Molecular dynamics simulations of the effect of shape and size of SiO2 nanoparticle dopants on insulation paper cellulose

Abstract

The effect of silica nanoparticle (Nano-SiO2) dopants on insulation paper cellulose, and the interaction between them, was investigated using molecular dynamics simulations. The mechanical properties, interactions, and cellulose-Nano-SiO2 compatibility of composite models of cellulose doped with Nano-SiO2 were studied. An increase in Nano-SiO2 size leads to a decrease in the mechanical properties, and a decrease in the anti-deformation ability of the composite model. The binding energies and bond energies per surface area of the composite models indicate that the bonding interaction between spherical Nano-SiO2 and cellulose is the strongest among the four different Nano-SiO2 shapes that are investigated. The solubilities of the four composite models decrease with increasing Nano-SiO2 size, and the difference between the solubility of pure cellulose and those of the composite models increases with increasing Nano-SiO2 size. Good doping effects with the highest cellulose-Nano-SiO2 compatibility are achieved for the cellulose model doped with spherical Nano-SiO2 of 10 Å in diameter. These findings provide a method for modifying the mechanical properties of cellulose by doping, perhaps for improving insulation dielectrics.

Selection of Optimal Polymerization Degree and Force Field in the Molecular Dynamics Simulation of Insulating Paper Cellulose

“…The average δ of the 10 groups with DP of 10-100 is 28.4 (J/cm 3 ) 0.5 . This value is slightly different from the values obtained from References [30][31][32], but given that the models used are different, this value is still deemed to be reasonable.…”

“…To determine the variation of the mechanical properties and solubility of the cellulose chain, models of 19 groups of single cellulose chains in the amorphous region with the polymerization degrees of 2,4,6,8,9,10,12,16,20,25,30,35,40,50,60,70,80,90, and 100 were constructed using COMPASS and PCFF force fields. The model density obtained by W. Chen [21] was about 1.385 g/cm 3 , while K. Mazeau and L. Heux [11] achieved a model with four different densities of 1.34-1.3927 g/cm 3 by modeling with the same method and standpoint, and proposed that the density of cellulose in the amorphous region is 1.28-1.44 g/cm 3 .…”

Molecular Simulation of Improved Mechanical Properties and Thermal Stability of Insulation Paper Cellulose by Modification with Silane-Coupling-Agent-Grafted Nano-SiO2

“…In recent years, the rise of nanotechnology has prompted research on nanoparticle-modified cellulose insulating paper. Many researchers have made progress in this field [6][7][8][9][10]. Liu used nano-Al 2 O 3 to modify insulating paper and studied the depth and degree of the traps [11].…”

“…In this study, the nano-SiO 2 content in all of the models was 5% [9,12,14]. The mechanical properties (tensile modulus, shear modulus, volume model, and Poisson's ratio) and thermal stability (glass-transition temperature and free-volume fraction) of cellulose modified by nano-SiO 2 modified by different silane coupling agents were investigated and compared through a molecular dynamics simulation based on the same grafting rate of the silane coupling agent.…”

Effect of cellulose nanocrystals on the performance of oil-immersed transformer insulating paper

“…The addition of nano-TiO2 (Liao et al 2013) or nano-montmorillonite (Yuan and Liao 2014) could improve the AC breakdown strength of the paper. Howerver, mechanical properties, which play a crucial role in determining the lifetime of insulating paper, normally decreased (Zhang et al 2015;Tang et al 2016). In addition, preparation process for the aforementioned nanomodified paper was usually complex due to the incompatibility between inorganic nanoparticles and organic cellulose fibers (Huang et al 2017;Tang et al 2017;Cao et al 2019).…”