When Small is Different: The Case of Membranes Inside Tubes

2012 ◽  
Vol 1451 ◽  
pp. 15-20
Author(s):  
Eric Perim ◽  
Alexandre F. Fonseca ◽  
Douglas S. Galvão
Keyword(s):  
Molecular Dynamics ◽  
Boron Nitride ◽  
Structural Behavior ◽  
Relative Importance ◽  
Thin Sheets ◽  
Natural Question ◽  
Classical Elasticity ◽  
Cylindrical Tubes ◽  
Dynamics Simulations ◽  
Classical Elasticity Theory

ABSTRACTRecently, classical elasticity theory for thin sheets was used to demonstrate the existence of a universal structural behavior describing the confinement of sheets inside cylindrical tubes. However, this kind of formalism was derived to describe macroscopic systems. A natural question is whether this behavior still holds at nanoscale. In this work, we have investigated through molecular dynamics simulations the structural behavior of graphene and boron nitride single layers confined into nanotubes. Our results show that the class of universality observed at macroscale is no longer observed at nanoscale. The origin of this discrepancy is addressed in terms of the relative importance of forces and energies at macro and nano scales.

Experimental and molecular dynamics study of boron nitride nanotube-reinforced polymethyl methacrylate composites

2019 ◽  
Vol 54 (1) ◽  
pp. 3-11 ◽  
Author(s):  
Sumit Sharma ◽  
Prince Setia ◽  
Rakesh Chandra ◽  
Nitin Thakur
Keyword(s):  
Thermal Conductivity ◽  
Molecular Dynamics ◽  
Boron Nitride ◽  
Molecular Dynamics Simulations ◽  
Storage Modulus ◽  
Polymethyl Methacrylate ◽  
Loss Factor ◽  
Boron Nitride Nanotubes ◽  
Weight Percentage ◽  
Dynamics Simulations

Heat dissipation is very essential for the efficient working of electronic devices. There is a widespread demand for high thermal conductivity materials. Boron nitride nanotubes have high thermal conductivity but due to their poor interfacial adhesion with polymers, their use as heat dissipating material is restricted. In this study, a silane-coupling agent has been used to modify the boron nitride nanotubes. These tubes were then inserted in polymethyl methacrylate matrix. Various properties such as thermal conductivity, storage modulus, and loss factor have been predicted. Molecular dynamics simulations have also been used for accurate prediction of the properties of boron nitride nanotubes/polymethyl methacrylate composites. The boron nitride nanotubes weight percentage was varied from 0% to 70% for studying the effect on thermal conductivity, storage modulus, and loss factor. The experimentally obtained thermal conductivity increased rapidly from 0.6 W/mK at 40 wt.% of boron nitride nanotubes to about 3.8 W/mK at 80 wt.% of boron nitride nanotubes in polymethyl methacrylate matrix (an increase of nearly 533%). A similar trend was obtained using molecular dynamics simulations. The storage modulus increased from 2 GPa (for pure polymethyl methacrylate) to about 5 GPa (for 70 wt.% boron nitride nanotubes). The glass transition temperature of boron nitride nanotubes/polymethyl methacrylate composites shifted to higher temperatures with an increase in boron nitride nanotubes weight percentage.

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