Polymer-based nanocomposites: Overview,applications and perspectives

Polyamide 6 and pristine montmorillonite have been melt blended in an extruder and water was injected into the melt in order to produce polyamide-based nanocomposites. The pristine clay was found to be exfoliated and dispersed homogenously in the polyamide. A mechanism explaining the formation of such nanocomposites is presented. Concentrated systems were achieved and redispersed in polypropylene by reactive processing. It is shown that, by this way, polyamide acts as a “primary” compatibiliser, with the maleic anhydride modified polyolefin playing the role of a “secondary” compatibiliser.     

聚合物构筑的囊泡及应用

综述了形成囊泡的两亲聚合物的结构,如双链两亲聚合物、单链两亲聚合物、正／负离子复合聚合物、聚合物与小分子化合物及可聚合化两亲聚合物;介绍了这些聚合物形成囊泡的特点和形成条件;概括了囊泡在反应微环境、药物释放、基因载体和生物矿化等方面的潜在应用;并提出了聚合物构筑囊泡的发展前景。     

Polymer-based membranes for solvent-resistant nanofiltration:A review

Separation of organic mixture is an inevitable process in most modern industrial processes. In the quest for a more sustainable and efficient separation, solvent-resistant nanofiltration (SRNF) has emerged as a promising answer. This is because SRNF is a membrane-based process which offers the key advantages of high efficacy and lowenergy intensity separation. In particular, polymer-based membranes can offer compelling opportunities for SRNFwith unprecedented cost-effectiveness.As a result, intensive research efforts have been devoted into developing novel polymer-based membraneswith solvent-resistant capacities as well as exploring potential applications in different types of industries. In this review, we aim to give an overview of the recent progress in the development of the state-of-the-art polymer-based membranes for SRNF in the first section. Emerging nanomaterials for mixed matrix and thin film nanocomposite membranes are also covered in this section. This is followed by a discussion on the current status ofmembrane engineering and SRNFmembrane commercialization. In the third section,we highlight recent efforts in adopting SRNF for relevant industrial applications such as food, bio-refinery, petrochemical, fine chemical and pharmaceutical industries followed by separations of enantiomers in stereochemistry, homogeneous catalysis and ionic liquids. Finally, we offer a perspective and provide deeper insights to help shape future research direction in this very important field of SRNF.     

聚合物基烧蚀材料的研究进展

简述了烧蚀材料的分类和作用机理,重点介绍了酚醛树脂类、聚四氟乙烯类、聚酰亚胺类、聚芳基乙炔类、有机硅类烧蚀材料的研究进展,展望了烧蚀材料今后的发展前景。     

自控温发热高分子复合材料研究进展

简要介绍了高分子基自控温发热复合材料的自控温发热机理和主要特性参数(如FTC强度、自控系数等),并对影响自控温发热材料性能的因素及该材料应用进行了综述.     

Matrimid‐based carbon tubular membranes: The effect of the polymer composition

In this article, we present a development study of new membrane materials and enhancements of productive membranes to improve the current performance of polymeric membranes. Carbon membranes are a promising material for this matter as they offer an improvement in the gas‐separation performance and exhibit a good combination of permeability and selectivity. Carbon membranes produced from the carbonization of polymeric materials have been reported to be effective for gas separation because of their ability to separate gases with almost similar molecular sizes. In this study, a carbon support membrane was prepared with Matrimid 5218 as a polymeric precursor. The polymer solution was coated on the surface of a tubular support with the dip‐coating method. The polymer tubular membrane was then carbonized under a nitrogen atmosphere with different polymer compositions of 5–18 wt %. The carbonization process was performed at 850°C at a heating rate of 2°C/min. Matrimid‐based carbon tubular membranes were fabricated and characterized in terms of their structural morphology, thermal stability, and gas‐permeation properties with scanning electron microscopy, thermogravimetric analysis, Fourier transform infrared spectroscopy, and a pure‐gas‐permeation system, respectively. Pure‐gas‐permeation tests were performed with the pure gases carbon dioxide (CO₂) and N₂ at room temperature at a pressure of 8 bar. On the basis of the results, the highest CO₂/N₂ selectivity of 75.73 was obtained for the carbon membrane prepared with a 15 wt % polymer composition. © 2015 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2015 , 132, 42394.     

天然高分子基类表面活性剂研究概况

综述了淀粉类、纤维素类和氨基糖类等天然高分子基表面活性剂的研究概况,并对表面活性剂工业发展的方向提出了展望。     

High yield preparation of tubular carbon nanofibers over supported Co-Mo catalysts

In the search for high yield synthesis of carbon nanotubes (CNTs) at lower temperatures, Co-Mo catalysts on carbon black were investigated with ethylene and CO as carbon sources in catalytic gas-phase pyrolysis in comparison to that on TiO₂. The carbon black support was expected to be advantageous because of the feasibility of a CNT/carbon black composite possibly fabricated for several applications without removal of the support. Depending on the catalyst support, the catalytic activity toward CO and ethylene showed great differences. Co-Mo (9:1) catalysts on titania or carbon black provided a high carbon yield from CO and ethylene at the rather low temperatures of 450-530 °C.     

