Summary. In the present work, a study of H⁺ effects on the microstructure and morphology of hydroxyapatite synthesized by the hydrothermal method is reported. The synthesis was realized with pH values of 10, 9.6, 9, 8, and 7. To know the particle size distribution, growth habit, chemical composition, and crystalline phases present, SEM-EDS, XRD, AFM, and FTIR spectroscopy techniques were used and completed with Rietveld analysis. The obtained results showed an important effect of H⁺ on the morphological and crystallographic characteristics of the hydroxyapatite, demonstrating that the shape and nanoparticle size, as well as the number of crystalline phases, can change depending on the pH during the synthesis. It was observed that there is an increase in the formation of the monoclinic phase and a decrease of the hexagonal phase when the pH value diminishes from 9.6 to 7. The crystallite size also decreases from 46.69 to 19.56 nm. An explanation of the role of pH on the final characteristics of the hydroxyapatite was related to the amount of H⁺ and OH^- ions, and it was included in this work.

中文翻译：

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pH对水热法合成六方单斜羟基磷灰石生长的影响

摘要。在目前的工作中，研究了H ⁺对通过水热法合成的羟基磷灰石的微观结构和形态的影响。可以在10、9.6、9、8和7的pH值下进行合成。要了解粒径分布，生长习性，化学组成和结晶相，可以使用SEM-EDS，XRD，AFM和FTIR光谱技术使用Rietveld分析并完成。所得结果显示了H ⁺的重要作用关于羟基磷灰石的形态和晶体学特征，证明了形状和纳米粒子的大小以及结晶相的数量可以根据合成过程中的pH值而变化。观察到，当pH值从9.6减小到7时，单斜晶相的形成增加，而六方相的减少。微晶尺寸也从46.69 nm减小到19.56 nm。pH对羟基磷灰石的最终特性的作用的说明是有关H的量⁺和OH ^-离子，并且它被列入这项工作。