Advanced Chemically Bonded Ceramics for Medicine and Environment

在这项工作中，我们将研究新型骨水泥，特别是钙-磷-硅酸盐水泥(CPSC)和地质聚合物(GP)的微纤维增强的基础，以触发和评估这些材料的自愈过程。我们在生物陶瓷水泥领域最令人震惊的发现是，它们在模拟生物环境(SBF)中具有自我愈合的潜力。这些新型生物陶瓷在近室温下加固和强化，具有应变耐受性(在~2%应变下保持80%的强度，具有断裂韧性&2kJ/m2)，并可以通过与裂缝内的微环境的“智能”相互作用进行自我修复。我们认为这一发现足够重要，足以将其研究扩展到环境陶瓷，如化学结合的地质聚合物(GP)。在这里，我们将着眼于环境修复，包括“绿色”水泥，从长远来看，可能取代波特兰水泥，捕获重金属，或稳定尾矿。具体地说，我们建议对两种耐应变化学结合陶瓷的增韧和自愈进行研究：(1)用于生物医学(整形外科、牙科)的水力磷酸盐改性硅酸钙(CPSC)；(2)用于大规模环境应用的聚合物低成本碱性硅酸铝(GP)。两个研究主题定义如下：主题1：增韧(耐应变)磷硅酸盐生物水泥自愈合的基础和应用研究。长期目标是开发优于磷酸钙骨水泥的新型骨科/牙科生物粘固剂替代品的工艺技术。在短期内，我们将研究最近发现的增韧CPSC的自愈和力学性能的基本方面；并确定材料加工和材料特性对这种耐应变CPSC生物水泥的药物释放特性的影响。主题2：自我修复增韧(耐应变)结构土工聚合物的基础和应用研究。长期目标是开发具有自我修复特性的复合耐应变土工聚合物(STGP)的工艺技术，用于各种大规模环境和结构应用。在短期内，我们将开发短纤维在玻璃纤维中的分散和粘合工艺；研究不同增韧阶段和玻璃纤维变体之间的相互作用对新型STGP的机械、热和化学性能的影响；并研究和开发STGP的自愈机制。

In this work we will research the basics of micro-fibrous reinforcement of the novel bone cements, in particular the Calcium-Phosphate-Silicate Cement (CPSC) and Geo-Polymers (GP), en-route to trigger and assess self-healing processes in these materials. Our most stunning discovery in the area of bioceramic cements was their potential for self-healing in the simulated biological environment (SBF). These novel bioceramics consolidate and strengthen near- room temperature, are strain-tolerant (maintain > 80% strength at ~2% strain, with fracture toughness > 2 kJ/m2) and can repair themselves through the “smart” interaction with the micro-environment within the cracks. We consider this discovery important enough to extend its investigation to environmental ceramics, such as chemically bonded Geo-Polymers (GP). Here we will target environmental remediation including “green” cements, in the long term possibly replacing Portland cement, capture of heavy metals, or stabilization of mine tailings. Specifically, we propose research into toughening and self-healing of the two types of strain-tolerant chemically-bonded ceramics: (1) hydraulic phosphate-modified calcium-silicates (CPSC) for biomedical applications (orthopedic, dental), and (2) polymeric low-cost alkaline alumino-silicates (GP) for large-scale environmental applications. Two research themes are defined as follows: Theme 1: Basic and Applied Studies on Self-Healing of Toughened (Strain-Tolerant) Phospho-Silicate Biocements. The long-term objective is to develop process technology for the novel orthopedic/dental bio-cements alternatives superior to calcium phosphate cements. In the shorter term we will study the fundamental aspects of the recently discovered self-healing and mechanical performance of toughened CPSC; and determine the effects of materials processing and materials characteristics on drug-delivery characteristics of such strain-tolerant CPSC biocements. Theme 2: Basic and Applied Studies on Self-Healing Toughened (Strain-Tolerant) Structural Geo-Polymers. The long-term objective is development of process technology for the composite Strain-Tolerant Geo-Polymers (STGP) with self-healing characteristics, for variety of large-scale environmental and structural applications. In the shorter term we will develop processes for dispersion and bonding of short fibers within GP; study the effects of interactions between the various toughening phases and GP variants on the mechanical, thermal and chemical properties of the novel STGP; and study and develop self-healing mechanisms for STGP.