Polymeric monolithic materials: Syntheses, properties, functionalization and applications

The synthetic particularities for the synthesis of polymer-based monolithic materials are summarized. In this context, monoliths prepared via thermal-, UV- or electron-beam triggered free radical polymerization, controlled TEMPO-mediated radical polymerization, polyaddition, polycondensation as well as living ring-opening metathesis polymerization (ROMP) will be covered. Particular attention is devoted to the aspects of controlling pore sizes, pore volumes and pore size distributions as well as functionalization of these supports. Finally, selected, recent applications in separation science, (bio-) catalysis and chip technology will be summarized.     

High value-added applications of coal fly ash in the form of porous materials: A review

Coal fly ash (CFA) is a solid waste generated by coal-fired power plants, and its massive accumulation problem needs to be solved urgently. There are many ways of resource utilization of CFA, but the applications of high added value are rare. Preparation of porous materials is an effective way to realize its high value-added applications. In this paper, porous materials are divided into ceramic membranes, thermal insulation materials and adsorption materials according to application fields. The research progress of porous materials prepared from CFA and used for filtration, thermal insulation and adsorption is reviewed. Ceramic membranes can filter different types of wastewater from different industries at different levels. Thermal insulation materials, with relatively low added value though, are easier to achieve large-scale production. Zeolites, geopolymers and various composite materials are crackerjack adsorbents, which can effectively purify wastewater and exhaust gas. After summary, comparison and discussion, it is concluded that ceramic membrane is the most ideal and feasible material to realize high value-added application of CFA among the three porous materials. Finally, the existing problems and future prospects of the three porous materials are stated.     

Biomedical applications of polymeric materials and their interactions with blood components: a critical review of current developments

A critical review is presented of some of the current developments in the biomedical applications of polymeric materials, with emphasis on naturally occurring macromolecules present in blood vessel walls, synthesis and surface modifications, mechanical properties, and interactions between surfaces and blood components.     

锂离子二次电池新型正极材料LiMPO4(M=Fe、Co、Ni等)的研究进展

综述了锂离子二次电池新型正极材料LIMPO4(M=Fe、Co、Ni、Mn等)的研究进展。重点对该材料的结构、结构与电化学性能的关系、多种阳离子掺杂对材料性能的影响以及多种合成方法进行了较详细的评述,并对该材料的应用前景进行了展望。     

Superhydrophobic surfaces: a review on fundamentals,applications, and challenges

Superhydrophobicity is the tendency of a surface to repel water drops. A surface is qualified as a superhydrophobic surface only if the surface possesses a high apparent contact angle (>150°), low contact angle hysteresis (<10°), low sliding angle (<5°) and high stability of Cassie model state. Efforts have been made to mimic the superhydrophobicity found in nature (for example, lotus leaf), so that artificial superhydrophobic surfaces could be prepared for a variety of applications. Due to their versatile use in many applications, such as water-resistant surfaces, antifogging surfaces, anti-icing surfaces, anticorrosion surfaces etc., many methods have been developed to fabricate them. In this article, the fundamental principles of superhydrophobicity, some of the recent works in the preparation of superhydrophobic surfaces, their potential applications, and the challenges confronted in their new applications are reviewed and discussed.     

ZrN+AlN+Y2O3复合助烧结剂对Si3 N4陶瓷烧结性能的影响

对比了ZrN+AlN助烧结剂与ZrN+AlN+Y2O3助烧结剂对1800℃、25 MPa下热压烧成Si3N4陶瓷显微结构和力学性能的影响,并着重对ZrN+AlN+Y2O3复合助烧结剂促进Si3N4陶瓷烧结的机理进行了探讨.结果表明加ZrN+AlN+Y2O3助烧结剂能明显促进Si3N4陶瓷的烧结,提高陶瓷强度,其相对密度可达97.84%,常温弯曲强度为601.21 MPa,断裂韧性达8.9 MPa·m1/2;而加ZrN+AlN助烧结剂的Si3N4陶瓷未致密化.     

