As an important industrial material, polyurethane(PU) has many unique and excellent properties, which makes PU materials possess a wide range of applications in many fields. Due to the lack of further modified functional groups on the PU backbone, the high value-addition of PU materials is limited, and its widespread application in high-tech fields is hindered. Therefore, the modification and functionalization of PU is one of the hot topics in academia and industry. At present, there are many methods for modification and functionalization of PU materials. Among them, the Cu(Ⅰ) catalyzed Huisgen 1, 3-dipolar cycloaddition(CuAAC) between an azide and an alkyne compound forming trans 1, 2, 3-triazole compounds, which is the essence of click chemistry reaction, has the characteristics of simple operation, flexibility and high efficiency. It plays a unique and important role in the functional modification research of PU materials. This paper briefly introduces the design idea of functional modification of PU materials based on CuAAC reaction. The functional modification research and application of biocompatibility, hydrophobicity, fluorescence, antibacteria, flame retardancy, shape memory effect, mechanical properties and thermal stability of PU materials based on CuAAC reaction are highlighted. Finally, the main problems of the modified PU via CuAAC reaction are summarized, and the research direction is prospected.

N-alkyl amines are an important class of molecules in the chemical industry and are extensively applied in the syntheses of dyes, pharmaceuticals, agrochemicals, surfactants, rubber ingredients, and functional materials. Given the importance of N-alkyl amines, the development of efficient synthetic methodologies to synthesize these amines is of broad interest. Among various methods, the catalytic alcohol amination has been viewed as effective and green method for synthesis of N-alkyl amines because alcohol is readily available, and water is generated as the sole by-product. This review describes developments and recent advances in the alcohol amination with different heterogeneous catalyst systems, including nickel, copper, palladium, platinum, cobalt, manganese, iron, gold, ruthenium, silver, and other catalyst systems. The frontiers and future of the topic are also given.

As a cross-linked three-dimensional network of hydrophilic polymer materials, hydrogels have similar characteristics to biological tissues and can absorb a large amount of water. As a kind of smart hydrogel, pH-sensitive hydrogel has a certain amount of pH sensitivity due to its structure containing a large number of basic or acidic groups. With these properties, such hydrogels have attracted much attention of researchers in many research fields such as biology, medicine, physics, environment and textiles in recent years. This review mainly focuses on three aspects: the response mechanism, classification and application of pH-sensitive hydrogels. Firstly, the response mechanism of pH sensitivity is reviewed from three aspects: response process, influencing factors and swelling-diffusion model. According to the pH sensitivity of such hydrogel, it can be divided into two types: swelling-shrinking type and sol-gel type. Further, the swelling-shrinking type can be divided into three types: anionic, cationic and amphoteric ionic according to the pH working range of such hydrogel, and the sol-gel type can be divided into borates, hydrazine and imines. In the field of applied research, this article summarizes the research status of such hydrogels in some popular fields such as medicine, environment, biology, intelligent monitoring and functional materials. Finally, the future of such hydrogel is prospected.

Microporous organic polymers(MOPs) is one of the most promising new materials for many applications, such as gas capture and storage, gas separation, organic vapor adsorption, heterogeneous catalyst carrier, water treatment, functional materials and so on, making them to be a research hotspot. This is due to the fact that MOPs have shown many advantages in, for example, excellent thermal stability, chemical stability, low density, high specific surface area, and molecular pore size architecture. Generally, molecular building blocks, particularly being symmetrical in plane or space, are the core architecture in the synthesis of MOPs. Among various building molecules, multi-substituted adamantane, has been reported as a new molecular "knot" candidate for the creation of MOPs, by connecting with a "linkage" molecule, thanks to its highly stereoscopic symmetrical structure and structural rigidity. In addition, the adamantane-based MOPs have shown many advantageous and interesting properties in terms of synthetic yield, structural stability, pore size distribution, gas/vapor adsorption and separation. This mini review focuses on recent progress in the synthesis and interesting properties of the MOPs with adamantane incorporated(MOP-Ad). The MOP-Ad polymers are classified into phenyl-linkage, Schiff base linkage, imide linkage, and nitrogen-rich(benzimidazole and triazine) categories. Special attention is paid to the similarities and differences with comparison in the synthetic route, structural characteristics, stability and adsorption properties. Besides, some emerging new types of Ad-polymers are briefly introduced and an outlook is also proposed for the MOP-Ad.

