metal Particles and Clusters Deposited in UHV

It has been established for some time [1, 2] that small supported metal particles can be reproducibly prepared in a controlled way by ultrahigh vacuum (UHV) deposition onto planar supports. Such planar deposits have been employed in the past to study the physical [3–11] and chemical [12–20] properties of mesoscopic metal aggregates. In these studies, the emphasis has usually been placed on pointing out the differences in particle properties with respect to the bulk properties of the same material. Although it has often been found that the electronic properties reach bulk values at surprisingly small cluster sizes of about 30 to 50 atoms, it has also been observed that the chemical properties can change over a much wider particle size range [21] for structure-sensitive reactions [22]. Furthermore, it is generally realized that particle size alone is usually not the only important parameter but that the influence of the support in terms of electronic, structural, chemical, and morphological particle properties can be essential. which demonstrates the importance of experimental attempts to control the support properties as well as the particle properties.     

连续玄武岩纤维增强9518G树脂复合材料性能的研究

研究了连续玄武岩纤维增强9518G树脂复合材料的耐热性、力学性能和湿热对力学性能的影响,结果表明连续玄武岩纤维增强9518G树脂复合材料的玻璃化转变温度为199.11℃,具有较好耐热性;力学性能良好,与E玻璃布复合材料的力学性能相当;煮沸150 h后材料的力学性能最小保持率和最大吸水率分别为67.1%和0.35%。     

Effect of annealing on the properties of poly(ether ether ketone)

The effect of annealing on the properties of poly(ether ether ketone) has been studied by changing annealing temperature and time. Crystallinity increases with annealing temperature, but is little affected by annealing time. Annealing time results suggest an improved crystalline perfection as annealing time increases. Higher crystallinity levels cause an increase in stress-related properties and a decrease in strain-related properties. Crystalline perfection, however, seems to produce an increase in stress-related properties, but it does not affect strain-related properties. Consideration has also been given to the effect of other possible parameters different from crystalline structure, such as crosslinking, on the variation of properties.     

硅烷偶联剂对电场下丁腈橡胶与铁硫化粘接性能的影响

采用电化学反应的作用方法,研究硅烷偶联剂对丁腈橡胶（NBR）与铁（Fe）的热硫化粘接性能的影响。通过对胶接破坏表面进行扫描电镜以及能谱观察分析,明晰了NBR-Fe粘接界面层的结构特征,并对影响粘合性能以及硫化胶物理机械性能的因素进行了研究分析。结果表明,施加的电场强度、导电填料种类以及硅烷偶联剂的用量对粘合性能作用明显;硅烷偶联剂用量变化不仅对粘合性能影响较大,而且影响NBR硫化胶的导电性及物理机械性能。     

Processability of polyethylene homopolymers and copolymers with respect to their molecular structure

The processability of commercial polyethylene homopolymers and copolymers, including both high and low density polyethylenes, was evaluated with respect to their molecular structure by measuring their melt rheological and thermodynamic properties. Short chain branching (SCB) mainly controls the density and thermodynamic properties, but it has little effect on the melt rheological properties. Long chain branching (LCB) has little effect on the density and the thennodynamic porperties, but it has drastic effects on the melt rheological properties. LCB increases the pseudoplasticity and the flow activation energy, reducing the viscosity in processing and thus improving the processability. Very small amounts of LCB in metallocene type low density polyethylenes very effectively reduce the viscosity and improve the flow stability in processing.     

C—3阳离子淀粉增强助剂在纸袋纸生产中的应用

C－3阳离子淀粉作为湿部添加增强助剂在纸袋纸生产中进行了应用。结果表明：它能有效提高纸袋纸物理性能和使用性能。文中还对助剂作用机理进行了探讨。     

环番的合成及其应用的研究进展

环番作为一种人工合成受体,具有多个活性位点和一定的空腔尺寸等诸多特性,因而具有分子识别、光学性质、催化活性和药物活性等诸多性质,在许多领域有着广泛的应用前景。总结了近年来环番的合成方法及各自的优缺点,并介绍了其性质、应用等方面的研究进展。     

Correlation of blown film optical properties with resin properties

The optical properties of conventional, free-radical polymerized low density polyethylene (LDPE) blown films are due essentially to surface irregularities that develop during fabrication. Past studies have shown that the extent to which these irregularities occur (and therefore optical properties) correlates well with the melt elasticity of the resin. Specifically, it has been shown that resins with higher melt elasticity result in films with poorer optical properties. However, it was recently reported that the optical properties of film blown from a Sci of three generically similar LDPE resins were found to correlate with the crystallization kinetics of the resins. Specifically, it was reported that the resins that exhibited faster crystallization rates produced films with better optical properties. This present work shows, however, that this apparent correlation is only coincidental. It has been shown that resins exhibiting faster crystallization rates do not necessarily result in films with better optical properties. On the other hand, it has been shown that resins with higher melt elasticity consistently result in films with poorer optical properties.     

高交联多相聚合物热收缩材料的研究

研究了高交联多相聚合物热收缩材料的配方及性能,讨论了配方及辐照剂量对材料的收缩性能和物理性能的影响,得出了高交联多相聚合物不仅有良好的物理性能,而且有理想的热收缩性能,可用作电缆附套材料。