Preparation of amine-impregnated silica foams using agar as the gelling agent

Journal Article · Sat Oct 15 04:00:00 EDT 2016 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2016.09.002· OSTI ID:22689631

Souza, Douglas F.; Vasconcelos, Daniela C.L.; Nunes, Eduardo H.M. ^[1]

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1. Department of Metallurgical and Materials Engineering, Federal University of Minas Gerais – UFMG, Avenida Presidente Antônio Carlos, 6627, Campus UFMG, Belo Horizonte, MG, CEP: 31270-901, Escola de Engenharia, bloco 2, sala, 2230 (Brazil)

In this work we successfully prepared amine-impregnated gel-cast silica foams using agar and atmospheric air as the gelling agent and heat treatment atmosphere, respectively. The concentration of 3,6-anhydrogalactose in agar was evaluated by ultraviolet–visible spectroscopy (UV–Vis). The obtained foams were examined by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TG) coupled to mass spectrometry (TG-MS), scanning electron microscopy (SEM), X-ray microtomography (micro-CT), and Archimedes method. The cold crushing strength of the materials prepared in this work was assessed using a mechanical testing stage available in the micro-CT system. The obtained foams exhibited a highly interconnected pore network, with an expressive presence of open pores. Samples heat-treated at 1300 °C for 2 h showed both an expressive porosity (≈ 77%) and a significant cold crushing strength (≈ 1.4 MPa). It was observed that the calcination of the prepared materials at 1200 °C for times as long as 16 h may lead to the rupture of pore walls. FTIR and TG-MS revealed that amine groups were properly incorporated into the foams structure. - Highlights: •Successful preparation of amine-impregnated gel-cast silica foams •Agar used as the gelling agent •Samples with expressive porosity and cold crushing strength •Sintering times as long as 16 h led to the rupture of the pore network.

• OSTI ID: 22689631
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 120; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AGAR
AMINES
CALCINATION
CASTING
COMPUTERIZED TOMOGRAPHY
CRUSHING
FOAMS
FOURIER TRANSFORM SPECTROMETERS
GELS
HEAT
HEAT TREATMENTS
INFRARED SPECTRA
MASS SPECTROSCOPY
MECHANICAL TESTS
RUPTURES
SCANNING ELECTRON MICROSCOPY
SILICA
TEMPERATURE RANGE 1000-4000 K
THERMAL GRAVIMETRIC ANALYSIS
ULTRAVIOLET RADIATION