Dolado Jorge S, Goracci Guido, Duque Eduardo, Martauz Pavel, Zuo Yibing, Ye Guang
Centro de Física de Materiales, CSIC-UPV/EHU, Paseo Manuel de Lardizabal 5, 20018 Donostia/San Sebastián, Spain.
Donostia International Physics Center (DIPC), Paseo Manuel de Lardizabal 4, 20018 Donostia/San Sebastián, Spain.
Materials (Basel). 2020 Sep 21;13(18):4194. doi: 10.3390/ma13184194.
To find materials with an appropriate response to THz radiation is key for the incoming THz technology revolution. Unfortunately, this region of the electromagnetic spectra remains largely unexplored in most materials. The present work aims at unveiling the most significant THz fingerprints of cement-based materials. To this end transmission experiments have been carried out over Ordinary Portland Cement (OPC) and geopolymer (GEO) binder cement pastes in combination with atomistic simulations. These simulations have calculated for the first time, the dielectric response of C-S-H and N-A-S-H gels, the most important hydration products of OPC and GEO cement pastes respectively. Interestingly both the experiments and simulations reveal that both varieties of cement pastes exhibit three main characteristic peaks at frequencies around ~0.6 THz, ~1.05 THz and ~1.35 THz, whose origin is governed by the complex dynamic of their water content, and two extra signals at ~1.95 THz and ~2.75 THz which are likely related to modes involving floppy parts of the dried skeleton.
找到对太赫兹辐射有适当响应的材料是即将到来的太赫兹技术革命的关键。不幸的是，在大多数材料中，电磁频谱的这一区域在很大程度上仍未被探索。目前的工作旨在揭示水泥基材料最重要的太赫兹指纹特征。为此，对普通硅酸盐水泥（OPC）和地质聚合物（GEO）粘结剂水泥浆体进行了传输实验，并结合了原子模拟。这些模拟首次计算了C-S-H和N-A-S-H凝胶的介电响应，它们分别是OPC和GEO水泥浆体最重要的水化产物。有趣的是，实验和模拟都表明，两种水泥浆体在频率约为0.6太赫兹、1.05太赫兹和1.35太赫兹左右都表现出三个主要特征峰，其起源受其含水量复杂动态的支配，以及在1.95太赫兹和2.75太赫兹处的两个额外信号，这可能与涉及干燥骨架松散部分的模式有关。
