Zr-Based MOF-Stabilized CO2-Responsive Pickering Emulsions for Efficient Reduction of Nitroarenes.

A Pickering emulsion is a natural microreactor for interfacial catalysis in which an emulsifier is critical. Recently, a metal-organic framework (MOF) has attracted attention to emulsify water-organic mixtures for constructing a Pickering emulsion. However, a few stimuli-responsive Pickering emulsions based on MOFs have been reported, and the MOF emulsifiers cannot be regenerated at room temperature. Herein, the Zr-MOF with a rodlike morphology is synthesized using ionic liquid as a modulator and then modified with n-(trimethoxysilylpropyl)imidazole (C3im) to prepare a series of functionalized Zr-MOFs (MOF-C3im). It is found that MOF-C3im is an excellent emulsifier to construct stable and CO2-responsive Pickering emulsions even at low content (>0.20 wt %). Notably, the emulsification and demulsification of the emulsions can be easily and reversibly switched by bubbling of CO2 and N2 alternatively at room temperature because CO2 and imidazole molecules anchored on the Zr-MOF underwent a reversible acid-base reaction, resulting in an obvious change in the wettability of the emulsifier. As a proof of concept, the reduction reactions of nitrobenzene have been successfully carried out in these Pickering emulsions, demonstrating the efficient integration as a microreactor for chemical reaction, product separation, and emulsifier recycling under ambient conditions. This strategy provides an innovative option to develop stimulus-responsive Pickering emulsions for sustainable chemical processes.

[EMmim][NTf2 ]-a Novel Ionic Liquid (IL) in Catalytic CO2 Capture and ILs' Applications.

Ionic liquids (ILs) have been used for carbon dioxide (CO2 ) capture, however, which have never been used as catalysts to accelerate CO2 capture. The record is broken by a uniquely designed IL, [EMmim][NTf2 ]. The IL can universally catalyze both CO2 sorption and desorption of all the chemisorption-based technologies. As demonstrated in monoethanolamine (MEA) based CO2 capture, even with the addition of only 2000 ppm IL catalyst, the rate of CO2 desorption-the key to reducing the overall CO2 capture energy consumption or breaking the bottleneck of the state-of-the-art technologies and Paris Agreement implementation-can be increased by 791% at 85 °C, which makes use of low-temperature waste heat and avoids secondary pollution during CO2 capture feasible. Furthermore, the catalytic CO2 capture mechanism is experimentally and theoretically revealed.

Anchoring LiCl in the Nanopores of Metal-Organic Frameworks for Ultra-High Uptake and Selective Separation of Ammonia.

Ammonia (NH3 ) is an important chemical raw material and a unique carbon-free fuel with high hydrogen energy density. Thus, NH3 capture, storage, and desorption are of significant importance. However, high capacity capture, low energy desorption, and selective separation of NH3 are still challengs so far. Here, we report high-performance hybrid sorbents by anchoring LiCl in the nanopores of MIL-53-(OH)2 metal-organic frameworks (MOFs). It is found that the optimal composite shows a capture capacity of 33.9 mmol g-1 NH3 at 1.0 bar and 25 °C, which far exceeds the current record among the reported porous materials. Notably, the excellent capture capacity at low pressure and high temperature makes it possible to selectively capture NH3 from NH3 /N2 , NH3 /CO2 , and NH3 /H2 O. It is revealed that synergistic action of NH3 coordination to the highly dispersed Li+ in the MOF nanopores and hydrogen bonding of NH3 with Cl- account for such an excellent capture and selectivity performance.

Reinforcement Learning With Vision-Proprioception Model for Robot Planar Pushing.

We propose a vision-proprioception model for planar object pushing, efficiently integrating all necessary information from the environment. A Variational Autoencoder (VAE) is used to extract compact representations from the task-relevant part of the image. With the real-time robot state obtained easily from the hardware system, we fuse the latent representations from the VAE and the robot end-effector position together as the state of a Markov Decision Process. We use Soft Actor-Critic to train the robot to push different objects from random initial poses to target positions in simulation. Hindsight Experience replay is applied during the training process to improve the sample efficiency. Experiments demonstrate that our algorithm achieves a pushing performance superior to a state-based baseline model that cannot be generalized to a different object and outperforms state-of-the-art policies which operate on raw image observations. At last, we verify that our trained model has a good generalization ability to unseen objects in the real world.

SiGe/Si Multi-Quantum-Well Micro-Bolometer Array Design and Fabrication with Heterogeneous Integration.

