Self-assembly of “patchy” nanoparticles: a versatile approach to functional hierarchical materials

The solution-phase self-assembly or “polymerization” of discrete colloidal building blocks, such as “patchy” nanoparticles and multicompartment micelles, is attracting growing attention with respect to the creation of complex hierarchical materials. This approach represents a versatile method with which to transfer functionality at the molecular level to the nano- and microscale, and is often accompanied by the emergence of new material properties. In this perspective we highlight selected recent examples of the self-assembly of anisotropic nanoparticles which exploit directional interactions introduced through their shape or surface chemistry to afford a variety of hierarchical materials. We focus in particular on the solution self-assembly of block copolymers as a means to prepare multicompartment or “patchy” micelles. Due to their potential for synthetic modification, these constructs represent highly tuneable building blocks for the fabrication of a wide variety of functional assemblies.     

Poly(vinyl alcohol) physical hydrogels: new vista on a long serving biomaterial

Poly(vinyl alcohol), PVA, and physical hydrogels derived thereof have an excellent safety profile and a successful history of biomedical applications. However, these materials are hardly in the focus of biomedical research, largely due to poor opportunities in nano- and micro-scale design associated with PVA hydrogels in their current form. In this review we aim to demonstrate that with PVA, a (sub)molecular control over polymer chemistry translates into fine-tuned supramolecular association of chains and this, in turn, defines macroscopic properties of the material. This nano- to micro- to macro- translation of control is unique for PVA and can now be accomplished using modern tools of macromolecular design. We believe that this strategy affords functionalized PVA physical hydrogels which meet the demands of modern nanobiotechnology and have a potential to become an indispensable tool in the design of biomaterials.     

The emerging utility of ketenes in polymer chemistry

The continued evolution of functional materials that contribute to pressing societal challenges requires the development of powerful synthetic methodologies in polymer systems. Since their discovery by Staudinger in the early 20th century, the unique chemistry of ketenes have fascinated synthetic chemists and been the driver of revolutionary applications in photolithography, medicinal chemistry, and commodity materials. The versatile chemistry of ketenes, specifically their ability to act as an electrophile and/or undergo cycloaddition reactions, has recently been shown to provide a powerful platform for the design of next‐generation materials. This Highlight focuses on the history of ketenes in materials science and their recent renaissance in polymer chemistry, with specific focus being given to methodologies that provide reliable access to this important functional group in polymer systems. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 3769–3782     

The Chemistry and Properties of the Medical-Grade Silicones

The medical grade silicones are probably the most widely used of all the synthetic polymers for permanently implanted subdermal devices. This paper reviews the chemistry of these materials from the original polymer manufacturing through the various stages necessary to obtain the types of heat vulcanizing silicone rubber, room temperature vulcanizing silicone rubber, and silicone rubber adhesive most commonly used in medical applications.     

硫醇-烯/炔点击化学合成功能聚合物材料

点击化学具有反应条件温和、产率高、速率快、产物容易分离以及高度选择性等优点,成为国内外研究的热点之一。硫醇-烯/炔光化学反应作为新型高效的点击反应近年来备受关注,通过这种方法制备高性能及功能性聚合物材料也是新材料领域的前沿研究内容。本文综述了近年来硫醇-烯/炔点击化学在功能聚合物材料合成中的研究成果,详细介绍了硫醇-烯/炔点击化学的特点、优势及其反应机理,重点归纳了利用硫醇-烯/炔点击化学合成线型、超支化、交联等分子结构的功能聚合物材料的研究进展,并对由这种方法合成功能聚合物的单体特点、反应路线及产物应用进行了阐述,最后对硫醇-烯/炔点击化学的进一步应用前景做了展望。     

Shaping and exploring the micro- and nanoworld using bipolar electrochemistry

Bipolar electrochemistry is a technique with a rather young history in the field of analytical chemistry. Being based on the polarization of a conducting object which is exposed to an external electric field, it allowed recently the development of new methods for controlled surface modification at the micro- and nanoscale and very original analytical applications. Using bipolar electrodes, analyte separation and detection becomes possible based on miniaturized systems. Moreover, the modified objects that can be created with bipolar electrochemistry could find applications as key components for detection systems. In this contribution, the principles of bipolar electrochemistry will be reviewed, as well as recent developments that focus on the modification of objects at the nano- and microscale and their potential application in miniaturized analytical systems.     

Properties and applications of precision oligomer materials; where organic and polymer chemistry join forces

Precise oligomeric materials constitute a growing area of research with implications for various applications as well as fundamental studies. Notably, this field of science which can be termed macro-organic chemistry, draws inspiration from both traditional polymer chemistry and organic synthesis, combining the molecular precision of organic chemistry with the materials properties of macromolecules. Discrete oligomers enable access to unprecedented materials properties, for example, in self-assembled structures, crystallization, or optical properties. The degree of control over oligomer structures resembles many biological systems and enables the design of materials with tailored properties and the development of fundamental structure–property relationships. This Review highlights recent developments in macro-organic chemistry from synthetic concepts to materials properties, with a focus on self-assembly and molecular recognition. Finally, an outlook for future research directions is provided.     

