Influence of pore size and pore shape on thermo‐sensitive properties of poly[(ethylene terephthalate)‐graft‐(N‐isopropylacrylamide)] track membranes

Abstract

BACKGROUND: The main aim of this work was to prepare poly[(ethylene terephthalate)‐graft‐(N‐isopropylacrylamide)] (PET‐graft‐NIPAAm) track membranes with various pore shapes and pore sizes, and to investigate the influence of pore shape and pore size on the thermo‐sensitive properties of the membranes. The PET‐graft‐NIPAAm track membranes were prepared using UV illumination, chemical etching and γ‐irradiation polymerization. Their thermo‐sensitive properties were investigated using conductimetry. RESULTS: PET track membranes with four kinds of pore shapes and sizes were prepared using chemical etching by changing the UV illumination time. After γ‐irradiation, NIPAAm was grafted into the etched PET track membranes both inside the pores and on the membranes. Conductimetric measurements showed that only membranes with appropriate pore shape and pore size had thermo‐sensitive properties. When the grafting ratio was 5 wt%, membranes with both small double cone‐shaped pores and with very large cylinder‐shaped pores showed no thermo‐sensitive properties. CONCLUSION: Along with the grafting ratio, the pore shape and pore size also have an influence on the thermo‐sensitive properties of PET‐graft‐NIPAAm track membranes. Copyright © 2009 Society of Chemical Industry

Dielectric and optical properties of a poly(ethylene terephthalate) membrane in the temperature interval 150–400 K

“…It is semicrystalline in nature, resistant to heat and moisture, and virtually unattached by many chemicals . The high transmission in the visible range makes PET a substrate that is suitable and useful for a number of applications, including optoelectronic and other thin film applications …”

“…Polymeric etch track membranes are thin polymer films with discrete pores that are formed through a combination of heavy ion bombardment and chemical etching . Track membranes can serve as templates for making various microstructures and nanostructures .…”

Structure and performance of temperature‐sensitive poly(vinylidene fluoride) hollow fiber membrane fabricated at different take‐up speeds

“…Intelligent membranes show remarkable changes in properties as a response to the surrounding environment changes, such as pH [1–3], ionic field [4], temperature [5–19], and so on. Due to the unique property, they have a wide range of applications in the fields like drug controlled release [3], chemical sensors [5], and chemical separation.…”

“…As the temperature variation occurs naturally and the temperature stimuli can be easily and precisely controlled, lots of attentions have been paid to the temperature‐sensitive membranes. Poly( N ‐isopropylacrylamide) (PNIPAAm) is one of the most important temperature‐sensitive polymers [6–20]. It has been widely used to prepare temperature‐sensitive membrane by grafting NIPAAm onto various substrate materials or existing membranes such aspoly(vinylidene fluoride) [7–12], polypropylene [6, 13–15], poly(ethylene terephthalate) [16, 17], polysulfone [18], and polycarbonate [19, 20] via plasma polymerization technique, ozone‐pretreatment, ultraviolet (UV) photo‐polymerization, and so on.…”