This work investigates the effects of the type and concentration of acid catalysts on the microstructural features of silica‐rich bioactive glasses (75Si–16Ca–5Na–4P, in mol%) synthesized from acetate and nitrate precursor salts, using an innovative rapid sol‐gel method, followed by thermal stabilization at 550°C. The results of XRD, SEM, Fourier Transform Infrared Spectrometer (FTIR) and solid state MAS NMR analysis revealed that the lower degrees of polymerization and network connectivity were found for bioglass powders obtained in the presence of high acid concentrations. A low amount of citric acid gave a polymerization degree similar to that obtained in the absence of any catalyst, but the synthesis time was as short as that found for high acid concentrations. The XRD and FTIR results demonstrated amorphous glass powders free of any nitrate by‐products. The microstructure and degree of polymerization could be modified by changing the type and concentration of acid catalyst, enabling one to tailor the bioactivity of glasses even without changing the starting composition.

中文翻译：

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催化剂对溶胶-凝胶衍生生物玻璃聚合和微观结构的影响

这项工作研究了酸催化剂的类型和浓度对使用乙酸盐和硝酸盐前体盐合成的富含二氧化硅的生物活性玻璃（75Si–16Ca–5Na–4P，以mol％为单位）的微观结构特征的影响，凝胶法，然后在550°C下热稳定。XRD，SEM，傅立叶变换红外光谱仪（FTIR）和固态MAS NMR分析的结果表明，在高酸浓度下获得的生物玻璃粉末的聚合度和网络连通性较低。少量柠檬酸的聚合度类似于在没有任何催化剂的情况下获得的聚合度，但是合成时间短于高酸浓度时的合成时间。XRD和FTIR结果表明无定形玻璃粉末不含任何硝酸盐副产物。可以通过改变酸催化剂的类型和浓度来改变其微观结构和聚合度，即使不改变起始组成也可以调整玻璃的生物活性。