Design and synthesis of porous polymeric materials and their applications in gas capture and storage: a review

The design and synthesis of porous organic materials that have increasing physical and chemical characteristics have been discussed. For example, a variety of porous organic polymers, metal–organic frameworks, conjugated microporous polymers, and polymers of intrinsic microporosity have been designed and synthesized using simple and efficient procedures. Such materials have unique gas adsorption properties and can be used in gases separation and storage. In addition, they have high surface area, porosity, and selectivity towards carbon dioxide compared to other gases such as nitrogen and methane.     

Corrosion of Si3N4-ceramics in aqueous solutions Part I: Characterisation of starting materials and corrosion in 1 N H2SO4

The corrosion behaviour of silicon nitride materials in acids strongly depends on the composition and amount of the grain boundary. But there exist no systematic investigations of the relation between the corrosion behaviour and the composition and amount of the grain-boundary phase. The aim of the series of these papers is the systematic investigation of these relations. In the first part the methods of determination of the amorphous grain-boundary phases are described in detail. Additionally, the correlation between the corrosion behaviour and the composition of the grain-boundary phases are given. The structural reasons and the mechanisms behind the observed changes in the corrosion behaviour will be given in part II of this paper.     

Preparation and control of functional nano-objects: Spheres, rods and rings based on hybrid materials

This paper reports on a simple route to fabricate functional nano-objects via self-assembly of hybrid materials based on a diblock copolymer. In water-toluene mixtures, spheres, rod- and ring-like structures of metal loaded block copolymer micelles are fabricated. The binary solvent blends are modified to gain control over the formation of micellar morphologies. A mechanism leading to the formation of such aggregates is presented using a force balance approach. It is demonstrated that swelling of the micelle core due to the water content is the driving force that induces transitions of morphology. Based on various control experiments the effect of inorganic precursor and stoichiometric water contents on the micelle morphology is described.     

Laminated cermet composite materials: The main production methods,structural features and properties (review)

This paper reviews the main production methods of laminated cermet composite materials. The basic methods for obtaining individual macrolayers including cold pressing, slurry casting onto a moving tape substrate, electrophoretic deposition, infiltration (impregnation of a porous frame with a melt) and methods of their consolidation (hot pressing, explosion welding, spark plasma sintering, SHS (self-propagating high-temperature synthesis) compaction, unrestricted SHS compression are described. The structure of the laminated cermet composite materials depending on the production method, their physical and mechanical characteristics are considered.     

Damage formation and suppression in rotary ultrasonic machining of hard and brittle materials: A critical review

Rotary ultrasonic machining (RUM) combines diamond grinding with small-amplitude tool vibration, to improve machining processes of hard and brittle materials. It has been successfully applied to the machining of a number of brittle materials from optical glasses to advanced ceramics as well as ceramic matrix composites. The emphasis of this literature review was on formation mechanism and suppression methods of machining induced damages that truly limit RUM machining efficiency improvement of brittle materials. In this review paper, material removal mechanism and cutting force modeling of RUM of brittle materials were presented, as well as all corresponding roles in the damage formation process. The critical processing capacity of RUM machine tools was described, which guarantees the RUM effectiveness and consequently constitutes the boundary condition of processing parameters determination. Formation mechanisms of edge chipping, tearing defects, subsurface damages, and their interactive effects were summarized. Advances in damage suppression methods were also described, including optimization of processing parameters, tool design of low damage, and other methods such as rotary ultrasonic elliptical machining.     

Preparation, properties and applications of polysaccharide nanocrystals in advanced functional nanomaterials: a review

Intensive exploration and research in the past few decades on polysaccharide nanocrystals, the highly crystalline nanoscale materials derived from natural resources, mainly focused originally on their use as a reinforcing nanophase in nanocomposites. However, these investigations have led to the emergence of more diverse potential applications exploiting the functionality of these nanomaterials. Based on the construction strategies of functional nanomaterials, this article critically and comprehensively reviews the emerging polysaccharide nanocrystal-based functional nanomaterials with special applications, such as biomedical materials, biomimetic optical nanomaterials, bio-inspired mechanically adaptive nanomaterials, permselective nanostructured membranes, template for synthesizing inorganic nanoparticles, polymer electrolytes, emulsion nano-stabilizer and decontamination of organic pollutants. We focus on the preparation, unique properties and performances of the different polysaccharide nanocrystal materials. At the same time, the advantages, physicochemical properties and chemical modifications of polysaccharide nanocrystals are also comparatively discussed in view of materials development. Finally, the perspective and current challenges of polysaccharide nanocrystals in future functional nanomaterials are outlined.     

