Synthesis and Characterization of Hydroxyapatite Nanocoatings by Sol–Gel Method for Clinical Applications - Biological and Biomedical Coatings: Processing and Characterization - page 37

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SynthesisandCharacterizationof
HydroxyapatiteNanocoatingsbySol-Gel
Method fo rClinicalApplications
B.Ben-Nissan,A.H.Choi,D.W.Green,B.A.Latella,J.Chou,andA.Bendavid
CONTENTS
Introduction ................................................................................................................................... 38
Thick- and Thin-Film Coating Methods .................................................................................... 41
Biomimetics and SBF Hydroxyapatite .................................................................................. 41
Biomimetics Approach ....................................................................................................... 41
SBF Hydroxyapatite ............................................................................................................ 42
The Sol-Gel Process ...................................................................................................................... 44
Advantages and Disadvantages............................................................................................. 45
Precursors .................................................................................................................................. 46
Alkoxide Precursors ............................................................................................................ 46
Nonalkoxide Precursors ..................................................................................................... 46
Other Organic Additives .................................................................................................... 47
Process........................................................................................................................................ 47
Gelation................................................................................................................................. 47
Drying and Sintering of Gels ............................................................................................. 50
The Sol-Gel Process: Coating Techniques ............................................................................ 51
Dip Coating .......................................................................................................................... 51
Spin Coating ......................................................................................................................... 52
Sol-Gel Synthesis of Nanohydroxyapatite................................................................................ 53
Calcium Alkoxide..................................................................................................................... 55
Calcium Acetate........................................................................................................................ 56
Calcium Chloride ..................................................................................................................... 56
Calcium Hydroxide.................................................................................................................. 56
Calcium Nitrate ........................................................................................................................ 57
Dicalcium Phosphate Dihydrate ............................................................................................ 59
Sol-Gel Hydroxyapatite-Nanocoated Coralline Apatite......................................................... 60
Natural Skeletons ..................................................................................................................... 60
Coral and Coralline Apatite.................................................................................................... 61
Nanocoated Coralline Apatite ................................................................................................ 61
Mechanical Properties of Thin Films.......................................................................................... 63
Microtensile Testing ................................................................................................................. 66
Nanoindentation ...................................................................................................................... 68