Small molecular fluorescent probe technology has become a potential tool for biosensing and bioimaging since it can realize real-time dynamic tracking and monitoring of active molecules and microenvironment changes in living organisms with advantages of less disturbance to biological samples, extremely high sensitivity and specificity. In this review, we summarize some characteristics of cellular microenvironment and related bioactive molecules commonly found in them. The design strategies of the molecular fluorescent probes utilized to monitor changes of cellular microenvironments and active molecules are also discussed. Some recently developed molecular fluorescent probes used to monitor microenvironmental changes and active molecules in organisms have also been listed in this review. Additionally, sensing behavior and potential application of these fluorescent probes have also been discussed.

The high level liquid waste(HLLW) generated from PUREX reprocessing process contains more than 95% radioactivity of the spent fuel. Among HLLW, minor actinides with long half-life and high toxicity are one of the main factors that need to isolate HLLW from the biosphere for more than 100 000 years in the deep geological repositories. In order to solve the problem of HLLW more safely and reliably, “separation-transmutation” technology has been put forward, that is, the minor actinides and long-lived fission product elements are separated from HLLW by chemical methods, and then the separated elements are utilized or transmuted according to their properties. The effective separation of different kinds of elements from HLLW is the key step in the separation-transmutation technology. The diglycolamide extractants exhibit excellent extractability towards trivalent actinides and lanthanides in HLLW. In particular, the unsymmetric diglycolamides have greater advantage than the corresponding symmetric diglycolamides in relieving or avoiding the formation of the third phase in the extraction process, and at the same time maintain the good extraction performances. In this paper, the development history, synthesis method, extraction performance, coordination mechanism, flow process, and the third phase formation of unsymmetric diglycolamides are reviewed. The extraction ratio, the separation factor and the critical parameters of the third phase formation of lanthanides, actinides and other major fission elements are compared. Some suggestions are provided for the structural design, coordination mechanism research and process application of the unsymmetric diglycolamides.

The use of solid adsorbents to separate and remove pollutants from the environment is an effective and common method for environmental pollution control, in which functional adsorbents based on inorganic materials are more widely used. Silica nanoparticles feature good stability, easy modification, low cost and environmental friendliness, thus leading to widespread potential in the treatment of environmental pollutants. Compared with traditional silica nanoparticles, fibrous silica spheres have the advantages of large specific surface area and open pores, which can provide more effective adsorption sites and ensure that pore channels are not easily blocked during practical applications, and thus show more potential in adsorption applications. In this paper, the synthesis and preparation of fibrous silica spheres, in particular, the regulation of structural parameters, are summarized and analyzed based on the reported researches and the works of our group. The application of functional fibrous silica spheres in the adsorption and separation of environmental pollutants in recent years is then reviewed and summarized following the analysis of recent progress in the treatment of heavy metals, organics, radionuclides and other environmental pollutants. Finally, the application of functional fibrous silicon sphere in the field of adsorption and separation is prospected from the points of view of limitations of fiber-like silicon sphere synthesis and application potentials.

Ginsenosides are an important kind of active ingredients in Panax genus and can be classified into four main types: the protopanaxadiols(PPD), protopanaxatriols(PPT), oleanolic acids(OA) and ocotillol type(OT). Recently, more than 620 kinds of these compounds have been isolated. Their chemical structures are similar but have quite different medicinal functions. It is of vital importance to develop simple and facile sample pretreatment methods and detection techniques to detect the content of ginsenosides in complex matrix. This review includes many kinds of sample pretreatment methods(such as liquid phase extraction, and solid phase extraction) and detection methods(such as high performance liquid chromatography, ultra-performance liquid chromatography, thin layer chromatography, and gas chromatography), etc., summarizes the sensitivity and recovery of various methods, and reviews the advantages and disadvantages of each method and its research progress.

