Abstract Atrazine contamination of water is of considerable concern because of the potential hazard to human health. In this study, a magnetic molecularly imprinted polymer for atrazine was prepared by the surface‐imprinting technique using Fe 3 O 4 as the core, mesoporous silica as the carrier, atrazine as the template, and itaconic acid as the functional monomer. The magnetic molecularly imprinted polymer was characterized by Fourier‐transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction, and vibration‐sample magnetometry. The binding properties of the magnetic molecularly imprinted polymer toward atrazine were investigated by adsorption isotherms, kinetics, and competitive adsorption. It was found that the adsorption equilibrium was achieved within 2 h, the maximum adsorption capacity of atrazine was 8.8 μmol/g, and the adsorption process could be well described by the Langmuir isotherm model and pseudo‐second‐order kinetic model. The magnetic molecularly imprinted polymer exhibited good adsorption selectivity for atrazine with respect to structural analogues, such as cyanazine, simetryne, and prometryn. The reusability of the magnetic molecularly imprinted polymer was demonstrated for at least five repeated cycles without a significant decrease in adsorption capacity. These results suggested that the magnetic molecularly imprinted polymer could be used as an efficient material for the selective adsorption and removal of atrazine from water samples.
In the title compound, C(26)H(18)N(4)O(6), the amide units are approximately coplanar with the benzene ring bonded to the N atom [dihedral angles of 10.59 (10) and 24.00 (12)°], but twisted significantly out of the plane of the benzene ring bonded to the carbonyl C atom [dihedral angles of 57.82 (9) and 58.05 (9)°]. The dihedral angle between the two rings of the biphenyl unit is 77.66 (4)°. Intra-molecular N-H⋯O hydrogen bonds and weak C-H⋯O inter-actions occur. The crystal structure is stabilized by inter-molecular N-H⋯O hydrogen bonds and C-H⋯O contacts.
In the title compound, C(28)H(24)N(2)O(4), the dihedral angle between the two rings of the biphenyl unit is 75.34 (9)°. The outer aromatic rings form dihedral angles of 66.96 (1) and 85.69 (8)° with the rings to which they are attached . The mol-ecular structure is stabilized by intra-molecular C-H⋯O and N-H⋯O hydrogen bonds. In the crystal structure, inter-molecular N-H⋯O inter-actions are observed.
Fe based TiB 2 composite coating was in situ synthesised by plasma transferred arc cladding. The microstructure and microhardness of the composite coating were investigated by optical microscopy, SEM and microhardness tester. Sliding wear behaviour of the composite coating was investigated on a block on ring wear tester rubbing against GCr15 steel ring. Wear resistance of TiB 2 /Fe composite coating was 16–25 times than that of the uncoated iron matrix. The good interfacial bonding between TiB 2 particles and iron matrix led to no transition from mild wear to severe wear over the applied load range. The sliding wear resistance of the composite coating decreased with increasing sliding speed and applied load. The wear mechanism of the composite coating was a comprehensive action of microcutting wear, surface flaking, adhesive wear, slight abrasive wear and fatigue wear. High applied loads resulted in particle detachment and accelerated the abrasive wear and the fatigue wear.
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