Polyacrylonitrile-Chalcogel Hybrid Sorbents for Radioiodine Capture

• Published in: Environmental science & technology Vol. 48; no. 10; pp. 5832 - 5839
• Main Authors: Riley, Brian J, Pierce, David A, Chun, Jaehun, Matyáš, Josef, Lepry, William C, Garn, Troy G, Law, Jack D, Kanatzidis, Mercouri G
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 20.05.2014
• Subjects: Acrylic Resins - chemistry; Adsorption; Applied sciences; Atmospheric pollution; Diffraction; dimethyl sulfoxide; Exact sciences and technology; Gels - chemistry; General processes of purification and dust removal; Iodine; Iodine - analysis; Iodine Radioisotopes; Microscopy, Electron, Scanning; pellets; Pollution; polyacrylonitrile; Powders; Prevention and purification methods; Sorbents; Spectrometry, X-Ray Emission; Thermogravimetry; Time Factors; X-Ray Diffraction; X-rays; Radioactive pollution; Aerogel; Chalcogen; Hybrid material; Adsorption capacity; Radioisotope; Iodine 129; Gas solid adsorption; Acrylonitrile polymer; Decontamination; Preparation; Air pollution; Adsorbent
• ISSN: 0013-936X; 1520-5851; 1520-5851
• DOI: 10.1021/es405807w

Powders of a Sn2S3 chalcogen-based aerogel (chalcogel) were combined with powdered polyacrylonitrile (PAN) in different mass ratios (SnS33, SnS50, and SnS70; # = mass% of chalcogel), dissolved in dimethyl sulfoxide, and added dropwise to deionized water to form pellets of a porous PAN-chalcogel hybrid material. These pellets, along with pure powdered (SnSp) and granular (SnSg) forms of the chalcogel, were then used to capture iodine gas under both dynamic (dilute) and static (concentrated) conditions. Both SnSp and SnSg chalcogels showed very high iodine loadings at 67.2 and 68.3 mass%, respectively. The SnS50 hybrid sorbent demonstrated a high, although slightly reduced, maximum iodine loading (53.5 mass%) with greatly improved mechanical rigidity. In all cases, X-ray diffraction results showed the formation of crystalline SnI4 and SnI4(S8)2, revealing that the iodine binding in these materials is mainly due to a chemisorption process, although a small amount of physisorption was observed.