基于18-冠-6的铅离子检测技术研究进展

铅是一种对环境和人体有严重危害的重金属污染物,研究铅离子（Pb²⁺）检测技术具有重要的实用意义。近年来,利用18-冠-6的Pb²⁺特异识别性能,研究者们设计构建了一系列智能高分子材料系统,为Pb²⁺检测提供了新的策略和途径。本文综述了近年来基于18-冠-6的Pb²⁺检测技术研究进展,重点介绍了基于智能膜、智能光学元件、智能微芯片、智能微胶囊等智能材料系统的Pb²⁺检测技术,讨论了这些Pb²⁺检测技术在实际应用中需要重点关注和解决的问题,以期为这类基于18-冠-6的Pb²⁺检测技术的进一步开发和应用提供参考。     

智能高分子材料的应用现状及研究进展

智能高分子材料是材料研究的新领域,本文介绍了智能高分子材料的分类及研究现状。主要介绍了智能高分子凝胶、刺激响应性药物释放体系、智能膜材及具有表面智能的生物材料。     

智能高分子材料

智能高分子材料是一种刺激－响应型聚合物或称环境敏感聚合物,已成为功能高分子研究的前沿领域,本文对一些有代表性的智能高分子材料的发展,机理及应用作了简单的综述。     

Pb~(2+)识别响应型智能高分子功能材料的研究进展

发酵生物甲烷的菌群可以吸附Pb2+等重金属而在沼液和沼渣中富集;因此,在生物甲烷系统研究过程中,Pb2+等重金属离子的检测和处理是沼液和沼渣处理的关键问题之一。18-冠-6具有选择性络合Pb2+的能力,研究者们将18-冠-6的Pb2+识别特性与聚N-异丙基丙烯酰胺的相变行为特性相结合制备了一系列Pb2+识别响应型智能高分子功能材料。本文综述了基于18-冠-6和聚N-异丙基丙烯酰胺的离子识别响应型智能高分子材料在检测和去除Pb2+等方面的研究进展。     

智能膜材料研究新进展

能感知和响应外界物理和化学信号的智能膜是仿生功能膜领域的重要技术进展之一,已成为国际上膜科学领域研究的新热点。本文综述了智能膜材料方面的研究新进展,重点介绍了温度响应型、pH响应型、光响应型、葡萄糖浓度响应型以及分子识别响应型等环境刺激响应型智能膜的研究进展。     

智能微流控检测芯片的构建及其Pb2+检测性能

通过将具有Pb²⁺响应性的聚（N-异丙基丙烯酰胺-共聚-苯并-18冠-6丙烯酰胺）智能微凝胶与H型微通道相结合，构建了一种能便捷、灵敏、可视化检测水溶液中Pb²⁺浓度的新型智能Pb²⁺检测微流控芯片。该微流控检测芯片主要由软光刻技术构建，并结合紫外光照聚合在H型微通道中原位构建智能微凝胶。基于该微凝胶的Pb²⁺响应性体积相变和H型微通道中的流体流动，该微流控检测芯片能将Pb²⁺浓度信号有效转换为易于检测读取的、可视化的H型微通道中指示液覆盖的指示柱数目的变化信号。通过光学显微镜便捷观察测量指示液覆盖的指示柱数目的变化，实现了对水溶液中痕量Pb²⁺浓度的超灵敏定量检测。该微流控检测芯片为水环境中的痕量Pb²⁺浓度的便捷、灵敏、可视化检测提供了新策略。     

Pb2+识别响应型智能高分子功能材料的研究进展

发酵生物甲烷的菌群可以吸附Pb²⁺等重金属而在沼液和沼渣中富集;因此,在生物甲烷系统研究过程中,Pb²⁺等重金属离子的检测和处理是沼液和沼渣处理的关键问题之一。18-冠-6具有选择性络合Pb²⁺的能力,研究者们将18-冠-6的Pb²⁺识别特性与聚N-异丙基丙烯酰胺的相变行为特性相结合制备了一系列Pb²⁺识别响应型智能高分子功能材料。本文综述了基于18-冠-6和聚N-异丙基丙烯酰胺的离子识别响应型智能高分子材料在检测和去除Pb²⁺等方面的研究进展。     

智能水凝胶研究进展

作为一种智能高分子材料,智能水凝胶具有良好的应用前景,本文重点介绍了刺激响应型智能水凝胶、高强智能水凝胶及自愈合智能水凝胶的结构特征、性能特点及研究现状,并对智能水凝胶的未来发展进行了展望。     

