Recent Progress in the Development of Conducting Polymer‐Based Nanocomposites for Electrochemical Biosensors Applications: A Mini‐Review

Among various immobilizing materials, conductive polymer‐based nanocomposites have been widely applied to fabricate the biosensors, because of their outstanding properties such as excellent electrocatalytic activity, high conductivity, and strong adsorptive ability compared to conventional conductive polymers. Electrochemical biosensors have played a significant role in delivering the diagnostic information and therapy monitoring in a rapid, simple, and low cost portable device. This paper reviews the recent developments in conductive polymer‐based nanocomposites and their applications in electrochemical biosensors. The article starts with a general and concise comparison between the properties of conducting polymers and conducting polymer nanocomposites. Next, the current applications of conductive polymer‐based nanocomposites of some important conducting polymers such as PANI, PPy, and PEDOT in enzymatic and nonenzymatic electrochemical biosensors are overviewed. This review article covers an 8‐year period beginning in 2010.     

Cellulose as matrix component of conducting films

Conjugated polymers gain growing importance as conductive materials in industrial applications in various fields of electronic devices. Cellulose with its extraordinary supramolecular structure and material properties can help to awake the possibilities for conducting polymers in interplay of the two materials. The ability of additional derivatization, the stiff and oriented molecular structure and the inherent strength, stability and film-forming properties give cellulose a complementary role to the brittle conjugated polymers, cellulose imparting the features of a stable and robust carrier component. To go forward this way, making a composite out of cellulose and conducting polymers is a prerequisite. Different strategies to form composite materials of non-derivatized cellulose and conductive organic polymers were tested. Significant differences between various mixing strategies as well as between the conducting polymers polyaniline (PAni), polypyrrole (PPy), and polythiophen (PTh) were observed. In situ synthesis of the conducting polymers in cellulose solutions and microcellulose dispersions as well as blending of pre-synthesized conducting polymers in these cellulose systems were tested. Unexpectedly, not homogenous mixtures showed best results in respect to film formation and conductivity, but composites formed by heterogeneous mixtures of the conducting polymers within a cellulose gel. Best results were obtained with finely dispersed PAni. The results support development studies towards circuitry and photo-current systems based on cellulose carriers.     

液晶金属配位聚合物的合成及性能

基于国内外最新研究文献 ,系统论述了近年来液晶金属配位聚合物的合成方法、液晶行为及应用前景。指出液晶金属配位聚合物的合成方法可归纳为直接配位法、单体配位法、交联配位法和聚合物反应法四种。液晶金属配位聚合物一般呈现热致液晶行为 ,显示稳定的向列液晶相或近晶液晶相。有些金属配位聚合物还呈现互变性近晶态或单变液晶性。液晶金属配位聚合物具有金属的特殊性质 ,是一种新型高性能磁导、电导和光导材料 ,可望应用于液晶显示材料、磁性信息储存薄膜材料、润滑剂和各向异性催化剂等。     

Electrorheological response of polyaniline and its hybrids

One of the remarkable applications of conducting polymers is as an electrorheological (ER) fluid which is a smart suspension of polarisable particles dispersed in an insulating liquid with the capacity to effect a phase transition from a liquid-like to a solid-like state. Polyaniline (PANI) and its hybrids with inorganics or other polymers are active candidates for ER materials due to their various advantages, e.g., easy synthesis, controllable conductivity, and less friction than pure inorganics. In this short review, we review recent progress in the synthesis of semi-conducting PANI and its hybrids with diverse morphologies and their ER performance measured by a rotational rheometer using the applied electric field strength. The dielectric properties of these ER fluids, as an important analytical method for their ER performance, are also discussed.     

Multifunctional micro-/nanoscaled structures based on polyaniline: an overview of modern emerging devices

With the advent of Materials Science-based technological advances, the fabrication of materials that could simultaneously exhibit both mechanical and processing properties of polymers and unique electrical characteristics of metals is a requirement with prior mandate. With the development of conducting polymers, great opportunities have been established, and novel devices with the significant features have emerged. Polyaniline (PANI) and its derivatives have attracted immense attention because of their fascinating properties, including high conductivity, inexpensiveness of starting material, unique redox behavior, facile synthesis, tunable properties, appropriate electrochemical and environmental stability, and strong bimolecular interactions. Nanostructures based on PANI have shown improved functionalities in various applications. In this article, different synthesis strategies such as interfacial polymerization, microwave-assisted polymerization, and sonochemical polymerization among others have been summarized. Besides, PANI-based nanocomposites and their various industrial, as well as biomedical applications in supercapacitors, batteries, gas vapor sensors, printable electronics, electrochromics, actuators, electrostatic dissipation, electromagnetic interference shielding, corrosion protection, filtration membranes, microbial fuel cell, biosensors, tissue engineering, and drug delivery systems, have been discussed in detail.     

