Hydrothermal Synthesis of Calcium Borate Whiskers

Abstract

A type of calcium borate whiskers with highly thermal stability was synthesized by hydrothermal method at 180 °C for 2 h, using borax, calcium chloride and sodium hydroxide as raw reactants. The X-ray powder diffraction (XRD) indicated that as-prepared products were composed of monoclinic Ca2B2O5·H2O phase. Scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed calcium borate whiskers with a length of 50~100 μm and diameter 1.0 ~3.0 μm. Selected-area electron diffraction (SAED) pattern showed that the calcium borate whiskers were single crystalline structure. The adjustment of temperature of hydrothermal reaction, can lead to obvious morphology changes of products, and the possible chemical reaction and growth mechanism were proposed. Furthermore, the analysis of thermogravimetry (TG) showed the calcium borate whiskers released crystal water at 370~425 °C.

Study on Properties of Cottonseed Protein Plastics

“…After the cross-linking with GA(b), the absorption of amino around 3300cm -1 increased obviously, which was due to the formation of an amino linkage between cottonseed protein and GA. Moreover, in view of the obvious change of the N-H bending absorbance (from 3300cm -1 to 3400cm -1 ) and amide II absorbance (from 1540cm -1 to 1570cm -1 ) [10], it is believed that the number of hydrogen bondings decrease obviously, indicating that MMT insert into protein matrix successfully, and have high affinity between GA modified cottonseed protein and Na + -montmorillonite for the surface electrostatic interaction(c). Mechanical properties.…”