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p-Hydroxybenzoic acid is an emerging contaminant because it has multiple sources such as the hydrolysis of methylparaben, ethylparaben and propylparaben used widely as preservatives in food and drinks, and as well as from the agro-industrial wastewaters. In this study, the nano-ZIF-8@chitosan microspheres (ZIF-8@CSM) were fabricated via the combination of inverse emulsion method and in-situ growth method. The performance of ZIF-8@CSM for the adsorption of p-hydroxybenzoic acid from aqueous solution was studied. The adsorption kinetics showed that the adsorption rapidly reached the equilibrium about 30 s. The equilibrium data were well described by the Langmuir isothermal model and the estimated maximum adsorption capacity was 128.70 mg/g. The thermodynamics analysis indicated negative free energy, enthalpy, and entropy changes suggesting that the adsorption process was spontaneous and exothermic. ZIF-8@CSM is promising to be used as a good adsorption material to remove p-hydroxybenzoic acid rapidly from aqueous solutions.

The current domestic and foreign research on azide polymers such as glycidyl azide polymers (GAP) mainly focuses on the design, synthesis, modification, and performance of elastomers; it is difficult to prepare the GAP/NC (nitrocellulose) blends, and they have poor mechanical properties. Here, we developed a green and safe strategy for the blending and compounding of azide binder and NC by blending the emulsion with NC in water and demulsifying. Considering the structural characteristics of GAP, a novel energetic aqueous GAP-E (energetic elastomer) emulsion was prepared by anionic self-emulsion polymerization using 2,2-dimethylol propionic acid as the hydrophilic chain extender, 1,4-butanediol as the chain extender, and triethylamine as a neutralizer. Furthermore, the GAP-E emulsion/triethylene glycol dinitrate/nitrocellulose blends (GAP-E/TEGN/NC) with different proportions were prepared in aqueous phase by the precipitation method. The related properties of the emulsion were studied by gel permeation chromatography, Fourier transform infrared, universal material testing machine, dynamic mechanical analyzer, thermogravimetric analysis, and scanning electron microscopy (SEM). Our results indicated the emulsion exhibited good stability with the number average molecular weight of 76,600. The GAP-E film showed a tensile strength of 17.8 MPa, elongation at break of 415%, glass transition temperature of −28.5 °C, and initial degradation temperature of 242 °C. The GAP-E emulsion and TEGN/NC can be blended in the aqueous phase by the demulsification method to prepare a homogeneous GAP-E/TEGN/NC blend. Fourier transform infrared spectroscopy (FTIR) showed that there was a certain hydrogen bond interaction between GAP-E and TEGN/NC molecules, which was conducive to the improvement of the mechanical properties. The results of SEM indicated that GAP-E could obviously soften the rigid fiber structure of TEGN/GN, and the blends were well mixed with good interfacial compatibility between the GAP-E (5%) and TEGN/NC. When the mass fraction of GAP-E was 5%, the tensile strength and the elongation at break of the blend reached up to 32.1 MPa and 54.4%, which were improved by 33 and 46% compared to those of the TEGN/NC blend system, respectively. The transition temperature remained at −21.6 °C with obvious enhancement on the mechanical properties.

Tough and transparent polyurethane networks with self-healing capability at mild temperature conditions were successfully prepared in a 1-pot procedure. The self-healing ability of synthesized polyurethane comes from the covalent disulfide metathesis and non-covalent H-bonding. The mechanical testing indicates that disulfide metathesis reforms the covalent bonds on a longer time scale, while H-bonding gives rise to a healing efficiency of around 46% in the early healing processing. The compromise between mechanical performance and healing capability is reached by tailoring the concentration of disulfide. The tensile strength of the sample with 100% self-heal efficiency can get to 5.01 MPa, which can be explained by higher mobility of polymer chain under ambient temperature from creep testing.

Ag loaded mesoporous silica-embedded TiO2 nanocomposites were successfully synthesized via two different routes, including one-pot solvothermal method and solvothermal-chemical reduction method, both using Titanium (IV) n-butoxide (Ti(OC4H9)4) as a precursor, formic acid as a solvent and reducing agent, silver nitrate as a silver source and tetraethyl silicate (TEOS) as a stabilizer. The transmission electron microscopic (TEM) images showed that silica-embedded anatase TiO2 sample exhibited approximately rhombic shape and Ag nanoparticles could be embedded into the nanocomposites or deposited on the surface with high dispersion. The N2 adsorption-desorption isotherms indicated that the silica-embedded anatase TiO2 had obvious mesoporous structure with a BET specific surface area of 203.5 m2·g-1. All Ag loaded silica-embedded TiO2 composites showed a higher photocatalytic H2-generation activity from water splitting under simulative solar light irradiation than that of TiO2 products. The maximum H2 production rate (6.10 mmol·h-1·g-1) was obtained over 2% Ag/silica-embedded TiO2 nanocomposites (2% Ag/MST) prepared by solvothermal-chemical reduction method, which was 20 times that achieved on the silica-embedded TiO2 sample. The enhanced photocatalytic H2-evolution activity of Ag loaded mesoporous silica-embedded TiO2 nanocomposites can be attributed to the multi-function of surface Ag co-catalyst, mesoporous structure, and embedding of silica.

MoO3 nanobelts were prepared by a one-step hydrothermal method and then assembled with aluminum nanoparticles using polyvinylpyrrolidone as a binder. The physicochemical properties of the as-prepared samples were carefully characterized by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis/differential scanning calorimetry, and drop weight impact test. The results showed that the T onset of Mo-Al-0, Mo-Al-1, Mo-Al-2, and Fe-Al-0 are 474.8°C, 484.2°C, 478.5°C, and 514.8°C, respectively, which are 66.0°C, 56.6°C, 62.3°C, and 26.0°C lower than that of pure Al-NPs (540.8°C). The total exothermic heat of self-assembled MoO3/Al during DSC test is about 2626.9 J/g, which is 229.6, 420.8, and 11.1 J/g higher than that of Al/commercial MoO3, Al/hydrothermal MoO3, and Al/referenced Fe2O3. Furthermore, the high exothermic self-assembled MoO3/Al thermite is totally insensitive to impact.

A pollen-like porous Fe2O3/Al thermite was prepared by a templated method, with aluminium nanoparticles (Al-NPs) embedded in the porous channels. The thermite prepared by reduced pressure released the largest exothermic heat during DSC testing period compared with Fe2O3/Al thermites prepared by ultrasonic mixing and physical mixing. The exothermic heats in the range of 773 K to 1273 K are 3742.3 J g−1, 2279.0 J g−1, 1981.1 J g−1, and 2621.0 J g−1 for pollen-like Fe2O3/Al by reduced pressure, pollen-like Fe2O3/Al by ultrasonic mixing, pollen-like Fe2O3/Al by physical mixing, and commercial Fe2O3/Al by ultrasonic mixing, respectively. The reactivity between Fe2O3 and Al-NPs was efficiently improved, corresponding to its enlarged contact surface area between Al-NPs and the porous pollen-like Fe2O3, and the reduced pre-combustion sintering. Furthermore, pollen-like Fe2O3/Al has good compatibility with both RDX and HMX and it is not compatible with Cl-20 and GAP.