A Carbon Negative Self-Healing Enzymatic Construction Material

仅次于水，混凝土是地球上消耗最多的材料。每年，来自建筑的废弃混凝土以及水泥生产和运输的二氧化碳排放量都在增加，仅混凝土就占二氧化碳排放总量的9%。此外，混凝土本身是易碎的，需要频繁的维修和更换，这在经济上是昂贵的，并进一步产生大量的二氧化碳。几十年来，科学家们一直在努力寻找环保和低成本的混凝土替代品。该奖项的目标是使用建模和实验框架相结合的方法来创建一种新型的廉价，负碳，自我修复的建筑材料。该材料利用了一种安全、普遍存在的生物酶，可以在生产过程中有效地捕获二氧化碳。使用这种新的范例，将产生一种自我修复的酶结构材料。这种酶建筑材料可以显著延长民用基础设施的使用寿命，同时捕获碳。据预测，一立方码的酶建筑材料将储存约18磅的二氧化碳。 相比之下，一立方码的混凝土排放约400磅的二氧化碳。研究任务将通过培训研究生和本科生以及制定一项计划来补充，以帮助激励贫困女孩学习建筑和工程。受酶在细胞中高效运输CO2过程的启发，引入了一种新的范例来创建具有自修复特性的酶促建筑材料。碳酸酐酶催化碳酸钙晶体沉淀，沿着将聚集体结合在一起的聚合物支架建立矿物质桥。因此，材料的固化可以在短时间内在低温下进行。该材料的平均强度值是水泥砂浆最低要求的三倍，并且还能够在断裂后维持许多愈合周期。该项目的科学贡献包括以下方面。(1)通过酶促结晶沉淀法制备新型建筑材料。通过酶机制的晶体沉淀速率比细菌方法快四个数量级，使其可扩展到工业应用。(2)酶促机制为碳负性材料的开发提供了一种手段，以最终取代混凝土。(3)一种新的基于波动的半正则蒙特卡罗模拟方法将被用作酶结构材料热力学行为的建模技术。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Second only to water, concrete is the most consumed material on earth. Every year, waste concrete from construction and carbon dioxide excretion from cement production and transport is increasing, and concrete alone now contributes to 9 percent of the overall CO2 emissions. Additionally, concrete is inherently brittle, and it requires frequent repair and replacement, which are economically expensive and further generate large volumes of carbon dioxide. Scientists have been trying to find environmentally friendly and low-cost substitutes for concrete for decades. The goal of this award is to create a new class of inexpensive, carbon-negative, self-healing construction materials using a combined modeling and experimental framework. The material utilizes a safe, ubiquitous, biological enzyme that can efficiently capture CO2 during its production. Using this new paradigm, a self-healing Enzymatic Construction Material will be produced. This Enzymatic Construction Material can significantly lengthen the service life of civil infrastructure while capturing carbon. It is predicted that one cubic yard of Enzymatic Construction Material will approximately store 18 pounds of CO2. In contrast, one cubic yard of concrete emits around 400 pounds of CO2. The research tasks will be complemented by training both graduate and undergraduate students and developing a program to help inspire underprivileged girls to learn about construction and engineering. Inspired by the efficient process of CO2 transport in cells by enzymes, a new paradigm is introduced to create the Enzymatic Construction Material with self-healing properties. The enzyme, carbonic anhydrase, catalyzes calcium carbonate crystal precipitation, establishing mineral bridges along the polymer scaffolding that bonds the aggregate together. Hence, curing of the material can be performed at low temperatures in a short timeframe. The material exhibits an average strength value that is three times as high as the minimum requirement for cement mortar and is also capable of sustaining many cycles of healing after fracture. The scientific contribution of the project includes the following. (1) The formulation of a new class of construction materials through enzymatic crystal precipitation. The rate of crystal precipitation through the enzymatic mechanism is four orders of magnitude faster than bacterial methods making it scalable to industrial applications. (2) The enzymatic mechanism provides a means for the development of carbon-negative materials to ultimately replace concrete. (3) A novel fluctuation-based Semi-Grand Canonical Monte Carlo simulation method will be used as a modeling technique for the thermodynamic behavior of the Enzymatic Construction Material.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.