Mixtures of yttrium and aluminum isobutyrates, M(O2CCHMe2)3= M(O2CiPr)3 (M = Y or Al), were examined as precursors for processing yttrium aluminum garnet (YAG, A15Y3O12). Both precursors were synthesized by reacting the respective metal with isobutyric acid. The individual compounds and the 5Al(O2CiPr)3:3Y(O2CiPr)3 YAG composition mixture were characterized by TGA, DTA, XRD, NMR, and FTIR. Pyrolytic decomposition of Al(O2CiPr)3 at temperatures ≤700°C produces amorphous A12O3, which partially crystallizes to α‐alumina at 840°C (by DTA), and finally to a‐alumina at 1120°C. The pyrolysis behavior of Y(O2CiPr)3 is quite different. Samples start to decompose at 260°C, producing mixtures of Y2O3 with minor quantities of a yttrium carbonate species. On further heating to 300°C, the amorphous Y2O3 crystallizes (bcc). The carbonate remains stable until ∼900°C, and phase‐pure, bcc Y2O3 is obtained only on heating to 1400°C. Mixtures of Al(O2CiPr)3 and Y(O2CiPr)3 provide a precursor to polycrystalline YAG. Rheologically useful solutions are obtained by dissolving a 5:3 mixture of Al(O2CiPr)3 and Y(O2CiPr)3 in THE Solvent removal provides bulk samples of the YAG precursor. The pyrolytic decomposition patterns of bulk samples of this YAG precursor were studied by heating to selected temperatures and characterizing by TGA, DTA, XRD, and FTIR. The crystallization behavior of the mixture is quite different from the constituent compounds. The precursor decomposes to an amorphous material on heating above 300°C. On continued heating (5°C/ min/air) this amorphous intermediate crystallizes (∼910°C) to phase‐pure YAG with a final ceramic yield of 26% at 1000°C. No other phases are observed to form over this temperature range.

A novel method for fabricating magnetic hypercross-linked polymers (MHCPs) with high Brunauer−Emmett− Teller (BET) specific surface area, large pore volume, and good magnetic properties was developed. The synthesis process of MHCPs included two steps: the preparation of HCPs by external cross-linker and the in situ oxidation of the iron source in the structure of HCPs. On the basis of the systematic investigation of the influences of oxidation time and amount of hydrogen peroxide added, a series of MHCPs with different specific surface area, pore volume, and magnetic responsiveness was controllably prepared with the highest BET specific surface area and maximum saturation magnetization of 729.93 m 2 /g and 12.4 emu/g, respectively. Furthermore, the adsorption performance of MHCPs with antibiotics was studied by using chloramphenicol (CAP) and tetracycline hydrochloride (TC) as model adsorbates. The kinetics isotherms of CAP and TC followed a pseudo-second-order model, and the adsorption isotherms of them were proved to fit the Langmuir adsorption model. The maximum adsorption capacity of CAP and TC at the temperature of 20 °C could reach 114.94 and 212.77 mg/g, respectively. The above results showed that the MHCPs would be one of the most promising candidates for application in the adsorption of antibiotics.

A series of benzyl alcohol (BA)-based hypercross-linked microporous polymers (HCPs) were designed and synthesized via facile Friedel−Crafts alkylation using formaldehyde dimethyl acetal (FDA) as external cross-linker promoted by anhydrous ferric chloride (FeCl 3 ). Results demonstrated that Brunauer−Emmett−Teller (BET) specific surface area and pore volume for the HCPs could be controlled by adjusting the amount of FDA and FeCl 3 . The HCPs obtained under optimal conditions showed a BET specific surface area up to 1101 m 2 /g, whose capacity of CO 2 uptake could be as high as 3.03 mmol/g at 273 K/1.0 bar. The isosteric heats of CO 2 sorption for the BA-based HCPs exceed 27 kJ/mol at the low coverage. In addition, the polymer networks possessed high CO 2 /N 2 selectivity of 42. Compared with those BA-based HCPs which is without FDA, the prepared material has higher BET specific surface area and superior CO 2 adsorption properties. These results demonstrated that these prepared HCPs are promising for CO 2 capture and sequestration.

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