Multi-wall carbon nanotube networks prepared from pure MWCNT and their oxidised forms effect of compressive strain on electric resistence

Abstract

Multi-wall carbon nanotube networks were prepared by process of filtration of CNT aqueous dispersions. CNT dispersions were prepared with help of surfactant system (Sodium dodecyl sulfate with amylalcohol) by ultrasonication. Three types of MWCNT tubes were used. The first were pure CNT material delivered by supplier. The other were chemically treated in aim to prepare CNT oxidised forms (1. acid solution of KMnO(4), 2. mixture of acids H(2)SO(4) + HNO(3)). It was found that chemical modification significantly changes properties of prepared carbon nanotube networks ("Buckypaper"). There were observed differences in porous structure between all of the forms analysed by SEM microscopy. Further, apparent density of prepared "Buckypapers" changes in respect of used CNT material leading to different porosity of Buckypapers. Electrical resistance is also affected by process of MWCNT oxidation together with its temperature dependence. Effect of compressive strain on electric resistance of multi-wall carbon nanotube networks was further tested. It was found that resistance is sensitive to compressive strain both in the course of strain growth and when loading/unloading cycles are imposed.