Synthesis and characterization of Zn-doped MgAl layered double
hydroxide nanoparticles for PVC heat stabilizer
Supporting Information
The calculation process of the compositions of the LDHs:
The calculation process of chemical formulae includes the following steps:
Step 1
Their chemical formulae of the LDHs can be written as MgaZnbAlc(OH)6(CO3)d·xH2O or (MgxZn2-x)Al (OH)6
(CO3)d·xH2O, wherein (a+b)/c equals 2 because the molar ratio of M2+/M3+ was set as 2 and here the amount of OH
was set as 6 according to the basic cell structure of LDHs (Cavani F et al, 1991 ).
Step 2
The molar ratio of Mg/Zn/Al was calculated according to different concentration of metal elements based on results
of ICP test. Take the sample LDH-e for example, the mass concentration of Mg2+, Zn2+, and Al3+ were 4.19ppm,
11.5ppm, and 4.66ppm respectively, then molar concentration of each element equals 0.873 mol/L, 0.885mol/L,
0.863mol/L respectively. So the value of a, b, and c were 1.01, 1.00 and 0.99.
Step 3
The value of d was calculated according to charge balance on the basis of the mentioned structure of the LDHs.
When based on step 1, the value of d was 0.49. As a result, the molar mass of LDH-e without water (indexed as MA)
was 248.124g/mol.
Step 4
The water content was obtained from result of TG test, as the mass loss of LDHs from room temperature to around
200 oC was derived from interlayer water. For the sample LDH-e, the water content was 16.9. According to the
formula listed below, the value of x equals 2.80.
water content % 
x  M H2O
x  M H2O  M A
As a result, the formula of LDH-e was calculated as
Mg1.00Zn1.01Al0.99(OH)6(CO3)0.49·2.80H2O.
Figure S1 TG curves of different LDHs:
(a)2.0/0; (b)1.7/0.3; (c)1.5/0.5; (d)1.3/0.7; (e)1.0/1.0
Figure S2 SEM images of the LDH-e
Figure S3 XRD patterns of different LDHs after heated at 195 oC for 5mins
(a) LDH-a, (b) LDH-b, (c) LDH-c, (d) LDH-d, (e) LDH-e
Table S1 FT-IR band positions and suggested assignments of LDHs
FT-IR bands of different LDHs
Suggested assignment
3466
OH-
3080
CO32--H2O
1598
H2O bending
1366
3 CO32-
941
M-O
867
2 CO32-
783
M-O
674-651
4 CO32-
552
M-O
455-439
M-O