(010) facets dominated LiFePO4 nano-flakes confined in 3D porous graphene network as a high-performance Li-ion battery cathode

Olivine-structured LiFePO₄ (LFP) has been widely considered as one of the most promising and safest high-power positive electrode materials for lithium-ion batteries (LIBs) as a power source in the electric transportation. However, the electrochemical behavior of LFP for lithium-storage is seriously restrained by its intrinsic feature of low electrical conductivity and poor lithium-ion diffusion ability. In this research, LFP nano-flakes with oriented (010) facets were prepared through the solvothermal method, and 3D porous composite of LFP nano-flakes confined on graphene (LFP@G) was synthesized by freeze-drying concentrated graphene-oxide-gel containing LFP nano-flakes followed by a heat-treatment process. As the cathode materials for LIBs, LFP@G composite can release a reversible specific capacity of 129 mAh g^?1 at a high current rate of 20?C. Meanwhile, a long cycling stability for LFP@G composite with a capacity of 139.8 mAh g^?1 over 600 cycles up to 10?C can be achieved. The superior electrochemical Li-storage properties of LFP@G composite can be ascribed to the fast lithium-ion transfer channels of LFP originated from the exposed (010) planes, shortened lithium-ion diffusion distance, and the excellent two-phase electric contact between LFP and graphene in the 3D porous graphene conductive network for fast electron and lithium-ion transport.     

染料中间体N,N'-1,4-苯基二-(3-氨基-4-甲氧基)苯磺酰胺的合成

以邻氨基苯甲醚、乙酸酐、氯磺酸、对苯二胺为原料,经乙酰化、氯磺化、酰胺化、脱乙酰基等步骤,研究合成了无致癌性染料中间体N,N'-1,4-苯基二-(3-氨基-4-甲氧基)苯磺酰胺。考察了影响酰胺化反应的因素,其优化条件为:反应物用量n(4-甲氧基-3-乙酰氨基-苯磺酰氯)∶n(对苯二胺)为2.2∶1(摩尔比),反应在40°C进行,反应时间为5.0h。产率可达88.46%。产品经红外、核磁、质谱、元素分析等测定确证了结构。     

水热法对Eu3＋掺杂CaMoO4微纳米荧光体的制备及其发光性能

采用水热法成功的制得了不同形貌的CaMoO4：Eu3＋微纳米荧光体。实验结果表明,溶液的pH值在控制产物形貌上起了决定性的作用。用X射线粉末衍射（XRD）、场发射扫描电镜（FE—SEM）和荧光光谱（PL）等分析手段研究了荧光体的结构和光致发光性能。结果表明,CaMoO4：Eu3＋荧光体的激发光谱由两部分组成：1个宽的激发带（240～360nm）和属于Eu3＋的f—f跃迁的锐线谱（395nm、465nm）,它的发射光谱只出现常见的2个发射峰：592nm（5D0→F1）、615nm（5D0→7F2）,中5D0→7F2跃迁发射峰强度明显高于5D0→7F1跃迁发射峰强度,这表明Eu3＋在CaMoO4基质中处于无反演中心或偏离反演中心的格位上。本文还对造成发射峰强度变化的原因进行了分析,认为影响发射峰强度的原因有两个：表面积和对称性,材料的表面积越大,发光的猝灭越严重,荧光发射越弱;材料的结构对称性越差,跃迁戒律打破地越彻底,荧光发射越强。     