Dendrimer has several unique properties, including well-defined and highly branched three-dimension structures, uniform size, internal space, substantial number of surface groups, and so forth. Thus, dendrimer has potential applications in catalysis, sensing, and biomedical applications. To improve or achieve these applications, inorganic nanoparticles are incorporated to generate dendrimer-based inorganic nanoparticles. On the other hand, the presence of dendrimers can inhibit the aggregation and improve the stability of inorganic nanoparticles in solution, preserving the excellent properties of these nanoparticles. Over the past decades, dendrimer-based inorganic nanoparticles have attracted wide attention of many researchers owing to their excellent properties and potential applications. Based on the distinct structures, dendrimer-based inorganic nanoparticles have three categories:(1) dendrimer-encapsulated inorganic nanoparticles;(2) dendrimer-stabilized inorganic nanoparticles;(3) dendron-stabilized inorganic nanoparticles. Here we review the advances of the synthesis and applications of dendrimer-based inorganic nanoparticles mainly in recent five years, focusing on catalysis, sensing and biomedical applications. And we outlook the future development of dendrimer-based inorganic nanoparticles.

The sillenite-based photocatalytic materials have attracted the researchers’ interests because of their unique crystal and electronic structures, as well as remarkable visible light absorption abilities. However, they usually have poor photocatalytic activities and stabilities owing to their structural and functional defects, such as high recombination efficiencies of photo-generated charges, low quantum yields, limited active sites, and insufficient exposure of active crystal planes. Therefore, how to achieve optimal modulation of photocatalytic activity and stability based on the structural design and functional integration of sillenite-based photocatalysts on the micro-nano scale is still a key scientific problem. This paper mainly reviews the synthesis strategies of sillenite-based micro/nanomaterials and their latest research progress in the field of photocatalysis, especially focusing on the morphology control, noble metal loading, semiconductor/graphene coupling, ion doping and the development of new sillenite-based photocatalytic systems. Moreover, the photocatalytic applications of sillenite materials are discussed. Finally, the future research prospects of such photocatalytic materials are also pointed out.

Two-dimensional Covalent organic frameworks(2D-COFs), as a new type of crystalline porous materials constructed with organic building blocks, possessing regular pore structure, good stability, high surface area and extended π-conjugation system, have shown good photoactivity and tremendous potential for light-driven chemical transformations. Therefore, the application of 2D-COFs in light-driven chemical transformations has recently garnered great attention in both porous materials science and photocatalysis. This review mainly summarizes and discusses the applications of photoactive 2D-COFs in light-driven chemical transformations in recent years. Future development is also prospected.

Organic dyes possess high molar extinction coefficient and good fluorescence emission performance in visible and NIR region, thus they are often used in spectrochemical sensing. Generally, organic dyes usually contain a large π system, and are easy to form assemblies with specific structures through weak intermolecular interactions(such as, hydrogen bonds, halogen bonds, hydrophobic interactions, π-π stacking interactions, van der Waals forces.) in solution. The aggregation process is often accompanied by obvious color or spectral changes. If a specific functional group is introduced into a dye molecule, binding with an analyte induces the aggregation or disaggregation to produce obvious spectral changes, which can be used for the detection of the analyte. Supramolecular aggregates can provide multiple binding sites simultaneously, and have adjustable spatial orientation between assembly units and higher local concentration of sensing binding groups. Therefore, photochemical sensing based on aggregation process shows superior sensing sensitivity and selectivity. In this review, the application of the aggregation of organic dyes in photochemical sensing is reviewed based on our own research work in recent years. Three aspects of induced aggregation, disaggregation and aggregation re-arrangement are discussed respectively, and the future research and development direction of such fluorescent sensing systems are also prospected.

