ERIC Number: EJ921265
Record Type: Journal
Publication Date: 2010-Dec
Pages: 3
Abstractor: As Provided
ISBN: N/A
ISSN: ISSN-0021-9584
EISSN: N/A
"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.)
Descriptors: Plastics, Chemistry, Scientific Concepts, Class Activities, Science Education, Laboratory Experiments, Undergraduate Students, Foreign Countries
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: eic@jce.acs.org; Web site: http://pubs.acs.org/jchemeduc
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
Grant or Contract Numbers: N/A