The micro-bolometer is important in the field of infrared imaging, although improvements in its performance have been limited by traditional materials. SiGe/Si multi-quantum-well materials (SiGe/Si MQWs) are novelty thermal-sensitive materials with a significantly high TCR and a comparably low 1/f noise. The application of such high-performance monocrystalline films in a micro-bolometer has been limited by film integration technology. This paper reports a SiGe/Si MQWs micro-bolometer fabrication with heterogeneous integration. The integration with the SiGe/Si MQWs handle wafer and dummy read-out circuit wafer was achieved based on adhesive wafer bonding. The SiGe/Si MQWs infrared-absorption structure and thermal bridge were calculated and designed. The SiGe/Si MQWs wafer and a 320 × 240 micro-bolometer array of 40 µm pitch L-type pixels were fabricated. The test results for the average absorption efficiency were more than 90% at the wavelength of 8-14 µm. The test pixel was measured to have a thermal capacity of 1.043 × 10-9 J/K, a thermal conductivity of 1.645 × 10-7 W/K, and a thermal time constant of 7.25 ms. Furthermore, the total TCR value of the text pixel was measured as 2.91%/K with a bias voltage of 0.3 V. The SiGe/Si MQWs micro-bolometer can be widely applied in commercial fields, especially in early medical diagnosis and biological detection.

Wafer-Level 3D Integration Based on Poly (Diallyl Phthalate) Adhesive Bonding.

Three-dimensional integration technology provides a promising total solution that can be used to achieve system-level integration with high function density and low cost. In this study, a wafer-level 3D integration technology using PDAP as an intermediate bonding polymer was applied effectively for integration with an SOI wafer and dummy a CMOS wafer. The influences of the procedure parameters on the adhesive bonding effects were determined by Si-Glass adhesive bonding tests. It was found that the bonding pressure, pre-curing conditions, spin coating conditions, and cleanliness have a significant influence on the bonding results. The optimal procedure parameters for PDAP adhesive bonding were obtained through analysis and comparison. The 3D integration tests were conducted according to these optimal parameters. In the tests, process optimization was focused on Si handle-layer etching, PDAP layer etching, and Au pillar electroplating. After that, the optimal process conditions for the 3D integration process were achieved. The 3D integration applications of the micro-bolometer array and the micro-bridge resistor array were presented. It was confirmed that 3D integration based on PDAP adhesive bonding is suitable for the fabrication of system-on-chip when using MEMS and IC integration and that it is especially useful for the fabrication of low-cost suspended-microstructure on-CMOS-chip systems.

Light-Responsive, Reversible Emulsification and Demulsification of Oil-in-Water Pickering Emulsions for Catalysis.

Pickering emulsions are an excellent platform for interfacial catalysis. However, developing simple and efficient strategies to achieve product separation and catalyst and emulsifier recovery is still a challenge. Herein, we report the reversible transition between emulsification and demulsification of a light-responsive Pickering emulsion, triggered by alternating between UV and visible light irradiation. The Pickering emulsion is fabricated from Pd-supported silica nanoparticles, azobenzene ionic liquid surfactant, n-octane, and water. This phase behavior is attributed to the adsorption of azobenzene ionic liquid surfactant on the surface of the nanoparticles and the light-responsive activity of ionic liquid surfactant. The Pickering emulsion can be used as a microreactor that enables catalytic reaction, product separation as well as emulsifier and catalyst recycling. Catalytic hydrogenation of unsaturated hydrocarbons at room temperature and atmospheric pressure has been performed in this system to demonstrate product separation and emulsifier and catalyst re-use.

Ambient CO2/N2 Switchable Pickering Emulsion Emulsified by TETA-Functionalized Metal-Organic Frameworks.

In recent years, metal-organic frameworks (MOFs) have been explored as emulsifiers for the fabrication of Pickering emulsions and then used for hybrid material synthesis and interface catalysis. Nevertheless, stimuli-responsive Pickering emulsions stabilized by MOFs have been rarely reported so far, although they are of great importance for fundamental research studies and practical applications. Herein, for the first time, triethylenetetramine (TETA)-functionalized MOFs (ZIF-90/TETA) have been designed, synthesized, and used for fabricating CO2-/N2-response Pickering emulsions. It is shown that even at the ZIF-90/TETA content of 0.25 wt %, the functional MOF can still efficiently emulsify n-hexane and water to form a high internal phase Pickering emulsion. Importantly, the Pickering emulsion can be easily and reversibly switched between emulsification and demulsification by bubbling of CO2 and N2 alternatively at atmospheric pressure. The possible mechanism of the CO2/N2 switchable emulsion is investigated by zeta potential, water contact angle, interfacial tension, 13C NMR spectroscopy, and an optical microscope. It is found that the acid-base reaction of CO2 with TETA anchored on the surface of ZIF-90 leads to the production of hydrophilic ammonium bicarbonate and carbamate, which results in the emulsification of the Pickering emulsion. However, when N2 is bubbled to remove CO2, the reverse reaction takes place to cause the demulsification of the Pickering emulsion. Moreover, the CO2/N2 switchable Pickering emulsion has been successfully used as a microreactor for Knoevenagel reactions to demonstrate a highly efficient integration of chemical reaction, product separation, and ZIF-90/TETA recycling for a sustainable chemical process.

