Advanced Chemically Bonded Ceramics for Medicine and Environment

在这项工作中，我们将研究新型骨水泥的微纤维增强基础，特别是钙-磷酸盐-硅酸盐水泥（CPSC）和土工聚合物（GP），以触发和评估这些材料的自修复过程。我们在生物陶瓷水泥领域最惊人的发现是它们在模拟生物环境（SBF）中具有自我修复的潜力。这些新型生物陶瓷在室温下固化和强化，具有应变耐受性（在~2%的应变下保持> 80%的强度，断裂韧性> 2kj /m2），并且可以通过与裂纹内微环境的“智能”相互作用进行自我修复。我们认为这一发现非常重要，足以将其研究扩展到环境陶瓷，如化学键合土工聚合物（GP）。在这里，我们将针对环境修复，包括“绿色”水泥，在长期可能取代波特兰水泥，捕获重金属，或稳定矿山尾矿。具体来说，我们建议研究两种类型的耐应变化学键合陶瓷的增韧和自修复：(1)用于生物医学应用（骨科，牙科）的液压磷酸盐改性硅酸钙（CPSC），以及(2)用于大规模环境应用的低成本聚合碱性硅酸铝（GP）。确定了两个研究主题：主题一：增韧（耐应变）磷硅酸盐生物水泥自愈的基础与应用研究。长期目标是开发优于磷酸钙水泥的新型骨科/牙科生物水泥替代品的工艺技术。在短期内，我们将研究最近发现的自愈和增韧CPSC力学性能的基本方面；并确定材料加工和材料特性对此类耐菌株CPSC生物水泥的药物传递特性的影响。主题2：自愈增韧（应变耐受）土工聚合物结构的基础与应用研究。长期目标是开发具有自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，我们将在GP中开发短纤维的分散和粘合工艺；研究了不同增韧相和GP变体之间的相互作用对新型STGP力学、热、化学性能的影响；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.