Fabrication of Hydrophilic and Hydrophobic Sites on Polypropylene Nonwoven for Oil Spill Cleanup: Two Dilemmas Affecting Oil Sorption

This article mainly deals with the following dilemmas, which affect oil sorption and sorbent preparation: (1) hydrophobization could facilitate oil sorption but has adverse impacts on emulsion sorption; (2) micropores of conventional oil sorbent do not exhibit effective emulsion sorption. To solve the above contradictions, hydrophilic and hydrophobic sites were fabricated onto polypropylene (PP) nonwoven through electron beam radiation and subsequent ring-opening reaction. Further, a similar structure without a hydrophilic site was constructed as comparison to verify the dilemmas. An oil sorption and emulsion adsorption experiment revealed that the PP nonwoven with specific hydrophilic and hydrophobic sites is more suitable for oil cleanup. The hydrophobic site preserved its hydrophobicity and sorption capacity, and the hydrophilic site on PP surface effectively increased the affinity between the hydrophilic interface of emulsion and sorbent. The overlapped and intertwined structures could provide spaces large enough to accommodate oil and emulsion. In addition, the oil and emulsion sorption behaviors were systematically analyzed. The PP nonwoven fabricated in this study may find practical application in the cleanup of oil spills and the removal of organic pollutants from water surfaces.