@article{oai:repo.qst.go.jp:00080417,
 author = {T. Aranilla, Charito and Jeremiah D. Barba, Bin and S. Relleve, Lorna and Nagasawa, Naotsugu and Nagasawa, Naotsugu},
 issue = {1},
 journal = {The Philippine Journal of Science},
 month = {Oct},
 note = {Carboxymethyl derivatives of k-carrageenan(CMkC), with different degrees of substitution, were gamma-irradiated in viscous or paste solutions. Successfully obtained chemically crosslinked hydrogels showed dependence on the degree of substitution(DS), concentration, and radiation dose. The highest gel fraction was 76% exhibited by CMkC-3s hydrogel with a DS of 1.58. The hydrogels showed different swelling degrees in water and saline. Swelling behavior versus time, in both solvents, corresponded to 2nd order kinetics. The CMkC-3s at 20% concentration irradiated at 15 kGy had the highest water absorption of 324 g water/g dry gel. Selected hydrogels were evaluated for applications as wound dressing, as water retainer in sandy soil, and as metal adsorbent. As a wound dressing, CMkC-2s and CMkC-3s hydrogels exhibited considerable tensile strengths, abilities to absorb pseudo extracellular fluid and extractables with pH/conductivity conducive for healing promotion.  In addition, the CMkC-3s hydrogel had no cytotoxic potential based on the MTT test.  As water retainer in sandy soil, test samples with 0.1, 0.3 and 0.5% CMkC-3s granules retained 25.1%, 32.2%, and 42.6% water, respectively, at day 0 compared to 19.2% of the sandy soil alone. On day 7, the three sandy soil-CMkC groups still had 13.7%, 19.4%, and 29.3% water while the control had only 3.85%.  In the batch adsorption studies, the hydrogels adsorbed heavy metals (Cu2+, Zn2+, Cd2+ and Pb2+) in the solution at different capacities, with Cd2+ as the highly adsorbed and Pb2+ as the least.  The CMkC-3s hydrogel showed the highest metal uptake and adsorption efficiency, followed by CMkC-2s, then CMkC-1s. The CMkC-3s hydrogel, further tested on pH effect, had optimum metal uptake at neutral pH.},
 pages = {85--97},
 title = {Properties and Potential Applications of Carboxymethyl-kappa-carrageenan Hydrogels Crosslinked by Gamma Radiation},
 volume = {150},
 year = {2020}
}