Ultrahigh‐Conductivity Polymer Hydrogels with Arbitrary Structures

A poly(3,4‐ethylenedioxythiophene):poly(4‐styrenesulfonate) (PEDOT:PSS) hydrogel is prepared by thermal treatment of a commercial PEDOT:PSS (PH1000) suspension in 0.1 mol L^?1 sulfuric acid followed by partially removing its PSS component with concentrated sulfuric acid. This hydrogel has a low solid content of 4% (by weight) and an extremely high conductivity of 880 S m^?1. It can be fabricated into different shapes such as films, fibers, and columns with arbitrary sizes for practical applications. A highly conductive and mechanically strong porous fiber is prepared by drying PEDOT:PSS hydrogel fiber to fabricate a current‐collector‐free solid‐state flexible supercapacitor. This fiber supercapacitor delivers a volumetric capacitance as high as 202 F cm^?3 at 0.54 A cm^?3 with an extraordinary high‐rate performance. It also shows excellent electrochemical stability and high flexibility, promising for the application as wearable energy‐storage devices.     

Highly Conductive Ti3C2Tx MXene Hybrid Fibers for Flexible and Elastic Fiber‐Shaped Supercapacitors

Fiber‐shaped supercapacitors (FSCs) are promising energy storage solutions for powering miniaturized or wearable electronics. However, the scalable fabrication of fiber electrodes with high electrical conductivity and excellent energy storage performance for use in FSCs remains a challenge. Here, an easily scalable one‐step wet‐spinning approach is reported to fabricate highly conductive fibers using hybrid formulations of Ti₃C₂T_x MXene nanosheets and poly(3,4‐ethylenedioxythiophene):polystyrene sulfonate. This approach produces fibers with a record conductivity of ≈1489 S cm^?1, which is about five times higher than other reported Ti₃C₂T_x MXene‐based fibers (up to ≈290 S cm^?1). The hybrid fiber at ≈70 wt% MXene shows a high volumetric capacitance (≈614.5 F cm^?3 at 5 mV s^?1) and an excellent rate performance (≈375.2 F cm^?3 at 1000 mV s^?1). When assembled into a free‐standing FSC, the energy and power densities of the device reach ≈7.13 Wh cm^?3 and ≈8249 mW cm^?3, respectively. The excellent strength and flexibility of the hybrid fibers allow them to be wrapped on a silicone elastomer fiber to achieve an elastic FSC with 96% capacitance retention when cyclically stretched to 100% strain. This work demonstrates the potential of MXene‐based fiber electrodes and their scalable production for fiber‐based energy storage applications.     

An Investigation of PS‐b‐PEO Polymersomes for the Oral Treatment and Diagnosis of Hyperammonemia

Ammonia‐scavenging transmembrane pH‐gradient poly(styrene)‐b‐poly(ethylene oxide) polymersomes are investigated for the oral treatment and diagnosis of hyperammonemia, a condition associated with serious neurologic complications in patients with liver disease as well as in infants with urea cycle disorders. While these polymersomes are highly stable in simulated intestinal fluids at extreme bile salt and osmolality conditions, they unexpectedly do not reduce plasmatic ammonia levels in cirrhotic rats after oral dosing. Incubation in dietary fiber hydrogels mimicking the colonic environment suggests that the vesicles are probably destabilized during the dehydration of the intestinal chyme. The findings question the relevance of commonly used simulated intestinal fluids for studying vesicular stability. With the encapsulation of a pH‐sensitive dye in the polymersome core, the local pH increase upon ammonia influx could be exploited to assess the ammonia concentration in the plasma of healthy and cirrhotic rats as well as in other fluids. Due to its high sensitivity and selectivity, this polymersome‐based assay could prove useful in the monitoring of hyperammonemic patients and in other applications such as drug screening tests.     

