In recent years, potentially toxic elements (PTEs) have environmental contaminants that may cause many human diseases through exposure, especially in high concentrations. As a possible adsorbent to remove PTEs, composite aerogels are candidates to improve properties and synergistic effects, based on the same theory of matrix phase and dispersed phase, to improve the final material's properties, which is particular of composite material science. Incorporating nanostructures in starch-based aerogels aims to intensify their adsorbent effect, act as a substrate to anchor nanoparticles, and optimize properties to improve compatibility and complexation with contaminants. This work aims to evaluate the effect of nanocellulose on the crosslinking of starch matrix composite aerogels containing nanocellulose (NC) and the Cd(II) removal. The methodology involves dissolving nanocellulose in a sodium hydroxide and urea solution to promote better dispersion of the cellulose nanostructures in the corn starch matrix. This solution was added to hydrogel synthesis with trisodium citrate as a crosslinking agent, followed by freeze-drying (lyophilization). The concentrations of nanocellulose added to develop composite aerogels were 1, 3, and 5% by weight. The chemical groups in nanocellulose and composite aerogels were evaluated using Fourier transform infrared spectroscopy (FTIR). The crystallinity of nanocellulose and composite aerogels was evaluated by X-ray diffraction (XRD). Metal ion sorption tests were conducted through a mono element evaluation of Cd(II) ions from a 100-ppm solution, at pH 4.0, at room temperature, under agitation at 120 rpm, for 12 hours, whose dosage of nanocellulose and modified nanocelluloses was 30 g.L-1. The aqueous solutions' efficiency and sorption capacity were obtained after testing, subjecting them to inductively coupled plasma mass spectrometry (ICP-MS) measurements. A 140%, 160%, and 120% increase was verified for FTIR deconvolution's crosslinking ratio on the aerogel structure. The high crystallinity of composite aerogels was confirmed due to the high degree of crosslinking caused by incorporating NCs in the aerogel structure. Nanocellulose generated the densification of the aerogel, seen by the increase in density and the increase of crystalline domains in the aerogel, changing chain conformation. Besides, nanocellulose significantly impacted the removal of Cd(II), which promoted a growth from 30% to 99-100% of Cd(II) ions removal, also increasing the adsorption capacity of composite aerogels compared to NC-free aerogels. Therefore, the addition of nanocellulose in the starch aerogel matrix increased the crosslinking and crystallinity of the aerogel. In addition to the impact on aerogel crosslinking, nanocellulose resulted in a higher density of available hydroxyl groups, which increased adsorption efficiency and a slight increase in adsorption capacity.
Bem-vindo(a) aos Anais do VII NanoMat, evento organizado pela Pós-graduação em Nanociências e Materiais Avançados da Universidade Federal do ABC (UFABC) com o intuito de reunir e debater trabalhos desenvolvidos por alunos e pós-doutorandos em Materiais e áreas afins.
Comissão Organizadora
Pedro Alves da Silva Autreto
Andre Luiz Martins de Freitas
Aryane Tofanello
Comissão Científica
Ferramenta completa de submissão, avaliação e publicação de anais para eventos científicos.