Cellulomonas telluris sp. nov., an endoglucanase-producing actinobacterium isolated from Badain Jaran desert sand.

A Gram-stain-positive, aerobic bacterium, designated CPCC 204705T, was isolated from a desert soil sample, collected from the Badain Jaran desert. Growth of strain CPCC 204705T was observed at pH 6.0-8.0 and 15-37 °C, with optimal growth at 28 °C and pH 7.0. Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain CPCC 204705T belonged to the genus Cellulomonas, showing the highest similarity (98.54 %) of 16S rRNA gene sequence to Cellulomonas oligotrophica JCM 17534T. The peptidoglycan type was A4ß, containing d-ornithine and d-glutamic acids as diagnostic amino acids. Rhamnose and galactose were detected in the whole-cell hydrolysate as diagnostic sugars. The major cellular fatty acids were anteiso-C15 : 0, anteiso-C15 : 1A, C14 : 0 and C16 : 0. The major menaquinone was MK-9 (H4) and the polar lipid system contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol mannoside, one unidentified lipid, one unidentified aminolipid and two unidentified aminophospholipids. The DNA-DNA hybridization value between strain CPCC 204705T and C. oligotrophica JCM 17534T was 7.1±0.4 %, and the value of average nucleotide identity between these two strains was 79.8 %. The DNA G+C content of strain CPCC 204705T was 75.4 mol%. Based on the results of physiological experiments, chemotaxonomic data, phylogenetic analysis and DNA-DNA hybridization value, strain CPCC 204705T should be classified as a novel Cellulomonas species. The name Cellulomonas telluris sp. nov. is proposed, with strain CPCC 204705T (=DSM 105430T=KCTC 39974T) as the type strain.

A novel crystalline azine-linked three-dimensional covalent organic framework for CO2 capture and conversion.

The targeted synthesis of three-dimensional covalent organic frameworks (3D COFs) is a great challenge, especially those synthesized by using a new kind of organic linkage. Herein, for the first time, a novel 3D azine-linked COF (3D-HNU5) has been synthesized and characterized. It is shown that the obtained 3D COF has a 2-fold interpenetrated diamond topology, and shows good chemical/thermal stability and a narrow pore size distribution, which exhibits excellent performance in the selective uptake of CO2 over N2. Moreover, the 3D-HNU5 is found to be an efficient catalyst for the cycloaddition of propargylic alcohols with CO2 into carbonates with excellent catalytic activity under mild conditions.

Imidazolium-Salt-Functionalized Covalent Organic Frameworks for Highly Efficient Catalysis of CO2 Conversion.

The conversion of CO2 into valuable chemicals is an ideal pathway for CO2 utilization in industry, although the development of highly efficient catalysts remains a challenge. Herein, the design and synthesis of two covalent organic frameworks (COFs) functionalized with imidazolium salts were reported as catalysts for CO2 conversion. The resultant COFs possessed highly crystalline structures, showed high stability and surface area, and contained dense catalytic active sites on the pore walls. They exhibited outstanding catalytic performances for the reaction of CO2 with epoxides without any solvent or cocatalyst under mild conditions and afforded a record turnover number of 495 000. In addition, the COFs could serve as effective catalysts in the reductive reaction of CO2 with amines. The results presented here thus demonstrate the exceptional potential of the functionalized COFs for various challenging CO2 transformations.

Simplicispira lacusdiani sp. nov., a novel betaproteobacterium isolated from a freshwater reservoir.

A Gram-stain-negative, motile, rod-shaped bacterium, designated CPCC 100842T, was isolated from a freshwater reservoir in south-west China. The 16S rRNA gene sequence comparison of strain CPCC 100842T with the available sequences in the GenBank database showed that the isolate was closely related to members of the family Comamonadaceae, with the highest similarities to Simplicispira metamorpha DSM 1837T (98.05 %), Simplicispira limi KCTC 12608T (97.86 %), Simplicispira psychrophila LMG 5408T (97.04 %) and Simplicispira piscis JCM 19291T (97.0 %). In the phylogenetic tree based on 16S rRNA gene sequences, strain CPCC 100842T formed a distinct phylogenetic subclade within the genus Simplicispira. The major cellular fatty acids were as C16 : 0 and summed feature 3 (C16 : 1 ω7c/C16 : 1ω6c). Q-8 was detected as the only respiratory quinone. Phosphatidylethanolamine, phosphatidylglycerol, diphosphatidylglycerol, aminophospholipid and glycolipid were found in the polar lipid extraction. The genomic DNA G+C content was 67.4 mol%. The average nucleotide identity value was 80.4 % by comparing the draft genome sequences of strain CPCC 100842T and S. metamorpha DSM 1837T. The DNA-DNA hybridization result between strain CPCC 100842T and S. metamorpha DSM 1837T showed 37±3 % genomic relatedness. On the basis of the genotypic analysis and phenotypic characteristics, we propose that strain CPCC 100842T represents a novel species of the genus Simplicispira in the family Comamonadaceae with the name Simplicispira lacusdiani sp. nov. Strain CPCC 100842T (=KCTC 52093T=DSM 102231T) is the type strain of the species.