银/聚合物纳米复合材料

银/聚合物纳米复合材料是一种典型的聚合物基复合材料, 其结构和性能依赖于合成方法,因此开发材料的优异性能必须以深入研究纳米材料的先进合成技术为前提。本文综述了纳米银粒子及其与聚合物形成的纳米复合材料的最新合成进展, 重点介绍了基于液相化学还原方法合成纳米银粒子的新方法, 如溶胶-凝胶法、沉淀法、微乳液法和离子液体法, 以及纳米银粒子的分散技术和原位法合成银/聚合物纳米复合材料的新技术, 并介绍了纳米银复合材料的电绝缘性、表面增强拉曼散射性能、抗菌性及其在生物医学等领域中的应用。     

Synthetic Hydrogels with Covalently Incorporated Saccharides Studied for Biomedical Applications – 15 Year Overview

Glycosylated materials have attracted special attention in biomedical field because of the unique properties of the individual carbohydrates in recognition mechanisms in many biological events. Sugar residues decorating a polymer surface can be regarded as multivalent ligands for interaction with various glycoproteins. This phenomenon provides the basis for several biomedical applications; of these, ligand-based targeted therapy is the most frequently cited. Materials functionalized with individual carbohydrates can be used for the selective binding of lectin proteins. Carbohydrate–lectin interactions underpin the development of diverse biosensor devices and bioassays aimed at pathogen detection. Because of the high content of hydroxyl groups and the consequent high hydrophilicity, saccharide-based monomers are perfect candidates for incorporation into hydrogels. Such functionalization allows synthetic materials to acquire unique properties and enhance their performance. This review covers developments over the past 15 years in the field of the synthesis of chemically crosslinked nano-, micro- and bulk hydrogels with covalently incorporated mono-, di- or trisaccharides. A brief view on the potential biomedical applications of these unique hydrogels is provided with particular emphasis on carriers for delivery of bioactive molecules, bioactivated materials for cell culture and tissue engineering as well as capture systems for pathogenic microorganisms.     

展望21世纪的高分子化学

回顾了高分子合成化学方法和高分子材料的发展历史,结合高分子化学的研究现状,展望了２１世纪的高分子化学的发展前景。     

Progress in Molecular Nanoarchitectonics and Materials Nanoarchitectonics

Although various synthetic methodologies including organic synthesis, polymer chemistry, and materials science are the main contributors to the production of functional materials, the importance of regulation of nanoscale structures for better performance has become clear with recent science and technology developments. Therefore, a new research paradigm to produce functional material systems from nanoscale units has to be created as an advancement of nanoscale science. This task is assigned to an emerging concept, nanoarchitectonics, which aims to produce functional materials and functional structures from nanoscale unit components. This can be done through combining nanotechnology with the other research fields such as organic chemistry, supramolecular chemistry, materials science, and bio-related science. In this review article, the basic-level of nanoarchitectonics is first presented with atom/molecular-level structure formations and conversions from molecular units to functional materials. Then, two typical application-oriented nanoarchitectonics efforts in energy-oriented applications and bio-related applications are discussed. Finally, future directions of the molecular and materials nanoarchitectonics concepts for advancement of functional nanomaterials are briefly discussed.     

铌多酸三维框架材料的研究进展

铌多酸三维框架材料是近年来无机合成化学与材料化学领域的研究热点. 该类材料不但可以将铌多酸的优异特性与框架结构的优点复合起来, 而且在光催化、 主客体化学、 能源转化等领域具有重要的应用前景. 本文总结了近10年来铌多酸三维框架材料的研究进展, 包括了该类材料的合成策略、 结构调控、 性质及应用探索. 此外, 还对当前该类材料的发展所面临的挑战进行了总结, 并对其发展前景进行了展望.     

Dye Diffusion Systems in Color Photography

Dye diffusion instant color photography has been a commercial success ever since its introduction in 1963. No doubt this is partly due to the spectacular nature of this innovation, and for the same reason it has never really rid itself of its gadget image. Moreover, the picture quality was inferior to that of traditional color photography. Photographic materials are now available whose image quality approaches that of the traditional color print. It is not well known that chemistry, and organic chemistry in particular, is the cornerstone of these new photographic products. Insights from this field have spurred creativity, not only in the fields of dye and polymer chemistry, but above all in the search for more efficient and, hopefully better, dye diffusion transfer systems. The result of all these efforts is a finely tuned microscale chemical factory which continues to open rewarding perspectives for the photographic industry.     

