Purpose The purpose of this paper is to prepare a dual-encapsulated halloysite nano-container to release the capsuled inhibitor as an additive for corrosion protection of epoxy coating. Design/methodology/approach Halloysite nano-containers (HNT) were prepared by simultaneously implanting inhibitor benzotriazole (BTA) into the inside and outside of the halloysite using reduced pressure and layer-by-layer (LBL) assembly, respectively. The microstructure and morphology of treated HNT were investigated using Fourier transform infrared spectroscopy and transmission electron microscopy. In addition, the anti-corrosion behaviors of the composite polyepoxy coating with inhibitor-loaded nano-containers BTA@HNT-2 were investigated using the electrochemical impedance spectroscopy and neutral salt spray test. Findings Test results showed that the LBL assembly structure of the halloysite nano-container makes the BTA@HNT-2 nano-container be controlled and sustained to release BTA, relying on the pH. Very importantly, the obtained nano-container is also responsive to temperature, owing to the thermosensitivity polyelectrolyte out-shell of the HNT. The result showed Rct of the composite polyepoxy coating can be sufficient to maintain higher than 8.510E+7 Ω·cm2 over 72 h of immersion test. Moreover, the artificial induced defects on the coating surface were sufficiently inhibited in the presence of BTA@HNT-2 nano-container in the polyepoxy coating. Originality/value Use of the BTA@HNT-2 as corrosion inhibitor nano-container, with good anti-corrosion property and dual-responsive to pH and temperature, offers a significant rout to prepare smart anti-corrosion coating for protecting metal substrate.

A method consisting of solvent extraction followed by liquid chromatography-quadrupole-time of flight- tandem mass spectrometry analysis was developed for the identification of Imazaquin and its metabolite. The relationships between detector response and sample concentrations showed a high degree of linearity (r > 0.998) over the range 0.03-10 microg/g. The recoveries obtained were in the acceptable range of 86%-104% between spiked. The relative standard deviation of this method was 6.4%-17.1%. A 35-day study of Imazaquin degradation was taken in agricultural soil from Binzhou, China. The degradation followed first order kinetics (C = 0.7672e(-0.0774t)), with half-life of less than 8.5 days. Investigation of the by-products from liquid chromatography-quadrupole-time of flight- tandem mass spectrometry has shown that there were four important metabolites 4-methylene-2-(quinolin-2-yl)-1H-imidazol-5(4H)-one, quinoline-3-carbaldehyde, 1-amino-2,3-dimethyl-1-oxobutan-2-ylium and 1H-[1,2]oxazino[4,5-b]quinolin-1-one in the degradation process. The accurate mass measurements error was 5 ppm in this study. The method was successfully applied to the analysis of imazaquin and its metabolite residues in soil.

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In order to reduce the mechanical sensitivity of cyclotrimethylenetrinitramine (RDX) and improve its energy density, spherical RDX/PMMA/NC composite particles were prepared by spray drying method, selecting polymethyl methacrylate (PMMA, hydrocarbon binder) with excellent mechanical properties and nitrocellulose (NC, energy-containing binder) with higher density as the desensitizing shell material, RDX as the core material. PMMA/NC composite particles of the same component were prepared by a simple solvent evaporation method at the same time. Structural characterizations and thermal stability of the composites were systematically studied by scanning electron microscopy (SEM), X-ray diffraction (XRD), and differential scanning calorimeter (DSC), respectively. Moreover, the safety performance has been qualitatively tested and analyzed through impact sensitivity and friction sensitivity. The results show that the addition of NC/PMMA binder would not change the original crystal structure of RDX, and the RDX/NC/PMMA composites fabricated by spray drying presented spherical particles with uniform distribution and smooth surface. The Tp0 of RDX/NC/PMMA composite particles increased from 220.3°C to 228.2°C, improving the thermal decomposition performance. The H50 rose from 29.32 cm to 84.3 cm, and the probability of friction explosion decreased from 96% to 8%, significantly enhancing the safety performance. In short, the RDX/NC/PMMA composites prepared via the spray drying method and the improvement of their performance have positive significance for the development of explosives in pursuit of high energy and low sensitivity.

A simple and widely applicable methodology was presented to synthesize monodisperse micrometer hollow titania spheres (HTS) based on the templating method. It was performed by using the preformed poly(styrene-acrylic acid) (PSA) as template spheres which was mixed with tetrabutyltitanate (TBOT) in an ethanol solvent under steam treatment. The HTS which were obtained by the calcination of PSA/TiO 2 composite core-shell spheres had a narrow particle size distribution and commendable surface topography characterized by SEM. The calcined HTS at 500 ∘ C displayed crystalline reflection peaks that were characteristic to the anatase phase by XRD. Moreover, some key influencing factors including TBOT concentration and reaction time were analyzed. As expected, the diameter of HTS could be readily controlled by altering the size of PSA template spheres. In addition, the approach was also applied to fabricate hollow zirconia spheres and other inorganic spheres.