Hard-soft matter interfaces: from understanding to engineering

术语材料非常广泛，因此为了简单起见，材料通常被描述为硬或软。虽然陶瓷等硬质材料很坚固，但它们通常很脆。相比之下，诸如聚合物的软材料通常机械强度较弱，但可以显示出有价值的弹性。因此，将这两种成分结合在一种新的复合材料中，可以产生引人注目的新材料，这些材料受益于这两种成分的优点。这只是硬材料和软材料相结合的好处之一。事实上，硬材料和软材料之间的相互作用发生在各行各业。医疗植入物是否被人体接受取决于细胞如何识别并与硬植入物表面相互作用。控制这一点需要我们了解分子尺度的过程，这决定了软生物分子如何与表面相互作用-以及发生在更大长度尺度上的过程，最重要的是细胞如何相互作用并识别硬表面。在这种情况下，软物质必须适应硬表面，可能会改变其形状和化学性质。这对许多应用都很重要-从纳米颗粒的毒理学到环境修复策略。也许令人惊讶的是，不仅是硬材料控制软材料，匡威也会发生。生物矿化--生物体形成骨骼、牙齿和贝壳等矿物结构--完美地展示了这一点。正是通过不断生长的矿物质与柔软的有机物质的相互作用，大自然才产生了这些具有非凡形状和特性的材料。生物矿物通常与合成矿物非常不同。虽然在实验室中沉淀的方解石（碳酸钙）晶体具有规则的几何形状，但在海胆的棘中，方解石单晶是海绵状的，弯曲的表面取代了平坦的晶面。生物矿物也几乎总是复合材料-软有机分子嵌入晶体中。正是这种结构赋予了生物矿物如此奇妙的机械性能-事实上，牙釉质是已知最坚硬的材料之一。软物质不仅影响生物矿物的性质，而且几乎控制着它们形成的每一个阶段-从最早的成核阶段，通过生长，到最终生物矿物的产生。不溶性有机分子定义了生物矿物形成和成核的特殊环境，而小的可溶性有机分子在生长过程中与晶体结合，影响其形状。显然，了解软材料和硬材料如何相互作用和相互控制非常重要，并且具有从医学到地质学，从气候科学到纳米技术的跨学科应用。生物学用于生产生物矿物的策略可以应用于新材料的设计和制造-其中结构可以在原子尺度上控制，并且在温和的条件下进行合成。如果我们能设计出能牢固附着在表面的分子，我们就能用它们来抑制晶体生长。晶体生长在不应该生长的地方--锅炉、供暖系统和油井威尔斯--仍然是工业和家庭生活中的一个主要问题。最后，许多生物材料是碳酸盐。它们是地球碳循环的一部分--这是二氧化碳从大气中长期去除的主要方式。在海洋中，由于海洋条件的变化，珊瑚礁等结构受到威胁;我们需要了解它们生长的机制，以充分了解原因。从大气中去除二氧化碳并将其转化为碳酸盐是一种可能的碳捕获策略。在这项资助下进行的研究将以独特的方式使用实验和理论来阐明生物圈这种最迷人和最重要的能力背后的基本机制，并利用这些知识来开发新材料。

The term material is extremely broad, so for simplicity's sake, materials are often described as either hard or soft . While hard materials such as ceramics are strong, they are often brittle. In contrast, soft materials such as polymers are often mechanically weak, but can show valuable elastic properties. Combining these two in one new composite can therefore give rise to remarkable new materials, which benefit from the advantages of both components. This is just one benefit of combining hard and soft materials. In fact, interaction between hard and soft materials occurs in all walks of life. Whether a medical implant is accepted in the body depends on how cells recognise and interact with the hard implant surface. Controlling this requires that we understand molecular-scale processes, which govern how soft biomolecules interact with surfaces - and also processes occurring on much larger length-scales, most importantly how cells interact and recognise a hard surface. In this case, the soft matter must adapt to the hard surface, potentially changing its shape and chemical properties. This is important for many applications - from the toxicology of nanoparticles to strategies for environmental remediation. Perhaps surprisingly, it is not only hard materials which control the soft - the converse also occurs. Biomineralisation - the formation of mineral structures such as bones, teeth and seashells by organisms - shows this beautifully. It is through interaction of growing minerals with soft, organic matter that Nature produces these materials with their remarkable shapes and properties. Biominerals are often very different from synthetic minerals. While a crystal of calcite (calcium carbonate) precipitated in the lab has a regular, geometric form, in the spines of a sea urchin a calcite single crystal is sponge-like, with curved surfaces replacing flat crystal planes. Biominerals are also almost always composites - soft organic molecules are embedded within the crystal. It is this structure which gives biominerals such wonderful mechanical properties - indeed, tooth enamel is one of the hardest materials known. Soft matter not only affects the properties of biominerals, but controls almost every stage of their formation - from the earliest stages of nucleation, through growth, to production of the final biomineral. Insoluble organic molecules define the special environments in which biominerals form and nucleate, while small, soluble organic molecules bind to a crystal during growth, influencing its shape. Clearly, understanding how soft and hard materials interact and control each other is of great importance, and has applications spanning disciplines from medicine to geology, from climate science to nanotechnology. The strategies used by biology to produce biominerals can be applied to the design and fabrication of new materials - where the structure can be controlled at the atomic scale, and the synthesis carried out under mild conditions. If we can design molecules to attach to surfaces strongly, we can use them to inhibit crystal growth. Crystals growing where they should not - in boilers, heating systems and oil wells - remains a major problem in industry and domestic life. Finally, many biomaterials are carbonates. They are a part of the planet's carbon cycle - a major way in which carbon dioxide is removed from the atmosphere for long periods. In the oceans, structures such as coral reefs are under threat due to changes in oceanic conditions; we need to understand the mechanisms of their growth to understand fully why. Removing carbon dioxide from the atmosphere and converting it into carbonates is a possible carbon capture strategy. The research carried out in this grant will use both experiment and theory in a unique way to shed light on the fundamental mechanisms behind this most fascinating and essential capability of the biosphere and to harness this knowledge to develop of novel materials.