Characterization of a Thermoresponsive Chitosan Derivative as a Potential Draw Solute for Forward Osmosis.
A thermoresponsive chitosan derivative was synthesized by reacting chitosan (CS) with butyl glycidyl ether (BGE) to break the inter- and intramolecular hydrogen bonds of the polymer. An aqueous solution of the thermoresponsive CS derivative exhibits a lower critical solution temperature (LCST) than CS, and it undergoes a phase transition separation when the temperature changes. Successful incorporation of BGE into the CS was confirmed by FTIR and XPS analyses. Varying the BGE content and the concentration of the aqueous solution produced different LCST ranges, as shown by transmittance vs temperature curves. The particle size was observed by scanning electron microscopy, which revealed that the particles were smaller and well dispersed at 15 °C, whereas the particles became larger and tended to aggregate at 60 °C. A similar trend was observed with the mean particle size measured using dynamic light scattering. Positron annihilation lifetime spectroscopy data also revealed the reversibility of the particle properties as a function of temperature. Microstructure analysis showed that the particles had larger free-volume sizes at 15 °C than at 60 °C. The particles were also found to be nontoxic with 92% cell survival. A simple forward osmosis (FO) test for dye dehydration revealed the potential use of the thermoresponsive chitosan derivative as a draw solute with a flux of 8.6 L/m2h and rejection of 99.8%.
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University , Chung Li 32023, Taiwan.
Rumwald Leo G
RL
Lecaros
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University , Chung Li 32023, Taiwan.
Zih-Chi
ZC
Syu
Department of Chemical Engineering, University of Arkansas , Fayetteville, Arkansas 72701, United States.
Yu-Hsuan
YH
Chiao
Department of Chemical Engineering, University of Arkansas , Fayetteville, Arkansas 72701, United States.
S Ranil
SR
Wickramasinghe
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University , Chung Li 32023, Taiwan.|MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science & Engineering, Zhejiang University , Hangzhou 310027, China.
Yan-Li
YL
Ji
MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science & Engineering, Zhejiang University , Hangzhou 310027, China.
Quan-Fu
QF
An
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University , Chung Li 32023, Taiwan.
Wei-Song
WS
Hung
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University , Chung Li 32023, Taiwan.
Chien-Chieh
CC
Hu
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University , Chung Li 32023, Taiwan.
Kueir-Rarn
KR
Lee
R&D Center for Membrane Technology and Department of Chemical Engineering, Chung Yuan University , Chung Li 32023, Taiwan.
Juin-Yih
JY
Lai
D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry; D009995:Osmosis; D010316:Particle Size; D011108:Polymers / Q000737:chemistry; D012996:Solutions
D011108:Polymers; D012996:Solutions; D048271:Chitosan