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Temperature‐responsive permeability of porous PNIPAAm‐ g ‐PE membranes
Author(s) -
Peng Tao,
Cheng YuLing
Publication year - 1998
Publication title -
journal of applied polymer science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.575
H-Index - 166
eISSN - 1097-4628
pISSN - 0021-8995
DOI - 10.1002/(sici)1097-4628(19981212)70:11<2133::aid-app6>3.0.co;2-p
Subject(s) - membrane , permeation , polymer , polymer chemistry , materials science , permeability (electromagnetism) , grafting , chemical engineering , monomer , porosity , polyethylene , yield (engineering) , chemistry , composite material , biochemistry , engineering
Grafting a temperature‐responsive polymer, poly( N ‐isopropylacrylamide) (PNIPAAm), onto porous polyethylene (PE) membranes by UV irradiation was investigated. A wide range of graft yields (5–449%) was achieved by varying irradiation time (20–240 min) and monomer concentration (1.2–3.6 wt %). Characterization by XPS and SEM shows that the graft polymers are located both on the external surfaces as well as inside the pores of the membranes. Diffusional permeation experiments show that two distinct types of temperature responses were observed, depending on the graft yield; permeability increases with temperature in low graft yield membranes, while permeability decreases with temperature in high graft yield membranes. A mechanism explaining the dual valve functions of the graft membrane is proposed based on the location of the graft polymers on the membrane. It was also observed the permeability response exhibits a maximum with permeant molecular weight. © 1998 John Wiley & Sons, Inc. J Appl Polym Sci 70: 2133–2142, 1998