导电水凝胶的制备

作为一种新型的功能材料,导电水凝胶已经引起广泛的关注。本文根据目前的研究现状,将导电水凝胶大致分为聚电解质导电水凝胶,酸掺杂导电水凝胶,无机物添加导电水凝胶以及导电高分子基导电水凝胶等几大类,并综述了它们的制备方法。另外,由于大分子体系的导电高分子和水凝胶都有着独特和重要的性能,这使得它们具有广阔的应用价值。所以,本文在综述导电水凝胶制备进展的同时着重综述了导电高分子基导电水凝胶的制备进展。     

聚苯胺/尼龙-11共混导电纤维的形态

七十年代后期由于聚乙炔的发现而迅速产生了以共轭高分子为基础的导电高分子学科 ,聚苯胺 (ＰＡｎ)也于 1 984年被ＭａｃＤｉａｒｍｉｄ等重新开发[1 ] .相对于其它共轭高分子而言 ,聚苯胺原料易得、合成简单 ,具有较高的电导率和潜在的溶液、熔融加工可能性 ,同时还有良好的环境稳定性[2～ 5] .以导电高分子为导电剂的导电纤维有其独特的优点 .与颗粒状填料为导电剂不同 ,导电高分子在纺丝拉伸过程中会产生大分子取向 ,形成更多的导电通道 ,纤维的导电性能得到提高 ,导电阈值较小 .因此 ,研究导电组分在材料中的形态分布对研制导电共混复合…     

微孔发泡聚合物基导电复合材料的研究进展

概述了用超临界流体作为物理发泡剂对聚合物基导电复合材料进行微孔发泡的基本原理,总结了聚合物基导电复合材料及其微发泡复合材料的几种导电机理,简要介绍了近年来微孔发泡聚合物基导电复合材料电学性能的研究现状。并从微发泡聚合物基导电复合材料的基体特性、所使用的导电填料类型、导电填料的含量、填料在基体中的分散方法及微发泡复合材料的泡孔形态等几个方面,分析了影响微孔发泡聚合物基导电复合材料电学性能的主要因素,并展望了新型微孔发泡聚合物基导电复合材料的研究和发展趋势。     

高分子导电水凝胶的制备及在柔性可穿戴电子设备中的应用

水凝胶是具有高含水量、可变形性和良好生物相容性的材料,其中导电水凝胶具有良好的导电性、可调节的机械性及自黏附性等特征,逐渐成为制备柔性可穿戴电子设备的最佳候选材料。近年来,具有生物相容性、机械柔韧性和抗疲劳性的导电水凝胶得到广泛研究,能够实现多种生理信号和物理信号的监测及传输,促进了柔性可穿戴电子设备的发展。柔性可穿戴电子设备逐渐成为人机交互技术和人工智能领域的主要研究方向。导电水凝胶通过使用导电聚合物、导电填料、自由离子及其混合物来合成,根据导电机理,所制备的导电水凝胶可分为电子导电水凝胶、离子导电水凝胶和混合电子-离子导电水凝胶。本文讨论了导电水凝胶的制备方法,总结了导电水凝胶在可拉伸性、导电性、生物相容性和自修复性等功能方面的研究进展及其在柔性可穿戴电子设备中的应用,期望导电水凝胶可以取得更好的发展。     

自组装聚合法制备木质素磺酸/聚吡咯柔性导电纸

以造纸废液中的木质素为分散剂和掺杂剂,采用自组装聚合法制备了具有高电导率、负载可控、高稳定性且抗张强度保持较好的木质素磺酸/聚吡咯柔性导电纸.采用红外光谱、四探针、扫描电镜、抗张强度和电化学等手段对导电纸的性能进行了表征,并研究了掺杂剂类型和组装层数对导电纸导电性能和力学性能的影响.结果表明,随着组装层数的增加,聚吡咯导电纸的负载量、电导率及导电稳定性均有提高.与原位聚合法相比,自组装聚合法制备的导电纸的性能更优.木质素磺酸在聚吡咯导电纸体系不仅可以起到掺杂和分散的作用,其对导电纸综合性能的增强效果优于盐酸和聚苯乙烯磺酸.由于木质素磺酸具有三维网络空间结构及其与纤维之间具有较强的氢键作用力,显著提高了导电纸的抗张强度及弯曲状态下的导电稳定性,其抗氧化和防水性还可以提高导电纸在空气和湿气中的导电稳定性.     

