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Recently, double network (DN) gels with dynamic non‐covalent interaction such as hydrogen bonds has drawn much attention as an innovative material having both high water content and high mechanical strength. Research efforts have identified DN gels as a promising class of materials due to their unique network architecture. These gels comprise two interpenetrating networks formed by different types of polymer. Herein, we report a tough DN hydrogel with high mechanical strength and high swelling ability. The DN gel is synthesized via a two‐step network formation. The first network gel was synthesized via frontal polymerization. Then, the first gel is immersed in an aqueous solution of a second monomer and carrying out a second polymerization in the presence of first network. The spectroscopic analysis and thermal behavior with differential scanning calorimeter measurements corroborated the existence of hydrogen bonds. The mechanical test and microscopic morphology were further explored to explain the strength and high imbibing characteristics. We expect that this facile strategy may explore a dynamic and tunable hydrogel to expand its potential applications in biomedical field.

Hydrogels have been attracting much attention as smart soft materials. The exploration of methods allowing hydrogels to have anisotropic composition, structure, and properties would benefit the fabrication of smart materials with versatile multi‐functions. Here we report the rapid frontal polymerization (FP) of bilayer hydrogels possessing good water swelling, mechanical strength, self‐healing, biocompatibility, and antibacterial capabilities. The bilayer hydrogels, consisting of poly(AM‐co‐AMPS) (G‐1) and poly(AM‐co‐HPA) (G‐2) (AM, acrylamide; AMPS, 2‐acrylamide‐2‐methylpropanesulfonic acid; HPA, hydroxypropyl acrylate), are synthesized in one step within 6 minutes (min) by horizontal FP. These polymer hydrogels have hierarchical porous morphology with pore sizes of several micrometers and several hundreds of micrometers respectively, equilibrium swelling ratio up to 3371% in water, tensile strength up to 0.204 MPa, and self‐healing ability. The good cytocompatibility and low toxicity of the hydrogels are demonstrated through cell culture of L929 fibroblasts in vitro experiments. The tests of hydrogels with Escherichia coliand Staphylococcus aureusreveal their antibacterial property. The results demonstrate that biocompatible anisotropic hydrogels with versatile functions could be fabricated via the rapid and energy‐saving approach of FP.

AbstractLiquid–liquid extraction (LLE) and solid-phase microextraction (SPME) methods were applied to extract the aroma compounds of rum. Aroma compounds were separated and analyzed with gas chromatography–mass spectrometry of DB-WAXetr capillary columns. One hundred and twelve compounds, including alcohols, esters, aldehydes, ketones, phenols, acids, and other compounds, were identified by two extraction methods. Among them, 88 and 74 compounds were identified by SPME and LLE, respectively. SPME and LLE methods were suitable for the qualitative and semi-quantitative analysis of rum, respectively. Principal component analysis results showed that the first principal component (PC1) and the second principal component (PC2) explained 80.9% of the difference in variable samples (PC1 = 52.7%, PC2 = 28.2%), which can represent the variable characteristics of the samples. The extraction effects of LLE and SPME on the aroma compounds of rum obviously differed, however, the aroma compounds obtained by the two extraction methods can complement each other.Supplemental data for this article is available online at at [publisher’s weblink].

[Display omitted] • Single sensitive photonic crystal supraballs are prepared via microfluidics. • Hierarchical Janus and molecular-shaped supraballs are manipulated. • Quadruple responses are achieved simultaneously in a supraballs. • 2D multi-responsive patterns were printed by a facile automatic printing system. The design and fabrication of anisotropic photonic crystal supraballs with multiple responses are highly desirable for versatile environmental sensing and flexible displaying. Herein, we developed an available strategy to construct a series of multi-responsive magnetic colloidal photonic crystal (CPC) supraballs with Janus and molecular-analogue structures. Initially, the humidity and temperature sensitive CPC supraballs were obtained via immobilization of polyacrylamide (PAM) and polyisopropylacrylamide (PNIPAM) hydrogels into the CPC structure, respectively, and CdTe/ZnS quantum dots endow the supraballs fluorescent signal under UV light. Furthermore, Fe 3 O 4 nanoparticles (NPs) were served as a magnetic hemisphere to construct CPC Janus supraballs which can be subsequently assembled into three different molecular-shaped cluster particles that integrate more response types via Fe 3 O 4 NPs hemisphere coalescence to a magnetic coupling center, recognizing multiple responses simultaneously that correspond the environmental altering. In addition, 2D polychromatic patterns with sensitive CPC pixels printed by automatic printing system were demonstrated, which could monitor the changes of temperature and humidity. The multi-responsive magnetic controlling supraballs and 2D patterns reveal the promising applications in environmental sensing, anti-counterfeiting and displaying. [ABSTRACT FROM AUTHOR]

