Bacterial cellulose-modified castor oil-based polyurethane sponge for hexavalent chromium removal

Author(s)

Maia, Lana S. ; Pinhati, Fernanda R. ; Monteceli, Francisco M. ; Colturato, Vitoria M. M. ; Barbosa, Rennan F. S. ; Barud, Hernane S. ; da Conceicao, Monique T. ; Rosa, Derval S. ; Mulinari, Daniella R.

• Document type: Journal article
• Source: Journal of Applied Polymer Science; v. 140, n. 38, p. 14-pg., 2023-07-25.

Abstract

Due to the multiple industrial applications of chromium compounds and their dangerous nature for the environment, the development of adsorbent materials has been investigated. In line with this reality, bacterial cellulose (BC) has become a potential filler in the polymeric matrix due to its ability to remove toxic metals; however, its performance is little explored. This research proposes a new approach for BC as a filler in castor oil-based polyurethane, obtaining a sponge for Cr(VI) removal. The pure PU and PU + X%BC sponges (X stands for BC content between 5 and 20 wt%) were characterized by Fouriertransform infrared spectroscopy, scanning electron microscopy, optical microscopy, density, contact angle (CA), and thermogravimetric analysis. Sorption capacity and efficiency were evaluated as a function of the fiber content, with tests performed in function of contact time (2.5 min to 3 h) at 50 mg L-1. The BC fillers of the sponges increased the density and influenced the morphological, chemical structural, thermal, and sorption properties. Thus, the sponge (PU + 20%BC) presented the highest CA (104.4 degrees) and the best sorption capacity and efficiency (4.3 mg g(-1) and 43.2%). The sorption mechanism was welldefined by isotherm models, presenting a maximum adsorption capacity of 23.5 mg g(-1) and best fit (R-2 = 0.989) with the Freundlich isotherm. The sponge is an efficient material for Cr (VI) removal and provided a promising insight into an adsorption mechanism study. (AU)

• FAPESP's process: 20/13703-3 - Environmentally friendly porous materials for the recovery and revaluation of metals reclaimed from contaminated water
• Grantee: Derval dos Santos Rosa
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 13/07276-1 - CEPOF - Optics and Photonic Research Center
• Grantee: Vanderlei Salvador Bagnato
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC
• FAPESP's process: 21/08296-2 - Development of chitosan hydrogels containing modified cellulose nanostructures for metal removal and recovery from contaminated water
• Grantee: Rennan Felix da Silva Barbosa
• Support Opportunities: Scholarships in Brazil - Doctorate