Effect of Crosslinkers on the Microstructure and Swelling Properties of the N-Isopropyl Acrylamide Gels: A Positron Annihilation Study


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The Poly N-Isopropyl acrylamide (PNIPA) gels were prepared in different synthesis media by crosslinking with acrylate monomers with varying chain length. The microstructural characterization in terms of the free volume fractions and distributions were studied using positron annihilation lifetime spectroscopy (PALS). The equilibrium swelling of the PNIPA in distilled water was measured. An attempt has been made to understand the correlations between microscopic free volumes and the equilibrium swelling of the gels. The free volume fraction of the gels prepared in Dimethyl formamide (DMF) was directly correlated with swelling while it varied inversely with chain length of the crosslinker. The microstructure of the gels was found to be very sensitive to the solvent/medium used for polymerization. Our studies show that the swelling property is influenced by the free volumes, chain relaxation as well as the chemical nature of the cross linkers.



Edited by:

Jozef Krištiak, Jan Kuriplach and Pradeep K. Pujari




P. N. Patil et al., "Effect of Crosslinkers on the Microstructure and Swelling Properties of the N-Isopropyl Acrylamide Gels: A Positron Annihilation Study", Materials Science Forum, Vol. 733, pp. 155-158, 2013

Online since:

November 2012




[1] Y. Osada, J. P. Gong and Y. Tanaka: J. Macromol. Sci. Olym. Rev.C. Vol. 44 (2004), p.87.

[2] T.G. Park and A. S. Hoffman: J. Bomed. Res. Vol. 24 (1990), p.21.

[3] R. F. S. Freitas and E. L. Cussler: Separation Sci. Tech-nol. Vol. 22 (1987), p.911.

[4] O. Hirasa: Bull. Res. Inst. Polym. Text. Vol. 129 (1981), p.63.

[5] A. Yamauchi: in Polymer Gels- Fundamentals and biomedical Applications. Plenum Press, (New York 1991), p.127.

[6] X. Zhang, R. Zhuo and Y. Yang: Biomaterials. Vol. 23 (2002), p.1313.

[7] D. Singh, D. Kuckling, V. Koul, V. Choudhary, H-J. Adler and A. K. Dinda: Eur. Polym. J. Vol. 44 (2008), p.2962.

[8] A. Panda, H. S. Sodaye, R. N. Acharya, A. Goswami, P. K. Pujari, S. Sabharwal and S. B. Manohar: J. Polym. Sci. A: Polym. Chem. Vol. 38 (2000), p.3462.

DOI: https://doi.org/10.1002/1099-0518(20001001)38:19<3462::aid-pola20>3.0.co;2-i

[9] S. Harms, K. Rätzke, F. Faupel, W. Egger, L. Ravello, A. Laschewsky, W. Wang and P. Müller-Buschbaum: Macromol. Rapid comm. Vol. 31 (2010), p.1364.

DOI: https://doi.org/10.1002/marc.201000067

[10] P. J. Flory: Principles of polymer chemistry. Cornell University Press (New York 1953).

[11] Y. C. Jean: Macromolecules Vol. 29 (1996), p.5756.

[12] R. A. Pethrick: Prog. Polym. Sci. Vol. 22 (1997), p.1.

[13] P. N. Patil, S. Kathi, D. Dutta and P. K. Pujari: Polym. Bull. Vol. 65 (2010), p.577.

[14] R. G. Sousa, R. F. S. Freitas and W. F. Magalhaes: Polymer. Vol. 39 (1998), p.3815.

[15] Y. Tang, Y. Ding and G. Zhang: J. Phys. Chem. B Vol. 112 (2008), 8447.

[16] N. B. Graham and A. Cameron: Pure. And Appl. Chem. Vol. 70 (1998), p.1271.

[17] Y. Yagi, H. Inomata and S. Saito: Macromolecules Vol. 25 (1992), p.2997.