Mullite whiskers were novelty prepared via pressure field assisted polycondensation nonaqueous precipitation method. The precipitate phase transition in heating process, phase compositions and microstructure of samples calcined at different temperatures, effect of pressure field on precursors polycondensation and AlF3 amount on sample morphology, the structure and the growth mechanism of whiskers were investigated. The results indicate that pressure field caused by kettle treatment promotes the polycondensation reaction between AlF3 and tetraethyl orthosilicate (TEOS), the excess aluminum fluoride coordinates with the precipitate skeleton of the =Al–O–Si≡, which brings about the low mullitization temperature (900 °C). The sample prepared with the optimal amount of aluminum fluoride (1.3 of the theoretical amount) calcined at 1100 °C presents high yield and aspect ratio (>15, 100 nm in diameter) of mullite whiskers. Growth of whiskers prepared via pressure field assisted polycondensation nonaqueous precipitation method is attributed to a vapor-solid (VS) mechanism with the inducement of screw. These mullite whiskers with the structure of multi-needle whiskers connected in the same center can be distributed evenly in epoxy resin, which greatly improves the mechanical properties of epoxy resin.

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A novel porous egg-white (EW)/titania composite material was prepared via a facile nonaqueous precipitation method with EW as the porous skeleton.

Magnesium-stabilized aluminum titanate powder was prepared via non-hydrolytic sol-gel method using titanium tetrachloride and anhydrous aluminium chloride as precursors, anhydrous ethanol as the oxygen donor, magnesium powder, magnesium fluoride, magnesium ethoxide and anhydrous magnesium acetate as stabilizers. The effect of magnesium stabilizers on low temperature synthesis of aluminum titanate was investigated, and their role and mechanism in stabilizing aluminum titanate were also studied by XRD, FT-IR and thermal expansion dilatometer. The results show that introducing magnesium powder or magnesium fluoride can’t stabilize aluminum titanate, they also lead to the failure of aluminum titanate low-temperature synthesis at 750 °C due to its promotion of non-hydrolytic homogeneous condensation. Anhydrous magnesium acetate and magnesium ethoxide can react with aluminum alkoxide and titanium alkoxide in the precursor mixture to form heterogeneous condensation bonds, which promotes magnesium ion to dope into aluminum titanate lattice at 750 °C, and hence to improve its thermal stability.

A novel method for hydroxyapatite fiber preparation with highly large-scale production prospects is of paramount importance but remains particularly difficult. Here, group replacement–rearrangement-triggered linear-assembly nonaqueous precipitation synthesis has been proposed for hydroxyapatite fibers under mild conditions. Pure hydroxyapatite fibers can be fabricated taking disodium hydrogen phosphate, calcium acetate, and glycerol as the phosphorus source, calcium source, and solvent, respectively. Single hexagonal crystal structures of hydroxyapatite fibers growing along the c-axis and preferential growth of the (002) crystal plane similar to the layered stacking structure of an adult bone have been confirmed by XRD refinement tests and calculation, TEM electron diffraction calibration, and FE-SEM. Highly active carbonate apatite is further demonstrated by EDS, FT-IR, Raman spectroscopy, and XPS. Unsaturated P–O and O–Ca bonds at both ends of the hexagonal-sheet assembly unit in a high-polarity nonaqueous glycerol environment without strongly coordinated OH– confirm the solution spontaneous linear assembly to form the single hydroxyapatite fibers.