1－（3，4，5－三甲氧基苯甲酰基）－4－芳酰基氨基硫脲的合成及其酸催化环化反应的研究

芳酰基异硫氰酸酯与３，４，５－三甲氧基苯甲酰肼在无水乙腈中缩会，制得一系列新的１－（３，４，５－三甲氧基苯甲酰基）－４－芳酰基氨基硫脲。产物的结构已经元素分析、ＩＲ．１ＨＮＭＲ和ＭＳ方法确证。经初步筛选发现一些化合物有抑制大肠杆菌繁殖的活性。     

新型先导化合物4-[4-(3,4-二甲氧苯基)-2-甲基噻唑-5-甲酰基]吗啉的设计、合成与生物活性

以3,4-二甲氧基苯乙酮为原料,经酯化、氯化、环化、水解、酰氯化和胺化六步制得新型先导化合物4-[4-(3,4-二甲氧苯基)-2-甲基噻唑-5-甲酰基]吗啉(5)。化合物5及其中间体的化学结构经红外、核磁、高分辨质谱和元素分析确认。生物活性测定结果表明化合物5在300ga．i．／hm^2剂量下对马铃薯晚疫病的防效为90％。     

Advances in modifications and high-temperature applications of silicon carbide ceramic matrix composites in aerospace: A focused review

This article is a detailed review of the measures to modify the high-temperature mechanical properties of silicon carbide ceramic matrix composites (SiC CMCs), namely toughness, high-temperature stability and wear resistance. Additionally, it briefly describes the common processing methods of the SiC CMCs and their application in the high-temperature field of aerospace. The advantages and disadvantages of various existing processing and molding methods for the SiC CMCs are also discussed. The high-temperature mechanical properties of the SiC CMCs are mainly affected by the properties of the matrix, added phase and interface. It is crucial to reduce the crystal defects of the matrix and select a suitable enhancement phase for an elevated performance. Moreover, it is important to improve the bonding at the interface between the enhancement phase and the matrix. This review is expected to provide useful information for the subsequent development of complex SiC CMCs for high-temperature applications.     

Influence of lime, fertilizer and manure applications on soil organic matter content and soil physical conditions: a review

The effects of lime, fertilizer and manure applications on soil organic matter status and soil physical properties are of importance to agricultural sustainability. Their effects are complex and many interactions can occur. In the short-term, liming can result in dispersion of clay colloids and formation of surface crusts. As pH is increased the surface negative charge on clay colloids increases and repulsive forces between particles dominate. However, at higher lime rates, Ca²⁺ concentrations and ionic strength in soil solution increase causing compression of the electrical double layer and renewed flocculation. When present in sufficient quantities, both lime and hydroxy-Al polymers formed by precipitation of exchangeable Al, can act as cementing agents bonding soil particles together and improving soil structure. Liming often causes a temporary flush of soil microbial activity but the effect of this on soil aggregation is unclear. It is suggested that, in the long-term, liming will increase crop yields, organic matter returns, soil organic matter content and thus soil aggregation. There is a need to study these relationships on existing long-term liming trials.Fertilizers are applied to soils in order to maintain or improve crop yields. In the long-term, increased crop yields and organic matter returns with regular fertilizer applications result in a higher soil organic matter content and biological activity being attained than where no fertilizers are applied. As a result, long-term fertilizer applications have been reported, in a number of cases, to cause increases in water stable aggregation, porosity, infiltration capacity and hydraulic conductivity and decreases in bulk density. Fertilizer additions can also have physico-chemical effects which influence soil aggregation. Phosphatic fertilizers and phosphoric acid can favour aggregation by the formation of Al or Ca phosphate binding agents whilst where fertilizer NH₄ ⁺ accumulates in the soil at high concentrations, dispersion of clay colloids can be favoured.Additions of organic manures result in increased soil organic matter content. Many reports have shown that this results in increased water holding capacity, porosity, infiltration capacity, hydraulic conductivity and water stable aggregation and decreased bulk density and surface crusting. Problems associated with large applications of manure include dispersion caused by accumulated K⁺, Na⁺ and NH₄ ⁺ in the soil and production of water-repellant substances by decomposer fungi.