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ERIC Number: EJ921265
Record Type: Journal
Publication Date: 2010-Dec
Pages: 3
Abstractor: As Provided
Reference Count: 19
ISSN: ISSN-0021-9584
"JCE" Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More
Chen, Yueh-Huey; Lin, Jia-Ying; Wang, Yu-Chen; Yaung, Jing-Fun
Journal of Chemical Education, v87 n12 p1329-1331 Dec 2010
This classroom activity connection demonstrates the differences between the effects of NaCl (a salt of monovalent metal ions) and CaCl[subscript 2] (a salt of polyvalent metal ions) on swollen superabsorbent polymer gels. Being ionic compounds, NaCl and CaCl[subscript 2] both collapse the swollen polymer gels. The gel contracted by NaCl reswells in deionized water, but that contracted by CaCl[subscript 2] does not reswell. The CaCl[subscript 2] contracted gel is subsequently immersed in concentrated NaCl solution to reverse the ion exchange. The Ca[superscript 2+] ions in the contracted gel are released, and Na[superscript +] ions are redistributed in the polymer network. The ion-exchange cycle is accomplished and the water-absorbing ability of the gel is recovered. Other compound pairs of monovalent versus polyvalent metal ions involving LiCl, NaCl, KCl, CaCl[subscript 2], BaCl[subscript 2], and ZnCl[subscript 2] give similar results. (Contains 1 figure, 1 scheme and 7 notes.)
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail:; Web site:
Publication Type: Journal Articles; Reports - Descriptive
Education Level: Higher Education
Audience: N/A
Language: English
Sponsor: N/A
Authoring Institution: N/A
Identifiers - Location: Taiwan