Hernández Marta I, Bartolomei Massimiliano, Campos-Martínez José
Instituto de Física Fundamental, Consejo Superior de Investigaciones Científicas (IFF-CSIC) Serrano 123, 28006 Madrid, Spain.
Nanomaterials (Basel). 2020 Dec 31;11(1):73. doi: 10.3390/nano11010073.
We report accurate quantum calculations of the sieving of Helium atoms by two-dimensional (2D) graphtriyne layers with a new interaction potential. Thermal rate constants and permeances in an ample temperature range are computed and compared for both Helium isotopes. With a pore larger than graphdiyne, the most common member of the γ-graphyne family, it could be expected that the appearance of quantum effects were more limited. We find, however, a strong quantum behavior that can be attributed to the presence of selective adsorption resonances, with a pronounced effect in the low temperature regime. This effect leads to the appearance of some selectivity at very low temperatures and the possibility for the heavier isotope to cross the membrane more efficiently than the lighter, contrarily to what happened with graphdiyne membranes, where the sieving at low energy is predominantly ruled by quantum tunneling. The use of more approximate methods could be not advisable in these situations and prototypical transition state theory treatments might lead to large errors.
我们报告了利用一种新的相互作用势对二维石墨炔层筛选氦原子进行的精确量子计算。针对两种氦同位素，计算并比较了在很宽温度范围内的热速率常数和渗透率。由于该孔隙比γ-石墨炔家族中最常见的成员石墨二炔的孔隙大，预计量子效应的表现会更有限。然而，我们发现了一种强烈的量子行为，这可归因于选择性吸附共振的存在，在低温区域有显著影响。这种效应导致在非常低的温度下出现一些选择性，并且较重的同位素比较轻的同位素更有效地穿过膜，这与石墨二炔膜的情况相反，在石墨二炔膜中低能筛选主要由量子隧穿主导。在这些情况下，使用更近似的方法可能不可取，典型的过渡态理论处理可能会导致较大误差。