Applications of Inorganic Polymeric Materials II: Polysilanes

Polysilanes which cover one of the most attractive and challenging fields, are high molecular weight polymers with inorganic elements in their backbone. These materials have silicon atoms in their main chain and exhibit unique properties resulting from the easy delocalization of sigma electrons in the Si─Si bonds. There are many technical uses as well as applications of these materials such as precursors of silicon carbide ceramics; a strengthening agent in porous ceramic; imaging materials in microlithography; photoiniting in radical reactions; and photoconducting, conducting, and semiconducting which are due to the unusual mobility of sigma electrons. In this work, the main structural features, properties, and some other important and recent applications of polysilanes are discussed.     

Current trends in spinel based modified polymer composite materials for electromagnetic shielding

The present article deals with current trends in spinel based modified polymer composite materials for applications in the field of electromagnetic shielding. The interaction between the various spinel based materials and polymers is an emerging field of studies among various researchers. The thermal stability, electrical conductivity, the bonding between the metal ferrites and the polymer plays an important role in the interaction of electromagnetic radiation. These properties also effect the mechanism of the EM waves for the shielding applications. Considering these all properties, polyaniline appears to be an suitable polymer for electromagnetic shielding applications. Polyaniline composites not only reinforced the properties of spinel materials but also enhanced the dielectric properties of the composite material. When carbon based materials such as graphene, graphene oxide and CNT was added along with spinel material in polyaniline based composite, they accelerate the electrical properties and enhances the shielding applications. In this paper the various synthesis methods, fabrication methods of polyaniline, and the properties of polyaniline based composites have been discussed. In addition, the various salient features and futuristic challenges of polyaniline based composite materials for EMI shielding applications were attempted to make a well equipped material for radar absorption.     

Graphene and its nanocomposites used as an active materials for supercapacitors

This review article investigates the hot topics by presenting the latest advances on graphene-based nanostructures for supercapacitors. In literature, many scientists have studied the nanomaterials and combination of conducting polymers in supercapacitor (SC) devices. The main aim of this review article is to present the higher capacitance, and higher power and energy density performances of the SC devices, which includes the active materials of carbon-based materials, metal oxides, conducting polymers, nanocomposites, etc. Many conventional techniques have already been used such as photolithography, inkjet printing, etc. Each of these methods has specific advantages and some drawbacks, with some working better in different environments. Among various nanoscaled materials, nanocrystal oxides of transition metals play an important role in advanced materials development. In addition to design of active material, symmetric and asymmetric supercapacitor device fabrication is also directly effect to obtain a higher capacitance, energy and power density performances. Therefore, this review article focuses on supercapacitor technology in new developments, such as design of active materials, device fabrication, etc.     

Cubic Polyhedral Oligomeric Silsesquioxane Based Functional Materials: Synthesis,Assembly, and Applications

Organically modified cubic polyhedral oligomeric silsesquioxanes (POSS) have attracted increasing attention in the design of novel functional hybrid materials for applications such as porous materials, liquid crystals, semiconductors, high‐temperature lubricants, fuel cells, and lithium batteries. The nanosized POSS moiety can be conveniently modified on the periphery with a variety of functional groups to lead to hybrid materials with desired functions. In addition, suitable mono‐functionalized POSS derivatives can be incorporated into polymers as side chains via various synthetic strategies to offer a wide class of functional polymeric materials with tunable physical properties for targeted applications. In this Focus Review, we aim to summarize the recent developments on the chemistry and applications of POSS‐based molecules and polymers. Moreover, the properties as well as assembly behavior of the POSS‐based functional hybrid materials will be reviewed, and the relationship of the performance of the hybrid materials with the intrinsic nature of the POSS unit will be addressed.     

Conducting polymers in chemical sensors and arrays

The review covers main applications of conducting polymers in chemical sensors and biosensors. The first part is focused on intrinsic and induced receptor properties of conducting polymers, such as pH sensitivity, sensitivity to inorganic ions and organic molecules as well as sensitivity to gases. Induced receptor properties can be also formed by molecularly imprinted polymerization or by immobilization of biological receptors. Immobilization strategies are reviewed in the second part. The third part is focused on applications of conducting polymers as transducers and includes usual optical (fluorescence, SPR, etc.) and electrical (conductometric, amperometric, potentiometric, etc.) transducing techniques as well as organic chemosensitive semiconductor devices. An assembly of stable sensing structures requires strong binding of conducting polymers to solid supports. These aspects are discussed in the next part. Finally, an application of combinatorial synthesis and high-throughput analysis to the development and optimization of sensing materials is described.     

