Optical and mechanical properties of PNIPAm-MWCNTs and PNIPAm-GO composites

Abstract

The aim of this study is to investigate drying, swelling, elastic properties, and to produce optical band gap energies on the performance of Poly (N-Isopropyl acrylamide) - Multi walled carbon nanotubes (PNIPAm – MWCNTs) and Poly (N-Isopropyl acrylamide)- Graphene Oxide (PNIPAm-GO) composites, respectively. The composites were prepared by free radical crosslinking copolymerization. Drying and swelling of PNIPAm-MWCNTs and PNIPAm- GO composites were performed by using steady state fluorescence technique. Firstly, the desorption coefficients of the composites were modeled by using Fick's Law. Cooperative diffusion coefficients were calculated by employing Li-Tanaka Model. When composite doped with 10 wt% of MWCNTs has a higher desorption coefficient than composite doped with the same amount of GO, 40 wt% of GO content in the PNIPAm has a higher diffusion coefficient than the composite that has 40 wt% of MWCNTs content in the swelling process. Secondly, the composite that has 40 wt% of MWCNTs content has a higher modulus before swelling than the composite that has the same amount of GO contents. Lastly, optical band gap energies were calculated by using Tauc's approach, and Urbach's relation by using the data performed UV Spectroscopy. We found that PNIPAm -GO has a much narrower band gap value.