Preparation and Evaluation of Polymer Aerogel Adsorbents Based on Polyacrylonitrile Fibers to Remove Oil Contaminants from Seawater

Spills of oil and its products into the open-waters of the world and the creation of oil slicks have become a global concern due to severe environmental and economic problems. Therefore, achieving an effective technology in cleaning up spilled oil is very important for environmental protection. One of the effective methods in separating oil stains is the use of adsorbents based on nanocomposite aerogels. The current study was carried out on the preparation of polyacrylonitrile aerogels for oil adsorption and separation of water from oil effluents, to improve the mechanical properties of aerogels due to the presence of polyacrylonitrile fibers in the aerogel structure, while extending the study on the effect of various parameters on morphology, and the porosity and percentage of aerogel oil adsorption.

Aerogels were characterized by conventional methods such as Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), optical microscopy (OM), BET, thermogravimetric analysis (TGA) and their density and adsorption rate were measured. Parameters such as fiber percentage, fiber length, and PVA percentage are effective on the adsorption rate, however the percentage of PVA is the most effective parameter on the adsorption rate.

The results showed that a chemical bond was formed between fibers and poly(vinyl alcohol) (PVA) and a network structure was obtained. Optimal conditions were determined as 3% by weight of polyacrylonitrile fibers, 5 mm length of polyacrylonitrile fibers and 1% by weight of PVA, in which the adsorbent was able to absorb about 1294% of oil. In addition, the specific surface area of the optimal sample was determined at 100.35 m2/g, which indicated that the prepared adsorbent could be suitable for oil adsorption.