Swelling of Acrylamide-Tartaric Acid Hydrogels Iranian Journal of Pofyyner Science and Technology Vol 4 No 3 (1995) Erdener Karadag and Dursun Saraydin Department of Chemistry, Cunihuriyet University, 58140 Sivas, Turkey O1gun 0-Liven Department of Chemistry, Hacettepe University, Beytepe, 06532 Ankara, Turkey Received; 31 August 1944; accepted 27 February 1995 ABSTRACT Acrylamideltartarlc acid hydrogels in the form of rods are prepared by irradiating aqueous solutions of 1 g of acrylamide and varying quantities of tartaric acid between 0-60 mg in 1 mL of water, with 2.605 .71 Id3y Y-rays. The influence of dose and relative content of tartaric acid on the swelling properties, diffusional behavior of water, diffusion coefficients and network properties (i .e ., number-average molar mass between crosslinks, crosslink density, number of elastically effective chains, number of repeating units between crosslinks and mesh size) of hydrogel systems is examined. Hydrogels are swelled in the range 700-1400%, while polyacrylamide hydrogels are swelled In the range 650-700% . Water diffusion to hydrogels is non-Fickian type diffusion . Key Words acrylamide/tartaric acid, hydrogel, swelling, diffusion INTRODUCTION Hydrogels are water-swellable, three-dimensional polymeric networks . The capacity of hydrogels to absorb water is enormous and can be as much as 1000 times the mass of polymer [1-4] . For this reason they are used in many fields . Hydrogels find application in food industry (as thickening agents, etc .), in pharmaceuticals (as controlled release preparations etc .), agriculture and related fields (in controlled release of moisture, fertilizers, pesticides, etc .), technical and electronic instruments (as a protector from corrosion, and short circuits, etc.) biomedicine (as artificial organs etc .), bioengineering (in biomolecular immobiliz- ation), veterinary medicine, photographic tech- nology and as an adsorbent for removal of some unwanted agent in environmental application [4-6]. Polyacrylamide (PAAm) hydrogels and their derivatives have been used extensively . PAAm and copolymers of PAAm have the capability to absorb water, have biocompatibility with physiology of 218