One-pot fabrication of magnetic fluorinated carbon nanotubes adsorbent for efficient extraction of perfluoroalkyl carboxylic acids and perfluoroalkyl sulfonic acids in environmental water samples

Abstract(#br)Efficient extraction of perfluoroalkyl carboxylic acids (PFCAs) and perfluoroalkyl sulfonic acids (PFSAs) is challenging due to their highly fluorinated property. Based on the particular characters of PFCAs and PFSAs, a new type of magnetic fluorinated carbon nanotubes adsorbent (MFCA) for magnetic solid phase extraction (MSPE) was fabricated facilely using one-pot hydrothermal approach. The morphology, structure and magnetic properties of the prepared MFCA were investigated by Fourier transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy and vibrating sample magnetometry. It was observed that the resultant adsorbent possessed satisfactory superparamagnetism and saturation magnetism. Furthermore, the MFCA exhibited excellent enrichment performance for target PFCAs and PFSAs by means of fluorous-fluorous, hydrophobic and hydrogen bonding interactions. Under the most favorable preparation and extraction conditions, the proposed MFCA/MSPE was combined with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) to quantify ultra trace target analytes in environmental water samples. The limits of detection (S/N = 3) of PFCAs and PFSAs were 0.010–0.036 ng/L and 0.024–0.50 ng/L, respectively. In addition, the introduced approach also displayed other features such as quick extraction procedure, wide linear dynamic ranges, excellent method precision and eco-friendliness. Finally, the concentrations of PFCAs and PFSAs in tap, river, lake and waste water samples were successfully measured by isotope internal standard calibration curve method

Electric-field-induced selective catalysis of single-molecule reaction

随着单分子电学检测技术的迅速发展，分子电子学的研究不再局限于分子电子学器件的构筑及其电学性质的测量，而且扩展到单分子尺度化学反应过程的探索。然而目前相关的研究仍然局限于理论计算方面，在单分子尺度上实时监测和调控化学反应的活性和选择性是化学领域的长期目标和挑战。针对这一挑战，洪文晶教授课题组与程俊教授课题组合作，自主研发了精密科学仪器，将单个有机分子定向连接在两个末端尺寸为原子级的电极之间，解决了化学反应中分子取向控制的问题.理论计算结果证实了定向电场可以有效地稳定化学反应的过渡态，从而降低反应能垒。该研究工作在化学化工学院洪文晶教授、程俊教授、能源材料化学协同创新中心（iChEM）刘俊扬副研究员的共同指导下完成，由硕士研究生黄晓艳、iChEM博士研究生唐淳、博士研究生李洁琼以及兰州大学的陈力川博士作为共同第一作者，化学化工学院师佳副教授、陈招斌高级工程师、夏海平教授和田中群教授，萨本栋微纳研究院杨扬副教授、环境与生态学院白敏冬教授以及兰州大学张浩力教授参与了研究工作的讨论并给予指导，博士后乐家波、博士研究生郑珏婷、张佩（已毕业）、李瑞豪、李晓慧也参与了研究工作。Oriented external electric fields (OEEFs) offer a unique chance to tune catalytic selectivity by orienting the alignment of the electric field along the axis of the activated bond for a specific chemical reaction; however, they remain a key experimental challenge. Here, we experimentally and theoretically investigated the OEEF-induced selective catalysis in a two-step cascade reaction of the Diels-Alder addition followed by an aromatization process. Characterized by the mechanically controllable break junction (MCBJ) technique in the nanogap and confirmed by nuclear magnetic resonance (NMR) in bottles, OEEFs are found to selectively catalyze the aromatization reaction by one order of magnitude owing to the alignment of the electric field on the reaction axis. Meanwhile, the Diels-Alder reaction remained unchanged since its reaction axis is orthogonal to the electric fields. This orientation-selective catalytic effect of OEEFs reveals that chemical reactions can be selectively manipulated through the elegant alignment between the electric fields and the reaction axis.This work was supported by the National Key R&D Program of China (2017YFA0204902), the National Natural Science Foundation of China (21722305, 21703188, 21673195, 21621091, 51733004, 51525303, and 91745103), the China Postdoctoral Science Foundation (2017M622060), and the Young Thousand Talents Project of China. 该工作得到国家自然科学基金委（21722305、21703188、21673195、51733004、51525303、91745103），国家重点研发计划课题（2017YFA0204902），中国博士后面上基金（2017M622060）的资助，以及固体表面物理化学国家重点实验室、醇醚酯化工清洁生产国家工程实验室、能源材料化学协同创新中心的支持

Rapidly eliminating pathogenic microorganisms in large air space using spraying &bullOH radicals

