A universal approach to ‘host’ carbon nanotubes on a charge triggered ‘guest’ interpenetrating polymer network for excellent ‘green’ electromagnetic interference shielding

Abstract

The widespread usage of miniaturized electronic gadgets today faces stiff reliability obstacles from factors like stray electromagnetic signals. The challenge is to design lightweight shielding materials that combine small volume...

Polyoxometalate-immobilized carbon nanotube constructs triggered by host–guest assembly result in excellent electromagnetic interference shielding

“…S11†) of K–En–CNT, it is evident that the value of A eff is close to 1; contrary to that, T is close to 0 and R lies in the range of 0.5 to 0.7 throughout the entire X-band frequency regime as shown in Table 4. 55,56 Such a high A eff value of the K–En–CNT construct throughout the whole X-band further emphasizes the absorption-based shielding.…”

“…To further strengthen the absorption-dominated mechanism of K–En–CNT, we calculated the reflection coefficient (R), transmission coefficient ( T ), and effective absorption ( A eff ) as SE A ≫ 10 dB, in the case of our present findings using the formulae derived in the ESI 3 † 55,56.…”

“…Although MWCNTs have high conductivity, their random and unparallel orientation in the POM immobilized construct leads to two types of electron transport models, namely, migration and hopping. 55 With the proliferation of incidental EM waves into the 3D unique architecture of the POMs-immobilized CNT construct sandwiched between CNT-impregnated PU foams, the electrons move in the aligned direction of the EM wave. As a consequence of this, the interaction of the electrons with the EM waves results in the migration of the electrons in one graphene layer, termed as migrating electrons.…”

“…54 To further strengthen the absorption-dominated mechanism of K-En-CNT, we calculated the reflection coefficient (R), transmission coefficient (T ), and effective absorption (A eff ) as SE A ≫ 10 dB, in the case of our present findings using the formulae derived in the ESI 3. † 55,56 From the plot of A eff -R-T vs. the frequency (Fig. S11 †) of K-En-CNT, it is evident that the value of A eff is close to 1; contrary to that, T is close to 0 and R lies in the range of 0.5 to 0.7 throughout the entire X-band frequency regime as shown in Table 4.…”

“…Another aspect of the interaction is the hopping of electrons across the defects or interface between layers. 55 On account of the high aspect ratio of the MWCNTs, they can form a conductive network in the POMs-immobilized CNT construct. POMs being poorly conducting in nature increase the energy barrier between MWCNTs and, therefore, the hopping electrons are bound to jump across the POM-CNT interfaces.…”