Abstracts Book - IMRC 2018

• SA1-O019
COMPARATIVE OF THE ADSORPTION CAPACITY OF GRAPHENE
NANOSHEETS FOR TEXTILE DYES REMOVAL WITH DIFFERENT
WAVELENGTH.
Barbara Souza Damasceno 1 , Marcos Gomes Ghislandi 1 , Lilian Kássia de Assis 1 , Nathália
Nogueira 1
1
Universidade Federal Rural de Pernambuco, UACSA, Brazil.
The concept of physical adsorption was applied for the removal of two common
textile dyes (direct red 80 and Indosol SFGL direct blue) industrial effluents,
using graphene nanoplatelets (xGnP ® ) as adsorbent. The xGnP ® was
characterized via point of zero charge (pHpcz), transmission electron (TEM) and
atomic force (AFM) microscopies, and surface area analysis. The pHpcz occurs
when the system is balanced. It was verified that this stability value occurred in
final pH values between 3.6-3.9. By TEM it was possible to analyze the surface
dimensions (average diameter) of the analyzed samples (~20), these sheets have
lateral sizes typically of no more than 5µm. In some cases, the sheet edges tend
to scroll and fold slightly. AFM analysis shows the average thickness of the
graphene nanoplatelets. Most of the samples presented an average thickness
higher than ten nm. However, the few samples of exfoliated platelets that could
be found had an average thickness of less than five nm. It was also possible to
visualize that the samples exhibited no surface area greater than five μm 2 ,
confirming the information obtained by TEM. Using the BET method ranged an
averaged specific surface area of 90.08 ± 12.36 m²/g. Adsorption tests were
conducted to optimize the process; parameters such as adsorbent mass, dye
concentration and contact time were varied, obtaining as optimum values 0.01g,
100 mg.L -1 and 6h, respectively. A mechanism of adsorption was proposed
based on the interactions between the chemical structures of the graphenedyes.
The study of graphene synthesis using a modified Hummers method has
been developed in our group aiming to compare the adsorptive capacity and the
removal efficiency between the xGnP ® and the synthesized graphene.
Keywords: graphene, adsorption, textile industries
Presenting authors email: barbdara@gmail.com