Energetic heavy ion passing through polymeiic materials can produce a cylindrical intensively damaged area along the ion path, which is referred to as latent ion track. Large amount of small molecule fragments are pro...Energetic heavy ion passing through polymeiic materials can produce a cylindrical intensively damaged area along the ion path, which is referred to as latent ion track. Large amount of small molecule fragments are produced inside ion track through interactions between the ion and the target atoms, which made it easy to be chemically etched compared to the bulk material. Porous membranes with nanometer and micrometer sized pores can therefore be produced through proper etching of the ion irradiated polymer film. As the pores are well aligned with respect to each other and the pore geometric shape can be finely controlled, the so produced ion track membrane has found wide applications.展开更多
Heavy ion irradiated polymers can be chemically etched to form track membrane with pores in the micro and sub-micro ranges. The basic proccsses of track membrane production are irradiation of thin polymer films throug...Heavy ion irradiated polymers can be chemically etched to form track membrane with pores in the micro and sub-micro ranges. The basic proccsses of track membrane production are irradiation of thin polymer films through heavy ions followcd by chemical ctching. The track mcmbrane parameters such as pore size and shape, pore density, aspect ratio etc. depend on many factors such as material properties, irradiation conditions (ions, ion energy and fluence etc.) and etching conditions (etchant concentration, etching temperature etc.), as well as the treatmcnts of the material before or during chemical etching. In this work the Xe-ion irradiated PET fihns were chcmically etchcd and the pore growth processes were followed from which the etching parameters were evaluated and analyzed with respect to etchant concentration and applied voltages.展开更多
UV-VIS spectra of poly(ethylene terephthalate) (PET) solutions formed by etching PET in NaOH solution were analyzed with respect to the etching time. Two bands centered at 4.45 eV and 5.11 eV can be well separated (Fi...UV-VIS spectra of poly(ethylene terephthalate) (PET) solutions formed by etching PET in NaOH solution were analyzed with respect to the etching time. Two bands centered at 4.45 eV and 5.11 eV can be well separated (Fig.l). They are attributed to π→π^n transition from the chromophore of-O-CO-C6H4-CO-O-which is the main origin of optical absorption in the wavelength range from 240 nm to 320nm, both for the solid and dissolved PET. As shown in Fig.2, the integrated absorbance (A) of the two bands as well as weight loss of PET after etching in 0.74 N NaOH at 40°C increase linearly with etching time. A linear relationship between absorptions of the two bands and weight loss of PET in NaOH solution can therefore be established. As less than 2μg/ml of PET dissolved in NaOH solution can be resolved by spectrophotometer, it supplies a sensitive way to study the etching process even after very short time of etching.展开更多
Heavy ion irradiated polymers can be chemically etched to form track membrane with pores in the micro and sub-micro ranges. It has been reported that pore growth during etching can be related to track structures. A la...Heavy ion irradiated polymers can be chemically etched to form track membrane with pores in the micro and sub-micro ranges. It has been reported that pore growth during etching can be related to track structures. A latent track has a track core inside and a track halo surrounding the track core. By single track etching it is observed that etching in the track core is much faster than in the track halo where the etching rate is even lower tlian that of bulk material. For multi-track etching, no such stages can be seen by the conductance measurements.展开更多
文摘Energetic heavy ion passing through polymeiic materials can produce a cylindrical intensively damaged area along the ion path, which is referred to as latent ion track. Large amount of small molecule fragments are produced inside ion track through interactions between the ion and the target atoms, which made it easy to be chemically etched compared to the bulk material. Porous membranes with nanometer and micrometer sized pores can therefore be produced through proper etching of the ion irradiated polymer film. As the pores are well aligned with respect to each other and the pore geometric shape can be finely controlled, the so produced ion track membrane has found wide applications.
文摘Heavy ion irradiated polymers can be chemically etched to form track membrane with pores in the micro and sub-micro ranges. The basic proccsses of track membrane production are irradiation of thin polymer films through heavy ions followcd by chemical ctching. The track mcmbrane parameters such as pore size and shape, pore density, aspect ratio etc. depend on many factors such as material properties, irradiation conditions (ions, ion energy and fluence etc.) and etching conditions (etchant concentration, etching temperature etc.), as well as the treatmcnts of the material before or during chemical etching. In this work the Xe-ion irradiated PET fihns were chcmically etchcd and the pore growth processes were followed from which the etching parameters were evaluated and analyzed with respect to etchant concentration and applied voltages.
文摘UV-VIS spectra of poly(ethylene terephthalate) (PET) solutions formed by etching PET in NaOH solution were analyzed with respect to the etching time. Two bands centered at 4.45 eV and 5.11 eV can be well separated (Fig.l). They are attributed to π→π^n transition from the chromophore of-O-CO-C6H4-CO-O-which is the main origin of optical absorption in the wavelength range from 240 nm to 320nm, both for the solid and dissolved PET. As shown in Fig.2, the integrated absorbance (A) of the two bands as well as weight loss of PET after etching in 0.74 N NaOH at 40°C increase linearly with etching time. A linear relationship between absorptions of the two bands and weight loss of PET in NaOH solution can therefore be established. As less than 2μg/ml of PET dissolved in NaOH solution can be resolved by spectrophotometer, it supplies a sensitive way to study the etching process even after very short time of etching.
文摘Heavy ion irradiated polymers can be chemically etched to form track membrane with pores in the micro and sub-micro ranges. It has been reported that pore growth during etching can be related to track structures. A latent track has a track core inside and a track halo surrounding the track core. By single track etching it is observed that etching in the track core is much faster than in the track halo where the etching rate is even lower tlian that of bulk material. For multi-track etching, no such stages can be seen by the conductance measurements.
