Synthesis and characterization of high-surface-area millimeter-sized silica beads with hierarchical multi-modal pore structure by the addition of agar

Journal Article · Tue Apr 01 00:00:00 EDT 2014 · Materials Characterization

DOI:https://doi.org/10.1016/J.MATCHAR.2014.01.018· OSTI ID:22340345

Han, Yosep; Choi, Junhyun ^[1]; Tong, Meiping ^[2]; Kim, Hyunjung ^[1]

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1. Department of Mineral Resources and Energy Engineering, Chonbuk National University, 567 Baekje-daero, Deokjin-gu, Jeonju-si, Jeollabuk-do 561–756 (Korea, Republic of)
2. The Key Laboratory of Water and Sediment Sciences, Ministry of Education, College of Environmental Sciences and Engineering, Peking University, Beijing 100871 (China)

Millimeter-sized spherical silica foams (SSFs) with hierarchical multi-modal pore structure featuring high specific surface area and ordered mesoporous frameworks were successfully prepared using aqueous agar addition, foaming and drop-in-oil processes. The pore-related properties of the prepared spherical silica (SSs) and SSFs were systematically characterized by field emission-scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), small-angle X-ray diffraction (SAXRD), Hg intrusion porosimetry, and N{sub 2} adsorption–desorption isotherm measurements. Improvements in the BET surface area and total pore volume were observed at 504 m{sup 2} g{sup −1} and 5.45 cm{sup 3} g{sup −1}, respectively, after an agar addition and foaming process. Despite the increase in the BET surface area, the mesopore wall thickness and the pore size of the mesopores generated from the block copolymer with agar addition were unchanged based on the SAXRD, TEM, and BJH methods. The SSFs prepared in the present study were confirmed to have improved BET surface area and micropore volume through the agar loading, and to exhibit interconnected 3-dimensional network macropore structure leading to the enhancement of total porosity and BET surface area via the foaming process. - Highlights: • Millimeter-sized spherical silica foams (SSFs) are successfully prepared. • SSFs exhibit high BET surface area and ordered hierarchical pore structure. • Agar addition improves BET surface area and micropore volume of SSFs. • Foaming process generates interconnected 3-D network macropore structure of SSFs.

• OSTI ID: 22340345
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Vol. 90; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
77 NANOSCIENCE AND NANOTECHNOLOGY
ADSORPTION
AGAR
COPOLYMERS
DESORPTION
FIELD EMISSION
FOAMS
ISOTHERMS
NANOSTRUCTURES
PORE STRUCTURE
POROSITY
SCANNING ELECTRON MICROSCOPY
SILICA
SPHERICAL CONFIGURATION
SURFACE AREA
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY
X-RAY DIFFRACTION