CuS表面改性聚丙烯腈纤维的结构及导电机理的研究

研究了用一步反应法制备的CuS表面改性的聚丙烯腈导电纤维的微观结构、导电性和温度的变化规律及其导电机理,观察了CuS在纤维表面上的结晶态及晶型变化现象,证实了该导电纤维的以电子导电为主的导电机理。     

无水硫酸能否导电

长期以来,人们都认为无水硫酸不能导电,目前中学化学课本中也一直认为无水硫酸不能导电。电解质能够导电要具备导电的外因,就是说,电解质要受极性水分子的作用或热作用,才能电离产生自由移动的离子,有自由移动的离子存在,电解质溶液才能导电。电解质溶液的导电是离子导电。硫酸是电解质,无水硫酸没有水分子的作用,不能电离产生自由移动的离子,因而,一直认为无水硫酸不能导电。笔者在做电解质的导电性实验时,发现:把两根碳棒插入试验的物质中,线路中串连小电珠,接通直流电源。硫酸溶液导电装置中的小电珠发亮,硫酸溶液能导电。试验浓硫酸(比重1.84,98%),小电珠发亮,浓硫酸能导     

LaxBa1—xCoO3系导电陶瓷导电性研究

对ＬａｘＢａ１－ｘＣｏＯ导电陶瓷的导电性及其导电机制进行了研究，在ｘ＝０．５ｍｏｌ处，导电陶瓷具有金属态导是性，在Ｌａ０．５Ｂａ０．５ＣｏＯ３陶瓷中，存在着氧缺位和导电电子，并且此种导电陶瓷具有较高的电子和氧离子混合导电特性。     

电磁屏蔽导电涂料

综述了电磁屏蔽用掺合型导电涂料的导电机理以及组成,展望了导电涂料的发展。     

聚乙烯/炭黑复合材料导电体系的结构形态

将导电填料（例如炭黑）加入绝缘的聚合物基体即得到导电复合材料,两组混全物的电阻率随导电填料体积分数的变化而改变,电阻率与导电填料体积分数的关系称为渗流曲线,可分为三个主要区域：低导电填料含量区域,复合材料的电阻率很大,聚合物的电阻率占主导;渗流区域,导电填料含量少量的增加会引起复合材料电阻率很大的提高;高导电填料区域,复合材料电阻率很大的提高;高导电填料区域,复合材料电阻率主要由导电填料的电阻率决定,对于导电复合材料已有大量的实验和理论工作来解释导电复合材料已有大量的实验和理论工作来解释导电填料含量和复合材料各组分的形貌对电性能的影响,其中有效介质普适方程（GEM方程）已经对大量的渗流曲线进行了精确的拟合。聚乙烯／炭黑复合材料中由于炭黑的大量分布很难观测其微观形貌,本文对不同辐照交联程度和不同环境温度下聚乙烯／炭黑复合材料的渗流曲线进行分析,试图找出GEM方程各参数与复合材料各组分形貌的关系,为导电复合材料的设计和制备提供理论基础。     

A confirmatory method for the simultaneous extraction,separation, identification and quantification of Tetracycline,Sulphonamide, Trimethoprim and Dapsone residues in muscle by ultra-high-performance liquid chromatography–tandem mass spectrometry according to Commission Decision 2002/657/EC

A rapid confirmatory multi-residue method for the analysis of tetracyclines, sulphonamides, trimethoprim and dapsone by UPLC-MS/MS is described. The method is able to quantify and confirm the following 19 compounds, oxytetracycline, tetracycline, chlortetracycline, doxycycline, sulfadiazine, sulfathiazole, sulfapyridine, trimethoprim, sulfamerazine, sulfamethizole, sulfamethazine, sulfamethoxypyridazine, sulfamonomethoxine, sulfachlorpyridazine, dapsone, sulfamethoxazole, sulfisoxazole, sulfaquinoxaline and sulfadimethoxine. Samples are extracted with 0.1 M EDTA and acetonitrile, which is then evaporated under a stream of nitrogen and reconstituted in water. Following centrifugation and filtering, an aliquot is analysed by UPLC-MS/MS using positive electrospray ionisation and multiple reaction monitoring. The method is deemed rapid as all analytes are extracted by a single extraction technique, with no solid-phase extraction clean up required. Validation is according to Commission Decision 2002/657/EC and was carried out for bovine, porcine, ovine and poultry species. Specificity, recovery, repeatability, reproducibility, CCα and CCβ data is presented.     

