Modeling of negative Poisson’s ratio (auxetic) crystalline cellulose Iβ

Abstract

Energy minimizations for unstretched and stretched cellulose models using an all-atom empirical force field (molecular mechanics) have been performed to investigate the mechanism for auxetic (negative Poisson's ratio) response in crystalline cellulose I b from kraft cooked Norway spruce. An initial investigation to identify an appropriate force field led to a study of the structure and elastic constants from models employing the CVFF force field. Negative values of on-axis Poisson's ratios m 31 and m 13 in the x 1 -x 3 plane containing the chain direction (x 3 ) were realized in energy minimizations employing a stress perpendicular to the hydrogen-bonded cellobiose sheets to simulate swelling in this direction due to the kraft cooking process. Energy minimizations of structural evolution due to stretching along the x 3 chain direction of the 'swollen' (kraft cooked) model identified chain rotation about the chain axis combined with inextensible secondary bonds as the most likely mechanism for auxetic response.

Silver Oxalate: Mechanical Properties and Extreme Negative Mechanical Phenomena

“…The crystal structure and mechanical properties of silver oxalate were determined using first principles solid‐state methods. The description of solid‐state crystalline compounds using computational modelling techniques is sufficiently advanced nowadays to predict their mechanical properties in good agreement with experimental measurements . The present computations were carried out separately with several different sets of calculation parameters associated to increasingly more demanding computations and the analysis of the convergence of the calculated crystal structures, associated energies, and properties showed that they were nearly converged with respect to the calculation parameters.…”

Negative linear compressibility in uranyl squarate monohydrate

“…The description of solid-state crystalline compounds using computational modelling techniques, appears to be sufficiently advanced nowadays to predict their mechanical properties in good agreement with experimental values . Following the pionering work by Keskar and Chelikowsky [15] in 1992 in which the anomalous mechanical behavior of crystalline SiO 2 was studied theoretically, many other successsful studies were performed as those of Grima et al [17] and Coudert et al [18][19] on zeolites, Yao et al [20] on crystalline cellulose, Tan et al [21][22] on zeolitic imidazolate frameworks (ZIFs), Sun et al [23] on pentagraphene and phagraphene, Du et al [24] on black phosphorus, Li et al [25] on an ammonium-zinc metalorganic framework, Qiao et al [26] on ammonium oxalate monohydrate, Coates et al [27] on Cd(NH 3 ) 2 [Cd(CN) 4 ], Marmier et al [28] on platinum sulfide and Kang et al [29] on α − BiB 3 O 6 .…”

Revealing Rutherfordine Mineral as an Auxetic Material

“…Several published works in which the theoretical methodology has been used in the research of auxetic materials, i.e., exhibiting negative Poisson ratios (NPR) [16][17][18], are given in References [19][20][21][22][23][24][25][26][27][28][29][30][31][32]. For example, we may recall the papers by Keskar and Chelikowsky [19] and Grima et al [20] on crystalline SiO 2 , Grima et al [21] on zeolitic compounds, Yao et al [22] on crystalline cellulose, Tan et al [23,24] on zeolitic imidazolate frameworks (ZIFs), and Du et al [25] on black phosphorus. The description of solid-state crystalline compounds using computational modeling techniques appears to be sufficiently advanced nowadays to predict their mechanical properties in good agreement with experimental values.…”