Soft nanotechnology with soft nanoparticles

The last decade of research in the physical sciences has seen a dramatic increase in the study of nanoscale materials. Today, "nanoscience" has emerged as a multidisciplinary effort, wherein obtaining a fundamental understanding of the optical, electrical, magnetic, and mechanical properties of nanostructures promises to deliver the next generation of functional materials for a wide range of applications. While this range of efforts is extremely broad, much of the work has focused on "hard" materials, such as Buckyballs, carbon nanotubes, metals, semiconductors, and organic or inorganic dielectrics. Meanwhile, the soft materials of current interest typically include conducting or emissive polymers for "plastic electronics" applications. Despite the continued interest in these established areas of nanoscience, new classes of soft nanomaterials are being developed from more traditional polymeric constructs. Specifically, nanostructured hydrogels are emerging as a promising group of materials for multiple biotechnology applications as the need for advanced materials in the post-genomic era grows. This review will present some of the recent advances in the marriage between water-swellable networks and nanoscience.     

Fluorinated liquid crystals--properties and applications

This critical review begins with a brief, but essential, introduction to the special nature of liquid crystal materials, their peculiar properties, and their commercial applications, followed by an introductory insight into the remarkable nature of the fluoro substituent, and its fascinating influence on the properties of organic compounds. However, the main focus of the review is to discuss the enormous amount of exciting research on fluorinated liquid crystals that has been reported. The small size of the fluoro substituent enables its incorporation into all types of liquid crystal, including calamitic, discotic, banana, lyotropic, and polymers, without ruining the liquid crystalline nature of the material. However the fluoro substituent is larger than hydrogen, and hence causes a significant steric effect, which combined with the high polarity, confers many fascinating, and often remarkable, modifications to melting point, mesophase morphology and transition temperatures, and the many other very important physical properties, such as dielectric anisotropy, optical anisotropy, and visco-elastic properties. There are many different positions within a liquid crystal structure where a fluoro substituent can be located, including (i) a terminal position, (ii) within a terminal chain, as a semi-fluorinated or as a perfluorinated chain, or as one fluoro substituent at a chiral centre, (iii) as part of a linking group, and (iv) a lateral position in the core section. Such variety enables the interesting and advantageous tailoring of properties, both for the fundamental purposes of establishing structure-property relationships, and for materials targeted towards commercially-successful liquid crystal display applications.     

Fabrication and Optical and Electrical Properties of Poly(2,5-di-n-butoxyphenylene) Nanowire Arrays

Regular patterned arrays of nanomaterials have been widely fabricated and studied for their benefits in construction of novel type of optical, electron and magnetic device1-2, these kinds of devices center on the inorganic materials. With the development of synthesis and application of new type of polymer material, the design and construction of organic nanopolymer have become a great interest. Poly(p-phenylene)(PPP) and some derivatives have been widely investigated as a candidate for high strength, high temperature and conducting polymers, and can be used as electrode materials in electrochemical cells, blue emitting diodes: The polymers obtained by oxidative coupling polymerization of benzene nuclei with aluminum chloride and copper(Ⅱ) chloride is insoluble in all solvent and inflexible, which hinders revealing their basic properties. Introduction of flexible side chains into the aromatic rings can not only render solubility and processibility, but also improve or modify optical and electrical properties of the polymers. As a further step in assembling method and optoelectronic studies, it is attractive to investigate the properties of photoluminescence and electroluminescene of regular patterned arrays of poly(p-phenylene) deriva-tives nanowires.     

Integrated zwitterionic conjugated poly(carboxybetaine thiophene) as a new biomaterial platform

An integrated zwitterionic conjugated polymer-based biomaterial platform was designed and studied to address some of the key challenges of conjugated polymers in biomedical applications. This biomaterial platform consists of conjugated polymer backbones and multifunctional zwitterionic side chains. Zwitterionic materials gain electrical conductivity and interesting optical properties through conjugated polymer backbones, and non-biocompatible conjugated polymers obtain excellent antifouling properties, enhanced electrical conductivity, functional groups of bioconjugation and response to environmental stimuli via multifunctional zwitterionic side chains. This platform can potentially be adapted to a wide range of applications (e.g. bioelectronics, tissue engineering and biofuel cell), which require high performance conducting materials with excellent antifouling/biocompatibility at biointerfaces.     