Hg2+响应型智能凝胶检测光栅的构建与性能

高灵敏度、高选择性检测水中Hg²⁺对于人类健康和环境生态可持续发展具有重要意义。本文基于硫脲基团与Hg²⁺的选择性强螯合作用来调控光栅微结构和实现信号转化，构建了用于高灵敏、高选择性便捷检测水中痕量Hg²⁺的智能凝胶光栅。该凝胶光栅的交联高分子网络结构中具有硫脲基团，可高选择性地与Hg²⁺进行强螯合，从而诱导光栅起伏高度发生变化，实现由水中Hg²⁺浓度到衍射光强度的信号变化。通过利用该智能凝胶光栅构建光学检测系统来便捷检测衍射光强度变化，可高灵敏、高选择性地检测水中浓度低至10-9mol/L的Hg²⁺。相关工作为面向水中痕量Hg²⁺的便捷灵敏检测技术的开发提供了新途径。     

基于激励响应的输油管道泄漏检测技术研究

基于激励响应法,假定管道末端阀门快速部分关闭,求出了出管道末端处的瞬态压力响应.根据定义的负压波反射系数关系式和瞬态压力响应图,应用行波计算方法得到泄漏点的全部信息(泄漏流量和位置).本文对一个实例进行了计算,并应用小波方法对瞬态压力信号的奇异点进行识别,准确判断出泄漏点位置,两者表明基于激励响应的输油管道泄漏检测技术是充分有效的一种新方法.     

环境刺激响应型高强度智能水凝胶研究进展

环境刺激响应型智能水凝胶能够对外界环境因素的变化产生显著的体积或其他特性的变化,且其性质和结构与生物组织类似,有望应用于人工软骨、人造肌肉、组织工程等领域,引起了广泛的关注。提高环境刺激响应型智能水凝胶的力学性能是智能水凝胶应用研究的重要方向之一。本文综述了近年来环境刺激响应型高强度智能水凝胶的研究进展,简述了高强度智能水凝胶的网络结构的构建策略与方法,分析了其具备高力学性能的机理,重点介绍了4类不同结构的高强度智能水凝胶,即超低交联结构水凝胶、纳米颗粒复合水凝胶、拓扑结构水凝胶以及双网络结构水凝胶,最后讨论了环境刺激响应型高强度智能水凝胶在面向应用的研究过程中仍然需要解决的关键科学问题,如智能水凝胶的环境刺激与力学性能的博弈效应以及响应环境刺激前后的力学性能差异等。     

Preparation and characterization of novel pH‐sensitive binary grafted polymeric blends of gelatin and poly(vinyl alcohol): Water sorption and blood compatibility study

In this study, we attempted the synthesis and characterization of novel biocompatible hydrogels of binary polymeric blends of crosslinked poly(acrylic acid) grafted onto poly(vinyl alcohol) and gelatin by a redox polymerization technique. The end polymer was characterized by IR spectral analysis, differential scanning calorimetry measurements, and scanning electron microscopy. The prepared smart, environment‐responsive hydrogels, containing polyelectrolyte domains, were assessed for their water sorption potential under various experimental conditions and were further used to evaluate important network parameters such as the crosslink density, number of elastically effective chains, and molecular mass between crosslinks. The diffusion mechanism of the solvent–polymer interaction was also analyzed to predict the behavior of continuously relaxing chains containing several carboxylate ions. The blood compatibility of premeditated hydrogels was also judged by in vitro methods such as protein adsorption, blood clot formation, and hemolysis percentage assay measurement. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 100: 599–617, 2006     

A novel approach for evaluation of polymeric interface materials for chemical sensors using alternate indirect methods

The heart of a chemical sensor based on bulk or surface acoustic wave devices is a polymer‐coated piezoelectric substrate that selectively sorbs and concentrates the target analyte vapors. The development of such sensors often necessitates the screening and evaluation of suitable polymeric interface materials meeting the specified sensitivity and selectivity toward the analytes of interest. The magnitude and dynamics of sorption–desorption of the vapors in the polymer and the extent of polymer–vapor interactions largely determine the performance of a sensor. The standard protocol used for the purpose is rather tedious, involving the generation and calibration of individual analyte vapors, with stringent control on temperature, humidity, and test parameters. This article outlines four different alternative techniques based on mass uptake of the analyte vapors, on its partitioning in polymers, or both, which in combination can determine the characteristics of an interface material used for coating a piezoelectric substrate in acoustic wave‐based chemical sensors. These methods were applied to poly(ethylene maleate), a representative interface material. The analytes ranged from volatile organic chemicals to sarin—a chemical warfare agent—and its simulant, dimethyl methylphosphonate. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 91: 3428–3432, 2004     

Hydration of phosphorylcholine groups attached to highly swollen polymer hydrogels studied by thermal analysis

