SYNTHESIS AND APPLICATION RESEARCH OF NANO-HYDROTALCITES
*Tan Qi1, 2, Liu Lei1,2, Zhao Yi1,2, Liu Yulin1,2
(1 Zhengzhou Institute of Multipurpose Utilization of Mineral Resources CGS; 2 Key
Laboratory for Polymetallic Ores' Evaluation and Utilization，MLR )
Zhengzhou 450006, P.R.China.
(*Corresponding author: tanqibaby@163.com)
ABSTRACT
Hydrotalcite is one kind of layered double hydroxides, and has special crystal chemical
characteristics. Due to its good thermal stability, hydrotalcite used as the PVC heat stablier has
attracted scientists’ attention. In this study, nano-hydrotalcite was synthesized by the method of
mechanochemistry/crystallization, using brucite, Al(OH)3 and Na2CO3 as raw materials, and added into
PVC to investigate the effect of hydrotalcite on thermal stability of composites. The synthesis
mechanism was suggested by virtue of XRD, FE-SEM, FT-IR, and XPS. It has been indicated that at
the first of dry milling process, the parical sizes of brucite and Al(OH)3 decrease, while specific surface
areas of them increase by the action of mechanical force, until produced amorphous particles. In the
process of wet milling, metal ions in the amorphous body, which has high surface energy, can easily
react with H2O, and produce the precursor of Mg6Al2(OH)18•4.5H2O, which has the same crystal
structure as hydrotalcite. Under the hydrothermal condition, anions of OH- in the interlamination of
precursor are exchanged by CO32- in the solution and nano-hydrotalcite is generated at last.
The thermal stability was characterized by Congo red method. The results have revealed that
hydrotalcite is one kind of long-term heat stabilizer, and residual stability time increase with the rise of
added hydrotalcite amounts.
Mg(OH)2

Mg6Al2(OH)18•4.5H2O
Mg6Al2(OH)16CO3•4H2O
(a)

Intensity/(a.u.)





(b)





10
20
30


40
(c)

50
60
70
80
2
Figure 1 – XRD patterns of amorphous body, precursor and hydrotalcite
Figure 2 –FE-SEM images of hydrotalcites
KEYWORDS
Nano-hydrotalcite, Synthesis, Application, PVC heat stablier