伊敏褐煤中微量元素的地球化学特征及其无机-有机亲和性分析

采用脱矿物质、提取腐殖酸等方法结合ICP-MS对伊敏15_上、16_下煤中的32种微量元素的含量及其赋存特征进行了分析。与地壳克拉克值及中国侏罗-白垩纪煤和世界褐煤中微量元素含量相比,伊敏褐煤中微量元素没有明显富集。脱矿物质处理后,Ni明显富集,As略比原煤高,其他微量元素都低于原煤。原煤提取腐殖酸和脱矿物煤提取腐殖酸中Ni、Mo、Cd、Sn、W明显富集,这表明Ni、Mo、Cd、Sn、W和腐殖酸形成了稳定的有机态化合物。原煤提取腐殖酸残煤和脱矿物煤提取腐殖酸残煤中V、Ni、As富集,表明V、Ni、As与煤的大分子结构形成了稳定的有机态化合物。根据微量元素和灰分的相关性系数,把微量元素分为以下几类:无机富集元素Cr、U;亲无机元素Cu、Cd、In、Sn、Ga、Y、Zr、Hf、Bi、Th;偏无机元素Be、Sc、Rb、Sr、Nb、Cs、Ta、Pb;偏有机元素V、As、Tl、Ba、Se;亲有机元素Li、Co、W;有机富集元素Ni、Zn、Mo、Sb。     

Simultaneous Determination of Cadmium,Mercury, Lead,Arsenic, Copper,and Zinc in Human Breast Milk by ICP‐MS/Microwave Digestion

Abstract

An analytical method using microwave digestion and inductively coupled argon plasma-mass spectrometry (ICP‐MS) analysis was developed for the measurement of Cd, Hg, Pb, As, Cu, and Zn in human breast milk. We applied external calibration, internal calibration, and standard addition for reference material and pooled milk analysis. Method performances were defined in terms of detection limits, accuracy, and precision. Accuracy varied between 93% and 105% and precision between 3% and 8%. External calibration and background interferences were checked through a calibrator addition procedure. Our method has shown high accuracy, precision, and sensitivity, as well as linearity within a wide range of values. Our methodology, developed by treatment of reference material and pooled milk samples, was applied for determination of Cu, Zn, As, Cd, Hg, and Pb in 120 human breast milk samples.     

Organic heterocyclic-based colorimetric and fluorimetric chemosensors for the detection of different analytes: a review (from 2015 to 2022)

Heterocyclic organic compounds, also called heterocycles, are any major class of organic compounds having at least one atom other than carbon in the ring. Due to their excellent electronic and structural features, these compounds exhibit a wide range of biological and nonbiological applications. Among these, indole, benzimidazole, benzothiazole, and benzoxazole are versatile organic heterocyclic compounds widely used in different fields. They show a wide range of applications in polymer, coordination chemistry, pharmacy, dyes, food packages, medicine, and industries. These compounds contain heteroatoms like S-, N-, and O-, through which they interact with metal ions, anions, and neutral species, giving measurable analytical signals that can be used as fluorimetric and colorimetric chemosensors for detecting different analytes in biological, agricultural and environmental samples. This review summarizes indole, benzimidazole, benzothiazole, and benzoxazole-based fluorimetric and colorimetric chemosensors for detecting metal ions, anions, and neutral species. Furthermore, the recognition mechanisms have been discussed in detail, which could help researchers to design efficient, highly selective, and sensitive chemosensors to recognize and determine heavy metal cations.     

Tools and resources for metabolomics research community: A 2017–2018 update

The scale at which MS‐ and NMR‐based platforms generate metabolomics datasets for both research, core, and clinical facilities to address challenges in the various sciences—ranging from biomedical to agricultural—is underappreciated. Thus, metabolomics efforts spanning microbe, environment, plant, animal, and human systems have led to continual and concomitant growth of in silico resources for analysis and interpretation of these datasets. These software tools, resources, and databases drive the field forward to help keep pace with the amount of data being generated and the sophisticated and diverse analytical platforms that are being used to generate these metabolomics datasets. To address challenges in data preprocessing, metabolite annotation, statistical interrogation, visualization, interpretation, and integration, the metabolomics and informatics research community comes up with hundreds of tools every year. The purpose of the present review is to provide a brief and useful summary of more than 95 metabolomics tools, software, and databases that were either developed or significantly improved during 2017–2018. We hope to see this review help readers, developers, and researchers to obtain informed access to these thorough lists of resources for further improvisation, implementation, and application in due course of time.     

