Shella Permatasari Santoso, Artik Elisa Angkawijaya, Vania Bundjaja, Alfin Kurniawan, Maria Yuliana, Chang-Wei Hsieh, Alchris Woo Go, Kuan-Chen Cheng, Felycia Edi Soetaredjo, Suryadi Ismadji
Hydrogels represent an attractive soft material with promising applications in many fields. Conventional methods for hydrogel preparation typically involve heat curing either by water-bath (WB) heating or microwave (MW) irradiation to facilitate crosslinking. However, a detailed investigation of the influence of WB- and MW-mediated crosslinking process on the characteristics of hydrogels has been rarely reported. This work aims to evaluate the physicochemical properties of epichlorohydrin (ECH) crosslinked cellulose hydrogels prepared by WB and MW heating methods, including pore morphology, chemical composition, crystallinity, thermal stability, and water absorption capacity. The results showed that MW heating could accelerate the crosslinking reaction between cellulose and ECH to produce robust hydrogel, with a 3 min total irradiation time at 400 W compared to 2 h at 60 °C under conventional WB heating. The total utility cost to produce WBH is US$ 0.052, which is 14 times higher than MWH (US$ 0.004). The estimation of the total production cost of MWH on a large scale is US$ 2.86 per kg. Moreover, the as-prepared MWH displayed outstanding performance in Cu(II) removal at 30 °C and pH 7, with a maximum adsorption capacity of 119 mg/g, respectively. The kinetic and equilibrium behaviors of Cu(II) ions on WBH and MWH were best described by pseudo-second order and Langmuir isotherm models, respectively. © 2021 Elsevier Ltd
Department of Chemical Engineering, Widya Mandala Surabaya Catholic University, Kalijudan 37, Surabaya, 60114, Indonesia; Department of Chemical Engineering, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Rd., Taipei, 10607, Taiwan; Graduate Institute of Applied Science and Technology, National Taiwan University of Science and Technology, No. 43, Section 4, Keelung Rd., Taipei, 10607, Taiwan; Department of Food Science and Biotechnology, National Chung Hsing University, 145 Xingda Rd., South Dist., Taichung, 40227, Taiwan; Institute of Food Science and Technology, National Taiwan University, #1, Section 4, Roosevelt Rd., Taipei, 10617, Taiwan; Institute of Biotechnology, National Taiwan University, #1, Section 4, Roosevelt Rd., Taipei, 10617, Taiwan; Department of Medical Research, China Medical University Hospital, China Medical University, 91, Hsueh-Shih Road, Taichung, 40402, Taiwan; Department of Optometry, Asia University, 500, Lioufeng Rd., Wufeng, Taichung, 41354, Taiwan