Phonon scattering at SWCNT–SWCNT junctions in branched carbon nanotube networks

نویسندگان

  • Jungkyu Park
  • Jonghoon Lee
  • Vikas Prakash
چکیده

In this research article, we analyze phonon scattering in branched single-walled carbon nanotube (SWCNT) networks with SWCNT–SWCNT Tand Xjunctions using the wave packet method. Five phonon branches including the longitudinal acoustic, twisting, transverse acoustic, radial breathing, and flexural optical modes are selected to study energy reflection, ramification, and transmission through Tand X-junctions with (6,6) and (4,4) SWCNTs. The results of the simulations indicate that the diameter of SWCNTs affects phonon scattering at carbon nanotube junctions; T-junctions of (6,6) SWCNTs transmit energy more efficiently when compared to T-junctions with (4,4) SWCNTs. In addition, T-junctions of both (6,6) and (4,4) SWCNTs transmit vibrational energy more efficiently when compared to X-junctions in the same phonon frequency range—for example, in the case of the longitudinal acoustic branch, the average energy transmission at T-junctions for low-frequency phonons (lower than 6 THz) was found to be 1.8–2.4 times higher [for the case of (6.6) and (4,4) SWCNTs, respectively] when compared to the X-junctions. It is also observed that energy transmission at the T-junctions shows a dependency on the phonon group velocity with the higher group velocity phonons showing higher energy transmission; however, for the case of the X-junctions, there is little or no correlation observed between the group velocity and energy transmission indicating a complete energy redistribution of the incoming phonons at the junction. Moreover, for the SWCNT–SWCNT branched networks, the energy ramification at the T-junctions was found to be very similar to that at the X-junctions for both (6,6) and (4,4) SWCNTs indicating transverse thermal transport at the X-junctions to be as efficient as the T-junctions.

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Synthesis and investigation of thermal conductivity carbon nanotubes: MWCNT and SWCNT

In this study, Bio-based carbon nanotubes (CNTs) have received considerable research attention due to their comparative advantages of high level stability, simplistic use, low toxicity and overall environmental friendliness. New potentials for improvement in heat transfer applications are presented due to their high aspect ratio, high thermal conductivity and special surface area. Phonons have ...

متن کامل

Thermal Resistance across Interfaces Comprising Dimensionally Mismatched Carbon Nanotube-Graphene Junctions in 3D Carbon Nanomaterials

In the present study, reverse nonequilibrium molecular dynamics is employed to study thermal resistance across interfaces comprising dimensionally mismatched junctions of single layer graphene floors with (6,6) single-walled carbon nanotube (SWCNT) pillars in 3D carbon nanomaterials. Results obtained from unit cell analysis indicate the presence of notable interfacial thermal resistance in the ...

متن کامل

Thermal conductance and thermopower of an individual single-wall carbon nanotube.

We have observed experimentally that the thermal conductance of a 2.76-microm-long individual suspended single-wall carbon nanotube (SWCNT) was very close to the calculated ballistic thermal conductance of a 1-nm-diameter SWCNT without showing signatures of phonon-phonon Umklapp scattering for temperatures between 110 and 300 K. Although the observed thermopower of the SWCNT can be attributed t...

متن کامل

Synthesis and investigation of thermal conductivity carbon nanotubes: MWCNT and SWCNT

In this study, Bio-based carbon nanotubes (CNTs) have received considerable research attention due to their comparative advantages of high level stability, simplistic use, low toxicity and overall environmental friendliness. New potentials for improvement in heat transfer applications are presented due to their high aspect ratio, high thermal conductivity and special surface area. Phonons have ...

متن کامل

Electrical conductivity enhancement of metallic single-walled carbon nanotube networks by CoO decoration.

We report that the decoration of metallic single-walled carbon nanotube (m-SWCNT) networks with cobalt(ii) oxide (CoO) can improve the electrical conductivity of the networks. To measure the electrical conductivity, we prepared m-SWCNT networks between the source and drain electrodes of field-effect transistors (FETs). Then, the amount of CoO nanoparticles (NPs) used for decoration was controll...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2015