Evaluation of Hydrophobic Polyvinyl-Alcohol Formaldehyde Sponges As Absorbents for Oil Spill

Abstract

Macroporous materials are a class of absorbents used for oil spill cleanup. In this article, novel macroporous and hydrophobic polyvinyl formaldehyde (PVF-H) sponges were prepared by the reaction of stearoyl chloride with hydroxyl groups of hydrophilic PVF sponge at different temperatures. Attenuated total reflectance-infrared (ATR-IR) spectroscopy confirmed the successfully anchoring of hydrophobic stearoyl groups on the PVF networks. Scanning electron microscopy (SEM) images demonstrated that the as-prepared PVF-H had interconnected open-cell structures, and mercury intrusion porosimetry indicated that the average pore size ranged from 60 to 90 μm and porosity was greater than 94.8%. Such PVF-H sponges can absorb oil products effectively, such as toluene, n-hexane, kerosene, soybean oil, hydraulic oil, and crude oil up to 13.7 g·g(-1) to 56.6 g·g(-1), and this level of absorption was approximately 2-4 times higher than that absorbed by commercial polypropylene nonwoven mat. In low-viscosity oils, the samples can reach the saturated absorption amount only in 1 min, but in higher-viscosity oils, absorption equilibrium can be reached in 10 min. In a simulated oil slick system, these macroporous and hydrophobic sponges can still maintain high oil absorption capacities within the range of 14.4 g·g(-1) to 57.6 g·g(-1), whereas a relatively low absorption rate (approximately 20 min) indicated high absorption performance and excellent selectivity in the oil-water mixture. In addition, the absorbed oils were collected effectively only through a simple squeeze. The PVF-H sponges were subjected to 35 absorption-squeeze cycles and exhibited good reusability and 90% recovery for oils. The samples prepared at different temperatures differed in their absorption capacities to some extent. However, this new kind of macroporous and PVF-H sponges had excellent absorption performance on oil products.

Superhydrophobic and Oleophilic Open-Cell Foams from Fibrillar Blends of Polypropylene and Polytetrafluoroethylene

“…The physical characteristics and specifications of these PP-based materials can be found elsewhere. 38,39,41 With the exception of heavy crude oil, and kerosene, the open-cell foam outperforms these PP-based absorbents for the uptake of all other studied petroleum products. In general, the uptake capacity of the open-cell foam varies from oil to oil and ranges from around 5 to 24 g g −1 of foam.…”

Magnetic Poly(Ionic Liquid) Microcapsules for Oil Capture and Recovery

“…and hydrophobic enough to exclude water from the material and oleophilic in order to “wet” with low surface tension liquids. This combination of properties allows for oil removal from oil/water mixtures as a semisolid oil‐sorbent composite . The gold standard for synthetic oil sorbent materials used during oil spill cleanup today is made from polypropylene and absorbs approximately oils ten time of its own weight .…”

Superhydrophobic/superoleophilic magnetic polyurethane sponge for oil/water separation

“…As for the high-viscosity lubricating oil, it requires at least 5 min to reach equilibrium because the absorption process is dominated by the diffusion step 28 . As for the high-viscosity lubricating oil, it requires at least 5 min to reach equilibrium because the absorption process is dominated by the diffusion step 28 .…”