As the secondary battery with the highest specific energy, lithium ion battery is widely used in portable electronic devices, new energy vehicles and large-scale energy storage power stations. Currently, commercial lithium-ion batteries are facing some technical bottlenecks, such as low energy density and short service life. There are many reports about the anode materials of lithium ion batteries, but most of them cannot overcome the shortcomings such as the huge volume expansion before and after lithium, the pulverization of electrode materials, and the large electrode impedance. However, metal oxides derived from metal-organic frameworks(MOFs) and composites are widely used in lithium ion batteries due to their low level charge-discharge potential platform, high capacity and stable cycle performance. Therefore, in this paper, metal oxides derived from MOFs and composites are divided into four modules: mono-metal oxides, bi-metal oxides, bi-component metal oxide composites and metal oxide/carbon composites. The relationships between their synthesis methods, morphologies and electrochemical properties are summarized, and the opportunities and challenges for their future development are forecast.

Mesoporous carbon spheres are a new type of porous spherical carbon materials. They are promising in many fields such as biomedicine, energy storage/conversion, environmental treatment, and catalysis, thanks to their high surface area, good chemical stability, excellent biocompatibility, tunable pore sizes and volume, and controllable particle size distribution. In the present work, recent advances in the preparing methods of mesoporous carbon spheres, including templating methods, St?ber methods, and microfluidic droplets methods, are summarized. Moreover, the applications of mesoporous carbon spheres as drug delivery system(DDS) including controlled surface property release, stimuli-responsive release, targeted delivery, and theranostic delivery, are reviewed. Finally, the main problems and development trends in the synthesis of mesoporous carbon spheres and applications in DDS for cancer therapy are proposed and discussed.

Due to its extreme non-wetting properties, superhydrophobic surface has a wide range of potential applications in the fields of drag reduction, wear resistance, anti-corrosion, anti-icing, self-cleaning, etc. Surface roughness and low surface free energy are the two determinants of forming superhydrophobic surface and the main reasons of excellent tribological properties of superhydrophobic surface. In this paper, the research on superhydrophobic surface in the field of tribology in recent years is summarized. Firstly, the related theories of the tribology of superhydrophobic surface are analyzed. Then the research status of superhydrophobic surface in the field of tribology is emphatically expounded, and the factors affecting the tribological properties of superhydrophobic surface and its mechanism are discussed. In addition, the tribological study of wear-resistant superhydrophobic surface and slippery liquid infused porous surface(SLIPS) are also analyzed. Finally, the paper puts forward the focus and direction of tribology research on superhydrophobic surface. This review, which has important theoretical and practical significance for expanding the application field of superhydrophobic surface, aims to attract more scholars’ attention to the tribological study of superhydrophobic surface.

Poly(N-(2-hydroxypropyl) methacrylamide) (PHPMA), a water soluble polymer bearing a stable structure, can be metabolized in the human body. Because of that, PHPMA is widely used in anticancer drug’s delivery systems. The drug delivery systems based on the PHPMA have been extensively studied over the past few decades. Scientists use different kinds of functional groups to modify the polymer, which can deliver drugs to targeted tissue or detect pathogenic tissue. In recent studies, scientists enhance the degradability of the polymer and decrease the cytotoxicity, which makes the delivery system based on PHPMA more suitable to be utlized in human body. In this paper, we summarize the recent works about PHPMA and studies of different methods to modify the polymer with drugs or functional groups.

Electrospun 1D nanomaterials have the advantages of such as large specific surface area, high porosity, and superior electrochemical properties, which can significantly improve the sensitivity of gas sensors, making them the most widely used materials in the gas sensor field. In this review, the classification of gas sensor, the principle of electrospinning technology and the sensing mechanism of semiconductor metal oxide gas sensor is highlighted. And the research status of different sensing materials, including semiconductor metal oxide, doped semiconducting metal oxide, polymer-metal oxide, graphene-metal oxide composite material that are prepared by electrospinning and applied in gas sensors is reviewed in detail. Finally, the research prospect in this field is presented.