'JCE' Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More
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| Title: | 'JCE' Classroom Activity Connections: NaCl or CaCl[subscript 2], Smart Polymer Gel Tells More |
|---|---|
| Language: | English |
| Authors: | Chen, Yueh-Huey, Lin, Jia-Ying, Wang, Yu-Chen, Yaung, Jing-Fun |
| Source: | Journal of Chemical Education. Dec 2010 87(12):1329-1331. |
| Availability: | 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 |
| Peer Reviewed: | Y |
| Page Count: | 3 |
| Publication Date: | 2010 |
| Document Type: | Journal Articles Reports - Descriptive |
| Education Level: | Higher Education |
| Descriptors: | Plastics, Chemistry, Scientific Concepts, Class Activities, Science Education, Laboratory Experiments, Undergraduate Students, Foreign Countries |
| Geographic Terms: | Taiwan |
| DOI: | 10.1021/ed100205h |
| ISSN: | 0021-9584 |
| Abstract: | 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.) |
| Abstractor: | As Provided |
| Number of References: | 19 |
| Entry Date: | 2011 |
| Accession Number: | EJ921265 |
| Database: | ERIC |
| Abstract: | 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.) |
|---|---|
| ISSN: | 0021-9584 |
| DOI: | 10.1021/ed100205h |
