amounts of CNT and ENP were added to make 1.0 M Solution A and appropriate

amount of KDP to make 0.6 M Solution B.

Ammonium fluoride (AF, Merck, AR grade) and tetraethoxysilane (TEOS,

Merck, AR grade) were used as fluorine and silicon precursors for the synthesis of

fluorine-substituted nanodimensional hydroxyapatite (FHA, Ca10(PO4)6OHF) and

silicon-substituted

nanodimensional

hydroxyapatite

(SiHA,

Ca10(PO4)5.8(SiO4)0.2(OH)2), respectively. In the case of FHA, 1.0 M Solution A

was made by adding appropriate amount of CNT and Solution B was made by

adding 0.1 M AF and 0.6 M KDP, maintaining P/F ratio at 6.0. In the case of SiHA,

1.0 M Solution A was made by adding appropriate amount of CNT and 0.6 M

Solution B was made by adding appropriate amounts of KDP and TEOS.

All other steps in sol-gel synthesis of nanodimensional single-ion-substituted

hydroxyapatites were adopted as such.

23.4.3 Dual-Ion-Substituted Nanodimensional Hydroxyapatites

To synthesize potassium and silicon nanodimensional hydroxyapatite (KSiHA,

K0.2Ca9.8(PO4)5.8(SiO4)0.2(OH)2), appropriate amounts of CNT and potassium

nitrate (KN) were added to make 1.0 M Solution A and 0.6 M Solution B was

made by adding appropriate amounts of KDP and TEOS. To synthesize zinc and

fluorine

co-substituted

nanodimensional

hydroxyapatite

(ZnFHA,

Zn0.2Ca9.8(PO4)6OHF) and strontium and fluorine co-substituted nanodimensional

hydroxyapatite (SrFHA, Sr1.2Ca8.8(PO4)6OHF), 1.0 M Solution A was made by

adding appropriate amounts of CNT and ZNT or SNT and Solution B was made by

adding 0.6 M KDP and 0.1 M AF while maintaining P/F molar ratio at 6.0.

Magnesium nitrate tetrahydrate (MNT) and strontium nitrate (SNT, Sr(NO3)2,

Merck, AR grade) were taken as magnesium and strontium precursors for the

synthesis of magnesium- and strontium-substituted nanodimensional hydroxyapatite

(MgSrHA, Mg0.2Sr1.2Ca8.6(PO4)6OH). 1.0 M Solution A was made by adding

appropriate amounts of CNT, MNT, and SNT and 0.6 M Solution B was made by

adding appropriate amount of KDP. Rest same procedure of sol-gel synthesis as

adopted for HA was followed for all dual-ion-substituted nanopowders.

23.4.4 Multi-Ion-Substituted Nanodimensional Hydroxyapatite

For

synthesizing

magnesium,

strontium,

and

fluorine

multi-substituted

nanodimensional hydroxyapatite (Mg0.2Sr1.2Ca8.6(PO4)6OHF), appropriate amounts

of CNT, MNT, and SNT were added for making 1.0 M Solution A and Solution B

was made by adding 0.6 M KDP and 0.1 M AF while maintaining P/F molar ratio at

6.0. Rest same procedure of sol-gel synthesis as adopted for HA was followed for

multi-ion-substituted nanopowder.

428

S. Kapoor et al.