CaCl2-in-Mesoporous Silica Grown on Superabsorbent Polymer to Enhance Water Uptake

• Main Authors: Ki Woong Ahn, Soo Yeon Jang, Min Hyuk Hwang, Sun-Geon Kim
• Format: Article
• Language: English
• Published: Hosokawa Powder Technology Foundation 2014-09-01
• Series: KONA Powder and Particle Journal
• Subjects: mesoporous silica; superabsorbent polymer; template growth; calcium chloride; water uptake
• Online Access: https://www.jstage.jst.go.jp/article/kona/32/0/32_2015011/_html/-char/en

Super absorbent polymer (SAP) sorbs copious amount of liquid water but its sorption power for water vapor is quite low. On the other hand, mesoporous silica loaded with CaCl2 (MPS-CC) has high sorption capacity for water vapor. However, this is determined by the salt loading, which is limited due to its corrosiveness. Even by simple powder blending of 75 mass% of SAP and the balance of MPS-CC (SAP75/MPS-CC25), the 3-hour maximum specific water uptake (g H2O/g sorbent) reached the maximum, 3 times the equilibrium uptake of MPS-CC. The sorption property was further enhanced by developing a new sorbent in which mesoporous silica was grown on the surface of swelling SAP and then impregnated by CC in ethanol. In the new sorbent (SAP-iMPS-CC), MPS grew organized, straight and lengthwise by the help of SAP. Owing to such intimate contact between MPS and SAP, the 3-hour specific water uptake of the new sorbents grown for more than 24 h (SAP-iMPS-CC24) was kept constant at the value of 2 times that of SAP75/MPS25. The SAP mass% of SAP-iMPS-144 could reach 25 without the sacrifice of sorption capacity.