Journal des nanomatériaux et de la nanotechnologie moléculaire

Ring formation of MWCNT by dewetting of thin film

Surita Basu, Prabir Patra  and Jayati Sarkar 

Patterns formed on the surface of a thin film are greatly inspired by nature and biological system. These patterns are formed spontaneously on the surface of polystyrene thin film by self-organization or self-assembly route. The formation of surface phenomenon by self-organization or self-assembly is more viable and cost effective as it does not involve any expensive and high end instrument for the formation of ordered and intricate patterns on the surfaces. These structures formed on the surface have wide range of technological applications. These patterns are created on the surface of thin polymeric film due to retraction of the liquid fluid from the surface that it was supposed to cover leading to a phenomenon of dewetting. Similarly multiwall carbon nanotubes (MWCNT) can self-assemble and form various topologies like coiled CNTs, CNT junctions and toroidal CNTs. Toroidal or circular ring carbon nanotubes are unique structure formed from both single wall and multi wall carbon nanotubes. The toroidal CNT is formed over thin polymeric film due to the self-organization of thin polystyrene film leading to the formation of arrays of holes because of dewetting.  Circular rings of CNT are formed on the surface by simple dewetting and Maragoni force. The self-organized patterns on the thin PS film along with Marangoni flow is the driving force behind the circular ring formation. These surface structures can be of great use in biomedical purposes like skin grafting, sensors, superhydrophobic coating and others.