Development of an external standard method for the high-throughput determination of broadly polar multiclass synthetic dyes in high-sugar, high-fat, and high-protein foods.

Simultaneous detection of multiple synthetic dyes in food additives presents a challenge. A high-throughput UPLC-Q-OMS method with purification-free extraction was developed for the simultaneous detection of 30 synthetic dyes across six categories in various foods. The results showed satisfactory separation of the dyes was achieved using a phenyl column, acetonitrile, and a 5 mmol/L ammonium acetate mobile phase.

Topology of Gemini-shaped Hexagonal Heterojunction for Efficient Stereoconvergent Transformation via Dynamic Kinetic Resolution.

Despite recent advances in the combination of kinetic resolution and racemization for efficient stereoconvergent transformation, the poor stability and limited reaction activities of the products restrict their wide application in industrial production. To overcome these problems, Gemini-shaped hexagons with para-heterojunctions for one-dimensional and two-dimensional supramolecular polymers were designed via hydrogen-bonding adhesion by racemization catalyst 1 and kinetic resolution 2 in this work. The polymers from the assembly of Gemini-shaped hexagons exhibit rapid catalytic behaviour with efficient selectivity for the desired configuration in the synthesis of tertiary alcohols with contiguous stereocenters through dynamic kinetic resolution for the nanoscale heterojunctions of dissimilar catalysts.

Hierarchical porous photosensitizers with efficient photooxidation.

Photosensitizers (PSs) with nano- or micro-sized pore provide a great promise in the conversion of light energy into chemical fuel due to the excellent promotion for transporting singlet oxygen (O) into active sites. Despite such hollow PSs can be achieved by introducing molecular-level PSs into porous skeleton, however, the catalytic efficiency is far away from imagination because of the problems with pore deformation and blocking. Here, very ordered porous PSs with excellent O generation are presented from cross-linking of hierarchical porous laminates originated by co-assembly of hydrogen donative PSs and functionalized acceptor.

Ambient air pollutants concentration prediction during the COVID-19: A method based on transfer learning.

Research on the correlation analysis between COVID-19 and air pollution has attracted increasing attention since the COVID-19 pandemic. While many relevant issues have been widely studied, research into ambient air pollutant concentration prediction (APCP) during COVID-19 is still in its infancy. Most of the existing study on APCP is based on machine learning methods, which are not suitable for APCP during COVID-19 due to the different distribution of historical observations before and after the pandemic.

Preparation of a laminated structured polyethyleneimine cryogel for carbon capture.

A cryogel solid amine adsorbent with a laminated structure has been prepared by crosslinking polyethylenimine (PEI) with ethylene glycol diglycidyl ether (EGDE) at a low temperature via liquid nitrogen treatment and freeze-drying. The effects of cryogenic treatment on the morphology of the cryogels were investigated. The liquid nitrogen treatment and freeze drying were critical to create the layered structure.

Preparation of a Fiber-Like 3D-Structured Adsorbent for CO Capture.

Solid amine adsorbents are promising materials to mitigate global warming. In this study, a commercially available melamine-formaldehyde sponge was adopted as a support to prepare a kind of solid amine adsorbent using polyethylenimine as a functional component and ethylene glycol diglycidyl ether as a cross-linker. The adsorbent, with abundant tunnels and a high amine loading amount, had a high adsorption capacity.

Synthesis and characterization of a thermosensitive solid amine biomass adsorbent for carbon dioxide adsorption.

A thermosensitive solid amine fiber SF-AM-co-NIPAM-HBP-NH was synthesized by grafting temperature-sensitive monomer N-isopropyl acrylamide (NIPAM) as well as acrylamide (AM) onto the surface of substrate sisal fiber, and further aminating with hyperbranched amine. FTIR, C NMR, SEM, EA and TGA were used to confirm the structure and chemical properties of the grafted fibers. Swelling ratio and CO adsorption-desorption experiment were investigated to verify the thermo-sensitivity of the grafted fibers and their CO adsorption-desorption behavior.

Preparation of a Solid Amine Microspherical Adsorbent with High CO Adsorption Capacity.

