Jia Li

In this study, a novel electrochemical sensing interface was developed for the detection of triazophos (TAP) in tea.

The sol–gel method and layer-by-layer self-assembly were used to graft dummy template molecularly imprinted polymers onto CG161M microspheres, yielding DMIPs@CG161M as an adsorbent for the detection of organophosphorus pesticides in food.

This review illustrates the construction of a deep eutectic solvent (HBA & donor) and its use in synthesizing molecularly imprinted polymers via polymerization, with HBAs participating in imprinting target molecules.

A series of molecularly imprinted polymers (MIPs) were prepared on the surface of microspheres(CG161M) and applied as adsorbent for the rapid and selective detection of phthalates compounds, including diethyl phthalate (DEP), dibutyl phthalate (DBP), dioctyl phthalate (DOP). Surface deposition and layer by layer self-assembling method were also utilized in the preparetion of molecularly imprinted polymers. The synthesized composites were characterized by Fourier transform infrared spectrometer, scanning electron microscope, thermo gravimetric analysis and Nitrogen adsorption analysis. The maximum adsorption capacities of the MIPs for DEP, DBP and DOP were 0.006, 0.008 and 0.007 mg g^− 1, respectively. The adsorption of phthalates reached equilibrium within 260 min and complied well with pseudo-second-order kinetic model and Langmuir model. Dioctyl phthalate(DOP) was used as a dummy template for diethyl phthalate(DEP) and dibutyl phthalate(DEP), allowing selective and specific identification of DEP and DBP and did not affect the accuracy of the analysis even if the leakage of template occured. Moreover, MIPs-based hollow fiber stir bar sorptive extraction followed by gas chromatography-mass spectrometry was applied to the detection of DEP, DBP and DOP in several food samples. Under the optimum conditions, the limits of detection (LODs) for DEP, DBP and DOP were 0.0047, 0.0054 and 0.0031 mg L^− 1, with spiked recoveries of 73.06–106.02% and relative standard deviations (RSDs) of 3.91–6.89%, exhibiting high adsorption capacity, good selectivity and fast kinetic towards DEP, DBP and DOP. Since the template of surface molecularly imprinted polymers could be changed with the analytes, MIPs-based molecularly imprinted polymers combining with hollow fiber stirring bar sorptive extraction can be a promising and selective method for separation and extraction of series analytes with similar structure in complicated samples without sample clean-up.

To meet the requirements of friction and corrosion resistance performance of helicopter transmission bearings under harsh environments, Ti/TiN/Ti-DLC multilayer composite films were prepared on a 40Cr15Mo2VN substrate by a non-equilibrium magnetron sputtering technique. The effects of different titanium currents on the structure, mechanical properties, and friction properties of the films were investigated by SEM, Raman spectroscopy, and nanoindentation. Moreover, the tribological and corrosion resistance of developed films under acidic conditions were investigated. The results show that the sp³-C/sp²-C ratio in the films gradually decreases with increasing Ti current from 0 A to 2 A, leading to decreased hardness and elastic modulus. The bonding force of the DLC films also gradually increases with increasing Ti current and reaches the maximum value of 41.69 N at 2 A; the friction coefficient of the films gradually decreases under a load of 20 N. In summary, the best performance of thin film at Ti-2 A was compared with the corrosion and wear performance of thin film and substrate in acetic acid solution and aqueous solution at Ti-2 A. The wear amount of thin film and substrate in aqueous solution is significantly lower than in acetic acid solution, and the corrosion potential of thin film is higher than that of substrate in both solutions, which can play a protective role against the substrate.

Molecular imprinting technology for the preparation of polymers with specific molecular recognition function had become one of the current research hotspots.

Three types of multi-walled carbon nanotubes (MWCNTs)/oxide reinforced hollow fibers, i.e. MWCNTs/SiO₂, MWCNTs/TiO₂, MWCNTs/ZrO₂, based on sol–gel techniques were fabricated, compared and applied to extract metronidazole in milk samples by solid phase microextraction (SPME) and gas chromatography-mass spectrometry (GC-MS). The factors influencing the extraction and desorption process were optimized, and the adsorption mechanism of MWCNTs/SiO₂ reinforced hollow fibers was briefly discussed. MWCNTs/SiO₂ reinforced hollow fiber might be selective to some organic compounds due to specific and non-specific adsorption of MWCNTs and SiO₂ nanoparticles. It was found that the method provided linear range from 0.01–1000 mg L⁻¹ (R = 0.9985), low detection limit of 0.01 mg L⁻¹, preferable recoveries (69–96%) at three different concentrations. The obtained results demonstrated that MWCNTs/SiO₂ hollow fiber solid phase microextraction could become a potential tool for quality control to monitor the amount of metronidazole residues in milk products.