This work reports the synthesis and application of metal-organic framework (MOF)@microporous organic network (MON) hybrid materials. Coating a MOF, UiO-66-NH2, with MONs forms hybrid microporous materials with hydrophobic surfaces. The original UiO-66-NH2 shows good wettability in water. In comparison, the MOF@MON hybrid materials float on water and show excellent performance for adsorption of a model organic compound, toluene, in water. Chemical etching of the MOF results in the formation of hollow MON materials.

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Cobalt-, zinc-, and nickel-zinc-substituted nano-size manganese ferrite powders, MnFe 2 O 4 , Mn 0.8 Co 0.2 Fe 2 O 4 , Mn 0.8 Zn 0.2 Fe 2 O 4 and Mn 0.8 Ni 0.1 Zn 0.1 Fe 2 O 4 , were fabricated using a sol-gel method, and their crystallographic and magnetic properties were subsequently studied. The MnFe 2 O 4 ferrite powder annealed at temperatures above 523 K exhibited a spinel structure, and the particle size increased as the annealing temperature increased. All ferrites annealed at 773 K showed a single spinel structure, and the lattice constants and particle size decreased with the substitution of Co, Zn, and Ni-Zn. The Mössbauer spectrum of the MnFe 2 O 4 ferrite powder annealed at 523 K only showed a doublet due to its superparamagnetic phase, and the Mössbauer spectra of the MnFe 2 O 4 , Mn 0.8 Co 0.2 Fe 2 O 4 , and Mn 0.8 Zn 0.2 Fe 2 O 4 ferrite powders annealed at 773 K could be fitted as the superposition of two Zeeman sextets due to the tetrahedral and octahedral sites of the Fe 3+ ions. However, the Mössbauer spectrum of the Mn 0.8 Ni 0.1 Zn 0.1 Fe 2 O 4 ferrite powder annealed at 773 K consisted of two Zeeman sextets and one quadrupole doublet due to its ferrimagnetic and paramagnetic behavior. The area ratio of the Mössbauer spectra could be used to determine the cation distribution equation, and we also explained the variation in the Mössbauer parameters by using this cation distribution equation, the superexchange interaction and the particle size. Relative to pure MnFe 2 O 4 , the saturation magnetizations and coercivities were larger in Mn 0.8 Co 0.2 Fe 2 O 4 and smaller in Mn 0.8 Zn 0.2 Fe 2 O 4 , and Mn 0.8 Ni 0.1 Zn 0.1 Fe 2 O 4 . These variations could be explained using the site distribution equations, particle sizes and magnetic moments of the substituted ions.

The Zn, Co and Ni substituted manganese ferrite powders, Mn 1-x (Zn, Co, Ni) x Fe 2 O 4 , were fabricated by the solgel method, and their crystallographic and magnetic properties were studied. The Zn substituted manganese ferrite, Zn 0.2 Mn 0.8 Fe 2 O 4 , had a single spinel structure above 400 o C, and the size of the particles of the ferrite powder increased when the annealing temperature was increased. Above 500 o C, all the Mn 1-x (Zn, Co, Ni) x Fe 2 O 4 ferrite had a single spinel structure and the lattice constants decreased with an increasing substitution of Zn, Co, and Ni in Mn 1-x (Zn, Co, Ni) x Fe 2 O 4 . The Mössbauer spectra of Mn 1-x Zn x Fe 2 O 4 (0.0 ≤ x ≤ 0.4) could be fitted as the superposition of two Zeeman sextets due to the tetrahedral and octahedral sites of the Fe 3+ ions. For x = 0.6 and 0.8 they showed two Zeeman sextets and a single quadrupole doublet, which indicated they were ferrimagnetic and paramagnetic. And for x = 1.0 spectrum showed a doublet due to a paramagnetic phase. For the Co and Ni substituted manganese ferrite powders, all the Mössbauer spectra could be fitted as the superposition of two Zeeman sextets due to the tetrahedral and octahedral sites of the Fe 3+ ions. The variation of the Mössbauer parameters are also discussed with substituted Zn, Co and Ni ions. The increment of the saturation magnetization up to x = 0.6 in Mn 1-x Co x Fe 2 O 4 could be qualitatively explained using the site distribution and the spin magnetic moment of substituted ions. The saturation magnetization and coercivity of the Mn 1-x (Zn, Co, Ni) x Fe 2 O 4 (x = 0.4) ferrite powders were also compared with pure MnFe 2 O 4 .