General synthesis of high-performing magneto-conjugated polymer core–shell nanoparticles for multifunctional theranostics

Recently,increasing attention has been paid to magneto-conjugated polymer core-shell nanopartides (NPs) as theranostic platforms.However,the utilization of surfactants and extra oxidizing agents with potential toxidty in synthesis,the lack of general methods for the controlled synthesis of various kinds of magnetic NP (MNP)@conjugated polymer NPs,and the difficulty of obtaining balanced magneto-optical properties have greatly limited the applications of magneto-conjugated polymers in theranostics.We developed an in situ surface polymerization method free of extra surfactants and oxidizing agents to synthesize MNP@polypyrrole (PPy) NPs with balanced,prominent magneto-optical properties.MNP@PPy NPs with an adjustable size,different shapes,and a controlled shell thickness were obtained using this method.The method was extended to synthesize other MNP-conjugated polymer core-shell NPs,such as MNP@polyaniline and MNP@poly(3,4-ethylenedioxythiophene):poly(4-styrenesulfonate) (PEDOT:PSS).We discuss the formation mechanism of the proposed method according to our experimental results.Finally,using the optical and magnetic properties of the obtained MNP@PEDOT:PSS NPs,in vivo multimodal imaging-guided hyperthermia was induced in mice,achieving an excellent tumor-ablation therapeutic effect.Our work is beneficial for extending the application of MNP-conjugated polymer core-shell NPs in the biomedical field.     

Drift in the resistance of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) printed films during thermal cycling

We report on the investigation of the suitability of printed poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) films for temperature sensing devices. Gravure printing with the advantage of low cost production was used to prepare thin films of PEDOT:PSS on a flexible foil substrate. The electrical resistance was studied during thermal cycling and exposure to elevated constant temperatures. A drift of the resistance which depends on time, temperature and sample makes the usage as simple temperature sensors not possible. However, a closer look on the drift of relative resistances reveals that integrated temperature-time-profiles can be measured, which might be interesting in connection with monitoring of conditions of storing and transport of sensitive goods.     

聚苯硫醚的结构改性

为改善聚苯硫醚在某些方面的性质而进行的结构改性,为拓宽其应用起到了积极的作用。本文综述了聚苯硫醚酮、聚苯硫醚砜、聚苯硫醚酰胺和聚苯腈硫醚等几种结构改性的聚苯硫醚的最新研究进展。     

乙二醇掺杂对PVA/PEDOT∶PSS导电纤维结构和性能的影响

通过湿法纺丝制备聚乙烯醇(PVA)/聚3,4-乙撑二氧噻吩:聚对苯乙烯磺酸(PEDOT∶PSS)共混纤维,为改善共混纤维的导电性能,在PVA/PEDOT∶PSS共混纺丝液中加入乙二醇,制备出掺杂不同乙二醇含量的共混纤维。探究了乙二醇掺杂对PVA/PEDOT∶PSS共混纤维结构和性能的影响,并分析机理。采用红外光谱、原子力显微镜、显微共聚焦激光拉曼光谱仪,高阻计和电子单纤维强力仪对共混纤维的结构和性能进行测试表征。结果表明,随着乙二醇掺杂量的增加,共混纤维电导率逐渐增加,最高达到15.9 S/cm;拉曼光谱显示乙二醇掺杂使PEDOT主链发生苯醌转变,PEDOT的主要特征峰发生红移;红外光谱显示掺杂不改变共混纤维的化学组成;原子力显微镜结果显示随着乙二醇掺杂质量分数的提高,PEDOT与过剩PSS发生相分离,共混纤维表面粗糙度增加;此外,随着乙二醇掺杂质量分数的提高,共混纤维的拉伸强度逐渐升高,断裂伸长逐渐降低。     

聚酯纤维的附生结晶法改善纤维的表面浸润性

将聚对苯二甲酸乙二醇酯(PET)纤维置入过冷态的聚乙二醇(PEG)和聚己二酸丁二酯(PBA)熔体,制备了PET纤维/PEG基体和PET纤维/PBA基体复合体系。使用偏光显微镜和原子力显微镜研究了这两种异质复合体系的界面结晶形态,利用接触角测量仪测量了附生结晶法改性前后PET纤维织物的接触角。结果表明,纤维置入温度和结晶等条件决定附生体系的横穿晶体形态结构,选取合适的树脂并采用附生结晶的方法可明显改善PET纤维织物的表面浸润性,并有望改善PET纤维增强复合材料内部的界面结构。