Study of conductive porous nanofibrous membranes for electromagnetic interference shielding

Abstract

Electromagnetic radiation is one of the most significant sources of pollution in the digital age. It has irreversible damage to equipment performance, human health, and the natural environment. High performance electromagnetic interference shielding effectiveness (EMI SE) materials can effectively improve this situation. At present, ultra-light and ultra-thin flexible shielding materials are still a huge difficulty. Moreover, designing the morphology and structure of the substrate and thus customizing the shielding material based on different shielding mechanisms is also a challenge. Here, with the help of the adhesion of polydopamine (PDA), this study innovatively developed the acetone&heat treatment process, and design two types of copper (Cu) coated poly(L-lactic acid) (PLLA) conductive porous fiber membranes. One is named as Cu/PLLA, whereas the second one is named as Cu/APLLA with an acetone&heat treatment process. After acetone&heat treatment, the morphology and structural strength of PLLA changes considerably. Therefore, these two kinds of Cu/PLLA membranes have quite different EMI SE mechanisms. The Cu/PLLA (28 µm) membrane has an EMI SE effectiveness to surface density of 3302.83 dB.cm2/g, which mainly depends on reflection; While the Cu/APLLA (15 µm) membrane has an EMI SE effectiveness to surface density of 4987.51 dB.cm2/g, which is dominant by absorption.

Date of Award	31 Dec 2022
Original language	English
Awarding Institution	The University of Manchester
Supervisor	Zhirun Hu (Supervisor) & Jiashen Li (Supervisor)