Study On The Preparation And Properties Of Gd³⁺/Tb³⁺ Co-doped Hydroxyapatite

Nanomaterials have important applications in medicine and bioengineering nowadays.Hydroxyapatite?HAp?,as the main inorganic component of human bones which has a certain degree of solubility in human body.It can participate in part of internal metabolism,promote the re-growth and repair of bone defect tissue,and it also can be an inducer of bone tissue in human body,therefore it has good biocompatibility.In recent years,with the development of science and technology and biomedicine,the applications of HAp and the related synthesis of HAp have become the focus of scholars at home and abroad.HAp,due to its special crystal structure,it can be endowed with new properties by substituting rare earth ions for calcium ions in the cell.Tb³⁺has good fluorescence performance and good tracking and labeling effect,so it is widely used in nano-probe materials.Gd³⁺has the inherent magnetic moment due to its unfilled electron shell structure,which is widely used in nuclear magnetic image.The atomic size of Tb³⁺and Gd³⁺are close to the calcium atom in HAp cell.This paper will take the HAp as the matrix material,take the Tb³⁺and Gd³⁺as doping elements.Firstly,the deviation between theoretical doping concentration and actual doping amount is studied,and then study the effect of various content of doping elements on structure and performance of codoping modified HAp material respectively.And discusses the affect of calcination temperature on the structure and properties of codoping modified HAp at the same time.Finally,expect to obtain fluorescent and magnetic multifunctional materials with good and adjustable properties at the same time.The research contents and conclusions of this paper are as follows:?1?Influence of Tb³⁺contents on structure and properties of xTb-HApThe results of ICP-AES showed that the actual doping amount of Tb³⁺was less than the theoretical value,and the larger doping amount is,the greater deviation will be.SEM and EDS analysis showed that the samples prepared were HAp nanorod particles,and Tb³⁺was successfully incorporated into HAp lattice.FT-IR results showed that the samples doped with Tb³⁺were still the structure of HAp.XRD results showed that the main crystal phase of the samples which doped with various contents of Tb³⁺is still the structure of HAp.The grain size of samples increased first and then decreased with the increase content of Tb³⁺.The fluorescence intensity of the samples first increased and then decreased with the increase content of Tb³⁺.The fluorescence attenuation curve and fluorescent lifetime decreased with the increase content of Tb³⁺,respectively.?2?The effect of Tb³⁺concentration on structure and properties of xTb-6%Gd-HApWith the increase of the concentration of Tb³⁺,the strength of the main diffraction peak?211?will decrease.At the same time,the diffraction peak at?211?and?300?were shifted to a higher Angle,and the greater the content of Tb³⁺was,the higher angle the peak will shift.The fluorescence intensity of samples first increased and then decreased.?3?The effect of Gd³⁺concentration on structure and properties of6%Tb-xGd-HApWith the increase of Gd³⁺content,the main characteristic peak located in?211?gradually shifted to a higher angle,the grain size and crystal plane spacing revealed a downward trend.The crystal morphology changed from irregular oval leaves to sharp bamboo leaves gradually,and the dispersion of the samples became better.The fluorescent intensity of the samples decreased first and then increased,while the fluorescence lifetime showed a trend of increasing first and then decreasing.Finally,the results of the magnetization curve showed that:the magnetization of samples increased first and then decreased.?4?The influence of calcination temperature on the structure and properties of 6%Tb-6%Gd-HApWith the increase of calcination temperature,the peaks of samples become sharp,which means the crystallinity of the samples become higher.The strength of the main diffraction peak?211?of each sample increased obviously with the increase of the calcination temperature,and the grain size and spacing of the samples presented a wave-like change tendency which first increased,then decreased and then increased.The fluorescence intensity of samples increased first and then decreased.When the calcination temperature was 600?,the luminous intensity reached the maximum,the fluorescent lifetime increased and then decreased at the same time.The tendency of the magnetization of the samples is first increased and then decreased,when calcination temperature was600?,the peak of magnetization reached maximum.