Zirconia nanopowders were prepared in the ultrasonic field by the sol-gel method and the sonochemical effect on the structure of zirconium hydroxide and the zirconia nanopowder properties were systematically investigated in this work. Ultrasound was introduced into the different stages of the synthesis of zirconia nanopowders in sol-gel reaction system, and zirconium hydroxides and the zirconia nanopowders with different properties were obtained. The results indicated that ultrasonic cavitation could not only disaggregate the agglomerates of zirconia colloidal particles but also reduce the amount of coordinated H2O, free H2O and free hydroxyl groups of the zirconium hydroxide colloidal particles, thus effectively preventing the formation of hard agglomerates in zirconia powders. Moreover, the effects of different ultrasonic output powers and treatment cycles on the structure and properties of ZrO2 nanopowders were studied by TEM, XRD and SAXS. Zirconia nanopowders with an extremely small crystallite size (10.3 nm) and a narrow size distribution were yielded with 520 W ultrasound for 6 treatment cycles on the formation period and 600 W ultrasound for 2 treatment cycles on the washing period. It is concluded that the ultrasonic field is a potential method for nanopowder preparation.

This article reviews recent advances in polymer blends and composites from renewable resources, and introduces a number of potential applications for this material class. In order to overcome disadvantages such as poor mechanical properties of polymers from renewable resources, or to offset the high price of synthetic biodegradable polymers, various blends and composites have been developed over the last decade. The progress of blends from three kinds of polymers from renewable resources-(1) natural polymers, such as starch, protein and cellulose; (2) synthetic polymers from natural monomers, such as polylactic acid; and (3) polymers from microbial fermentation, such as polyhydroxybutyrate-are described with an emphasis on potential applications. The hydrophilic character of natural polymers has contributed to the successful development of environmentally friendly composites, as most natural fibers and nanoclays are also hydrophilic in nature. Compatibilizers and the technology of reactive extrusion are used to improve the interfacial adhesion between natural and synthetic polymers.

A novel method to enhance sucrose crystal growth was proposed and investigated. It was found that when sucrose solutions are irradiated by microwaves, the crystal growth rate is greater that in the traditional vacuum-evaporative crystallization. A kinetic model was established for the microwave-assisted crystal growth and X-ray diffraction analysis was also undertaken.

Certain physical properties of distilled water, tap water and sugar solution are affected when they are treated with a magnetic fileld. In particular, the evaporation rated of sugar solntion can be improved with a suitable magnetie field. The mechanism of this magnelic trcatment is discussed and the optimum magnetic conditions are proposed ofr improing the evaporation rated. It is concluded that magnetic teehnology could provide good prospects of energy saving in the sugar industry.