Keywords : functionalization

Functionalized graphene oxide as an electrochemical sensing platform for detection of Bisphenol A

Upama Baruah;Devasish Chowdhury

Advanced Materials Letters, 2018, Volume 9, Issue 7, Pages 516-525
DOI: 10.5185/amlett.2018.2067

The present work demonstrates the electrochemical detection of the endocrine disruptor Bisphenol A in solution by three different types of functionalized graphene samples viz. graphene oxide (GO), ester functionalized graphene oxide (GO-ES) and amine functionalized graphene oxide (GO-en) modified glassy carbon electrode (GCE) using a very simple drop casting method without the use of any toxic organic compounds or polymeric binders via cyclic voltammetry. The system developed showed detection of BPA via formation of a π-stacked layered functionalized graphene oxide-BPA (π-s-GO-BPA) nanocomposite accompanied by a reduction in the oxidation peak current value associated with a significant shift in the peak potential value. The electrochemical sensing materials developed showed good sensitivity compared to already reported systems and furthermore high selectivity in presence of other structurally similar kinds of molecules in solution without the use of any toxic organic chemicals thereby demonstrating the practical applicability of the material and the technique developed. The practical viability of the material developed is also demonstrated via testing with a real low quality plastic sample that contains Bisphenol A. A plausible mechanism to justify the detection process is also being discussed. 

Solvent Free, Efficient, Industrially Viable, Fast Dispersion Process Based Amine Modified MWCNT Reinforced Epoxy Composites Of Superior Mechanical Properties

Bhanu Pratap Singh; Veena Choudhary; Satish Teotia; Tejendra Kumar Gupta; Vidya Nand Singh; Sanjay Rangnath Dhakate; Rakesh Behari Mathur

Advanced Materials Letters, 2015, Volume 6, Issue 2, Pages 104-113
DOI: 10.5185/amlett.2015.5612

Dispersion of multiwalled carbon nanotubes (MWCNTs) into epoxy resin is a challenging task for the process to be viable on industrial scale. Herein, amine functionalized MWCNTs (Am-MWCNTs) were reinforced into epoxy resin using industrially viable, fast, efficient, solvent free, high speed homogenizer dispersion technique. Am-MWCNTs ranging from 0.1 to 0.75% by w/w were loaded in epoxy and the effects of loading of Am-MWCNTs on mechanical properties of epoxy composites are investigated. The flexural strength of Am-MWCNTs based epoxy composites reached up to 163 MPa for 0.5 wt% MWCNTs loaded sample compared to 95 MPa for pure cured epoxy sample; an overall improvement of 72% in the flexural strength. In addition to this, the flexural modulus value reached to 3795 MPa for 0.75 wt% Am-MWCNTs loaded sample from 2250 MPa for pure epoxy sample, an improvement of 69%. The enhancement in the mechanical properties was correlated with the dynamic scanning calorimeter results, TEM and SEM images of fractured surface. The substantial improvement in the mechanical properties of the epoxy resin at such low CNT loading can open a venue for the preparation of structurally strong structures for aerospace, defence, automobile and sports industries.