За последние десятилетия мембранная технология стала новым перспективным способом решения проблем в области подготовки и очистки воды в нефтехимической, фармацевтической, пищевой и других отраслях промышленности. В качестве материалов для производства мембран нашли применение фторсодержащие полимеры, которые обладают рядом выдающихся свойств: высокой температурной стабильностью, химической стойкостью, механической прочностью, биологической инертностью и т.д. Поливинилиденфторид рассматривается как один из наиболее перспективных материалов для создания мембран. Мембраны из поливинилиденфторида эффективны для очистки вод от крупных коллоидных частиц, бактерий, простейших микроорганизмов, эмульгированных нефтепродуктов и т.п. В то же время при использовании мембран из поливинилиденфторида для очистки водных сред возникают сложности с гидрофобностью ее поверхности, биообрастанием, что ведет к засорению пор, снижению проницаемости и, в результате, приводит к сокращению срока службы мембраны. В данной работе задачу по повышению гидрофильности поверхности мембраны из поливинилиденфторида решали путем обработки ее раствором окислителя, состоящего из смеси концентрированной серной кислоты и медицинской перекиси водорода заданной концентрации, с целью формирования на поверхности мембраны гидроксильных групп. Мембраны на основе поливинилиденфторида были получены методом «замораживания» из раствора в диметилсульфоксиде. Образование гидроксильных групп подтверждено методами ИК-спектроскопии и рентгенофлуоресцентной спектроскопии. Повышение гидрофильности мембран подтверждено снижением краевого угла смачивания по воде для мембран, обработанных раствором окислителя в сравнении мембранами до обработки. Over the last decades, membrane technology has become a new promising way to solve problems of water treatment and purification in the petrochemical, pharmaceutical, food and other industries. Fluorine-containing polymers have been used as materials for the production of membranes because of a number of outstanding properties: high temperature stability, chemical resistance, mechanical strength, biological inertness, etc. Poly (vinylidene fluoride) is considered as one of the most promising materials for membranes production. Poly (vinylidene fluoride)membranes are effective for water purification to separate large colloidal particles, bacteria, protozoa, emulsified oil products, etc. At the same time using poly (vinylidene fluoride) membranes for purification of aqueous media there are difficulties arise with the hydrophobicity of its surface, biofouling, which leads to clogging of pores, a decrease in permeability and, as a result, leads to a reduction of usage time of the membrane. In this work, the increasing the hydrophilicity of the poly (vinylidene fluoride) membrane surface made by treating it with an oxidizing agent solution consisting of a mixture of concentrated sulfuric acid and medical hydrogen peroxide. As the result the hydroxyl groups occurs on the membrane surface. Poly (vinylidene fluoride) membranes were prepared by freeze-casting from dimethyl sulfoxide solution. The formation of hydroxyl groups was confirmed by IR spectroscopy and X-ray fluorescence spectroscopy. An increase in the hydrophilicity of the membranes surface was confirmed by a decrease in the water wetting angle for membranes treated with an oxidizing agent solution in comparison with membranes before treatment respectively.

Poly (vinylidene fluoride) membranes were prepared by freeze-casting. The effects of PVDF concentration, and freezing temperature on the morphology, crystallization, and performance of prepared membranes were examined. Polymer concentration was varied from 10 to 25 wt%. The freezing temperature was varied from −5 to −25 °C. Dimethyl sulfoxide (DMSO) and distilled water were used as solvents and non-solvents, respectively. The first step of this study was devoted to estimating the optimal concentration of PVDF solution in DMSO. Membranes prepared at different ratios were characterized using physical and mechanical characteristics and porosity. The second step was to optimize the time required for the production of the membranes. In the third step, it was shown that the freezing temperature had a remarkable effect on the morphology of the membranes: as the temperature decreases, there is a transition from spherulite structures to interconnected pores. It was shown that the diversity in the pore pattern for PVDF affects remarkably the water permeability through the polymer membrane. During the monitoring of the spread of crystallized areas during the formation of the membrane, it was found that the crystallization of the solvent begins at localized points of the microscale, further crystallized areas spread radially or unevenly along the surface of the solution, forming contact borders, which can lead to changes in the properties of the membrane in its area.