Diversity of Bacteria and the Characteristics of Actinobacteria Community Structure in Badain Jaran Desert and Tengger Desert of China.

To assess the diversity of actinobacterial taxa in desert sands and obtain the novel microbial resources, 79 and 50 samples were collected from the Badain Jaran (BJD) and Tengger Deserts (TGD) of China, respectively. High-throughput sequencing (HTS) of environmental 16S rRNA genes within these samples was conducted on an Illumina Miseq platform, using universal bacterial primers targeting the V3-V4 hypervariable region. Based on the HTS analyses, cultivation-dependent (CULD) techniques were optimized to identify the cultivable Actinobacteria members. A total of 346,766 16S rRNA gene reads comprising 3,365 operational taxonomic units (OTUs) were obtained from the BJD sands using HTS, while 170,583 reads comprising 1,250 OTUs were detected in the TGD sands. Taxonomic classification indicated that Actinobacteria was the predominant phylum, comprising 35.0 and 29.4% of the communities in BJD and TGD sands, respectively. Among the Actinobacteria, members of the Geodermatophilaceae were considerably abundant in both deserts, indicating that they represent ubiquitous populations within the deserts. At the genus level, Arthrobacter spp. and Kocuria spp. were dominant, and corresponded to 21.2 and 5.3% of the actinobacterial communities in BJD and TGD deserts, respectively. A total of 786 and 376 actinobacterial strains were isolated and identified from BJD and TGD samples, respectively. The isolates comprised 73 genera of 30 families within the phylum Actinobacteria. In addition to the Geodermatophilaceae, Streptomyces spp. were a prominent component of the isolates, comprising 25% of the isolates from BJD and 17.5% of those from TGD. Comparison of the actinobacterial community structure in other ecosystems indicated that Geodermatophilaceae was the main actinobacterial group in desert sands, which is consistent with our results. Additionally, in these desert habits, Geodermatophilaceae and some other core groups may promote or inhabit the subsequent members' occurrence or prosper to shape the bacteria community structure. However, it should be noted that a number of other low-abundance bacteria appear to be specific to desert sands, which are worth further investigation. In antimicrobial activity assays, 10.36 % of the tested isolates showed antimicrobial activities in one or more screens. Importantly, 37 of the newly isolated strains reported here represent novel taxa that could be valuable resources for further research of novel secondary metabolites and their ecological significance in deserts.

Visible Light-Controlled Inversion of Pickering Emulsions Stabilized by Functional Silica Microspheres.

A new class of donor-acceptor Stenhouse adduct (DASA)-functionalized silica microspheres (SMs) is designed and described to formulate Pickering emulsions with inversion property and large polarity change upon visible light irradiation. By tuning the hydrophilicity of the functional SM particles with visible light, these Pickering emulsions can easily perform inversion from water-in-oil to oil-in-water. The inversion performance of the emulsions is ascribed to DASA photoisomerization from an extended, hydrophobic, and intensely purple-colored triene to a compact, zwitterionic, and colorless cyclopentenone upon irradiation with visible light. This unique inversion behavior has been applied to control encapsulation and the release of fluorescein sodium salt.

Reversible Switching of Amphiphilic Self-Assemblies of Ionic Liquids between Micelle and Vesicle by CO2.

The creation of CO2-responsive materials that undergo structural transition between micelle and vesicle is of great importance from both theoretical and practical points of view. In this work, we have developed a series of CO2-responsive single-tailed amphiphilic ionic liquids (ILs) composed of N-alkyl-N-methyldiethanolamine cation [CnMDEA](+) (n = 8, 10, 12, 14, 16, 18) and 2-pyrrolidinone [2-Pyr](-) anion. The aggregation behavior and self-assembly structures of the ILs in aqueous solution have been investigated by conductivity, surface tension, dynamic light scattering, cryogenic transmission electron microscopy, small-angle X-ray scattering, and nuclear magnetic resonance spectroscopy. For the first time, CO2 driven reversible switching of self-assembly between spherical micelle and unilamellar vesicle is found for [CnMDEA][2-Pyr] (n = 16, 18) in aqueous solutions at 20 °C and atmospheric pressure. It is shown that the mechanism behind the reversible micelle to vesicle transition involves the formation of carbamate anion from the reaction between [2-Pyr](-) and CO2.