In this work, three hydrogels, having % mole fraction of monomer sodium acrylate as 15, 32 and 47 and crosslinked with 65 mmol of methylene bisacrylamide (i. e. HG (15) 65, HG (32) 65, and HG (47) 65) exhibited equilibrium swelling ratios of 62. 8, 120. 8 and 189. 6 g/g respectively and the order of fitness of kinetic models was Power function \: > First order \: > Scott model. The sample HG (47) 65 was loaded with 5. 0, 10. 0 and 15. 0 mmol of salts LiCl, NaCl, CaCl2 and MgCl2 and the solvent glycerol and their anti-dehydration behavior was investigated. Of all, the samples HG (47) 65 /Mg (II) 15, and HG (47) 65 /Gly15, showed minimum percent dryness (PD) of 18. 0 and 23 0. 0 against the PD of 41% shown by the native hydrogel. These two samples were used to cool a smart phone pre-heated to 60 and 70 °C against open air as a control. Both of the samples cooled down the smart phone panel to 25. 5 °C within 20 s, while it required more than 720 s in air. These gels stuck well on the surface of mobile panel and required a pressure of 1. 03 and 0. 63 k Pa respectively for detachment from mobile panel. Their folding endurance was excellent (1150 plus) and the tensile at break (TS) was 39. 43 and 2. 13 k Pa respectively.
Katulkar et al. (Mon,) studied this question.