Advanced Chemically Bonded Ceramics for Medicine and Environment

在这项工作中，我们将研究新型骨水泥，特别是磷酸钙硅酸盐水泥（CPSC）和地质聚合物（GP）的微纤维增强的基础知识，以触发和评估这些材料的自我修复过程。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）中的自我修复潜力。这些新型生物陶瓷在近室温下固结和强化，是耐应变的（在~2%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的微环境的“智能”相互作用来自我修复。我们认为这一发现的重要性足以将其研究扩展到环境陶瓷，如化学键合的地质聚合物（GP）。在这方面，我们的目标是环境修复，包括“绿色”水泥，从长远来看可能取代波特兰水泥，重金属捕获或尾矿稳定。具体而言，我们建议研究两种类型的耐应变化学结合陶瓷的增韧和自修复：（1）用于生物医学应用（骨科，牙科）的水硬性磷酸盐改性硅酸钙（CPSC），和（2）用于大规模环境应用的聚合物低成本碱性铝硅酸盐（GP）。两个研究主题定义如下：主题1：韧性（应变耐受）磷硅酸盐生物水泥自愈合的基础和应用研究。长期目标是开发新的骨科/牙科生物骨水泥替代品的工艺技术，该替代品上级于磷酸钙骨水泥。在短期内，我们将研究最近发现的自愈合和增韧CPSC的机械性能的基本方面;并确定材料加工和材料特性对这种耐应变CPSC生物水泥的药物输送特性的影响。主题2：自修复增韧（耐应变）结构地质聚合物的基础与应用研究。长期目标是开发具有自修复特性的复合耐应变地质聚合物（STGP）的工艺技术，用于各种大规模的环境和结构应用。在短期内，我们将开发GP内短纤维的分散和粘合工艺;研究各种增韧相和GP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的自修复机制。

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.