Note: Thermal conductivity measurement of individual porous polyimide fibers using a modified wire-shape 3ω method

Abstract

Porous polyimide fiber enjoys a good reputation as a high temperature resistant thermal insulation material in an aircraft-carrier, a spacecraft, and other military sophisticated products. Understanding its thermal conductivity is especially important for the design optimization and thermal management in these applications. In this study, a modified wire-shape 3ω method is developed to measure the thermal conductivity of individual porous polyimide fibers, utilizing a platinum layer heater/thermometer deposited along the circumferential direction of the fiber. The new method is first validated using a platinum wire with known thermophysical properties such as thermal conductivity at room temperature and then applied to porous polyimide fibers with diverse porosities. The thermal conductivity of porous polyimide fibers at room temperature is 0.06–0.15 W m−1 K−1, which reflects a good thermal insulation performance.

Thermoelectric transports in pristine and functionalized boron phosphide monolayers

“…In order to extract the thermal conductivity in two-dimensional materials, extensive efforts 18 , 19 have been devoted to the development of 3 ω method, Raman spectroscopy method and so on. Qiu et al 20 proposed a modified 3 ω method for the measurement of thermal conductivity in non-conductive fiber. Balandin et al 21 conducted the measurement of suspended graphene monolayer using Raman spectroscopy method.…”

Synergistical thermal modulation function of 2D Ti3C2 MXene composite nanosheets via interfacial structure modification

“…To explore the thermal properties of MXene family materials, a new measurement technique is urgently needed. The well-known 3 ω method is verified to be useful for the thermal measurement of 2D materials ( Cahill and Pohl, 1987 ; Qiu et al., 2013 , 2018 , 2021a , 2021b ). The upgraded form of the 3 ω method, that is the freestanding thermosensor-based 3 ω method enables the 2D nanosheets can be noninvasively measured ( Qiu et al., 2011 ), which significantly retains the integrity of the 2D materials.…”

Realizing the Accurate Measurements of Thermal Conductivity over a Wide Range by Scanning Thermal Microscopy Combined with Quantitative Prediction of Thermal Contact Resistance

“…integration of devices have made heat conduction and dissipation crucially important, [1][2][3] which further poses the quick and versatile quantitative thermal characterization on the micro-/nano scale turn out to be a bottleneck for chip design, production, and performance evaluation. [4][5][6] Over the last few decades, the development of various experimental measurement techniques for the thermal properties of lowdimensional materials has generally fallen into two different categories: steady-state techniques based on Fourier's law, such as suspended-pad [7] and Raman optothermal [8,9] methods, and transient-state techniques completed before system equilibrium, such as three-omega, [10,11] timedomain thermoreflectance (TDTR), [12,13] frequency-domain thermoreflectance (FDTR), [14,15] and laser pulse thermal measurement. [16] However, all of the techniques listed above only provide an overall measurement value of the thermal conductivity for the samples, which is not desirable for understanding the local heat transport and further obtaining the one-to-one quantitative mapping of microstructures and thermal characteristics.…”