In this article, a decentralized adaptive finite-time tracking control scheme is proposed for a class of nonstrict feedback large-scale nonlinear interconnected systems with disturbances. First, a practical almost fast finite-time stability framework is established for a general nonlinear system, which is then applied to the design of the large-scale system under consideration. By fusing command filter technique and adaptive neural control and introducing two smooth functions, the “singular” and “explosion of complex” problems in the backstepping procedure are circumvented, while the obstacles caused by unknown interconnections are overcome. Moreover, according to the framework of practical almost fast finite-time stability, it is shown that all the closed-loop signals of the large-scale system are almost fast finite-time bounded, and the tracking errors can converge to arbitrarily small residual sets predefined in an almost fast finite time. Finally, a simulation example is presented to demonstrate the effectiveness of the proposed finite-time decentralized control scheme. [ABSTRACT FROM AUTHOR]

The theory of heat conduction paths has been widely recognized and widely studied in the research about the thermal conductivity of thermal conductive polymer composites at present. Encapsulating polymer pellets with thermally conductive fillers and processing them into thermally conductive polymer composites is a simple and effective method for constructing heat conduction paths. It is meaningful to investigate the related heat conduction mechanism of this method. Otherwise, this approach can significantly preserve the performance of the polymer substrate, making it highly valuable for practical material applications. In this work, polyethylene-octene elastomer (POE) pellets were encapsulated with thermal conductive fillers by physical absorption. Subsequently, the composite films containing heat conduction paths were fabricated using the encapsulated POE pellets through a heating press. Alumina (Al2O3), boron nitride (BN), and alumina/boron nitride hybrid (Al2O3/BN) fillers were used to prepare Al2O3@POE, BN@POE, and BN/Al2O3@POE composite films to investigate the influence of filler shapes on heat conduction path construction. The influence of the constitute and density of heat conduction paths on the thermal conductivity of composite films was analyzed by infrared thermal imaging, finite element analysis, and thermal resistance theory in detail. Owing to the reserved good adhesion and flexibility of the POE substrate, the composite films could be directly used as thermal interface materials for chip cooling, which presented a good heat dissipation effect. Furthermore, a series of integrated composite materials were prepared by the combination of encapsulated pellets with various functional films (copper foil, aluminum foil, and graphite sheet) through a one-pot heating press, exhibiting a good electromagnetic shielding effect. The performance of the composites and the corresponding preparation method demonstrate the strong significance of this research for practical applications.

Heavy metal ion pollution has been considered a big issue because of the high harmful and destructive effects to human beings. Hydrogel adsorption has received considerable interest in this aspect. However, the challenge still exists because the adsorption process is time-consuming. Herein, we designed and prepared poly(HPA-co-AA-co-NVP) hydrogels (HPA = hydroxypropyl acrylate, AA = acrylic acid, NVP = N-vinyl-2-pyrrolidone) via frontal polymerization (FP) for heavy ion removal. By virtue of high reaction rate of FP, the whole process of polymerization could be accomplished within 10 min without further energy. The as-prepared hydrogels exhibited pH sensitivity, excellent self-healing properties (a self-healing efficiency up to 90.9%), and heavy metal ion adsorption behavior. More importantly, we developed a new solar-driven method for rapid ion uptake, where solar energy was used to facilitate the adsorption rate. As compared to general adsorption in water without any treatment, this new solar-driven method provides a great efficient adsorption process toward heavy metal ions, which increases by 6 times. Furthermore, the application in desalination of seawater was also realized by the solar-driven method. This work not only provides a time-saving and low-energy synthesis pathway for multifunctional hydrogels via FP but also gives a new insight into rapid removal of ions by a new solar-driven method.

Macroscopic self-assembly has increasingly attracted numerous concerns because of the facile fabrication of complex structures and diversified morphologies. Key challenges still remain to design high-performance building blocks to increase the efficiency and diversity of macroscopic self-assembly. Here, we designed triple noncovalent interactions (carboxyl-Zn2+coordination, host–guest interactions, and hydrogen bonding interactions) to enhance the interactions between self-healing fibers, constructing multidimensional nonwoven fiber-based fabrics through macroscopic self-assembly without further postprocessing. Profiled from the strong interactions generated from triple noncovalent interactions, ordered two-dimensional plane and three-dimensional spiral gel fabrics were fabricated using polyvinyl pyrrolidone/gel-based fibers as building blocks toward a human motion sensor. Moreover, we demonstrated that the macroscopic self-assembly strategy is universal to construct three-dimensional film-based fabrics toward wound dressing based on the triple noncovalent interactions between two-dimensional films. This macroscopic self-assembly approach provides an alternative strategy to fabricate gel fabrics for various applications.