Pyrene-loaded polypyrrole microvessels

The encapsulation of guest molecules within polymeric hollow nano- or microscale structures is a rapidly developing field of interdisciplinary research due to a variety of applications ranging from drug delivery and sensor fabrication to nanoscale synthesis and bioinspired mineralization. We report on the encapsulation of pyrene within three-dimensional polypyrrole microvessels synthesized by precipitation polymerization of pyrrole onto toluene droplets that contain pyrene. Steady state and time-resolved fluorescence measurements show that the optical response and dynamics of encapsulated pyrene is significantly different from that in the free solution, likely due to interactions with oligomeric species generated during the polymerization process that partition into the organic core of the microvessel. Our results indicate that the encapsulation process can have a significant influence on the local environment of encapsulated species, an issue that is critical from the perspective of potential synthetic or medical applications.     

Phosphorus and Silicon-Based Macromolecules as Degradable Biomedical Polymers

Synthetic polymers are indispensable in biomedical applications because they can be fabricated with consistent and reproducible properties, facile scalability, and customizable functionality to perform diverse tasks. However, currently available synthetic polymers have limitations, most notably when timely biodegradation is required. Despite there being, in principle, an entire periodic table to choose from, with the obvious exception of silicones, nearly all known synthetic polymers are combinations of carbon, nitrogen, and oxygen in the main chain. Expanding this to main-group heteroatoms can open the way to novel material properties. Herein the authors report on research to incorporate the chemically versatile and abundant silicon and phosphorus into polymers to induce cleavability into the polymer main chain. Less stable polymers, which degrade in a timely manner in mild biological environments, have considerable potential in biomedical applications. Herein the basic chemistry behind these materials is described and some recent studies into their medical applications are highlighted.     

Recent developments in polymer–block–polypeptide and protein–polymer bioconjugate hybrid materials

In the last few years, polymer bioconjugates have been shown to be useful in many emerging areas of materials science. Consequently, the synthesis of polymer bioconjugates has suddenly become a central topic in polymer chemistry. The versatility and robust nature of modern synthetic methods such as controlled radical polymerisation (CLRP),¹ ring-opening polymerisation (ROP), and ‘click’ chemistry make them excellent tools for the preparation of tailor-made polymer bioconjugates. CLRP in combination with other techniques has been shown to be a mature technology for building tailor-made block copolymers and protein–polymer conjugates with a wide range of applications, especially in biomedical domains. This review describes the recent advances and progress in the rapidly expanding field of bioconjugation, outlining the work performed up to 2012.     

Miniaturization of Separation Systems and Its Applications

Development of miniaturized separation system consisted of microscale extraction and liquid phase separation processes has been reviewed. Various types of novel bonded stationary phases have been developed on the basis of the systematic analysis for the retention behavior of polycyclic aromatic hydrocarbons on experimentally synthesized phases. In this review, the miniaturization of microscale sample preparation technique and the effective on-line coupling to microcolumn liquid phase separations are also described especially focusing on the approach by the author‘‘s group. The novel use of synthetic polymer filaments as the stationary phase and extraction media in those microscale separation systems will be introduced along with the applications in gas chromatographic separation.     

From the reactivity of N-heterocyclic carbenes to new chemistry in ionic liquids

N-Heterocyclic carbenes have numerous applications in synthetic chemistry. We detail the reactivity and chemistry of these molecules including investigations into their reactions with small reagents, their use for the preparation of polarised azines and their potential application as NLO materials. The chemistry of imidazolium salts, which are related to NHCs by the addition of a proton, is also discussed. New chemistry for ionic liquids is also revealed.     

Interface-directed assembly of one-dimensional ordered architecture from quantum dots guest and polymer host

Assembly of inorganic semiconductor nanocrystals into polymer host is of great scientific and technological interest for bottom-up fabrication of functional devices. Herein, an interface-directed synthetic pathway to polymer-encapsulated CdTe quantum dots (QDs) has been developed. The resulting nanohybrids have a highly uniform fibrous architecture with tunable diameters (ranging from several tens of nanometers to microscale) and enhanced optical performance. This interfacial assembly strategy offers a versatile route to incorporate QDs into a polymer host, forming uniform one-dimensional nanomaterials potentially useful in optoelectronic applications.     

Transport Polymerization of Gaseous Intermediates and Polymer Crystals Growth

Man is always enchanted with discoveries of new and better ways of making things. Even after more than a hundred years of synthetic chemistry, scientists are today still as enthusiastic as ever looking for “novel” reactions and “novel” syntheses. One of the great achievements of the last decade was the development and usage of “intermediates” for syntheses. Knowing the extensive applications [1-4] of these intermediates in modern synthetic chemistry, it is, however, surprising to find that only few groups of these intermediates have been used in polymer syntheses. For instance [5], even though there are radical polymerizations and polymerizations involving carbanions and carbonium ions, there are practically no polymer syntheses using benzynes [2], carbenes [3], or nitrenes [4].