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Vol. 57 (2021), Issue 4, p. 54-60
https://doi.org/10.52577/eom.2021.57.4.54
Воздействие ультрафиолетового излучения на свойства полимерных мембран микрофильтрации
Abstract
УДК 66.086.2
Проведена обработка поверхности тонкопленочных мембран из нейлона, ацетата целлюлозы и политетрафторэтилена (ПТФЭ) ультрафиолетовым (УФ) излучением в диапазоне волн 280–320 нм, для улучшения параметров процесса мембранного разделения эмульсий типа «масло в воде». Выявлено изменение массы мембран в зависимости от времени обработки. Установлено повышение смачиваемости поверхностного слоя мембраны из ПТФЭ и нейлона. Изменения в надмолекулярной структуре мембран подтверждены результатами ИК-Фурье-спектрометрии: выявлено увеличение интенсивности полос поглощения в ИК-спектрах в интервале 600–3600 см-1. УФ-излучение повлияло и на основные параметры мембранного разделения водомасляной эмульсии: установлено повышение до 7% удельной производительности мембран из нейлона и ацетата целлюлозы в зависимости от времени УФ обработки. При воздействии УФ-излучения на мембрану из ПТФЭ наблюдается снижение удельной производительности на 14% при повышении эффективности разделения эмульсии на 14%.
Ключевые слова: мембраны, нейлон, ацетат целлюлозы, политетрафторэтилен, УФ-излучение, краевой угол смачивания, ИК-Фурье-спектроскопия, микрофильтрация, эмульсия
To improve the parameters of the process of membrane separation of oil-in-water emulsions, the surface of thin-film membranes of nylon, cellulose acetateб and polytetrafluoroethylene (PTFE) was treated with ultraviolet (UV) radiation in the wavelength range 280–320 nm at a radiation power of 36 W, during 1–10 min. As a result of exposure to UV radiation, a change in the mass of the membranes was revealed depending on the treatment time. Thus, for membranes made of nylon and PTFE, an increase in weight is not significant, while for a membrane made of cellulose acetate, a decrease in weight up to 2.5% was found. An increase in the wettability of the surface layer of a PTFE and nylon membranes, as a result of their exposure to UV radiation, has been established. Changes in the supramolecular structure of the membranes were confirmed by the results of Fourier transform infrared spectroscopy: an increase in the intensity of absorption bands in the IR spectra in the range 600–3600 cm-1 was revealed. An increase in the intensity of the absorption bands of the IR spectra after the treatment of the nylon membrane with UV radiation is associated with the destruction of the defective regions of the surface layer of the membrane as a result of oxidative destruction. A decrease in the intensity of the absorption bands in the IR spectra of the PTFE membrane is observed over the entire spectral range. In addition, the expansion of the bases of the most intense absorption bands related to stretching vibrations of CF2 groups (1203 and 1150 cm-1) was revealed, which may be associated with the formation of the oxide group of the C–O bond. That is, the surface layer of the membrane is oxidized, which leads to an increase in the membrane wettability. UV radiation also influenced the main parameters of the membrane separation of the oil-in-water-emulsion: an increase of up to 7% in the specific productivity of membranes made of nylon and cellulose acetate, depending on the time of UV treatment with a decrease in the separation efficiency was established. When the PTFE membrane was exposed to UV radiation, a decrease in the specific productivity of the process by 14% was observed with an increase in the separation efficiency of the studied emulsion by 14%.
Keywords: membranes, nylon, cellulose acetate, polytetrafluoroethylene, ultraviolet radiation, contact angle, Fourier transform infrared spectroscopy, microfiltration, emulsion
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