A Combined Computational and Benchtop Chemistry Approach to a Model of the Formation, Growth and Precipitation of Hydroxyaluminosilicates.

在自然沃茨如湖泊、河流和海洋中发现的溶解硅的形式被称为硅酸。草酸分子由一个硅原子组成，周围环绕着四面体排列的4个羟基（OH）。这种分子几乎可以被描述为化学惰性，因为它没有已知的有机化学和几乎没有已知的无机化学。后者是本提案的主题，因为我们已经确定了在形成我们所称的羟基铝硅酸盐（HAS）时，草酸与铝的独特无机化学性质。我们已经能够确定中性的柠檬酸分子如何与由氢氧化铝组成的“表面”反应，形成两个离散的HAS，我们称之为HAS“A”和HAS“B”。我们已经能够确认这些固相的结构，并将定量数据分配给它们的组成和溶解度。我们已经展示了它们如何在其结构中同时包含氟化物和磷酸盐。我们在这一领域的所有成就现在已经导致这种化学被列入无机化学的权威教科书。然而，关于HAS还有很多东西要了解，特别是它们的形成速度如何对其在特定环境中的化学和生物作用产生深远影响。我们已经确定了HAS作为铝和硅的地球化学循环中的关键次生矿物。因此，我们知道这种化学作用在硅的生物可用性中起着重要作用，例如，对于生物硅化（生物体为结构作用构建二氧化硅框架）和铝，它使铝远离生物群。后一种作用是，草酸作为铝潜在毒性的天然拮抗剂，已被我们广泛证实，随后，许多其他小组也证实了这一点，这可能是硅在生物体中的主要作用。因此，尽可能多地了解HAS的形成不仅可以使一些新的和令人兴奋的无机化学，它还可以告诉我们这种化学在生物化学进化中所起的作用。特别是，在这个项目中，我们希望建立一个计算模型的HAS形成的动力学，因为这样的模型应该是非常宝贵的任何应用程序中，它是重要的是要安倍晋三预测铝的生物利用度。我们将使用最先进的台式化学，包括粒度和质谱，以建立新的和创新的数据，关于如何HAS的形式，聚集和最终沉淀为动力学惰性的次生矿物样固相。这些数据将用于我们新的HAS形成动力学模型，以产生一个有效的和预测性的计算模型，该模型将容易被许多不同的感兴趣的方面访问，包括在基础化学，应用化学和毒理学中的应用。

The form of dissolved silicon which is found in natural waters such as lakes, rivers and the sea is called silicic acid. A molecule of silicic acid is composed of an atom of silicon surrounded by 4 hydroxyl (OH) groups in a tetrahedral arrangement. This molecule can almost be described as chemically inert as it has no known organic chemistry and almost no known inorganic chemistry. The latter is the subject of this proposal as we have identified the unique inorganic chemistry of silicic acid with aluminium in forming what we have called hydroxyaluminosilicates (HAS). We have been able to identify how the neutral silicic acid molecule reacts with a 'surface' composed of aluminium hydroxide to form two discrete HAS which we have called HAS'A' and HAS'B'. We have been able to confirm the structures of these solid phases and assign quantitative data to their composition and solubiblity. We have shown how they may also incorporate both fluoride and phosphate in their structures. All of our achievements in this field have now resulted in this chemistry being included in authoratative text books on inorganic chemistry. However, there is a great deal still to learn about HAS and in particular how their rate of formation will have profound influences upon their chemical and biological roles in specific environments. We have identified HAS as critical secondary minerals in the biogeochemical cycles of both aluminium and silicon. Thus we know that this chemistry plays an important role in the biological availability of silicon, for example, for biosilicification (organisms which build silica frameworks for structural roles) and aluminium, it keeps aluminium out of biota. The latter role of silicic acid as the natural antagonist to the potential toxicity of aluminium has been widely demonstrated by ourselves and, following us, many other groups and is probably the major role of silicon in living organisms. Thus gaining as much understanding as is possible about the formation of HAS will not only enable some new and exciting inorganic chemistry it will also inform us as to the role this chemistry plays and has played in biochemical evolution. In particular, in this project we wish to build a computational model of the kinetics of HAS formation as such a model should be invaluable to any application where it is important to be abe to predict the biological availability of aluminium. We will use state-of-the-art benchtop chemistry including particle-sizing and mass spectrometry to establish new and innovative data concerning how HAS form, aggregate and eventually precipitate as kinetcially inert secondary mineral-like solid phases. These data will be used in our new kinetic model of HAS formation to produce an effective and predictive computational model which will be readily accessible by many different interested parties including applications in fundamental chemistry but also in applied chemistry and in toxicology.