Amine-skeleton solid-amine materials are promising adsorbents for CO capture from flue gas. Here, a novel solid-amine microsphere was synthesized by cross-linking the skeleton poly(ethylenimine) (PEI) with ethylene glycol diglycidyl ether in a facile one-pot W/O emulsion system. The material had a remarkable CO adsorption capacity of 7.

PVAm Nanofibers Fabricated by Rotary Jet Wet Spinning and Applied to Bisphenol A Recognition.

Poly(vinylamine) (PVAm) is an important polymer with the highest content of primary amine groups of any polymer. PVAm has a great potential in selective separation and smart materials. It is difficult to fabricate pure PVAm nanofibers by electrospinning and rotary jet spinning (RJS) without additional polymers.

Adsorption behavior of Au(III) and Pd(II) on persimmon tannin functionalized viscose fiber and the mechanism.

A novel bio-adsorbent (DAVF-PT) was prepared by the introduction of persimmon tannin (PT) on the surface of viscose fiber (VF) through condensation reaction. The adsorbent was applied to the adsorption of Au(III) and Pd(II) from aqueous solution. Batch adsorption experiment found that the adsorption performance of DAVF-PT for Au(III) and Pd(II) was closely related to pH of solution, initial metal ion concentration as well as co-existing metal ions.

Synthesis of porous polymer based solid amine adsorbent: Effect of pore size and amine loading on CO adsorption.

A series of porous polymers was synthesized by a suspension polymerization of divinylbenzene (DVB) and ethylene glycol dimethyl acrylate (EGDMA), which was further functionalized with polyethyleneimine (PEI) for CO capture. The results showed that the synthesized DVB and EGDMA (DE) copolymers were an effective support for loading PEI because of its larger pore size and specific surfaces area. It was found that DE (30, 10) loaded with 30wt% PEI exhibited a higher CO adsorption amount of 3.

Preparation and Properties of A Hyperbranch-Structured Polyamine adsorbent for Carbon Dioxide Capture.

A fibrous adsorbent with amino-terminated hyperbranch structure (PP-AM-HBP-NH) was prepared by grafting hyperbranched polyamine (HBP-NH) onto the acrylamide-modified polypropylene (PP) fibers. The grafting of AM on PP fibers provided the active sites for introducing HBP-NH onto the PP fibers. This kind of "grafting to" procedure to synthesize hyperbranch-structured fiber could overcome the disadvantages of stepwise growth procedure, avoiding the complicated synthesis process and the requirement of strict experimental conditions.

Solid Amine Adsorbent Prepared by Molecular Imprinting and Its Carbon Dioxide Adsorption Properties.

A carbon dioxide imprinted solid amine adsorbent (IPEIA-R) with polyethylenimine (PEI) as a skeleton was conveniently prepared by using glutaraldehyde to cross-link carbon dioxide-preadsorbed PEI. As confirmed by FTIR, FT-Raman, and C NMR spectroscopy, CO preadsorbed on PEI could occupy the reactive sites of amino groups and act as a template for imprinting in the cross-linking process. The imino groups formed from the cross-linking reaction between glutaraldehyde and PEI could be reduced by NaBH to form CO -adsorbable amino groups.

Preparation and characterization of amine-functionalized sugarcane bagasse for CO2 capture.

A low-cost solid amine adsorbent for CO2 capture was prepared by using sugarcane bagasse (SB), a dominant agro-industrial residue in the sugar and alcohol industry as raw materials. In this preparation process, acrylamide was grafted on SB, and the grafted fiber was then aminated with different type of amine reagents to introduce primary and secondary amine groups onto the surface of SB fibers. The graft and amination conditions were optimized.

Design, synthesis, and characterization of 1,3,5-tri(1H-benzo[d]imidazol-2-yl)benzene-based fluorescent supramolecular columnar liquid crystals with a broad mesomorphic range.

A new kind of supramolecular columnar liquid crystal T-A with a broad mesomorphic range (up to 164.9 °C), good thermal stability, and strong fluorescence is designed and formed by the H-bonding between 1,3,5-tri(1H-benzo[d]imidazol-2-yl)benzene (T) and serial gallic acid derivatives (A). Two components are easily available because of simple routes, common reactions, high yields, commercial starting materials, and inexpensive catalysts.

