Biomimetic Interfacial Control in Polymer Nanocomposites

描述(申请人提供)：传统的牙科复合材料是由多功能单体在高体积分数的颗粒玻璃填充物存在下原位聚合而成的高度填充的聚合物系统。虽然这些系统得到了广泛的应用，通常对修复牙齿组织有效，但在机械强度、耐水性、耐磨性和其他性能方面仍需显著提高。具有高长径比的纳米颗粒填料具有显著的强度和其他性能改进的潜力；然而，由于极高的填料基质界面面积，基质-填料界面的特性有望在此类体系中表现得更加突出。因此，纳米增强牙科复合材料的新策略必须包括高度重视界面设计以及填充物的形状、大小和组成。 在这项研究中，我们建议开发由纳米二氧化钛颗粒增强牙科复合材料组成的新型牙科纳米复合材料。氧化物纳米颗粒将以球形、棒状和片状纳米颗粒的形式存在。在纳米颗粒开发的同时，将探索新的界面控制方法，这些方法受到海洋粘合蛋白的启发，这些粘合蛋白包含了不寻常的氨基酸，这些氨基酸在二氧化钛表面形成高强度、可逆和防水的键。这些化合物将被用来设计新型的交联剂和引发剂，将基质连接到具有高强度和耐水性的纳米颗粒表面。新的纳米复合材料将测试断裂强度、断裂能、吸水率以及水中老化对机械性能的影响。因此，这些候选牙科纳米复合材料的重要物理化学性质将在本研究中得到揭示，这些结果将为未来纳米二氧化钛增强复合材料在牙科中的应用提供详细研究的平台。

DESCRIPTION (provided by applicant): Conventional dental composites are highly filled polymer systems created by in situ polymerization of multifunctional monomers in the presence of a high volume fraction of particulate glass fillers. While these systems enjoy widespread use and are generally effective for restoring dental tissues, significant improvements in mechanical strength, water resistance, wear and other properties are still needed. Nanoparticulate fillers with high aspect ratios offer the potential for significant strength and other property improvements; however the characteristics of the matrix-filler interface are expected to assume an even greater prominence in such systems due to the extremely high filler matrix interfacial area. Thus, new strategies to nanoreinforced dental composites must include great attention to interfacial design as well as shape, size and composition of filler. In this study we propose to develop new dental nanocomposites consisting of TiO2 nanoparticle reinforced dental composites. The oxide nanoparticles will be in the form of spherical, rod-like and sheet-like nanoparticles. In parallel with nanoparticle development, new approaches to interfacial control will be explored that are inspired by marine adhesive proteins that incorporate unusual amino acids that form high strength, reversible and water resistant bonds to TiO2 surfaces. These compounds will be used to design novel cross-linking and initiating agents that link the matrix to the nanoparticle surfaces with high strength and water resistance. The new nanocomposites will be tested for fracture strength, fracture energy, water absorption, and the effect of aging in water on mechanical performance. Thus, important physicochemical properties of these candidate dental nanocomposites will be revealed during this study, with the results serving as a platform for future detailed studies toward utilization of nanoparticulate TiO2 reinforced composites in dentistry.