Green synthesis of biogenic metal nanoparticles by terrestrial and aquatic phototrophic and heterotrophic eukaryotes and biocompatible agents

The size, shape and controlled dispersity of nanoparticles play a vital role in determining the physical, chemical, optical and electronic properties attributing its applications in environmental, biotechnological and biomedical fields. Various physical and chemical processes have been exploited in the synthesis of several inorganic metal nanoparticles by wet and dry approaches viz., ultraviolet irradiation, aerosol technologies, lithography, laser ablation, ultrasonic fields, and photochemical reduction techniques. However, these methodologies remain expensive and involve the use of hazardous chemicals. Therefore, there is a growing concern for the development of alternative environment friendly and sustainable methods. Increasing awareness towards green chemistry and biological processes has led to a necessity to develop simple, cost-effective and eco-friendly procedures. Phototrophic eukaryotes such as plants, algae, and diatoms and heterotrophic human cell lines and some biocompatible agents have been reported to synthesize greener nanoparticles like cobalt, copper, silver, gold, bimetallic alloys, silica, palladium, platinum, iridium, magnetite and quantum dots. Owing to the diversity and sustainability, the use of phototrophic and heterotrophic eukaryotes and biocompatible agents for the synthesis of nanomaterials is yet to be fully explored. This review describes the recent advancements in the green synthesis and applications of metal nanoparticles by plants, aquatic autotrophs, human cell lines, biocompatible agents and biomolecules.     

Indole-Containing Natural Products 2019–2022: Isolations,Reappraisals, Syntheses,and Biological Activities

Indole alkaloids represent a large subset of natural products, with more than 4100 known compounds. The majority of these alkaloids are biologically active, with some exhibiting excellent antitumor, antibacterial, antiviral, antifungal, and antiplasmodial activities. Consequently, the natural products of this class have attracted considerable attention as potential leads for novel therapeutics and are routinely isolated, characterized, and profiled to gauge their biological potential. However, data on indole alkaloids, their various structures, and bioactivities are complex due to their diverse sources, such as plants, fungi, bacteria, sponges, tunicates, and bryozoans; thus, isolation methods produce an incredible trove of information. The situation is exacerbated when synthetic derivatives, as well as their structures, bioactivities, and synthetic schemes, are considered. Thus, to make such data comprehensive and inform researchers about the current field’s state, this review summarizes recent reports on novel indole alkaloids. It deals with the isolation and characterization of 250 novel indole alkaloids, a reappraisal of previously reported compounds, and total syntheses of indole alkaloids. In addition, several syntheses and semi-syntheses of indole-containing derivatives and their bioactivities are reported between January 2019 and July 2022.     

A review on elastic graphene aerogels: Design,preparation, and applications

Graphene aerogels with unique properties, such as ultralow density, super-elasticity, high specific surface area, and excellent thermal stability, have undergone great progress in the past decades. Especially, super-elastic graphene aerogels provide a highly attention-catching platform for developing advanced energy devices, pressure sensors, contaminates adsorbents, and electromagnetic wave shielding and absorption materials, and so forth. In this review, we begin with the introduction and discussion of various fabrication techniques and compare their advantages and disadvantages, focusing on the template-free assembly process and template-assisted assembly process. Then, we summarize the factors influencing the compressibility and elasticity of graphene aerogels, including intrinsic properties of building blocks, constituent materials, and structure design, and their wide applications. At the end, we discuss the current challenges and future prospects of this field.     

Antihypertensive activity of indole and indazole analogues: A review

Heterocyclic compounds occupy an important position in chemistry because of their wide range of uses in drug design, photochemistry, agrochemicals, and other fields. Indole and indazole scaffolds are available from natural and synthetic sources, and molecules containing these scaffolds have been shown to have various biological effects, including anti-inflammatory, antibacterial, antiviral, antifungal, analgesic, anticancer, antioxidant, anticonvulsant, antidepressant, and antihypertensive activities. Indole and indazole molecules bind to receptors with high affinity, and thus are useful for the study of bioactive compounds involved in multiple pathways. In this review, we highlight the antihypertensive activity and the mechanisms of action of indole and indazole derivatives. In addition, structure–activity relationship studies of the antihypertensive effect are presented.     

Review: Recent Developments in Enzyme-Based Biosensors for Biomedical Analysis

The need for simple, rapid, cost-effective, and portable screening methods has boosted the development of practical biosensors with applications in clinical monitoring, and diagnosis of disease. Compared with traditional analytical methods, enzyme-based bioanalytical devices have several distinct advantages such as high sensitivity and specificity, portability, cost-effectiveness, and the possibilities for miniaturization and mass production. Additionally, they can be developed for point-of-care diagnostic testing. This paper reviews recent advances in the development of enzyme biosensors, design characteristics, performances, and applications with a focus on electrochemical and optical sensors. Recent emerging technologies and innovative biosensing designs, such as nanosensors, paper based-sensors, lab-on-a-chip, biochips, and microfluidic devices are discussed. Specific applications in bioanalysis, clinical diagnosis, and pharmacology are discussed.