A new method for rapidly eliminating pathogenic microorganisms in large air space using spraying &bullOH radicals is presented in this paper. With a physical method of strong electric-field discharge, large numbers of &bullOH radicals were produced by the oxygen activated particles of O2+, O(1D), O(3P), etc., and the introducing reagent HO2-. The gram-positive bacteria Bacillus subtilis, the gram-negative bacteria Serratia marcescens, and Bacillus spores were used for the eliminating experiments. Results show that the different microorganisms were rapidly killed by &bullOH radicals with a concentration of 0.8 mg/L and spraying density of 21 渭L/m2 within 4 sec. Cell morphological changes were also observed under microscope. The cells of B. subtilis and Bacillus spores in their cellular wall, cellular membrane, or cell protoplasm were greatly destroyed when being exposed to a killing dosage of &bullOH radicals. Implications: Increasing air spread of pathogenic microorganisms has prompted serious concerns for their threat to environmental safety. However, there is no an effective method to rapidly eliminate these harmful microorganisms in large air space. In comparison with conventional disinfectants, advanced oxidation technology (AOT) based on hydroxyl radicals (&bullOH) has excellent advantages. The main problem of how to produce the &bullOH radicals with high concentration and large production is solved by a physical method of strong electric-field discharge. A new method for rapidly eliminating pathogenic microorganisms in large air space using spraying &bullOH radicals is described in this paper. 漏 2012 A&WMA

Rapidly eliminating pathogenic microorganisms in large air space using spraying center dot OH radicals

A new method for rapidly eliminating pathogenic microorganisms in large air space using spraying center dot OH radicals is presented in this paper With a physical method of strong electric-field discharge, large numbers of center dot OH radicals were produced by the oxygen activated particles of O-2(+), O(D-1), O(P-3), etc., and the introducing reagent HO2-. The gram-positive bacteria Bacillus subtilis, the gram-negative bacteria Serratia marcescens, and Bacillus spores were used for the eliminating experiments. Results show that the different microorganisms were rapidly killed by center dot OH radicals with a concentration of 0.8 mg/L and spraying density of 21 mu L/m(2) within 4 sec. Cell morphological changes were also observed under microscope. The cells of B. subtilis and Bacillus spores in their cellular wall, cellular membrane, or cell protoplasm were greatly destroyed when being exposed to a killing dosage of center dot OH radicals. Implications: Increasing air spread of pathogenic microorganisms has prompted serious concerns for their threat to environmental safety. However, there is no an effective method to rapidly eliminate these harmful microorganisms in large air space. In comparison with conventional disinfectants, advanced oxidation technology (AOT) based on hydroxyl radicals (center dot OH) has excellent advantages. The main problem of how to produce the center dot OH radicals with high concentration and large production is solved by a physical method of strong electric-field discharge. A new method for rapidly eliminating pathogenic microorganisms in large air space using spraying center dot OH radicals is described in this paper.National Natural Science Foundation of China [NSFC: 61025001, 50877005]; Education Ministry of China [2012AA062609

基于多相互作用的整体纤维固相微萃取技术用于水和植物样品中全氟烷基膦酸的灵敏测定。

Due to highly fluorinated and di-anionic characters, it is great challenging to enrich perfluoroalkyl phosphonic acids (PFPAs). According to the unique chemical properties and molecular structure of PFPAs, a monolithic adsorbent using dodecafluoroheptyl acrylate and 4-vinylbenzyltrimethylammonium chloride as mixed functional monomers was synthesized and utilized as the extraction medium of multiple monolithic fibers solid-phase microextraction (MMF-SPME). Results well evidenced that the obtained adsorbent could enrich PFPAs effectively by means of multiple interactions including fluorophilic and anion-exchange interactions. Under the optimized synthesized and extraction conditions, a sensitive approach for the monitoring of trace levels of PFPAs in water and vegetable samples was developed by the combination of MMF-SPME and high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS). Limits of detection (LODs, S/N = 3) for water and vegetable samples were in the ranges of 0.00011-0.00086 μg/L and 0.0022-0.055 μg/kg, respectively. The introduced method was successfully applied to monitor target PFPAs in lake water, wastewater, pumpkin and cucumber samples. Recoveries at different spiking levels and the relative standard deviations for precision were in the ranges of 80.6-120% and 0.9-12%, respectively. Compared to previously reported approaches, the current method displays some merits such as simple operation, satisfactory sensitivity, low cost and eco-friendliness

Effect of hydroxyl radical on harmful microalgae: a potential technology for treatment of ship’s ballast water

