h-BN泡沫吸收CO₂，循环2000次，吸附量340%（附原文）

诸平

据物理学家组织网（Phys.org）2017年8月16日转载美国化学会主办的杂志ACS Nano的消息，美国赖斯大学（Rice University）的科学家研究发现，氮化硼（boron nitride） 泡沫可以吸收CO₂,图1就是用聚乙烯醇进行处理之后的六方氮化硼（hexagonal-boron nitride简称h-BN）的泡沫块，已经证明它能够吸附其自身重量三倍多的CO₂。

Fig. 2 A microscope image shows the high surface area of hexagonal-boron nitride foam glued together with polyvinyl alcohol. The tough, light foam can be used to soak up carbon dioxide or as a material to shield biological tissues from lasers. Credit: Ajayan Research Group/Rice University

图2是显微镜图像显示出h-BN泡沫与聚乙烯醇粘在一起的高表面积。这种坚硬的、轻型泡沫可以用来吸收CO₂或作为一种材料来保护生物组织不受激光的影响。当采用另一种聚合物即聚二甲基硅氧烷（Polydimethylsiloxane简称PDMS）进行涂饰时,此泡沫成为一种有效的保护材料，可以免遭激光影响，因此它可以用于生物医学、电子产品以及一些其他应用。最终,研究人员想要控制材料孔的大小，以便适宜于特定的应用,如从水中分离油品。

模拟工作是由合著者、巴西坎皮纳斯州立大学和美国赖斯大学联合培养的博士后研究者克里斯蒂亚诺·沃尔勒（ Cristiano Woellner）作为模拟实验的指导。克里斯蒂亚诺·沃尔勒说：“实验与理论计算相结合对于了解h-BN与粘合剂组成的力学响应是非常重要的,通过模拟可以是实验研究者提前了解他们将如何对其混合体系进行改进。”

Fig.3 A molecular dynamics simulation shows polyvinyl alcohol molecules of carbon (teal), oxygen (red) and hydrogen (white) binding two-dimensional sheets of hexagonal-boron nitride (blue and yellow). The reusable material created at Rice University can sequester more than three times its weight in carbon dioxide. Credit: Ajayan Research Group/Rice University

图3的分子动力学模拟结果显示，聚乙烯醇分子的碳(青色)、氧(红色)和氢(白色)与h-BN(蓝色和黄色)的二维薄片结合在一起。莱斯大学创建的可重用的材料可以吸收CO₂,吸附量使其吸附材料自重的三倍多。更多信息请注意浏览原文或者相关其他报道。

Graphene foam gets big and tough: Nanotube-reinforced material can be shaped, is highly conductive

Boron nitride foam soaks up carbon dioxide

Abstract

Weak van der Waals forces between inert hexagonal boron nitride (h-BN) nanosheets make it easy for them to slide over each other, resulting in an unstable structure in macroscopic dimensions. Creating interconnections between these inert nanosheets can remarkably enhance their mechanical properties. However, controlled design of such interconnections remains a fundamental problem for many applications of h-BN foams. In this work, a scalable in situ freeze-drying synthesis of low-density, lightweight 3D macroscopic structures made of h-BN nanosheets chemically connected by poly(vinyl alcohol) (PVA) molecules via chemical cross-link is demonstrated. Unlike pristine h-BN foam which disintegrates upon handling after freeze-drying, h-BN/PVA foams exhibit stable mechanical integrity in addition to high porosity and large surface area. Fully atomistic simulations are used to understand the interactions between h-BN nanosheets and PVA molecules. In addition, the h-BN/PVA foam is investigated as a possible CO2absorption and as laser irradiation protection material.

Keywords: CO2 absorption; h-BN; MD simulation; PVA; three-dimensional materials