Bioinspired control of colloidal silica in vitro by dual polymeric assemblies of zwitterionic phosphomethylated chitosan and polycations or polyanions.
Bioinspired control of colloidal silica in vitro by dual polymeric assemblies of zwitterionic phosphomethylated chitosan and polycations or polyanions.
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DOI：
10.1016/j.cis.2009.07.005
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发表时间：
2009-10
影响因子：
15.6
通讯作者：
K. Demadis;K. Pachis;Antonia Ketsetzi;A. Stathoulopoulou
中科院分区：
文献类型：
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作者：
K. Demadis;K. Pachis;Antonia Ketsetzi;A. Stathoulopoulou
本文着重介绍了生物聚合物和合成聚合物对无定形二氧化硅形成的影响。简要回顾了与生物硅化有关的文献。聚电解质之间的协同作用的重要性进行了讨论，对抑制柠檬酸缩合。进一步分析了两性离子聚合物膦甲基化壳聚糖（PCH）的具体实例的抑制活性。具体而言，PCH的能力，以延迟在circneutral pH值的过饱和水溶液中的柠檬酸缩合进行了探讨。发现在短期研究（0- 8h）中，抑制活性是PCH剂量无关的，但对于较长的缩合时间（>24 h），在PCH剂量增加时抑制明显增加。在160 ppm PCH存在下，24小时后可溶性琥珀酸水平达到300 ppm。此外，无论是纯阳离子（聚乙烯亚胺，PEI）或纯阴离子（羧甲基菊粉，CMI）聚电解质对PCH的抑制活性的影响进行了系统的研究。结果发现，抑制剂共混物的作用不是累积的。PCH/PEI共混物在短期（8小时）和长期（72小时）实验中稳定与单独PCH相同水平的柠檬酸。另一方面，PCH/CMI组合只能实现对辛酸聚合的短期抑制，但不能将其延长到前8小时。通过SEM研究了PCH及其与PEI或CMI的组合对二氧化硅颗粒形态的影响。根据添加剂或添加剂共混物的不同，可以得到球形颗粒及其聚集体、不规则形状的颗粒和多孔结构。FT-IR表明PCH被捕获在硅胶基质中。
This paper focuses on the effects of biological and synthetic polymers on the formation of amorphous silica. A concise review of relevant literature related to biosilicification is presented. The importance of synergies between polyelectrolytes on the inhibition of silicic acid condensation is discussed. A specific example of a zwitterionic polymer phosphonomethylated chitosan (PCH) is further analyzed for its inhibitory activity. Specifically, the ability of PCH to retard silicic acid condensation at circumneutral pH in aqueous supersaturated solutions is explored. It was discovered that in short-term studies (0–8 h) the inhibitory activity is PCH dosage-independent, but for longer condensation times (>24 h) there is a clear increase in inhibition upon PCH dosage increase. Soluble silicic acid levels reach 300 ppm after 24 h in the presence of 160 ppm PCH. Furthermore, the effects of either purely cationic (polyethyleneimine, PEI) or purely anionic (carboxymethylinulin, CMI) polyelectrolytes on the inhibitory activity of PCH is systematically studied. It was found that the action of inhibitor blends is not cumulative. PCH/PEI blends stabilize the same level of silicic acid as PCH alone in both short-term (8 h) and long-term (72 h) experiments. PCH/CMI combinations on the other hand can only achieve short-term inhibition of silicic acid polymerization, but fail to extend this over the first 8 h. PCH and its combinations with PEI or CMI affect silica particle morphology, studied by SEM. Spherical particles and their aggregates, irregularly shaped particles and porous structures are obtained depending on additive or additive blend. It was demonstrated by FT-IR that PCH is trapped in the colloidal silica matrix.