Oxidative coupling of methane over Sm-promoted MgO: Influence of composition and preparation conditions

Influences of promoter concentration (or Sm/Mg ratio), precursor for MgO (viz. Mg-acetate, Mg-carbonate and Mg-hydroxide), calcination temperature of Sm-promoted MgO catalyst on the catalytic activity/selectivity in the oxidative coupling of methane (OCM) at different temperatures (650–850°C) and CH₄/O₂ ratios in feed (2·0–8·0) at a high space velocity (51600 cm³ g⁻¹ h⁻¹) have been investigated. The catalytic activity/selectivity of Sm–MgO catalysts in the OCM are found to be strongly influenced by the Sm/Mg ratio, precursor used for MgO and catalyst calcination temperature. The catalyst with Sm/Mg ratio of 0·11, prepared using magnesium acetate and magnesium carbonate as a source of MgO and calcining at 950°C, is found to be highly active and selective in the OCM process. A drastic reduction in catalytic activity/selectivity is observed when the catalyst is supported on low surface area porous catalyst carriers, indicating strong catalyst–support interactions. ©1997 SCI     

聚合物基氧化石墨烯纳米复合材料研究进展

氧化石墨烯作为石墨烯的重要衍生物,原料来源广泛,制备过程简单,成本低廉,具有优异力学性能、耐磨性能以及吸附性能等,其还原产物具有优良的导电性能和导热性能等,是聚合物基纳米复合材料的理想填料。近年来,随着复合材料制备方法的不断革新,聚合物基氧化石墨烯纳米复合材料得到了快速发展,并在储能、阻燃等领域实现了规模化应用,有助于引领聚合物基氧化石墨烯纳米复合材料相关产品的进一步开发和应用。本文系统介绍了氧化石墨烯的改性方法,综述了聚合物基氧化石墨烯纳米复合材料的研究进展,展望了聚合物基氧化石墨烯纳米复合材料的发展前景。     

聚合物基氧化石墨烯纳米复合材料研究进展

氧化石墨烯作为石墨烯的重要衍生物,原料来源广泛,制备过程简单,成本低廉,具有优异力学性能、耐磨性能以及吸附性能等,其还原产物具有优良的导电性能和导热性能等,是聚合物基纳米复合材料的理想填料。近年来,随着复合材料制备方法的不断革新,聚合物基氧化石墨烯纳米复合材料在储能、阻燃等领域实现了规模化应用,有助于引领聚合物基氧化石墨烯纳米复合材料相关产品的进一步开发和应用。该文系统介绍了氧化石墨烯的共价改性方法以及非共价改性方法,综述了聚合物基氧化石墨烯纳米复合材料的研究进展,展望了聚合物基氧化石墨烯纳米复合材料的发展前景。     

Polymer-based hydrogel scaffolds for skin tissue engineering applications: a mini-review

Polymer hydrogels consist of a three-dimensional (3D) structure with cross-linked networks rich in a huge amount of water through hydrogen-bonding interactions, making them highly hydrophilic. Due to their impressive hydrophilic characteristics and cell non-cytotoxicity, polymer hydrogels are useful tissue engineering tools for the organization of cells and tissues and organ regeneration. Many biomedical engineers and researchers have recently begun to utilize polymer hydrogels as tissue or cell culture environments and as scaffolds for the stable growth of organs in tissue engineering and regeneration medicine. This paper focuses on skin regeneration in polymer hydrogels where skin is a means of protecting the body from infection or physical or chemical damage. Generally, skin tissue that has incurred minor damage or wounds can regenerate and heal in a relatively short time, while severe injuries may require transplantation or artificial skin. For those purposes, skin culturing in an in vitro environment is essential, and the environment produced using polymer hydrogel scaffolds needs to be both similar to the real environment and safe for skin cell growth. This paper reviews post-2000 skin regeneration research in the field of tissue engineering, focusing specifically on polymer hydrogels; it also discusses some of the central perspectives and key issues.     

Intermatrix synthesis: easy technique permitting preparation of polymer-stabilized nanoparticles with desired composition and structure

The synthesis of polymer-stabilized nanoparticles (PSNPs) can be successfully carried out using intermatrix synthesis (IMS) technique, which consists in sequential loading of the functional groups of a polymer with the desired metal ions followed by nanoparticles (NPs) formation stage. After each metal-loading-NPs-formation cycle, the functional groups of the polymer appear to be regenerated. This allows for repeating the cycles to increase the NPs content or to obtain NPs with different structures and compositions (e.g. core-shell or core-sandwich). This article reports the results on the further development of the IMS technique. The formation of NPs has been shown to proceed by not only the metal reduction reaction (e.g. Cu0-NPs) but also by the precipitation reaction resulting in the IMS of PSNPs of metal salts (e.g. CuS-NPs).     

