Rational integration of molecular and surface interactions for low friction - high wear resistance of soft surfaces

分子与表面相互作用的合理整合，实现软表面的低摩擦-高耐磨性

• 批准号: RGPIN-2014-06316
• 负责人: Banquy, Xavier
• 金额: $ 2.19万
• 依托单位: Université de Montréal
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=683599
• 关键词: Rational; integration; molecular; surface; interactions

The development of efficient and long lasting machines and devices requires a careful control of surface properties such as friction and wear. Soft surfaces are particularly vulnerable to wear and the lack of technology able to protect such surfaces from frictional degradation has hampered the development of numerous technologies such as artificial cartilage. The main goal of this research program is to fill this technological gap by developing a platform of polymeric lubricants and soft hydrogel coatings that can act synergistically to provide enhanced lubrication and wear protection. Our approach is to design such synergistic interactions using multiple molecular mechanisms recently discovered in articular joints. These mechanisms include the directional (anisotropic) flow of synovial fluid in the cartilage pores to the surfaces under normal compression, the local trapping of anti-wear macromolecules in and at the cartilage surface during compression and finally the strong interaction between highly ramified lubricating proteins such as lubricin (LUB) and glycoaminoglycans (GAGs) with the cartilage surface and hyaluronic acid which provides low adhesion and high hydration to the surfaces. *To reach our goal, we propose a research program divided into three complementary aims.*Aim 1. To develop bio-inspired and efficient polymeric lubricants *A key element in the development of a lubricant is the molecular architecture which defines the conformation, lubricating efficiency and load bearing capacity of the molecule. We will develop a library of multiblock polymers exhibiting the bottle-brush architecture which is extensively found in natural lubricating proteins. Two families of polymers mimicking lubricin and GAGs will be studied for their load bearing capacity, lubricating properties and wear protection ability on model flat surfaces before increasing the complexity of the system to hydrogel coatings. These measurements will be performed using the Surface Forces Apparatus (SFA) in order to establish structure-properties relationships of our polymers at the molecular level and to identify key structural parameters responsible for good lubrication and anti-wear properties.*Aim 2. To engineer micro/nano inclusions into hydrogel coatings to provide superior wear resistance *The poor wear resistance of hydrogel materials has hampered their biotechnological use. Nature uses abundantly soft porous collagen materials to protect hard bones from abrasion and wear. The ultrastructure of cartilage is thought to be responsible for its good anti-wear properties. We will explore this hypothesis by fabricating soft hydrogel coatings known to exhibit poor wear resistance and will modify them to incorporate certain key features of cartilage structure such as the pore structure, the pore distribution or the surface roughness. Wear resistance of the different families of coatings will be assessed by SFA and imaging in order to elucidate which structure is able to provide a significant improvement in the tribological properties.*Aim 3. To formulate synergistic interactions between "bottle-brush" lubricants and structured hydrogel coatings for the enhancement of their tribological properties *We will determine if combinations of bio-inspired structured hydrogel coatings and lubricating polymers can act synergistically to generate enhanced wear resistance and lubrication. Using the SFA we will elucidate the origin of such synergistic interactions by measuring how lubricant molecules adsorption, conformation, distribution and lubricating properties are controlled by the coating structure.

开发高效和耐用的机器和设备需要仔细控制表面特性，如摩擦和磨损。柔软的表面特别容易磨损，缺乏能够保护此类表面免受摩擦退化的技术，阻碍了人造软骨等众多技术的发展。该研究计划的主要目标是通过开发聚合物润滑剂和软性水凝胶涂层的平台来填补这一技术空白，该平台可以协同作用，提供增强的润滑和磨损保护。我们的方法是使用最近在关节中发现的多种分子机制来设计这种协同作用。这些机制包括在正常压缩下滑液在软骨毛孔中定向(各向异性)流向表面，在压缩过程中抗磨大分子在软骨表面的局部捕获，最后是高度支化的润滑蛋白如润滑素(Lub)和糖胺聚糖(GAG)与软骨表面和透明质酸之间的强烈相互作用，透明质酸为软骨表面提供了低粘附性和高水合作用。*为了达到我们的目标，我们提出了一个分为三个相辅相成的目标的研究计划。*目标1.开发生物灵感和高效的聚合物润滑剂*开发润滑剂的一个关键因素是分子的结构，它定义了分子的构象、润滑效率和承载能力。我们将开发一个多嵌段聚合物文库，展示在天然润滑蛋白中广泛存在的瓶刷结构。在增加水凝胶涂层系统的复杂性之前，将研究两类模拟润滑剂和GAG的聚合物在模型平面上的承载能力、润滑性能和磨损保护能力。这些测量将使用表面力装置(SFA)进行，以便在分子水平上建立我们聚合物的结构-性能关系，并确定对良好的润滑和抗磨性能负责的关键结构参数。*目标2.将微/纳米夹杂物设计到水凝胶涂层中以提供优异的耐磨性*水凝胶材料的耐磨性差阻碍了它们在生物技术中的应用。大自然使用大量柔软的多孔胶原蛋白材料来保护硬骨免受磨损。软骨的超微结构被认为是其良好的抗磨性能的原因。我们将通过制造已知耐磨性较差的柔软水凝胶涂层来探索这一假设，并对其进行修改，以纳入软骨结构的某些关键特征，如孔结构、孔分布或表面粗糙度。不同系列涂层的耐磨性将通过SFA和成像进行评估，以阐明哪种结构能够显著改善摩擦学性能。*目标3.制定“瓶刷”润滑剂和结构化水凝胶涂层之间的协同作用，以增强它们的摩擦学性能*我们将确定受生物启发的结构化水凝胶涂层和润滑聚合物的组合是否能够协同作用，产生更高的耐磨性和润滑性。使用SFA，我们将通过测量润滑剂分子的吸附、构象、分布和润滑性能如何由涂层结构控制来阐明这种协同作用的来源。