论文标题
在各种水性培养基中，磷酸钠玻璃钠玻璃的非线性溶解机制随pH的作用
Non-linear dissolution mechanisms of sodium calcium phosphate glasses as a function of pH in various aqueous media
论文作者
论文摘要
可生物可吸收植入物的磷酸盐玻璃显示出溶解速率，随着成分的变化很大，但是目前尚不清楚它们的溶解机制。基于这项系统的研究，我们对这些机制提出了新的见解。观察到两阶段的溶解，而时间依赖性最初是抛物线，然后是线性的，并开发了两阶段模型来描述这种行为。通过在玻璃中较低的Ca浓度加速溶解，并在溶解培养基中降低pH。提出了一种新的溶解机制，涉及到转化层扩散控制形成的初始阶段。一旦稳定转化层，层溶解反应就会限制。在这种机制下，过渡时间对转换层和溶液条件的性质敏感。这些结果揭示了p $ _ {2} $ o $ _ {5} $ - cao-na $ _ {2} $ o玻璃溶解在解决方案pH上的依赖性，并提供有关溶解机制的新见解，尤其是关于两个溶解阶段之间的过渡。
Phosphate glasses for bioresorbable implants display dissolution rates that vary significantly with composition, however currently their mechanisms of dissolution are not well understood. Based on this systematic study we present new insights into these mechanisms. Two-stage dissolution was observed, with time dependence initially parabolic and later linear, and a two-stage model was developed to describe this behaviour. Dissolution was accelerated by lower Ca concentration in the glass, and lower pH in the dissolution medium. A new dissolution mechanism is proposed, involving an initial stage where diffusion-controlled formation of a conversion layer occurs. Once the conversion layer is stabilised, layer dissolution reactions become rate-limiting. Under this mechanism the transition time is sensitive to the nature of the conversion layer and solution conditions. These results reveal the dependence of P$_{2}$O$_{5}$-CaO-Na$_{2}$O glass dissolution on solution pH, and provide new insight into the dissolution mechanisms, particularly regarding the transition between the two dissolution stages.