Hydrogels that are capable of autonomous healing upon damage have attracted wide attention in recent years. The design and fabrication of hydrogels possessing both excellent self-healing and high strength is highly desired. Herein, we report the facile synthesis of self-healing poly(MAH-β-CD-co-AA) hydrogels (MAH-β-CD = β-cyclodextrin grafted vinyl carboxylic acid groups; AA = acroleic acid) via frontal polymerization (FP) for the first time. When ignited by a soldering iron, frontal polymerization occurred to fabricate poly(MAH-β-CD-co-AA) hydrogels within 10 min. The as-fabricated hydrogels exhibited pH sensitivity and high mechanical strength and could repair themselves autonomously without any external stimuli. In addition, we reinforced poly(MAH-β-CD-co-AA) hydrogel through further cross-linking with N-isopropylacrylamide to form a double network (DN) hydrogel. Benefiting from the excellent self-healing property, a Janus bilayer hydrogel toward temperature-triggered actuator was achieved by simply sticking poly(MAH-β-CD-co-AA) and DN hydrogel together. This hydrogel actuator was very sensitive to thermal stimulus, which showed a rapid response in several seconds. This work might promote the development of diverse functional self-healing hydrogels via a facile and flexible pathway.

Heat dissipation has become a central issue for the development of the microelectronic industry. Thermal interface materials (TIMs) have been widely applied to electron component cooling, which is used to bond the heat spreader and the chip together. Most research on TIMs has only dealt with thermal conductivity enhancement. However, the mechanical properties and adhesion of TIMs are indispensable for practical applications, as well as postcleaning to remove TIMs. A graphene nanosheet/polyolefin elastomer (GNP/POE) film was designed and prepared by a facile method, in which the heat conduction paths were efficiently constructed, and the good mechanical properties of POE were reserved. The thermal conductivity of as-prepared GNP/POE film can reach 1.07 W m–1K–1at an extremely low filler loading of 0.62 wt %. Furthermore, the tensile strength, elongation at break, and adhesion of the prepared GNP/POE film are as good as those of commercial TIM productions. The prepared GNP/POE film can be used as TIMs for chip cooling and exhibits a good heat dissipation effect. Additionally, the prepared GNP/POE film can be peeled off from the chip without residue, after the chip has finished running, which is significant for practical production. This work provides valuable information and insight into the design and fabrication of TIMs in the future.

Several publications have documented the technical feasibility and efficacy of stent grafting for aortic injuries. We report short- and mid-term results of thoracic endovascular repair with covered stent grafts for type B blunt thoracic aortic injury.

Simulation of the absorption column was studied. A new mathematic model was developed and tested against the actual operation data. From this, the accuracy of the model was proved. The pressure, temperature and gas composition on absorption effect was discussed. And from the point of the practical production, more optimized operating conditions of the nitric acid absorption tower were showed. It makes the dilute acid concentration increase by 3 percent and the exhaust emission of NOx decrease by 45ppm.

The liquid lift-up of directed combined trapezoid spray tray (CTST) was studied. The relationship between Liquid lifting capability of combined CTST and clear liquid height on the plate, F-factor based on tray hole was concluded. In single cap and combined several caps, the change of relative and absolute lift-up was also studied. The effect of F-factor to absolute elevating amount was determined by clear liquid height. On the condition of the higher or the lower clear liquid height, the influence of the F-factor to absolute lift-up was considerable. The relation between the pressure drop inside/outside of the bottom gap and liquid lift-up was studied.

AbstractSemicarbazones of aldehydes and ketones are oxidized to the corresponding carbonyl compounds in excellent yields by tetrabutylammonium peroxydisulfate in dichlorlethane under mild conditions.

A series of primary amines are oxidized to the corresponding nitriles in excellent yields with tetrabutylammonium peroxydisulfate catalyzed by nickel copper formate under basic aqueous conditions.

A series of primary amines are oxidized to the corresponding nitriles in excellent yields with tetrabutylammonium peroxydisulfate catalyzed by nickel copper formate under basic aqueous conditions.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.