Biswas Protap, Livni Nitzan, Paul Debojit, Aram Lior, Safadi Razi, Varsano Neta, Elad Nadav, Kamyshinsky Roman, Leskes Michal, Gal Assaf
Department of Plant and Environmental Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel.
Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot 7610001, Israel.
ACS Nano. 2024 Dec 17;18(50):33998-34006. doi: 10.1021/acsnano.4c08707. Epub 2024 Dec 6.
Silica polymerization from its soluble monomers is fundamental to many chemical processes. Although industrial methods require harsh conditions and concentrated precursors, biological silica precipitation occurs under ambient conditions from dilute solutions. The hallmark of biosilica is the presence of amine-rich organic macromolecules, but their functional role remains elusive. Here, we show a pH-dependent stimulatory effect of such polyamines on silica polymerization. Notably, this process is decoupled from the saturation degree, allowing the synthesis of polymer-silica hybrid products with controlled network morphologies from undersaturated solutions. The data suggest a two-step phase separation process. First, an associative liquid-liquid phase separation forms a micrometer-size dense phase. Second, silica undergoes a liquid-to-solid transition in the supersaturated condensates to form a bicontinuous silica structure. This study can inspire "soft chemistry" routes to design organic-inorganic nanomaterials with regulatory principles optimized by evolution.
从可溶性单体聚合形成二氧化硅是许多化学过程的基础。尽管工业方法需要苛刻的条件和浓缩的前体，但生物二氧化硅沉淀是在环境条件下从稀溶液中发生的。生物二氧化硅的标志是富含胺的有机大分子的存在，但其功能作用仍然难以捉摸。在这里，我们展示了这种多胺对二氧化硅聚合的pH依赖性刺激作用。值得注意的是，这个过程与饱和度解耦，允许从不饱和溶液中合成具有可控网络形态的聚合物 - 二氧化硅杂化产物。数据表明这是一个两步相分离过程。首先，缔合性液 - 液相分离形成微米级致密相。其次，二氧化硅在过饱和凝聚物中经历液 - 固转变，形成双连续二氧化硅结构。这项研究可以启发“软化学”路线，以通过进化优化的调控原理来设计有机 - 无机纳米材料。