Design of a viscose based solid amine fiber: effect of its chemical structure on adsorption properties for carbon dioxide.

A solid amine fiber VF-AM-TETA was designed with viscose (VF) substrate for efficient CO2 capture, where its hydroxyl groups could serve synergizing effect in CO2-amine reaction. When grafting modification and subsequent amination were applied to VF, effect of structures of grafting monomers as well as amines on its CO2 adsorption properties was taken into account. Amines with different 1° and 2° amine ratios were investigated as amination agents in terms of amine efficiency, so as to afford the fibrous adsorbent with maximum effective reactive amine sites for CO2 capturing.

Surface molecular imprinting on polypropylene fibers for rhodamine B selective adsorption.

A surface molecular imprinted fiber (MIF-B) for rhodamine B (RhB) was prepared by bonding polyethylenimine (PEI) onto polypropylene (PP) fibers and subsequently cross-linking with epichlorohydrin (ECH) in the presence of RhB. The chemical structures of composites in each synthetic step were traced by FTIR analyses. The MIF-B exhibited excellent static and dynamic adsorption properties for RhB.

Preparation of an ion-imprinted fiber for the selective removal of Cu2+.

A novel Cu(2+)-imprinted fiber (IIF) was prepared by grafting acrylic acid (AA) onto the surface of a polypropylene (PP) fiber and subsequently modified with polyethylenimine (PEI). An examination by infrared spectroscopy and scanning electron microscopy confirmed that the ion-imprinted polymer was successfully introduced onto the surface of a PP fiber. The modification of PP fibers with AA was beneficial to the grafting of PEI onto the fibers.

Preparation and characterization of a solid amine adsorbent for capturing CO2 by grafting allylamine onto PAN fiber.

Solid amine adsorbents using synthetic fibers instead of silica as the matrix are expected to offer more benefits for the adsorption of CO(2) because of high external surface area, low pressure drops, and flexibility of the matrix fibers. A novel kind of solid amine-containing fibrous adsorbent (PAN-AF) was prepared by preirradiation grafting copolymerization of allylamine onto polyacrylonitrile (PAN) fiber, using the redox system of (NH(4))(2)S(2)O(8)/NaHSO(3) as initiator. The effects of the reaction conditions such as reaction time, temperature, monomer concentration, amount of the initiator on grafting degree were studied.

Preparation of amine group-containing chelating fiber for thorough removal of mercury ions.

An aminated chelating fiber (AF) with high adsorption capacity for mercury ions was prepared by grafting copolymerization of acrylonitrile onto polypropylene fiber, followed by aminating with chelating molecule diethylenetriamine. Effects of reaction conditions such as temperature, reaction time, bath ratio and dosage of catalyst on the grafting yield were studied. Chemical structure, tensile strength and thermal stability of AF were characterized.

CO2 capture by polyethylenimine-modified fibrous adsorbent.

This work focuses on developing a novel adsorbent for CO2 capture, by coating polyethylenimine (PEI) on glass fiber matrix and using epichlorohydrin (ECH) as cross-linking agent. The physicochemical properties of the fibrous adsorbent were characterized. The CO2 adsorption capacity was evaluated.

Preparation and characterization of a strong basic anion exchanger by radiation-induced grafting of styrene onto poly(tetrafluoroethylene) fiber.

A novel anion-exchange fiber with strong basic groups has been prepared by grafting styrene onto poly(tetrafluoroethylene) fibers via irradiation. Experiments were carried out to analyze the effects of synthesis conditions on the grafting degree and to characterize the physicochemical properties of the anion-exchange fibers. The experimental results showed that preirradiation grafting styrene onto poly(tetrafluoroethylene) fiber could significantly reduce the waste of raw material and the formation of homopolymer, although the grafting degree was relatively low.

Effect of activated carbon fiber anode structure and electrolysis conditions on electrochemical degradation of dye wastewater.

The alizarin red S (ARS) in simulated dye wastewater was electrochemically oxidized using an activated carbon fiber (ACF) felt as an anode. The influence of electrolytic conditions and anode structure on the dye degradation was investigated. The results indicated that initial pH, current density and supporting electrolyte type all played an important role in the dye degradation.