725-734In this study, the effects of hydroxyl radicals on harmful microalgae in ballast water were investigated experimentally. Using an improvised ballast water treatment system, large concentrations of ·OH were produced and subsequently dissolved in ballast waters of different salinities which are high salinity seawater (HS) and low salinity seawater (LS) in order to eliminate the microalgae. The results show that the outcome of the treatment system fully meets the requirements of G8. At total residual oxidant (TRO) concentrations of 0.41 mg/L and 0.93 mg/L, the maximum concentration of killed algae was observed as 0.5×103 cells/mL and 1×104 cells/mL, respectively. Furthermore, the ·OH efficiently decomposed most organic matter, resulting in an improvement of the ship’s ballast water quality. These results conform to the D-2 ballast water discharge standard of IMO and validate the ·OH as an effective, rapid way of killing algae in the course of conveying the ship’s ballast water

Treatment of 250 t/h ballast water in oceanic ships using -oh radicals based on strong electric-field discharge

The ballast water of oceanic ships is the main cause for worldwide transfer of non-indigenous aquatic species. The use of hydroxyl radicals is an efficient method for killing the aquatic species in ballast water. For practical application, a 250 t/h -OH ballast water-treatment system was designed and installed on the ship Yulong (ten thousand tons) in Dalian harbor. On this ship, a series of experiments were carried out. As a result, the concentration of total oxidants declined over time. Harmful aquatic organisms and pathogens in the ballast water were rapidly killed after -OH treatment and no re-growth was observed during a storage time of 5 days. The quality of the ballast water was considerably improved. Therefore, the D-2 ballast water discharge standard of the International Maritime Organization was satisfied. Compared with current methods, -OH treatment is a potentially effective technology which can be practically applied in the ballast water-treatment of oceanic ships in the future. 漏 Springer Science+Business Media, LLC 2012

Evaluation of the ecotoxicity and biological efficacy of ship's ballast water treatment based on hydroxyl radicals technique

National Natural Science Foundation of China [NSFC: 61025001, 50877005]; Education Ministry of China [2012AA062609]Ballast water has been identified as one of the key pathways for the movement of species between different ecosystems. The purpose of this study is to evaluate the biological efficacy and the potential toxicological impact of a proposed ballast water treatment using hydroxyl radicals as the main active substances. Living biomass of organisms kept in treated water for 2 days met the requirement stated in the International Maritime Organization (IMO) Ballast Water Convention (Regulation D-2), and no re-growth was observed over a period of 5 days. Aquatic toxicity tests of three trophic levels for the treated ballast water were performed. The results indicated that the toxicological risk of the discharge water to the receiving environment was not significant. (C) 2012 Elsevier Ltd. All rights reserved

center dot OH Treatment for Killing of Harmful Organisms in Ship's Ballast Water with Medium Salinity Based on Strong Ionization Discharge

Projects of Distinguished Young from National Natural Science Foundation of China (NSFC) [61025001]; National Science and Technology Support Program of China [2013BAC06B00]; National High Technology Research and Development Program of China [2012AA062609]; Special Fund for Marine Scientific Research in the Public Interest [201305027-5]; Fundamental Research Funds for the Central Universities in China [3132013316]A novel discharge mode consisting of alternate discharge of a micro-streamer and micro-glow was developed to induce the formation of center dot OH radicals in ballast water. A series of center dot OH killing experiments were then conducted using medium salinity ballast water. Five species of algae from three different phyla and three kinds of bacteria were killed by center dot OH radicals in compliance with the D-2 ballast water standard of International Maritime Organization. Moreover, the chlorophyll-a was fully discolored when the total reactive oxidants was 2.5 mg/L, indicating that the algae had died. Overall, the quality of medium salinity ballast water with heavy pollution was greatly improved. These results indicate that the use of center dot OH radicals is an effective method for the treatment of ship's ballast water

·OH treatment for killing of harmful organisms in ship's ballast water with medium salinity based on strong ionization discharge

A novel discharge mode consisting of alternate discharge of a micro-streamer and micro-glow was developed to induce the formation of·OH radicals in ballast water. A series of·OH killing experiments were then conducted using medium salinity ballast water. Five species of algae from three different phyla and three kinds of bacteria were killed by·OH radicals in compliance with the D-2 ballast water standard of International Maritime Organization. Moreover, the chlorophyll-a was fully discolored when the total reactive oxidants was 2.5 mg/L, indicating that the algae had died. Overall, the quality of medium salinity ballast water with heavy pollution was greatly improved. These results indicate that the use of·OH radicals is an effective method for the treatment of ship's ballast water. ? 2013 Springer Science+Business Media New York