Synthesis and dissolution behaviour of CaO/SrO-containing sol-gel-derived 58S glasses
Synthesis and dissolution behaviour of CaO/SrO-containing sol-gel-derived 58S glasses
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DOI：
10.1007/s10853-017-0869-0
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发表时间：
2017-08-01
影响因子：
4.5
通讯作者：
Jones, Julian R.
中科院分区：
文献类型：
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作者：
Macon, Anthony L. B.;Lee, Sungho;Jones, Julian R.
研究了三级SiO2-CaO-P2O5溶胶-凝胶生物活性玻璃58S(60SiO(2)中心点36CaO中心点4P(2)O(5),mol%)中锶替代钙对其结构及其在模拟体液中浸泡的化学耐久性的影响。选择58S作为起始组合物，并以25%的增量从0%到100%进行钙替代。本工作使用了一种新型磷酸源二乙基磷酸乙基三乙氧基硅烷，其由与乙烯基连接的Si和P组成。 XRD和FTIR表明，在130℃干燥后获得的凝胶具有典型的溶胶-凝胶结构，其中连续的无定形硅胶网络和表面结合的Ca(NO3)(2)和Sr(NO3)(2)矿物盐。一旦凝胶被热稳定以分解硝酸盐并将阳离子纳入网络中，含有 Sr 的样品就形成了硅酸锶晶相。随着组合物中Sr含量的增加，玻璃陶瓷的整体结晶度增加，而在100% SrO的最大取代度时，观察到宏观相分离，其特征是除了非晶区之外，还出现针状晶体的锶磷灰石(Sr-5(PO4)(3)OH)和硅酸锶(Sr2SiO4)相。 Tris 缓冲溶液中的溶解实验表明，尽管 Sr 作为晶相存在于玻璃陶瓷中，但它仍成功释放到介质中。此外，玻璃陶瓷诱导碳酸羟基磷灰石（HA）在其表面成核和生长，表明该材料具有潜在的生物活性。在较高的取代度（CaO 为 75% 和 100% SrO）时，未发现 HA 成核发生，这可能是由于原始玻璃陶瓷被锁定在锶磷灰石相中，释放出少量磷酸盐。
The effect of the substitution of strontium for calcium in the tertiary the SiO2-CaO-P2O5 sol-gel bioactive glass 58S (60SiO(2)center dot 36CaO center dot 4P(2)O(5), mol%) on its structure and its chemical durability on soaking in simulated body fluids was investigated. 58S was selected as a starting composition, and substitution for calcium was carried out from 0 to 100% with an increment of 25%. A novel phosphate source of diethylphosphatoethyltriethoxysilane, which consists of Si and P connected with ethylene group, was used in this work. XRD and FTIR showed that the gels obtained following drying at 130 A degrees C had a typical sol-gel structure, where a continuous amorphous silica gel network and surface bound mineral salts of Ca(NO3)(2) and Sr(NO3)(2). Once the gels were heat stabilised to decompose nitrates and incorporate the cations into the network, samples containing Sr formed a strontium silicate crystalline phase. With increasing levels of Sr in the composition, the overall crystallinity of the glass-ceramic increased, while, at the maximum substitution of 100% SrO, macroscopic phase separation was observed, characterised by needle-like crystals of strontium apatite (Sr-5(PO4)(3)OH) and strontium silicate (Sr2SiO4) phases in addition to amorphous regions. Dissolution experiments in Tris-buffered solution showed Sr successfully released into the media even though it existed as a crystalline phase in the glass-ceramic. Further, the glass-ceramics induced nucleation and growth of carbonated hydroxyapatite (HA) on their surface suggesting potential bioactivity of the materials. At higher substitutions (75 and 100% SrO for CaO), HA nucleation was not found to occur this may have been due to low amount of phosphate released from the original glass-ceramic as a result of it being locked up in the strontium apatite phase.