摘要：
Fluorocarbon-hydrocarbon hybrid cationic surfactants possess unique performance because they combine the characteristics of fluorocarbon and hydrocarbon surfactants, however, their potential as metal corrosion inhibitors has not been addressed. Here, two hybrid cationic surfactants (F4H6 and F6H6) were synthesized using perfluorobutylsulfonyl and perfluorohexylsulfonyl chains, respectively, through a cationic bridge of N-benzyl-N',N'-dimethyl ethylenediamine, to connect with a hexyl group as the hydrocarbon chain. Both F4H6 and F6H6 exhibited low critical micelle concentrations as 1.81 x 10(-3) and 3.76 x 10(-4) M and high aqueous surface activities with surface tensions as low as 22.07 and 1822 mN/m, respectively. Their anti-corrosion performance for carbon steel in 1.0 M HCl was demonstrated with inhibition efficiencies up to 92.7% and 95.8% at 15 x 10(-4) M by potentiodynarn ic polarization, similar to the results obtained by electrochemical impedance spectroscopy. Both surfactants belong to mixed-type inhibitors and adsorbed on carbon steel following the Langmuir isotherm model. Surface analyses by contact angle, SEM, and XPS revealed that F6H6 tended to form an adsorption layer more densely packed than F4H6 on carbon steel, more efficiently preventing corrosive species from corroding the metal. The results proved that such hybrid cationic surfactants can be utilized as promising metal corrosion inhibitors with the potential for wide applications. (C) 2020 Elsevier B.V. All rights reserved.
通讯机构：
[Duan, J; Zhang, AD] C;Cent China Normal Univ, Key Lab Pesticide Sc Chem Biol, Minist Educ, Coll Chem, Wuhan 430079, Hubei, Peoples R China.
摘要：
Urushiol is a resource-limited natural coating material with diverse applications; however, the synthesis of urushiol analogues and the realization of their urushiol-like performance remain challenging. Herein, four urushiol analogues, namely, 3-((4-alkenoylpiperazin-1-yl)methyl)catechols with the precise 3-substitution pattern on a catechol as that found in urushiol were synthesized by employing the Mannich reaction of catechol with formaldehyde and N-Boc-piperazine as the key step in a two-step route. By using optimization, the advantages of convenience in operation, cost-effectiveness, and scalability could be obtained. The electropolymerization of these analogues on copper was found to be practical due to their higher aerobic stability than urushiol, affording robust coatings with desirable hardness, adhesion strength, hydrophobicity, and thermal stability. Furthermore, the coatings exhibited effective corrosion protection on copper with initial anticorrosion efficiency up to 99.9% and comparatively higher efficiency (more than 97%) after 4 weeks of immersion in 3.5 wt% NaCl solution. The evidence from the electrochemical and infrared spectroscopic characterization data revealed that the electropolymerization process mechanically involved the free radical coupling of phenoxyl radicals to themselves and to the CC bonds in the side chain, forming a robust crosslinking coating. This work paves a way for the synthesis of high-performance urushiol analogues with potential applications as metal protection materials.
摘要：
Fluorinated surfactants have comprehensive performance superior to non-fluorinated ones, however, their role as metal corrosion inhibitors is elusive. Herein, two fluorinated surfactants, one bearing a branched chain perfluoro group (BFIS) derived from hexafluoropropene trimer and the other bearing a straight chain perfluorohexanesulfonyl group (SFIS), were synthesized and comparatively investigated for their anticorrosion performance on carbon steel in HCI solution. Potentiodynamic polarization and electrochemical impedance spectroscopy revealed that BFIS possessed a corrosion inhibition efficiency much higher than SFIS (95.7% versus 86.6%), although both have similar minimum aqueous surface activities down to 18.50 mN/m. Surface analyses including contact angle, SEM, and XPS and theoretical calculation evidenced that BFIS formed a more densely packed adsorption layer than SFIS on carbon steel, more efficiently preventing corrosive species from corroding the metal surface. The results proved that by taking advantage of the branched chain perfluoro group as the hydrophobic part, fluorinated surfactants can be used as promising metal corrosion inhibitors with excellent performance. (C) 2019 Elsevier B.V. All rights reserved.
摘要：
Regioselective reactions with supramolecular control are of great interest. Herein, the pars-regiose-lectivity in the Mannich reaction of phenol with formaldehyde and dimethylamine was achieved with the use of beta-cyclodextrin (beta-CD), giving 4-(N,N-dimethylaminomethyl)phenol (p-AP) as major product. H-1 NMR and ITC measurements of the binding of beta-CD with the reactants and the products o- and p-AP revealed a new mechanism, in which beta-CD includes p-AP instead of phenol to control the reaction regioselectivity. This product-inclusion mechanism is remarkably different to the known reactant inclusion process. (C) 2017 Elsevier Ltd. All rights reserved.
摘要：
The invention discloses a fluorine-containing epoxy resin monomer, a prepolymer and preparation and application of an initiator for the fluorine-containing epoxy resin monomer. A hexafluoropropene trimer is used as a fluorine-containing precursor material, and is subjected to an etherification reaction with bisphenol A and epoxy chloropropane to prepare a hexafluoropropene trimer based bisphenol A epoxy resin monomer; the hexafluoropropene trimer is used as the fluorine-containing precursor material, and is subjected to a reaction with p-hydroxybenzyl alcohol or p-hydroxyphenethyl alcohol and formaldehyde to prepare a hexafluoropropene trimer based epoxy-phenolic resin prepolymer; the hexafluoropropene trimer is used as the fluorine-containing precursor material, and is subjected to etherification, bromation and quaternization with the p-hydroxybenzyl alcohol, carbon tetrabromide and substituted imidazole to prepare a hexafluoropropene trimer based benzylimidazole cationic initiator. The fluorine-containing epoxy resin monomer, the prepolymer and the initiator for the fluorine-containing epoxy resin monomer can be used for preparing a fluorine-containing epoxy resin coating material; an obtained coating is good in heat stability, has multi-level morphology, has excellent hydrophobic-oleophobic performance and fouling resistance, and can be applicable to the field of various coatings.
关键词：
Magnetic nanoparticles;gold nanoparticles;magnetic nanocomposites;label-free impedimetric immunosensor;interleukin-8
摘要：
Interleukin-8 (IL-8), a dimeric protein composed of two identical subunits, is overexpressed in different human cancers, among them pancreatic cancers and head and neck cancers. There is a strong demand for monitoring of this biomarker protein for early cancer detection. A new concept of label-free impedimetric immunosensors for IL-8 detection is described in this work. A nanocomposite of gold nanoparticles (AuNPs) decorating a magnetic Fe3O4 core is synthesized using cysteamine as linker, and characterized using TEM and UV-Vis spectrometry. After immobilization of these Fe3O4@Au magnetic nanocomposites on a boron doped diamond (BDD) electrode using a simple magnet, anti-human IL-8 monoclonal antibody is linked to the AuNPs, previously functionalized with thioctic acid. The functionalization of the immunosensor was characterized using two electrochemical techniques: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), performed in phosphate buffer with ferro/ferricyanide as the redox probe. The EIS technique was used for affinity assays: antibody-Antigen binding. A linear relationship between the increment in the electron transfer resistance (R-CT) and the logarithmic value of IL-8 concentration was observed between 0.1pg/mL and 1000pg/mL. The limit of detection (LOD) was estimated at 0.03pg/mL.
