Composites Of Hydroxyapatite / Pamam Nano-hydrothermal Synthesis And Morphology Control

In this thesis, 0.5～4.5G poly(amidoamine) (PAMAM) dendrimers were firstly synthesized. The nine PAMAM dendrimers were characterized by FT-IR, 13CNMR and 1HNMR spectra. Then as the typical PAMAM, the 2.5G and 4.5G PAMAM were modified with different terminated groups. And 2.5G and 4.5G PAMAM terminated with polyhydroxy and carboxylic groups were synthesized, respectively. The results of 13CNMR and 1HNMR spectra indicated that the target samples have been successfully prepared.In our work, the Hap/PAMAM complex nanomaterials were also synthesized using as-prepared PAMAM as template in hydrothermal condition. The X-ray diffraction (XRD),infrared spectroscopy (IR),element analysis,transmission electron microscopy (TEM) and particle size distribution were used to characterize the structure and the morphology of the as-obtained complex. Besides, this paper studied the influence of different generation,terminated groups and concentration of PAMAM,the reaction time and temperature, as well as pH in the reaction condition to the structure and morphology of as-obtained samples. The mechanism of the Hap/PAMAM complex nanocrystal was studied by the experiments and got some reasonable and interesting conclusions. The detailed contents are listed as following.The influence of different generation PAMAM: The Hap/PAMAM complex nanomaterial was synthesized using ester terminated 2.5G,3.5G and 4.5G PAMAM as template by the hydrothermal method. The experiment results indicated that compared with the Hap nanonods prepared without template, the as-synthesized Hap/PAMAM nano-complex has a good dispersion with small particle size. The high generation PAMAM has much stronger restrainability to Hap nucleus than low generation PAMAM and the size for the particles decreases with the increase of the generation of PAMAM. Besides, the results of FT-IR spectra and element analysis indicate that the high generation PAMAM has more strong interaction with Hap than low generation PAMAM, and the as-obtained sample with high generation PAMAM has more amount of PAMAM.The influence of PAMAM with different terminated groups: (1) the Hap/PAMAM complex nanoparticles were synthesized using 2.5G PAMAM terminated with ester,carboxylic and polyhydroxy in the hydrothermal condition at 150oC for 15 hours, respectively. The analysis revealed that the samples prepared with ester terminated PAMAM are the nanorods and nanoparticles, and the nucleus site is internal amine of PAMAM; the samples prepared with carboxylic terminated PAMAM are the nanorods, and the nucleus site is external carboxyl of PAMAM; the samples prepared with polyhydroxy terminated PAMAM are the nanorods and nanoparticles, and the nucleus site mainly is internal amine of PAMAM. (2) the Hap/PAMAM complex nanoparticles were synthesized using 4.5G PAMAM terminated with ester,carboxylic and polyhydroxy in the hydrothermal condition at 150oC for 15 hours, respectively. The results indicate that the samples prepared with ester terminated PAMAM are the nanorods and nanoparticles with smaller size, and the nucleus site is internal amine of PAMAM; the samples prepared with carboxylic terminated PAMAM are the nanorods with smaller size, and the nucleus site is external carboxyl of PAMAM; the samples prepared with polyhydroxy terminated PAMAM are the amorphous Hap, and the nucleus site mainly is internal amine of PAMAM.The influence of concentration of 2.5G PAMAM: the Hap/PAMAM complex nanomaterials were synthesized using polyhydroxy terminated 2.5G PAMAM as template with the concentration 5g /L,10g /L,20g /L and 40g /L by the hydrothermal method, respectively. The images of particle size distribution,TEM and XRD spectra revealed that the size of as-obtained Hap nanoparticles decreases with the increase of the concentration of PAMAM.The influence of reaction time to the structure and morphology of the as-obtained samples was studied using polyhydroxy terminated G4.5 PAMAM as template at 150oC for 15h,24h,48h and 72h, respectively. It shows that the size of the as-obtained nanoparticles does not change much, but the crystallization is becoming intensive. The amorphous Hap/PAMAM,Hap/PAMAM nanobeards and Hap/PAMAM nanoparticles with good crystallization were synthesized by reacting for 15h,24h and 48h, respectively. And the size and morphology of Hap/PAMAM nanoparticles obtained for 72h are similar with that for 48h, just got regularly aggregated.The influence of reaction temperature to the structure and morphology of the as-obtained samples was studied using polyhydroxy terminated G4.5 PAMAM as template by reacting for 48h. With the increase of the reaction temperature, the size of the Hap grows larger. The Hap/PAMAM nanorods with 25nm length and 15nm diameter,Hap/PAMAM nanorods with 30nm length and 20nm diameter, as well as Hap/PAMAM nanonods with length 60nm and diameter 20nm and nanoparticles with 15nm diameter were synthesized at 100oC,150oC and 200oC, respectively.The influence of pH in the reaction system to the structure and morphology of the as-obtained samples was studied using polyhydroxy terminated G4.5 PAMAM as template by reacting for 48h at 150oC. The CaHPO4/PAMAM nanonods with length 100nm and diameter 20nm,CaHPO4/PAMAM nanonods and Hap/PAMAM nanoparticles,Hap/PAMAM nanonods with length 50nm and diameter 20nm and Hap/PAMAM nanonods and nanoparticles with less size were synthesized when pH = 6,7,8 and 9, respectively.