Hydration of polymer chains plays a key role for determining the extent of protein adsorption on polymeric materials. Here we investigated the hydration of poly(2-methacryloyloxyethyl phosphorylcholine (MPC)) chains, which resist protein adsorption and following cell adhesion effectively. The hydration was compared with that of poly(methoxy oligo(ethylene glycol)-monomethacrylate (Me(EG)_nMA)) chains, which also have hydrophilic units. The poly(MPC) and poly(Me(EG)_nMA) hydrogels with equilibrium water contents (EWCs) in the range from 86 to 97 wt% were prepared. By differential scanning calorimetric measurements, water in both the hydrogels was classified into two states: freezable and nonfreezable water. The poly(MPC) hydrogels had larger nonfreezable water than the poly(Me(EG)_nMA) hydrogels even when their EWCs were similar, which indicated the higher hydrating ability of poly(MPC) chains. We suggested that the difference in the amount of nonfreezable water around polymer chains may influence the degree of protein adsorption resistance after contact with body fluid for a long period.     

Models of the Conformational Behavior of Polymers in Mixed Solvents

Theoretical models of the conformational behavior of flexible polymer chains in mixed solvents enunciated in the world literature during the last decade are critically reviewed. Models describing different mechanisms of coil-to-globule transitions in a good solvent induced by cosolvent addition are highlighted. Special attention is given to the analysis of theoretical approaches to describing the collapse of polymer chains in binary mixtures of good solvents. The review addresses researchers engaged in polymer physics and chemistry and materials scientists involved in the design of smart polymers.     

Synthesis of a novel fluorene-based conjugated polymer with pendent bulky caged adamantane moieties and its application in the detection of trace DNT explosives

A novel fluorene-based conjugated polymer with phenylene spacers and steric bulky adamantane moieties in side chains has been synthesized by palladium-catalyzed Suzuki coupling reactions. This design strategy offers several advantages for the detection of trace 2,4-dinitrotoluene (DNT) vapor. The incorporation of the two groups into polymer side chains could retain an effective conjugation length and prevent the π-stacking of polymer chains. The detection of DNT vapor indicated that the polymer displayed higher fluorescence quenching sensitivity toward the explosives in films compared to reference polymers. The fluorescence quenching efficiency of the fluorescent polymer achieved 33.3% in 10 s and 71.1% in 60 s. The pathways or cavities generated by the two spacers are beneficial for the rapid diffusion of explosive vapor into the film interiors and increase the fluorescence quenching efficiency of the film.     

Photo-induced living/controlled surface radical grafting polymerization and its application in fabricating 3-D micro-architectures on the surface of flat/particulate organic substrates

This feature article covers the fundamental chemistry and applications of photo-induced living surface grafting polymerization. The mechanism of activation of inert alkyl C-H bonds of polymer substrates, the structures of the active free radical and reversible dormant species, the modes of the grafting chain growth (including linear, branched and cross-linked variants), and the role of spatial effect are discussed. Two technologies, i.e., 1-step and 2-step processes, their features and applications in fabricating polymer brushes with precisely controlled patterns, desired functions, branched and block grafting chains on planar substrates, and polymer lamination are presented. The fabrication of 3-dimensional covalently bonded polymer particles, such as nano-sized polymer particle monolayers (with uniform and bimodal distributions), discrete solid and hollow polymer particles of micrometer size, and multilayer polymer particles on polymeric substrates are also introduced. In the last part, the application of photo-induced living surface grafting polymerization in non-planar surface modifications, such as the preparation of core-shell polymer particles, Janus particles and cross-linked hydrogels with hairy polymer chains is summarized.     

An analytical investigation on the effect of porous conductive cellulose acetate composite morphology on the detection of organic compounds

A smart porous conductive polymer composite (CPC) consisting of cellulose acetate as matrix and multiwalled carbon nanotubes as conductive filler was prepared to detect a set of lung cancer biomarkers. The solvent evaporation-induced phase separation was used to introduce porosity into the conductive composite. The prepared sensitive layers exhibited high response intensity, low response time, and good recovery behavior toward the mentioned analytes. A thorough investigation was conducted on the morphology, response behavior, sensitivity, and selectivity of the prepared CPC transducer. The selectivity of responses was considered based on the thermodynamic and kinetic characteristics of polymer and analytes such as Hansen solubility parameters, Flory-Huggins interaction parameter, and diffusion coefficient of analytes into the polymer membrane. Moreover, the microstructure of porous layers was characterized by using SEM, contact angle, and BET. The volume porosity and specific surface area of the sensitive layers were increased by the introduction of porosity into the polymer composite, causing the improvement of sensing parameters. The obtained responses further confirmed the promising potential of the prepared porous CPC structure, for the detection of lung cancer biomarkers, from exhaled breath as an inexpensive, repeatable, accurate, and noninvasive method.