Polymer-based composites by electrospinning: Preparation & functionalization with nanocarbons

Electrospinning is a straightforward yet versatile technique for the preparation of polymeric nanofibers with diameters in the range of nanometers to micrometers, and has been rapidly developed in the last two decades. Nanocarbon materials, usually referring to carbon nanotubes, graphene, and fullerenes with their derivatives including quantum dots, nanofibers, and nanoribbons, have received increasing attention due to their unique structural characteristics and outstanding physico-chemical properties. Incorporation of nanocarbons in electrospun polymeric fibers has been used to increase the functionality of fibers, for example, to improve the mechanical, electrical, and thermal properties, as well as confer biofunctionality as scaffolds in tissue engineering and sensors, when the advantageous properties given by the encapsulated materials are transferred to the fibers. In this review, we provide an overview of polymer-based composites reinforced with nanocarbons via the electrospinning technique. After a brief introduction of various types of nanocarbons, we summarize the latest progress of the design and fabrication of electrospun polymeric nanofibers with nanocarbon fillers. With regard to the preparation of composites, we focus on functionalization strategies of nanocarbons and the production of random & aligned polymeric nanocomposites. Then, the physical properties such as mechanical, electrical, and thermal properties are also reviewed for electrospun nanocomposite nanofibers reinforced with nanocarbons, especially carbon nanotubes. Benefiting from the exceptional properties including superior electric conductivity, high porosities, unique mat structure, etc. the polymeric composite nanofibers have demonstrated numerous advantages and promising properties in the fields of tissue engineering and sensors. In the application section, we will give state-of-the-art examples to demonstrate the advantages of electrospun polymer-based nanocomposites. Finally, the conclusion and challenge of the polymer-based nanocomposites are also presented. We believe the efforts made in this review would promote the understanding of the methods of preparation and unique physical and chemical properties of nanocarbon reinforced polymer-based nanocomposites.     

Prevailing Research Trends in Carbon Nanohorn and Polymer-based Hybrids

This review outlines research progress on carbon nanohorn (CNH) and polymer/CNH hybrids including structure, properties, application, and future stance. Carbon nanohorn is a type of nanocarbon existing as dahlia-like, bud-like, and seed-like structures. Most widely known form is single-walled carbon nanaohorn with diameter of ～5?nm and tube length ～50?nm. Polymers such as polystyrene, polyaniline, polythiophene, poly(vinylalcohol), poly(methylmethacrylate), poly(ethyleneglycol), polycaprolactone, polyimide, poly(2-aminopyridine), and nylon have been interacted with CNH using various techniques. Structural and physical properties of fine-tuned carbon nanohorn and polymer/CNH hybrids have been used for versatile applications such as dye-sensitized solar cell, supercapacitor, drug delivery, fuel cell, and sensors.     

Medium-chain triglycerides—their composition,preparation, and application

Medium-chain triglycerides, prepared from fractionated fatty acids of vegetable oils ranging from caproic to lauric, have been prepared and used in the treatment of patients suffering from malabsorption syndromes. Commercial practices for processing of the kernel oils to obtain such fractionation of fatty acids are described, and the practical sources for such medium-chain fatty acids are given. Medium-chain esters of synthetic fatty acids and modifications of such esters for special medicinal and nutritional uses are suggested for future consideration and application.     

Addition of carbon nanotubes during the preparation of zirconia nanoparticles: influence on structure and phase composition

Zirconia powder with an average particle size of 10 nm was prepared by adding carbon nanotubes (CNTs) in the hydrolytic process of ZrO(NO₃)₂. The formation of zirconia nanoparticles was attributed to the addition of CNTs, which affected the zirconia precursor structure. The relation between the stability of cubic (c) and tetragonal (t) phase zirconia at room temperature, and the zirconia particle size and addition of carbon was studied. It was revealed that zirconia particles with nanometer size had took the form of t-phase and that the addition of carbon tended to favor m-phase ZrO₂ to c-phase ZrO₂ transformation and c-phase ZrO₂ stabilization at low temperature.     

Copper-assisted,templated preparation of submicron-sized tubular CNT arrays by corona discharge enhanced CVD

The corona discharge enhanced CVD technique is used to synthesize copper nanoparticle-doped submicron carbon nanotubes. The average diameter of prepared copper nanoparticles is as small as 3 nm. Under the blank membrane condition (no metal loading), however, no nanotubes are formed. The existence of copper nanoparticles seems to facilitate the homogeneous deposition of carbon species onto the interior surface of an AAO membrane.     

聚合物基纳米复合材料减摩耐磨性能研究进展

从填料的角度对聚合物基纳米复合材料的减摩耐磨性能研究进展进行了评述。主要介绍了减摩耐磨场合使用较多的纳米填料的研究进展。分析了不同填料填充的高分子复合材料的减摩耐磨性能,同一填料不同处理方式对复合材料减摩耐磨性能的影响,并展望了减摩耐磨用复合材料的发展趋势。