Bulk plastic materials obtained from processing raw powders of renewable natural polymers via back pressure equal channel angular consolidation (BP-ECAC)

Renewable natural polymers wheat starch (WS) and wheat gluten (WG) were successfully processed into plastic bulk materials using back pressure equal channel angular consolidation (BP-ECAC) without using any additional plasticizers at relatively low temperatures. The strong shear deformation occurred during the process caused an effective deformation of WS or WG granular structures and resulted in an efficient gelatinization of starch or plasticization of gluten with the natural moisture content. Sufficient chain entanglement was formed in both WS and WG materials for achieving strong cohesion among the macromolecule matrixes. The mechanical strength of the obtained plastic materials was comparable to that of conventional polymers but stronger than the strength of thermoplastic WS or plasticized WG. The processing temperature played an important role in determination of morphologies and properties of the plastic materials. Increasing processing temperature would cause more effective gelatinization or plasticization of the natural polymers, enhance the interactions among different components in the systems, and form materials with improved mechanical properties. Thermal cross-linking might play a positive role in the improvement of mechanical properties when processing temperature was increased. However, thermal decomposition could also occur under such severe shearing especially at high temperatures. The optimum temperature for conducting such process was around 100-120 °C for WS and WG. The BP-ECAC method provides a potential to manufacture natural polymer based plastic materials efficiently on an industrial scale for various applications.     

Photochromic Inorganic/Organic Thermoplastic Elastomers

Photochromic materials are an important class of “smart materials” and are broadly utilized in technological devices. However, most photochromic materials reported so far are composed of inorganic compounds that are challenging to process and suffer from poor mechanical performance, severely limiting their applications in various markets. In this paper, inorganic photochromic tungsten trioxide (WO₃) nanocrystals are conveniently grafted with polymers to hurdle the deficiency in processability and mechanical properties. This new type of photochromic material can be thermally processed into desired geometries like disks and dog‐bone specimens. Fully reversible photochromic response under UV light is also achieved for WO₃‐graft polymers, exhibiting tunable response rate, outperforming the pristine WO₃ nanocrystals. Notably, the resulted graft polymers show extraordinary mechanical performance with excellent ductility (≈800% breaking strain) and relatively high breaking strength (≈2 MPa). These discoveries elucidate an effective pathway to design smart inorganic/organic hybrid thermoplastic elastomers endowed with outstanding photochromic and mechanical properties as well as exceptional processability.     

Polypyrrole coating of inorganic and organic materials by chemical oxidative polymerisation

Polypyrrole is one of the most frequently studied conducting polymers, having high electrical conductivity and stability, suitable for multi-functionalised applications. Coatings of chemically synthesised polypyrrole applied onto various organic and inorganic materials, such as polymer particles and films, nanoparticles of metal oxides, clay minerals, and carbon nanotubes are reviewed in this paper. Its primary subject is the formation of new materials and their application in which chemical oxidative polymerisation of pyrrole was used. These combined materials are used in antistatic applications, such as anti-corrosion coating, radiation-shielding, but also as new categories of sensors, batteries, and components for organic electronics are created by coating substrates with conducting polymer layers or imprinting technologies.     

Improvement of Fibre-Matrix-Adhesion of Natural Fibres by Chemical Treatment

Plastics, also called synthetic polymers, are playing an important role in daily living. To raise more applications it is necessary to modify known polymeric systems to reach improved materials/material systems. A possibility to create new optimised materials out of neat polymers is offered by compounding them with different filling material. Besides chemical modification of polymers, mixing, combining or use of different fillers, one possibility is given by the composite technique, whereas the combination of the polymeric matrix and the embedded reinforcement (e.g. fibre) are yielding in optimised materials adjusted to the required properties. Concerning the polymeric matrix, either thermoplastic or thermoset material can be used. In case of the reinforcement, either synthetic (carbon-, glass- or polymeric fibres) or natural fibres are introduced to composites. To obtain an appropriate adhesion of the matrix to the reinforcement system, synthetic fibres are equipped with an avivage. For natural fibres, there are no such materials available and the hydrophilic property of this system surface prevents an adhesion to hydrophobic polymers, as well as to sizings. In this paper, ways are shown to modify the natural fibres via chemical treatment to yield higher physical properties at better adhesion. Also we will explain activities on the use of natural fibres as reaction systems and processing tools as well as the attempt to isolate the different compounds of the neat fibre via selective work-up.     

取代聚炔的合成及其分离性能

具有优异物理和化学性能的新聚合物开发推动了取代聚炔的设计与合成。聚炔中功能侧基的引入赋予其非线性光学、液晶、发光、螺旋手性和高气体渗透等性能。作为一种重要的分离膜材料,与传统的玻璃态聚合物膜材料不同,这种无定形、高刚性的聚合物的显著特点是具有非常高的气体渗透系数和蒸汽／气体分离系数。有关其气体分离、天然气净化和对映体拆...